Shallow marine syn-rift sedimentation: Middle Jurassic Pelion Formation, Jameson Land, East Greenland

The Middle Jurassic Pelion Formation – Fossilbjerget Formation couplet of Jameson Land, East Greenland, is a well-exposed example of the Middle Jurassic inshore–offshore successions characteristic of the rifted seaways in the Northwest European – North Atlantic region. Early Jurassic deposition took place under relatively quiet tectonic conditions following Late Permian – earliest Triassic and Early Triassic rift phases and the Lower Jurassic stratal package shows an overall layer-cake geometry. A long-term extensional phase was initiated in Middle Jurassic (Late Bajocian) time, culminated in the Late Jurassic (Kimmeridgian–Volgian), and petered out in the earliest Cretaceous (Valanginian). The Upper Bajocian – Middle Callovian early-rift succession comprises shallow marine sandstones of the Pelion Formation and correlative offshore siltstones of the Fossilbjerget Formation. Deposition was initiated by southwards progradation of shallow marine sands of the Pelion Formation in the Late Bajocian followed by major backstepping in Bathonian–Callovian times and drowning of the sandy depositional system in the Middle–Late Callovian. Six facies associations are recognised in the Pelion–Fossilbjerget couplet, representing estuarine, shoreface, offshore transition zone and offshore environments. The north–southtrending axis of the Jameson Land Basin had a low inclination, and deposition was sensitive to even small changes in relative sea level which caused the shorelines to advance or retreat over tens to several hundreds of kilometres. Eight composite sequences, termed P1–P8, are recognised and are subdivided into a total of 28 depositional sequences. The duration of the two orders of sequences was about 1–2 Ma and 360,000 years, respectively. The Upper Bajocian P1–2 sequences include the most basinally positioned shallow marine sandstones, deposited during major sealevel lowstands. The lowstands were terminated by significant marine flooding events, during which sandstone deposition was restricted to northern, more proximal parts of the basin. The Upper Bajocian – Middle Bathonian P3–4 sequences show an overall progradational stacking pattern. The sequence boundary at the top of P4 marks a significant shift in stacking pattern, and the Upper Bathonian – Middle Callovian P5–8 sequences show large-scale backstepping, terminating in a widespread condensed succession at the distal, southern end of the basin. The largescale backstepping was governed by combined tectonically-induced subsidence, reflecting increased rates of extension, and eustatic sea-level rise. The depositional trends of the Pelion Formation – Fossilbjerget Formation couplet provide a well-exposed analogue to contemporaneous subsurface deposits which form major hydrocarbon reservoirs on the west Norway shelf, and in the Northern North Sea.

The Middle Jurassic of East Greenland was characterised by the onset of rifting in the Late Bajocian, major reorganisation of drainage systems, and a high influx of sand. A gradual west-and northwards onlap onto pro-gressively older strata took place during Late Bajocian -Callovian times. Upper Bajocian sand-and siltstones of the basal Pelion Formation rest on Lower Bajocian mudstones of the Sortehat Formation in Jameson Land at the southern end of the East Greenland basin (Fig. 1); lithostratigraphic usage in this paper follows the provisional revised scheme in Surlyk (2003, this volume, fig. 5). The age of the Sortehat Formation is determined by dinoflagellates (Underhill & Partington 1994;Koppelhus & Hansen 2003, this volume), and by Sr-isotope stratigraphy (M. Engkilde, unpublished data). Further north, on Traill Ø, presumed Middle Jurassic fluvial pebbly sandstones of the Bristol Elv Formation (Therkelsen & Surlyk in press) or Upper Bajocian shallow marine sandstones of the Pelion Formation rest on Upper Triassic redbeds of the Flemming Fjord Formation and there is no evidence for the presence of Lower Jurassic strata. At Hold with Hope, the Pelion Formation overlies the Lower Triassic Wordie Creek Formation (Stemmerik et al. 1997;Vosgerau et al. in press a), and on Wollaston Forland it rests on a thin Upper Permian carbonate-evaporite unit or directly on Caledonian crystalline basement. Further north again, on Kuhn Ø, Upper Bathonian or Callovian strata of the fluvial Bastians Dal Formation (Alsgaard et al. 2003, this volume) or the marine Pelion Formation rest directly on the basement. In Hochstetter Forland, Callovian coal-bearing paralic deposits of the Upper Bathonian(?) -Middle Callovian Muslingebjerg Formation or marine Callovian-Oxfordian sandstones of the Payer Dal Formation onlap the Caledonian basement. The progressive northwards truncation of the underlying succession and younging of the base of the Middle Jurassic strata probably reflect late Early Jurassic development of a rift dome in North-East Greenland and subsequent Middle Jurassic domal erosion, deflation and transgression (Surlyk 1977a(Surlyk , 1978 similar to the roughly contemporaneous dome in the North Sea (Sellwood & Hallam 1974;Whiteman et al. 1975;Eynon 1981;Ziegler 1988;Underhill & Partington 1993. The reality of Early Jurassic uplift has been confirmed on the basis of fission track thermochronology by Johnson & Callagher (2000). In contrast, the Jameson Land area shows no evidence for Early Jurassic uplift and cooling (Mathiesen et al. 2000).
The low gradient physiography, and general shallow water depth of the basin during Middle Jurassic times, made deposition very sensitive to even small changes in relative sea level. Such changes caused the shorelines to advance or retreat over tens to several hundreds of kilometres, with the formation of laterally extensive depositional units. The interpretation of changes in spatial distribution of the units through time is controlled by a detailed ammonite biostratigraphy and large-scale depositional variations and geometries.
The aim of the study is to establish depositional models and a sequence stratigraphic framework for the Middle Jurassic succession of Jameson Land. The architecture and facies trends through time of the Pelion-Fossilbjerget couplet provide a well-exposed and welldated depositional analogue to contemporaneous major hydrocarbon reservoirs on the west Norway shelf and the Northern North Sea.

Geological setting
The Late Palaeozoic -Mesozoic extensional basins of East Greenland are exposed over c. 800 km in a southnorth direction, from Jameson Land and Milne Land in central East Greenland to Store Koldewey in North-East Greenland (Fig. 1). The Mesozoic deposits were largely deposited in two major basins, the Jameson Land and the Wollaston Forland Basins. The Jameson Land Basin is c. 140 km wide in south Jameson Land and Milne Land, narrowing northwards from Traill Ø to Geographical Society Ø and Hold with Hope (Figs 1, 3). The Wollaston Forland Basin is c. 50 km wide in the Clavering Ø -Wollaston Forland area, and narrows northwards through Kuhn Ø and Hochstetter Forland (Fig. 1). Marine Jurassic sandstones are found at Store Koldewey, and represent the western edge of a Mesozoic basin which continues offshore ( Fig. 4; Surlyk et al. 1981Surlyk et al. , 1986Surlyk 1990a). The East Greenland basins formed the westernmost segment of the major north-south-oriented system of rift basins situated between Greenland and Norway (Fig. 5;Ziegler 1988;Larsen 1990;Doré 1991Doré , 1992Surlyk et al. 1993). At least 5 km of Upper Permian -Mesozoic sediments were deposited in the Jameson Land Basin (Fig. 3). The Late Permian to Cretaceous basin evolution was characterised by post-rift thermal con-  Larsen (1990). traction and sediment loading, following Late Palaeozoic rifting, interrupted by rift events in Late Permian -Early Triassic, Early Triassic, Middle-Late Jurassic, Early and Late Cretaceous times (Donovan 1953;Callomon 1972;Surlyk et al. 1973;Surlyk 1977bSurlyk , 1990aSurlyk , 1991Surlyk , 2003Clemmensen 1980;Surlyk & Clemmensen 1983;Larsen 1990;Larsen & Marcussen 1992;Price & Whitham 1997;Surlyk & Noe-Nygaard 2001a). Major regional uplift of the areas north of Jameson Land took place in Early Jurassic times, probably close to the Early-Middle Jurassic transition. It was associated with changes in basin configuration and development of new drainage and transport patterns. The uplift has been related to the formation of a large rift dome north of Jameson Land, analogous to the North Sea dome developed at the triple junction between the Central Graben, the Viking Graben and the Witch Ground Graben (Surlyk 1977a(Surlyk , 1978. The uplift was marked by the sudden influx mainly from the north of large volumes of coarse-grained sediments in the northwards thickening succession (Surlyk et al. 1973(Surlyk et al. , 1981Surlyk & Clemmensen 1983;Heinberg & Birkelund 1984;Engkilde & Surlyk 1993;Engkilde 1994). Similar Middle Jurassic uplift, succeeded by deposition of large volumes of coarse clastic deposits, is also documented from the mid-Norway shelf and the North Sea (Doré 1991(Doré , 1992. These deposits now form many of the most productive oil reservoirs in the North Sea and at the mid-Norway margin (Doré 1991;Mitchener et al. 1992;Cordey 1993).
The eastern margin of the Jameson Land Basin, represented by the present-day Liverpool Land, was a structural high in Mesozoic times that was periodically exposed and accumulated only a thin sediment cover (Figs 2, 3;Rosenkrantz 1942;Birkelund & Perch-Nielsen 1976;Birkenmajer 1976;Clemmensen 1980;Surlyk et al. 1981;, 1998. By Middle Jurassic times, north-westerly and westerly sediment sources were dominant (Bromley et al. 1970;Surlyk et al. 1973;Birkelund & Perch-Nielsen 1976;Surlyk 1977bSurlyk , 1991Callomon & Birkelund 1980). Fluvial and deltaic sediments occur at the base of the succession on Traill Ø and Geographical Society Ø, and further north on Kuhn Ø and Hochstetter Forland (Price & Whitham 1997;Stemmerik et al. 1997;Alsgaard et al. 2003, this volume;Therkelsen & Surlyk in press). The nature of the southern basin margin is not known, but seismic data suggest that Jurassic deposits extend south of Scoresby Sund (Larsen & Marcussen 1992). The Middle Jurassic basin fill onlaps Precambrian and Caledonian crystalline basement along the western basin margin in Milne Land (Callomon & Birkelund 1980;Larsen & Marcussen 1992;Larsen et al. 2003, this volume).
The northwards termination of the Jurassic Liverpool Land basement high is not precisely known. An eastwards tilted fault-block was formed by Middle Jurassic rifting in south-eastern Traill Ø, and eastwards dips are also noted in north-east Jameson Land. This is opposite to all other Jurassic fault-blocks in East Greenland which show marked westwards dips and suggest direct marine communication towards the east in this area (Carr 1998;Vosgerau et al. in press b).
An important tectonic zone is situated in northern Jameson Land, separating the broad Jameson Land platform from the northern region which is characterised by Late Jurassic and Cretaceous tilted fault blocks. The cross fault zone probably coincides with a zone of NW-SE-trending deep-seated faults recognised by Dam et al. (1995). The fault zone was reactivated during Cenozoic basin uplift (Vischer 1943;Donovan 1953;Haller 1971;Surlyk 1977b;Surlyk et al. 1981Surlyk et al. , 1993Larsen & Marcussen 1992).

Stratigraphy of the Pelion and Fossilbjerget Formations
The Pelion and Fossilbjerget Formations (lower Vardekløft Group) form a north-westwards thickening wedge of Late Bajocian -Middle Callovian age, covering about 10 Ma (Fig. 6). The formations overlie the Aalenian -Lower Bajocian Sortehat Formation of the Neill Klinter Group in Jameson Land (Surlyk et al. 1973;Dam & Surlyk 1998;Surlyk 2003, this volume, fig. 5). The base of the Pelion-Fossilbjerget couplet is a major sequence boundary, marked by a dramatic increase in the influx of coarse clastic sediments (Surlyk 1991(Surlyk , 2003Surlyk et al. 1993;Dam & Surlyk 1998). Farther north, on Traill Ø, the Pelion Formation overlies Upper Triassic redbeds of the Flemming Fjord Formation (Clemmensen 1980;Fig. 6). In Milne Land, at the western basin margin, Middle Jurassic sandstones of the Charcot Bugt Formation onlap crystalline basement (Callomon & Birkelund 1980;Larsen et al. 2003, this volume). The top of the Pelion-Fossilbjerget couplet is a widespread condensed unit in southern Jameson Land. It is overlain by the Upper Callovian -Middle Oxfordian marine sandstones and mudstones of the Olympen Formation in northern Jameson Land and Traill Ø. In southern Jameson Land, the formations are overlain by condensed, distal deep-water mudstones of the Olympen Formation, followed by black mudstones and massive sandstones of the Upper Oxfordian -Lower Volgian Hareelv Formation (Surlyk 1987(Surlyk , 2003Surlyk & Noe-Nygaard 1998, 2001bLarsen & Surlyk 2003, this volume).
The Pelion-Fossilbjerget couplet thickens along the basin axis from 150 m in southern Jameson Land to 475 m in central and northern Jameson Land (Surlyk 1977b;Heinberg & Birkelund 1984). The Pelion Formation thickens in the same direction from c. 50 m to about 400 m. The very high thickness value, close to 700 m, reported for the Pelion Formation at Antarctic Havn in northernmost Jameson Land (Heinberg & Birkelund 1984), probably includes the Upper Callovian -Middle Oxfordian Olympen Formation. If this very poorly exposed and strongly faulted area is excluded, figure 25 of Heinberg & Birkelund (1984) shows uniform thicknesses for all time slices from Mikael Bjerg in southern central Jameson Land and further north. The only significant decrease in thickness thus seems to take place in the region of sandstone pinch-out from Mikael Bjerg and further south.
The Pelion Formation consists mainly of shallow marine sandstones, which are overlain by, and pass southwards into deeper-water, offshore siltstones of the Fossilbjerget Formation (Fig. 6) Gradstein et al. 1994). P1-8 indicate composite depositional sequences. The number of high-order depositional sequences within the composite sequences is indicated by the saw-tooth pattern. The bulk sandstone parts of the composite sequences are late highstand deposits throughout central and northern Jameson Land. Thick deposits of the transgressive and early highstand systems tracts are predicted to exist in western and northern basin margin areas; such deposits are not shown in this figure, but indicated schematically on Fig. 36. Two lowstand units are shown in sequences P1 and P2. It should be noted that precise correlation to the Bajocian and Bathonian Stages of Europe is not yet possible, due to faunal provincialism; the Jurassic ammonite zonation is from Callomon (1993). The figure is based on fig. 2 in Surlyk (1991), with the addition of new data on the sequence stratigraphy.
towards the north (Callomon 1959(Callomon , 1993Surlyk et al. 1973;Heinberg & Birkelund 1984). The formations show a record of cyclic regressions and transgressions on several orders, and the boundary between the formations is thus not one continuous surface, but can be considered a series of shingled marine flooding surfaces, which cap individual progradational shallow offshore -shoreface units of the Pelion Formation. The geometry of the formations, large-scale textural gradients, and the observed palaeocurrent patterns, indicate that the main sediment influx was from the north and northwest, and sediment transport was mainly towards the south, along the basin axis. The age relationships of the formations are based on a detailed ammonite biostratigraphy (Spath 1932;Callomon 1959Callomon , 1993Surlyk et al. 1973). The Pelion-Fossilbjerget couplet contains 16 ammonite zones, which are subdivided into 37 ammonite faunal horizons (Figs 6,7). Correlation with the European ammonite zonation in the Bajocian-Bathonian is not possible due to faunal provincialism (see Callomon 2003, this volume), and the precise age of the lower boundary of the Pelion Formation is uncertain but is tentatively placed in the earliest Late Bajocian (Fig. 6, left part; Callomon 1959Callomon , 1972Callomon , 1993Surlyk et al. 1973). This is corroborated by 87 Sr/ 86 Sr values which suggest an early Late Bajocian age for the base of the Pelion Formation, by comparison with the strontium isotope curve of Jones et al. (1994) (M. Engkilde, unpublished data). The sedimentary organic content is dominantly terrestrially derived and poorly preserved. Abundant terrestrial pollen and spores occur throughout the formations together with subordinate marine dinoflagellate cysts that are abundant only at certain levels. Spores and pollen have contributed little to the biostratigraphic subdivision of the formations as most Middle and Late Jurassic species are long-ranging (M.D. Muir in : Sarjeant 1972;Lund & Pedersen 1985). Dinoflagellate cysts have a higher stratigraphic potential which is not yet fully exploited (Sarjeant 1972;Smelror 1988;Larsen et al. 2003, this volume).
The Pelion-Fossilbjerget couplet consists of eight composite sequences which are subdivided into 28 simple coarsening-upwards sequences (following the definition of Mitchum & Van Wagoner 1991). The duration of the composite sequences is one to a few million years, and several hundred thousand years for the simple sequences (Fig. 6). The Pelion and Fossilbjerget Formations form the lower part of the long-term regressive-transgressive Vardekløft Group (Surlyk & Noe-Nygaard 2000;Surlyk 2003, this volume). In the Jameson Land Basin, the age of the composite sequences is wellestablished to ammonite zone or subzone level. Many of the simple sequences are also biostratigraphically dated by ammonites.

Sedimentology of the Pelion and Fossilbjerget Formations
Ten sedimentary facies (  Shoreface to shallow offshore, from below storm wave-base to above fair-weather wave-base Offshore, below or close to storm wave-base depositional environments: (1) the upper shoreface to offshore transition zone, and (2) the offshore. Facies associations A-E were deposited in shoreface and shallow offshore transition zone environments: A, shoreface association; B, estuarine association; C, tidal inlet association; D, sand sheet association; E, clinoform association. The offshore association (F) was deposited in a deeper-water environment.

A. Shoreface association
The shoreface association consists of fine-grained to pebbly sandstones and conglomerates and forms coarsening-upwards units, 5-12 m thick    (Fig. 2). The association belongs to sequence P1 (Fig. 6). The accompanying legend (facing page) also applies to the subsequent sedimentary logs in the paper; m a. sl, metres above sea level.  3 Fine-to medium-grained structureless to faintly laminated or cross-bedded sandstone 4 Cross-bedded, cross-laminated and wavy-bedded fine-to medium-grained sandstone 5 Heavily burrowed calcareous siltstone and fossilliferous laminated siltstone 6 Laminated silty, fine-grained sandstone 7 Fine-to coarse-grained, cross-laminated sandstone 8 Fine-to medium-grained, low-angle inclined and horizontally bedded sandstone 9 Cross-laminated, cross-bedded and structureless fine-to coarse-grained sandstone and conglomerate 10 Offshore facies: laminated to structureless siltstone 4 o zone deposits are dealt with separately due to the complex vertical and lateral relationships between facies. Shoreface deposits dominate the sedimentary record throughout the Pelion Formation.

Foreshore and upper shoreface
Foreshore and upper shoreface deposits consist of fineto coarse-grained, cross-laminated, cross-bedded and structureless sandstones, and structureless or cross-bedded conglomerates (facies 9). The deposits form units, 5-40 m thick. Units thicker than 5-10 m consist of amalgamated upper shoreface deposits. Marine body and trace fossils occur throughout and terrestrial deposits have not been recognised. Trace fossils are dominated by vertical burrows. Two types of upper shoreface deposits are recognised: barred and non-barred upper shoreface sandstones (Figs 8-11). Barred upper shoreface deposits vary from pebbly, poorly to well sorted medium-or fine-grained sandstones; grain-size variations between individual beds may be large. Sedimentary structures include a mixture of wave-and current-formed cross-lamination and crossbedding, and most sandstones show an intricate mixture of swaley cross-beds, rip-channel fills, shore-parallel trough fills, bar cross-beds, wave-surf and swash bar deposits. Wave-rippled sheets occur interbedded (Figs 12-15). Locally, cross-bed foresets show thin mudstone and siltstone drapes, and herringbone cross-bedding with bundled build-up of foresets also occurs. The lower boundary of the foreshore and upper shoreface deposits is sharp, erosional or gradational. The erosionally-based deposits show a low-angle master bedding, dipping up to 6°towards the south or south-east. The gradationally-based deposits show a horizontal to low-angle inclined master bedding, dipping less than 1-2°in a southerly direction. Palaeocurrent directions show a wide scatter, although southwards orientations dominate (Fig. 16). The deposits are capped by a marine surface of erosion, commonly overlain by a thin, coarsegrained sandstone or pebble lag, interpreted as genetically belonging to the overlying depositional unit . The pebble lags consist of discoid or rounded quartz pebbles, 0.5-10 cm in diameter, intraformational sandstone and mudstone clasts, fragmented belemnites and bivalves, and in some cases also subangular extraformational rock fragments.

Monocraterion tentaculatum and/or
Ophiomorpha nodosa of the Diplocraterion habichi and Ophiomorpha ichnocoenoses (Heinberg & Birkelund 1984). Body fossils are mainly preserved in the pebble beds, including fragmented belemnites, ammonites and bivalves. The trace fossil assemblage, pebble and conglomerate lenses, low-angle master bedding, with a dip direction parallel to the dominant current orientations of the ripchannel and bar deposits, and the generally complex bedding suggest a highly dynamic foreshore to upper shoreface environment (Clifton 1969(Clifton , 1976Davis & Fox 1972;Dörjes & Hertweck 1975;Ekdale et al. 1984;Curran 1985). Mudstone-draped foresets and herringbone cross-bedding with bundled build-up of foresets suggest that reversing tidal currents were active, at least locally. Tidal processes seem in general to have been overprinted by wave action and associated wave-induced currents. The wave-ripple cross-laminated sediments represent aggradational fair-weather deposits, whereas cross-beds were formed by stationary and seawards (southwards) migrating bars during storms (Clifton et al. 1971;Davis & Fox 1972;Clifton 1976;Hunter et al. 1979). Some shoreface deposits represent preserved shore-parallel bars, with wave-ripple cross-lamination and cross-bedding, and runnels with wave-ripple laminated fill, interpreted as fair-weather deposits .
The conglomerate lenses and the low-angle inclined laminated beds of barred upper shorefaces are interpreted as bar and swash-/surf-zone deposits (Clifton Fig. 14. Foreshore deposits with parallel to low-angle, inclined, fine-to mediumgrained sandstones of fair-weather origin, erosionally overlain by coarse-grained, belemnite-rich, pebbly storm sandstones. Bioturbation by Ophiomorpha nodosa. Pen (lower, right) is 14 cm long. Pelion Formation, locality 9 (Fig. 2).  (2), showing epsilon-infill pattern, caused by eastwards lateral migration of the rip-channel. 3, wave-rippled beds. Pelion Formation, locality 9 (Fig. 2). Total thickness of (2) is c. 2 m. 1969Hunter et al. 1979). The presence of conglomerates indicates proximity to a fluvial source, and they are interpreted to have been deposited in wavereworked fluvial mouth bars and adjacent beaches. The sediments are thought to have been delivered to the shoreface regions through braided fluvial channels, which must have been shallow, because no channel deposits survived subsequent transgressive marine erosion.
The seawards inclination of the master bedding in some upper shoreface sandstones is interpreted to indicate that shoreface progradation occurred during high energy conditions with high sediment influx (Cant 1991;. The master bedding marks an abrupt upwards change from lower to middle shoreface aggradation to dominantly upper shoreface progradation. The erosional surface which in many cases separates middle or lower from upper shoreface deposits Fig. 17. A fine pebble lag, 1 m thick, bounded below by a marine surface of erosion (MSE) and topped by a flooding surface (FS). The lag apparently forms a single cross-bed with foresets dipping up to 20°towards the south, indicated by the fracture pattern. The formation of the lower boundary (MSE) was followed by colonisation of Diplocraterion habichi and Monocraterion tentaculatum during an early stage of water deepening (arrow 1). During the subsequent winnowing and deposition of coarse material, the burrowing organisms still inhabited the sediment (arrow 2). The deposits become increasingly bioturbated upwards with nearly 100% burrowing at the top, and D. habichi descending from the top flooding surface. Pelion Formation, locality 7 (Fig. 2).
Current-ripple orientations in middle shoreface deposits, localities 10 and 11 Wave-ripple crestline orientations in middle shoreface deposits, locality 11 Current-ripple orientations in upper shoreface deposits, localities 6, 6A, 7, 9, 9A, 10, 11, 14 Wave-ripple crestline orientations in upper shoreface deposits, localities 6, 6A, 7, 9, 9A, 10, 11, 14 Current-ripple orientations in sand sheet deposits, localities 7, 8, 10, 11 Wave-ripple crestline orientations in shallow offshore sand sheet deposits, localities 7, 8, 10, 11  Fig. 16. Current-ripple foreset azimuths and wave-ripple crestline orientations in shoreface and shallow offshore sandstones. Data from several localities are included. The shoreface and shallow offshore units were most likely deposited by, or in connection with, progradation of roughly east-west-oriented shorelines. Each shoreface unit prograded from the north. This type of data does not allow precise interpretation of the shoreline orientation, due to possible wave and current interference patterns in the nearshore areas. The data may, however, indicate a general trend, as they show a pronounced lateral persistence. Fig. 18. Non-winnowed deposits, interpreted to have formed during transgressive deepening. They overlie a marine surface of erosion (MSE), and consist of massive or weakly laminated silty, fine-grained sandstones (arrow 1) overlain by coarse-grained, even, parallel bedded and cross-bedded sandstones (arrow 2). Bioturbation by Diplocraterion habichi and Monocraterion tentaculatum is concentrated in the uppermost part, descending from the top flooding surface (FS). The coarse grain size of the upper bed suggests that it was deposited as a shoreface-connected sand-sheet during shoreface retreat. Pelion Formation, locality 7 (Fig. 2).   (1), overlain by swaley cross-stratified beds (2), cut by S-SE-oriented rip-channel trough fills (3). Wave-ripple cross-laminated beds occur at different levels (4). Parallel-laminated surf-zone beds are also present (5). The sandstones are interpreted as wavedominated shoreface deposits. Hammer head (encircled) is 18 cm long. Pelion Formation, locality 7 (Fig. 2). was formed by storm-wave and current scour in front of the prograding upper shoreface. The surface is diachronous, and it has no regional significance in correlation (Nummedal & Swift 1987;. The southwards orientation of the inclined upper shoreface master bedding and the dominant east-west orientation of wave-ripple crests in both lower and upper shoreface deposits indicate that shorelines prograded southwards (Fig. 16). The overall grain-size gradients suggest sediment influx from the north-west.
Non-barred, wave-dominated upper shoreface sandstones were deposited in some areas, especially at localities 6, 6A, and 7 (Fig. 20). The sandstones are generally medium-grained, well sorted, and dominated by swaley and wave-ripple cross-laminated beds, erosionally cut by north-south oriented rip-channels and gutter casts (facies 9). The deposits always gradationally overlie fine-to medium-grained, low-angle inclined and horizontally-bedded sandstones of facies 8 (Fig. 20). The deposits are capped by a marine surface of erosion, overlain by erosionally-based swaley cross-beds. The degree of bioturbation is generally low, and Planolites vulgaris and Skolithos isp. have been identified. Belemnites occur scattered throughout the facies.
The dominance of swaley cross-bedding and waveripple cross-lamination, erosionally cut by rip-channels and gutter casts, suggests deposition in a storm-wave dominated upper shoreface (Plint 1988;Bhattacharya & Walker 1991). The fossil assemblage indicates marine conditions. The good sorting suggests a position well away from fluvial input sources. The predominant north-south orientation of gutter casts and rip-channels suggests an east-west oriented shoreline. The generally low degree of bioturbation may reflect the non-barred character of the shoreline, lacking protected areas.

Middle shoreface
The middle shoreface deposits consist of 1-10 m of fine-to locally coarse-grained sandstones (facies 7, 8), containing scattered bivalves and belemnites. Waveformed ripples and mega-ripples characterise most of the deposits, including lenses of cross-bedded, mediumto coarse-grained sandstones, and erosionally-based fine-to coarse-grained, laterally aggradational trough fill sandstones, up to 0.5 m thick (facies 7). Bioturbation is generally very intense. Horizontal traces dominate in the wave-rippled beds, and dominant trace fossils are: Taenidium serpentinum, Gyrochorte comosa, Planolites isp., Phycodes isp., and Thalassinoides suevica, whereas vertical traces dominate in the cross-beds, including notably Monocraterion tentaculatum, and Skolithos linearis. The trace fossils are referred to the Planolites, Curvolithus and Diplocraterion habichi ichnocoenoses of Heinberg & Birkelund (1984). The deposits may form bedsets, up to 8 m thick, of fine-to medium-grained, low-angle inclined to flat-bedded sandstones, interbedded with wave-rippled beds and overlain by swaley cross-bedded sandstones of the upper shoreface (facies 8; Figs 10, 20). Palaeocurrent directions are towards the west, through south to the east, but south to southeast orientations dominate (Fig. 16). The lower boundary of the deposits is erosional and wavy, or there is a gradual upwards change from hummocky cross-stratified or even, parallel-laminated beds, and the boundary is placed at the base of the wave-ripple laminated beds. The deposits may directly overlie marine lags without any intervening offshore or lower shoreface sediments. The upper boundary of middle shoreface deposits is in most cases erosional and sharp, showing a relief of up to 0.4 m, or there may be a textural and structural gradational change into upper shoreface deposits, showing both horizontal traces, and vertical traces.
The dominant fine-to medium-grained, ripple-laminated beds were deposited under the influence of fairweather waves. The dominance of horizontal traces indicates overall slow deposition, whereas the change to vertical traces represents a seawards translated upper shoreface fauna (Dörjes & Hertweck 1975;Frey 1975;Ekdale et al. 1984;Pemberton & Frey 1985). Fair-weather deposition was punctuated by storm erosion, reworking and deposition, represented by the medium-to coarse-grained, cross-bedded lenses. The cross-beds are interpreted to have been deposited in rip-channels, on rip-channel mouth-bars and as mega-ripples, formed during seawards transport of sediments during major storms. The current orientations obtained from the ripchannel and associated mouth-bar deposits, and waveripple crestline orientations suggest an east-west orientation of the coastline (Fig. 16). The large spectrum of preserved wave-and current-formed sedimentary structures suggests that deposition was influenced both by storm and fair-weather wave processes, and that the water depth was in the range of 5-15 m during deposition. Similar deposits have been described by Clifton (1976), Hunter et al. (1979), Dabrio & Polo (1981), and .
The flat-bedded sandstones are interpreted as sand sheets deposited from density currents, fed by laterally extensive erosion of upper shoreface deposits during storms. This process has been well described by Howard & Nelson (1982) and Nelson (1982). The flat-bedded sandstones may also have formed rip-channel mouth bars, deposited from a mixture of bedload and suspension fall-out, as indicated by the associated ripchannel fills which occur locally. Channelised and non-channelised sediment transport probably took place simultaneously during storms; this is indicated by the small size of the preserved rip-channels, compared to the thickness and lateral extent of the flat-bedded sandstones (Fig. 20).
Shoreface associations may lack lower shoreface and offshore transition zone deposits, and consist of middle shoreface deposits in the lower part, overlying lags or marine regressive surfaces of erosion (as shown in Figs 8,9). This is thought to indicate that the shoreface prograded into very shallow water, as described for Cretaceous deposits of the US Western Interior Seaway by Hart & Plint (1993).

Lower shoreface to offshore transition zone
The lower shoreface to offshore transition zone deposits are characterised by a backstepping, aggradational to forestepping facies stacking pattern. The deposits have a basal lag, ranging from a layer only one pebble thick up to 1 m thick (facies 1, 2), or rest directly on a strongly burrowed marine erosion surface, locally overlain by less than 2 m of fine-to medium-grained, structureless, faintly-laminated or cross-bedded sandstone (facies 3; Figs 17-19). The basal deposits are overlain by less than 0.5 m of strongly burrowed calcareous siltstone or laminated siltstone (facies 5; Figs 11, 21), locally rich in bivalves, belemnites and ammonites, sharply overlain by laminated, silty, fine-grained sandstone, 0.5-15 m thick (facies 6). The latter deposits consist of intercalated even, parallel-laminated or hummocky cross-stratified beds, or show an upwards transition from horizontally laminated to hummocky cross-stratified beds. Wave ripple-formsets locally occur in the uppermost part of the deposits. Burrows of Gyrochorte comosa, Taenidium serpentinum, Planolites vulgaris and Helminthopsis magna (Planolites ichnocoenosis) are restricted to the even, parallel laminated beds. Marine body fossils are found locally throughout. The association is capped by a sharp, wavy boundary, or shows a gradational contact to overlying fine-to coarse-grained pebbly, rippled or cross-bedded sandstones of the middle or upper shoreface .
The association was deposited in the lower shoreface to offshore transition zone. The coarse-grained basal lags and overlying calcareous deposits are interpreted as having been formed during and after transgressive erosion of the underlying shoreface deposits, and indicate an increase in water depth from above fair-weather wave base to near or below storm wave base (Nummedal & Swift 1987;Nummedal et al. 1993;. The lags were formed during a time of winnowing or erosion with no net deposition, and the overlying condensed facies (facies 5, 6) were deposited slowly from suspension fall-out, occasionally influenced by weak currents. The hummocky cross-stratified beds were formed by storm wave-oscillation, and individual beds represent single storm events (Harms 1975;Brenchley et al. 1986Brenchley et al. , 1993. Deposition took place at a minimum water depth of 5-15 m, interpreted from the thickness of the overlying middle and upper shoreface deposits, and the preserved bedforms and trace fossils. The marine trace fossils of the horizontally laminated beds are typical of an environment dominated by slow suspension fall-out (Seilacher 1967;Frey 1975;Heinberg & Birkelund 1984).

B. Estuarine association
Preserved estuarine deposits are rare, and have only been found at two localities. They are described below and include channel and shoal deposits.

Estuarine channel
Estuarine deposits are exposed in the valley between the mountains of Pelion and Parnas, where estuarine deposits of the Pelion Formation erosionally overlie the Sortehat Formation (Fig. 2, locality 10; see also Figs 22,23). Erosional incision reaches a presumed maximum of 30-40 m in the central part of the exposure, which is 1.5 km long and is oriented approximately east-west, perpendicular to the axis of the incised valley, as deduced from current orientations and large-scale bed geometries. The estuarine deposits are 30-40 m thick and are dominated by medium-grained sandstones with a few conglomerate beds (facies 9). Two channel sandstone bodies occur, separated by thin spit deposits. The upper estuarine channel unit is overlain by strongly burrowed offshore sandstones and siltstones of facies 6 and 7 (Fig. 22).
The basal erosion surface is draped by a discontinuous, allochthonous, vitrinite coal layer, up to 4 cm thick, overlain by a fine-grained sandstone, up to 0.5 m thick, rich in coal debris and mica (Fig. 23)  lying sandstones are characterised by low-angle master bedding, dipping c. 4°towards the east, representing the fill of a major, laterally migrating estuarine channel (Morton & McGowen 1980;Cotter 1983;Yang & Nio 1989;Sha & de Boer 1991). The general current orientation was towards the south, but other directions are also observed. Large-scale cross-beds, up to 2 m thick, dominate, showing planar and tangential foresets dipping towards the south. The concentration of organic debris is commonly high along bottomsets, and may form allochthonous coal beds up to a few centimetres thick. Petrified wood fragments are abundant throughout. Skolithos linearis and Diplocraterion habichi occur at eight levels from 4 m above the base of the deposits and upwards. The cross-beds may be separated by cross-laminated sandstone beds or bedsets 0.2-3 m thick, locally containing coal debris and centimetrescale, discoidal quartz pebbles. Ripple crests are generally oriented east-west. The lower channel unit is overlain by three coarsening-upwards units, each c. 1 m thick, with a horizontally bedded or cross-laminated lower part and a planar or trough cross-bedded upper part (Fig. 22). The top unit is erosionally overlain by the upper channel fill unit, which is up to 10 m thick, consisting of fairly well sorted, medium-grained sandstones, except for the lowermost metre, which is coarse-grained. The channel fill shows 1-20 m wide troughs, which cut into each other, with margins typically inclined less than 10°. The trough fills show concordant bedding and lamination, and occasionally wave-rippled surfaces, but lateral accretion surfaces also occur. Palaeocurrent orientations are consistently towards the south. The channel deposits are overlain by an erosionally-based sandstone unit, 3 m thick, rich in coal debris, larger fragments of plants, and petrified wood. The sandstones show wave-ripple cross-lamination, and locally wave-ripple formsets. This upper unit shows moderate to very strong burrowing, including Diplocraterion habichi, Monocraterion tentaculatum, Skolithos linearis and Teichichnus isp.
The succession is interpreted as the fill of a minor incised valley, cut into the dark offshore mudstones of the Sortehat Formation by fluvial erosion during a time of sea-level lowstand. The vitrinite coal layers and finegrained sandstones rich in coal debris of the basal valley-fill deposits are interpreted as the erosional remains of floodplain sediments, which escaped transgressive erosion during the transformation of the river mouth into an estuary.
The large-scale cross-beds of the lower estuarine channel unit were formed by migration of sub-channels and bars on the inclined accretion surface of the channel margin. The channel sandstones are interpreted as freshwater-influenced ebb-tidal deposits, based on the large amount of plant material, the dominance of southwards migrating bed-forms, and the restriction of marine trace fossils to channel inactivity surfaces (Barwis 1985;Yang & Nio 1989;Allen 1991). The fine-grained wave-rippled beds and bedsets rich in coal debris and with scattered discoidal pebbles that occur at different levels on the inclined master bedding surface, were possibly formed by wave reworking during channel inactivity. The predominant east-west orientation of wave-ripple crests is interpreted to reflect the north-south Fig. 23. Basal 4 m of the estuarine channel sandstones, filling a minor valley incised into the Sortehat Formation. The deposits belong to sequence P1 (Fig. 6). SB1, lower sequence boundary of the Pelion Formation, separating estuarine deposits from underlying marine silty shales of the Sortehat Formation; 1, floodplain deposits, representing the oldest deposits in the incised river valley; 2, allochthonous vitrinite and durite coal layer; 3, base of lower estuarine channel unit (dotted line); 4, Estuarine channel sandstones. Hammer for scale (at SB1). Pelion Formation, locality 10 ( Fig. 2). View is towards the south-west. orientation of the estuary. The three small-scale coarsening-upwards units, overlying the estuarine tidal channel deposits are interpreted as spit deposits. They were formed by laterally migrating spits, which filled the accommodation space left above the channel fill after the active channel had moved laterally by erosion and accretion (Terwindt 1971;Yang & Nio 1989;Allen 1991).
The upper channel unit is also interpreted as a freshwater-influenced ebb-tidal estuarine channel fill, based on the invariably southwards-oriented, erosionallybased large to giant-scale foresets, and the lack of marine fossils and trace fossils (Dalrymple et al. 1992). The amalgamated character of the channel deposits indicates a high sediment influx to the estuary, larger than the rate of creation of new accommodation space. The uppermost 3 m of burrowed, wavy bedded sandstones are interpreted as a sand sheet, deposited during marine flooding of the estuary (Campbell & Oaks 1973;Dalrymple et al. 1992).

Estuarine shoal
Estuarine shoal deposits are exposed low on the south slope of the Olympen mountain (Fig. 2, locality 8). The exposed part of the unit is 14 m thick and consists of fine-to medium-grained sandstones, with a few conglomeratic sheets and lenses, each less than 10 cm thick. Clay and coaly detritus form thin drapes and layers. The deposits overlie and are overlain by shallow offshore sediments; the lower boundary is only exposed at a single place, where it is overlain by bottomsets of a planar cross-bed, showing bundled, low-angle foresets, rich in coal debris. The sedimentary structures are dominated by large-scale trough and planar cross-bedding, low-angle trough cross-bedding, wavy bedding, and planar-bedding (facies 7, 9). Beds are generally less than 0.5 m thick.
In the lowermost part of the unit, individual crossbeds can be traced in a southwards, down-current direction for more than 80 m without significant variation in thickness. They show bundle-wise up-building of sigmoidal, tangential or angular foresets, which may be draped by coaly debris and dark clay. They are separated by wavy bedded, fine-grained sandstones. The middle part of the unit is dominated by interbedded low-angle, cross-bedded sandstone with shallow crossbedded sandstone trough fills, up to 1 m wide, with foresets draped by coal debris, and swaley cross-stratification. Cross-beds show foreset azimuths from 90°through 180°to 220°. Bed boundaries of the lower and middle part of the unit mostly have a wavy appearance, and can in most cases be followed throughout the exposure. The upper part is dominated by non-bioturbated, swaley cross-stratified sandstones. Ophiomorpha nodosa burrows occur in the lower and middle part of the unit, where they descend in great numbers from bedding planes.
The estuarine shoal interpretation is based on the internal sedimentary structures and the stratigraphic position, sandwiched between offshore sandstones and siltstones. The presence of sandstones rich in coal debris, coal layers at the base of troughs, small-scale waveformed ripples, and the dominance of Ophiomorpha nodosa indicate deposition at very shallow water depths, not far from a terrestrial source (Clifton 1976(Clifton , 1983Barwis 1985;Curran 1985;Pollard et al. 1993). The basal estuarine shoal beds with bundled foresets, are interpreted to have formed by migration of sub-to intertidal sand waves, under the influence of neap-spring fluctuations of tidal currents. The wave-rippled beds are interpreted as slack-water sediments. These lower deposits are interpreted to have accumulated in shallow tidal channels, probably less than a few metres deep, based on the thickness of the channel fills. The middle part of the estuarine shoal deposits strongly resembles modern tidal shoal sediments (de Raaf & Boersma 1971;Terwindt 1971;Reineck 1972;Boersma & Terwindt 1981). The non-bioturbated upper part of the deposits is interpreted to reflect a general increase in marine storm and wave influence. The vertical facies development of the estuarine shoal deposits closely resembles tidal flat associations from the Lower Cretaceous Fall River Formation, Wyoming (Campbell & Oaks 1973) and modern examples (de Raaf & Boersma 1971;Clifton 1983;Terwindt 1988). The estuarine shoal deposits are thought to represent non-erosional drowning of an estuarine shoal area (Campbell & Oaks 1973;Dalrymple et al. 1992). The top marine surface of erosion is interpreted to have formed during the final marine transgression of the estuary.

C. Tidal inlet association
Tidal inlet deposits are exposed at two stratigraphic levels at Trefjord Bjerg in the easternmost part of the exposure belt (Fig. 2, localities 6, 6A, 7). The lower and upper inlet units are 20-25 m and 20-35 m thick, respectively. Both units can be traced laterally east-west for 1.5 km. The lower can be followed north-south for 600 m, and the upper for several kilometres, without any change in facies pattern. Locally, mouth-bar deposits are present in the lower part of the association. In the absence of basal mouth-bar deposits, the tidal inlet units erosionally overlie offshore siltstones and sandstones.
The mouth-bar deposits are up to 8 m thick, and consist of fine-to medium-grained current-and wave-ripple cross-laminated sandstones (facies 7). The upper part of the mouth-bar deposits is especially rich in coal debris, plant fragments, bivalves and belemnites. The mouth-bar deposits are erosionally truncated by the base of the tidal inlet channel fill, and locally a large number of Diplocraterion habichi burrows descend from the erosion surface. The inlet channel fill consists of medium-to coarse-grained, generally well-sorted sandstones (facies 9), with very subordinate conglomerates. Vertical trends in grain size have not been recorded (Figs 24,25). The master bedding of the tidal inlet sandstones is inclined 4°in an easterly direction. The master bedding surfaces show tangential to angular lower bedding contacts and are erosionally truncated updip by a marine erosion surface. The inclined strata are 0.2-2 m thick and show planar and trough cross-bedding, massive bedding or ripple cross-lamination. Wave-ripples may occur at bed boundaries. Reactivation surfaces are common, both at bed and master bedding scale. Herringbone cross-bedding is common. Southerly palaeocurrent directions dominate with subordinate northerly directions, perpendicular, or at a very high angle, to the dip direction of the master bedding surfaces. Scattered Diplocraterion parallelum, Planolites isp., Phycodes isp. and a single Taenidium serpentinum were observed in the channel deposits. Diplocraterion habichi and Monocraterion tentaculatum descend in large numbers from the marine erosion surface at the top of the inlet channel sandstones. Ammonites occur in the lower part of the association, whereas belemnites and bivalves are found scattered in the upper part.  Fig. 24. Tidal inlet association (C), consisting of large-scale planar cross-bedded, medium-to coarse-grained sandstones (10-31 m), erosionally overlying finer grained, cross-laminated, and cross-bedded inlet mouth deposits (3.5-10 m). The largescale bedforms in the inlet deposits indicate that powerful currents were active at the time of deposition. Bedforms mainly migrated towards the south, perpendicular to the azimuth of the master bedding planes. Ammonites found in the offshore deposits below the inlet channel (at 0.5 m) belong to the Cranocephalites borealis β faunal horizon. Pelion Formation, locality 7 (Fig. 2). For legend, see p. 823.
The body and trace fossils indicate that normal marine salinities prevailed, at least periodically. The restriction of trace fossils to distinct levels suggests that rates of deposition and erosion of the active depositional surfaces were generally too high for colonisation, which only occurred during longer periods of bedform stillstand.
The tidal inlet interpretation is based on the lateral association with shoreface deposits, and by the internal sedimentary structures, including the inclined master bedding (Terwindt 1971(Terwindt , 1981Nio & Yang 1991). The eastwards inclined master bedding reflects lateral migration of the inlet, and the presence of up to 2 m thick cross-beds suggests deposition from powerful tidal currents. The common occurrence of herringbone cross-bedding suggests that both ebb-and flood-currents operated in the channels, although ebb-oriented currents dominated, as deduced from the dominant offshore, southwards palaeocurrent direction. The generally well-sorted nature of the deposits suggests that sorting processes operated so as to maintain a uniform grain size in the channels; finer grained sediment bypassed the channels to be deposited in adjacent shoreface, channel-mouth, and offshore environments. The sediment sources for the channel fills were presumably mainly cannibalised shoreface deposits, and to a lesser extent, primary fluvial sediments. The tidal inlets were subtidal as the inclined master bedding covers the full thickness of the preserved deposits. The depositional environment was probably somewhat similar to recent tidal inlets described from the Dutch North Sea coast by Yang & Nio (1989) and Sha & de Boer (1991). The bases of the inlet channels form channel diastems, and are locally strongly incised. They may be considered as unconformities as discussed below in the sequence stratigraphy section. The tidal range has not been calculated due to lack of relevant data, but is estimated to have been in the range of 1-2 m, by comparison with bedform patterns of the modern North Sea. The shoreface associations of the Pelion Formation show little evidence for tidal inlets, which would have dominated if the tidal range was larger. The modern example described by Sha & de Boer (1991) shows that at a tidal range of 1-2 m, the tidal inlets and estuaries are the only part of the sea-facing environment that are dominated by tidal processes. Adjacent shorefaces are dominated by waves, long-shore currents and shorenormal rip-currents which are not systematically reversing. This is compatible with the data from shoreface and tidal inlet channel deposits of the Pelion Formation.
stones. The sorting is locally very good, making foresets almost invisible. Belemnites, ammonites and bivalves occur scattered. Individual sand sheets are tabular, and have in some cases been traced over more than 9 km 2 . The sheets may be solitary, less than 1.5 m thick and interbedded with shallow offshore to middle shoreface deposits, or form vertically stacked successions, in which the individual sheets are separated by thin offshore or lower shoreface units. Some thin sheets consist of a single bed with planar cross-bedding. The upper boundary is a sharp, planar surface, or is marked by well-preserved wave-formed megaripples. Sedimentary structures in the association include trough and planar cross-bedding, cross-lamination and even, parallel lamination; the structures do not occur in any clear vertical succession (Figs 9, 26). Herringbone cross-bedding, showing bundled up-building of foresets, is locally observed. Internal scour fills showing lateral accretion are present in some units, reflecting local, confined currents. A wide range of palaeocurrent directions are observed in individual sand sheets, but southwards directions predominate (Fig. 16).
The sand sheet units are generally pervasively burrowed by Taenidium serpentinum, Planolites isp. and Gyrochorte comosa representing the Curvolithos ichnocoenosis. Diplocraterion habichi, Monocraterion tentaculatum and Skolithos linearis or Ophiomorpha nodosa of the Diplocraterion habichi and Ophiomorpha ichnocoenoses commonly descend in large numbers from the upper bounding surface, but may also occur within the units. Thalassinoides suevica and Phoebichnus trochoides may also occur in large numbers. In Jameson Land, Phoebichnus trochoides has previously been described from fine-grained offshore deposits of the Fossilbjerget Formation (Bromley & Asgaard 1972;Heinberg & Birkelund 1984), but also occurs in Pelion Formation sandstones in Wollaston Forland (Surlyk & Clemmensen 1983).
The body and trace fossils of the deposits indicate a fully marine environment. The sand sheet units resemble upper shoreface sandstones, but differ in many aspects (Surlyk & Noe-Nygaard 1991  The presence of pebbles and coarse-grained sandstone suggests that the sand sheets were closely associated with a shoreface during deposition. Pelion Formation, locality 8 (Fig. 2). For legend, see p. 823.
of Thalassinoides suevica and Phoebichnus trochoides is a distinct feature, which only characterises sand sheet and more fine-grained offshore deposits. The close association with lower shoreface to offshore fine-grained silty sandstones is also a distinct feature of the association. The wave-formed, mega-ripple formsets at the top of the sheets were formed by storm waves during abandonment. The trace fossil distribution shows that deposition was relatively slow with minor wave-reworking, alternating with times of storm-wave and current erosion and deposition. The horizontal traces of Planolites isp., Gyrochorte comosa and Taenidium serpentinum are interpreted to have been made during slow fairweather deposition, whereas Diplocraterion habichi, Monocraterion tentaculatum, Skolithos linearis and Ophiomorpha nodosa probably represent a seawards translated upper shoreface assemblage (Dörjes & Hertweck 1975). Phoebichnus trochoides and Thalassinoides suevica, which occur in the top of the sand sheets, were formed after abandonment, and mark the return to quiet offshore conditions, with slow deposition from suspension fall-out (Bromley & Asgaard 1972;Surlyk & Clemmensen 1983;Heinberg & Birkelund 1984). The occurrence of coarse-grained sandstone in some of the thick sand sheet units suggests a nearshore position, and some sheets pass into progradational shoreline deposits towards the north-west or north. The presence of herringbone cross-bedding probably indicates reversing tidal currents. The co-existence of smalland large-scale symmetrical and slightly asymmetrical ripples indicates that the depositional surface was influenced by both fair-weather and storm waves and currents and that deposition took place above fair-weather wave base.

E. Clinoform association
The clinoform association is only found at localities 3 and 4 (Fig. 2), where it forms the Ugleelv Member of the Pelion Formation (Surlyk 2003, this volume, fig. 5). It consists of a single tabular, clinoform bed or giantscale cross-bed, 8-35 m thick (locality 3), or two stacked beds, the lower up to 25 m thick and the upper up to 8 m thick (locality 4; Figs 27, 28). The upper clinoform bed at locality 4 wedges out towards the south, and is not present at locality 3 (Fig. 27). The association consists of well sorted fine-to coarse-grained sandstones, with tangential clinoforms dipping up to 10°towards the ESE. Systematic lateral grain-size variations are not observed. The clinoform beds have been traced over c. 50 km 2 . Towards the south and east, they rapidly give way to offshore siltstones and thin, fine-grained sandstones of the Fossilbjerget Formation. The association has not been traced west or north of locality 4, due to lack of exposure. The clinoform beds have non-erosional bases, and clinoforms pass downwards into bottomsets composed of strongly burrowed, structureless or horizontally bedded fine-grained silty, carbonaceous sandstone (Fig. 29). The clinoform beds are flat-topped, bounded by a sharp erosional surface (Figs 27, 28, 30). Erosion probably removed less than a few metres of the units, as deduced from the thickness of locally preserved wave-rippled and swaley cross-bedded topset deposits. The upper decimetres of the clinoform beds are strongly carbonate cemented. Diplocraterion habichi and Monocraterion tentaculatum descend in large numbers from the upper surface, which is overlain by strongly burrowed calcareous siltstones of the Fossilbjerget Formation (facies 5).
Reactivation and inactivity surfaces are developed throughout the clinoform beds, and are reflected by two types of bundling of the clinothems. Stillstand-surfaces are overlain by downlapping low-angle clinothems and are characterised by strongly burrowed carbonaceous deposits rich in fossils and plant fragments. Firmground-type burrowing of Thalassinoides isp. and other trace fossils dominates (Fig. 31). The reactivation surfaces are characterised by erosional truncation of low-angle clinoforms by higher-angle clinoforms.
Intrasets are 0.2-1 m thick, mainly planar cross-beds with sharp boundaries, locally showing small-scale scours. Some clinothems consist of a cross-bedded intraset or stacked cross-laminated, cross-bedded, planar bedded, or structureless sets. The intrasets locally show bundling of foresets, a lateral development from tangential to sigmoidal foresets, single and double clay drapes of bottomsets and foresets, reactivation surfaces, and herringbone cross-stratification. Wave-eroded intraset boundaries are common. The foreset azimuths of intrasets are generally towards the south, and the intrasetforming ripples migrated perpendicular to the dip or obliquely down the ESE-dipping clinoforms.
Ammonites, belemnites and bivalves occur scattered throughout the association, and are present in large numbers on the top surface of the clinothems. Crinoid ossicles are abundant in bottomsets of the distal, wedging-out parts of the clinothems. Petrified wood fragments and carbonised plant material are common. Trace fossils include Diplocraterion habichi, Monocraterion tentaculatum, Skolithos linearis, Thalassinoides suevica, Curvolithos multiplex, Planolites vulgaris, Teichichnus isp., and Phycodes isp. of the Cochlichnus and Diplocraterion habichi ichnocoenoses of Heinberg & Birkelund (1984). The clinoform beds were formed by progradation of thick marine sandbodies towards the ESE. The coarse grain size suggests that deposition took place in connection with shoreface progradation, and that powerful currents, which probably periodically reached 1-1.5 m/s (indicated by the presence of traction-transported coarse sand), shaped the clinoform beds. The fossil assemblage indicates a fully marine environment. The depositional environment was tidally-influenced and shallow marine. The coexistence of small-and large-

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Facing page: Fig. 27. Sections measured through the clinoform complex (association E) of the Ugleelv Member, exposed at localities 3 and 4 (Fig. 2), extending for 11 km in a north-south direction. The ammonites found just below the clinoform complex belong to the Cranocephalites borealis β faunal horizon (1b); the ammonite faunal horizons (1-21) shown on this and subsequent figures are listed in full on Fig. 37. A Cranocephalites indistinctus fauna is found in the basal beds of the lower clinoform unit (2), a Cranocephalites intermissus fauna (3) is found high in the unit, and a Cranocephalites gracilis fauna (4) is found on top of the lower unit at locality 4, and on the top of the upper unit throughout the area. Biostratigraphical correlation to locality 6 (to the north) and locality 2 (to the south) is indicated. To the north, at locality 6A, Cranocephalites carlsbergensis (5) occurs immediately above the Cranocephalites borealis β fauna. 9a indicates the Arctocephalites delicatus faunal horizon. For full legend, see p. 823.   (Fig. 27). Compass for scale (arrow). The view is towards the east. A tidal megaripple is seen below the compass; it shows bundled foresets, with azimuths towards the south. Bioturbated sandstones occur above the mega-ripple and become increasingly burrowed upwards, terminating in a 100% bioturbated sandstone; trace fossils recognised are Diplocraterion habichi, Skolithos isp. and Thalassinoides suevica. Pelion Formation, locality 3 (Fig. 2). scale wave-ripples and swales in the topset deposits suggests that the water depth was above fair-weather wave base in a shoaling wave environment. Wave-eroded intraset-boundaries indicate periods with no net deposition. Symmetrical mega-ripples were formed by storm waves, and plane-bedded intrasets were formed by suspension fall-out. Large-scale inactivity and reactivation surfaces internally in the clinoform beds indicate lateral shifting of the active depositional surface during deposition, or minor sea-level changes. The upper surface of the clinoform beds was erosionally planed off during transgressive marine erosion succeeding deposition of each unit. Marine erosion was followed by marked increase in the water depth, reflected by the presence of a strongly burrowed marine surface of erosion, overlain by burrowed calcareous offshore siltstones of facies 5.
Although the internal sedimentary structures of the clinoform beds closely resemble those observed on active depositional surfaces of modern offshore tidal sand bars, they are not analogous (Surlyk & Noe-Nygaard 1991). A comparable setting may, however, occur in the modern Niger delta, where a tabular, 20 km wide sandy, shoreface attached sand unit occurs at 5-10 m water depth in front of a marine, reworked, prograding delta (Allen 1965;Oomkens 1974). Similar high-angle clinoform beds are characteristic of the Volgian Raukelv Formation of southern Jameson Land and are inter- (arrow 2). The dark colour of the bioturbated levels is caused by the presence of carbonaceous debris, mud and carbonate cement. Pelion Formation, locality 3 (Fig. 2). preted as marine-reworked shelf-margin wedges formed during sea-level lowstand .

F. Offshore association
Thin offshore deposits that form part of shoreface associations have been described and interpreted in the shoreface section. Thick offshore deposits characterise the Fossilbjerget Formation, and are described and interpreted below (Fig. 32). The offshore association consists of sediments deposited from suspension fall-out, at some levels influenced by wave-agitation and currents (facies 5, 6, 10). Marine body fossils are abundant throughout, and are commonly concentrated at surfaces capping coarsening-upwards units. Offshore sediments immediately overlying such surfaces may contain Zoophycos laminatus? and Phoebichnus trochoides.
The facies associations of the Fossilbjerget Formation show a proximal-distal, north-south transition from shoreface and sand sheet associations in northern Jameson Land (facies 7, 9, 10) to fully offshore associations in central and southern Jameson Land (facies 10; Figs 32, 33). In southern Jameson Land, the offshore deposits consist of structureless and laminated siltstones and mudstones with bands and lenses of fossil-rich carbonate and phosphate-cemented siltstones. An overall fining-upwards tendency has been recorded in these deposits, and deposition took place well below stormwave base. In central Jameson Land (Fig. 2, locality 5), the offshore association is up to 10 m thick, and generally coarsens upwards, with an overall upwards increase in sand content. The association wedges out towards the south, and is generally less than 1 m thick at localities 3 and 4. It may internally contain coarsening-upwards units, grading upwards from structureless or laminated siltstones to fine-grained, structureless, micaceous, carbonaceous and glauconitic sandstones. Some units are very rich in fossils, and their upper parts may contain ammonites, embedded at all angles, and brachiopods and bivalves, commonly in life position. Proximal offshore units are exposed at locality 9, where a vertical stacking of offshore, shoreface, and shallow marine, nearshore sand sheet associations occur (Fig. 33).
The association is interpreted as the fully marine, distal offshore part of progradational sandy shoreface units, deposited near or below storm wave-base by suspension fall-out. The thin coarsening-upwards units may reflect minor progradational events. The overall southwards fining and tapering of the offshore deposits of the Fossilbjerget Formation reflect sediment influx  to the offshore environment from the north, and distal condensation. Biostratigraphical data show that the distal deposits of southern Jameson Land are strongly condensed at several levels (Fig. 6). The degree of condensation decreases gradually towards the north, and the area of condensation expanded northwards through time; the upper part of the Fossilbjerget Formation consists mainly of condensed, offshore facies throughout the study area (Surlyk et al. 1973Birkelund 1975;Heinberg & Birkelund 1984;Surlyk 1991Surlyk , 2003Callomon 1993).

Sequence stratigraphy
A hierarchy of depositional sequences is recognised in the Pelion and Fossilbjerget Formations (Surlyk 1990b(Surlyk , 1991Engkilde & Surlyk 1993;Surlyk et al. 1993;Engkilde 1994). A total of 28 sequences are recognised and are expressed by the facies associations. They are stacked into eight low-order composite sequences (P1-8, Fig.  6), each containing 3-5 higher order sequences, formed by shoreface progradation. The composite low-order sequences each cover a time span of 1-2 Ma, in the range of the third-order composite depositional sequences of Mitchum & Van Wagoner (1991) and are referred to as such in the following discussion. P1-8 are defined by the stacking pattern of the constituent high-order   fig. 5). Offshore mud-rich sediments of the Fossilbjerget Formation resume above 54 m. Locality 9 (Fig. 2). The deposits belong to the composite sequence P6, which is bounded by coincident sequence boundaries (SB) and transgressive surfaces of erosion (TSE), SB6/TSE beneath and SB7/TSE above. For legend, see p. 823. sequences and by the nature and extent of their bounding surfaces. The average duration of a high order sequence is about 360,000 years, in the range of the fourth-order depositional sequences of Mitchum & Van Wagoner (1991). They are referred to as sequences or simple sequences. The sequence boundaries of the composite sequences are defined by significant turn-around points in the stacking pattern of the constituent sequences (Fig. 6). Boundaries of composite sequences are interpreted to represent periods of widespread subaerial exposure in the basin, indirectly reflected by the texture and distribution of overlying lag deposits, areal distribution of underlying shoreface deposits, and in some cases directly by the biostratigraphic duration of the associated hiatuses.
The simple sequences form laterally linked sedimentary bodies, bounded by marine surfaces of erosion in shoreface and near-shore successions and correlative conformities in distal, offshore deposits. The marine erosion surfaces, which top most of the sequences in proximal areas are commonly overlain by laterally extensive pebble and sandstone lags (facies 1, 2) formed by transgressive erosion and winnowing of underlying deposits, and the surfaces are thus ravinement surfaces. The lags are generally significantly coarser-grained than the deposits below, implying that relatively large volumes of sediments have been eroded away (Engkilde 1994). They represent reworked fluvial, coarse delta-front, or adjacent shoreface deposits reworked during transgression, and their presence sug-gests that a zone of emergence, sedimentary bypass or erosion was formed after shoreface progradation. The lags thus represent a significant basinwards shift in facies. The lower boundary of a marine lag is accordingly interpreted as a sequence boundary, overprinted by a younger marine ravinement surface. In more distal areas, the sequence boundaries are expressed as submarine erosion surfaces and their correlative conformities.
The successions between the sequence boundaries are regarded as small-scale sequences (sensu Van Wagoner et al. 1990;Fig. 34). The top of a lag is interpreted as a marine drowning surface, formed at the time when the water depth became too great for wave reworking. The drowning surfaces do not represent significant hiatuses, but are levels of slow deposition and condensation. They are commonly overlain by laterally widespread mudstones, marls or fine-grained sandstones deposited below storm wave base during the time of maximum flooding. Overlying shoreface deposits, forming the bulk of the sequences in proximal areas, are generally 5-15 m thick, and represent southwards progradation over several hundred kilometres without significant changes in thickness and facies. A general thickening of the most basinally positioned parts of the shoreface/tidal inlet units occurs, however, and they may reach up to 35 m in thickness at localities 5, 6, 6A and 7. The basin deepened gradually towards the south, along the basin axis, as The relative sea-level stand and the lateral translation of the depositional system are indicated schematically for times 1-4. Progradation took place during slow rise or stillstand (time 1), followed by fall (time 1-2), and terminated by slow rise of relative sea level (times 2-3). Backstepping took place during the rise in relative sea level (times 3-4). It has not been possible to separate the highstand (HST) and the falling stage (FSST) systems tracts (terminology of Plint & Nummedal 2000), as there are no significant differences in vertical position. This is due to the low-gradient basin geometry, and to wave-ravinement processes active during transgression. In the field, sandstones of the late lowstand systems tracts (LST) tend to be significantly thicker than those of the HST and FSST. SB, sequence boundary; TSE, transgressive surface of erosion; TST, transgressive systems tract; MF, level of maximum flooding. throughout most of northern Jameson Land, except in the easternmost part where they are thicker. In central Jameson Land, the signature of the sequences is gradually lost, and the depositional pattern of the composite sequence is dominant. The overall geometry of the sequences is interpreted to reflect progradation during stillstand, fall, and early rise of relative sea level (Fig. 34). The bulk of the sandstone part of the sequences is accordingly interpreted to represent falling stage system tracts (terminology of Plint & Nummedal 2000), as the sandstones are relatively thin over large areas, without any offshore thickening, and as they are capped by complex erosion surfaces. The thicker distal parts of the sequences, composed of sandstone, are interpreted as lowstand systems tracts, deposited during stillstand and early rise in relative sea level. The lowstand systems tracts are attached to the falling stage systems tracts (Fig. 34). When the rate of relative sea-level rise became larger than the rate of sediment accumulation, the shoreface system rapidly backstepped towards the basin margins and up to several hundred kilometres northwards up the basin axis. Early highstand deltaic deposits are thus to be expected to occur in the marginal areas.

Composite depositional sequences
The eight composite depositional sequences of the Pelion-Fossilbjerget couplet are described from below (P1-8), including biostratigraphy, boundary relationships, large-scale depositional geometries (systems tracts), and internal architecture. Constituent higher order sequences are indicated by a letter suffix, P1A, P1B, etc. All systems tracts of a depositional sequence are not necessary represented at all localities, and successive systems tracts do not necessarily stack vertically . Throughout northern Jameson Land, the composite sequences are highly asymmetric, volumetrically dominated by the highstand systems tracts (Figs 35, 36). This is thought to reflect the low-gradient basin topography, high sediment influx and efficient sediment transport. After filling of the accommodation space in proximal areas during early highstand, a wide subaerial bypass zone was developed during late highstand, and rivers transported most sediment volumes to the rapidly prograding shorefaces. The shoreface successions were deposited during repeated higher order sea-level falls, and are stacked vertically in a forewards-stepping manner throughout northern Jameson Land. Further offshore in central Jameson Land, the higher order pattern is less distinct, and very thick coarsening-upwards offshore-shoreface units represent the distal parts of the highstand systems tracts of the composite sequences. The bulk of the transgressive systems tracts of the composite sequences are predicted to exist in the most marginal areas, in Milne Land to the west and in the western and northern parts of the Traill Ø -Geographical Society Ø -Hold with Hope area to the north (Fig. 36).  Surlyk et al. 1973Surlyk et al. , 1993Surlyk 1990aSurlyk , b, 1991Surlyk , 2003. This sequence boundary is present throughout central East Greenland. The ammonite fauna (Cranocephalites borealis) belongs to the Boreal faunal realm, which cannot be directly correlated with the Tethyan faunal realm. The C. borealis Chronozone is referred to the Upper Bajocian (Callomon 1961(Callomon , 1993 Callomon (personal communications 1992Callomon (personal communications , 1993Callomon (personal communications , 1994, ammonite collections by T. Birkelund and C. Heinberg (Birkelund 1970(Birkelund , 1971Birkelund & Heinberg 1974), data from Heinberg & Birkelund (1984) and Callomon (1959Callomon ( , 1961Callomon ( , 1993, J.H. Callomon (personal communications 1994Callomon (personal communications , 1996, and visual correlations in the field. A: Composite sequences P1 and P2. The transgressive surface of erosion (TSE) that coincides with sequence boundary SB2 in the northern areas is chosen as the datum for the correlation, as this surface is thought to have been essentially flat, or dipping only very slightly in a southwards direction. South of locality 3, this TSE passes into a nonerosional, marine flooding surface characterised by the presence of C. gracilis or C. carlsbergensis throughout the region. B: Composite sequences P3-8. The transgressive surface of erosion (TSE) that coincides with SB4 in the northern areas (locality 5 and northwards) is chosen as datum for the correlation of the northern sections, as it is easily identified in the field and occurs in one faunal horizon (A. micrumbilicatus) throughout the area. In central and south Jameson Land, the TSE that coincides with SB5 at locality 5, is chosen as the datum, as it is a very distinct surface in the field. At locality 5, the surface forms the boundary between the Pelion and Fossilbjerget Formations. South of locality 5, the surface is a non-erosional flooding surface, occurring in one ammonite subzone (A. ishmae β) throughout the area. Some of the numbers referring to faunal horizons 9, 12 and 16 do not have a suffix; this indicates that the ammonite in question may be one of two variants, α or β.
Bajocian and Bathonian in East Greenland is a best estimate of Callomon (1993). The internal zonal correlation within the framework of the Boreal Middle Jurassic ammonite zonation is, however, very precise (Surlyk et al. 1973;Callomon 1993 Jones et al. (1994). In Jameson Land, the Pelion Formation overlies the Sortehat Formation. 87 Sr/ 86 Sr data indicate that the Sortehat Formation at least in the southern and central part of Jameson Land includes the Aalenian -Lower Bajocian. Dinoflagellate data suggest that the Sortehat Formation covers the Aalenian and possibly part of the Bajocian (Underhill & Partington 1993;Koppelhus & Hansen 2003, this volume). Further north, on Traill Ø, the Pelion Formation rests on Upper Triassic redbeds of the Flemming Fjord Formation (Clemmensen 1980), indicating a northwards increase in the duration of the hiatus expressed by SB1 (Fig. 6). On northern Hold with Hope, the Pelion Formation overlies the Lower Triassic Wordie Creek Formation (Stemmerik et al. 1997;Vosgerau et al. in press a). In central and northern Jameson Land (Fig. 2, localities 5, 6, 6A , 7, 9, 11), SB1 is interpreted as a subaerial unconformity, coinciding with a transgressive surface of erosion (TSE). It appears as a sharp boundary, separating dark grey, shaly offshore siltstones of the Sortehat Formation from yellow, burrowed, wave-rippled shoreface sandstones, or laminated light grey, burrowed offshore siltstones and sandstones of the basal Pelion Formation. Mudstone clasts of the Sortehat Formation locally occur in the lower part of the Pelion Formation. SB1 is overlain by thin floodplain and estuarine deposits at locality 10, and the sequence boundary here coincides with the base of an incised valley (Figs 22,23,35,37A). In southern Jameson Land, SB1 is represented by a marine regressive surface of erosion, which marks a significant basinwards shift of facies. SB1 here separates dark, silty mudstones of the Sortehat Formation from shallow marine coarsegrained siltstones and fine-grained sandstones of the Pelion Formation, which form a lowstand wedge.

P1: Lowstand systems tract
Estuarine deposits, up to 40 m thick, are preserved at locality 10, in northern Jameson Land, and are interpreted to form part of the lowstand systems tract. The deposits fill a valley incised into the Sortehat Formation during falling and low sea-level stand. The base of the valley forms SB1 (Figs 22, 23, 35, 37A). The estuarine deposits may belong to the C. borealis Chronozone, but no ammonites were found. The incised valley was formed by fluvial erosion, as indicated by the basal erosional remnants of floodplain deposits. Possible correlative fluvial conglomerates of the Bristol Elv Formation occur below marine sandstones of C. borealis Chron age on Traill Ø and probably occupy a major incised valley complex (Therkelsen & Surlyk in press).
In southern Jameson Land (Fig. 2, localities 1-4), southwards thinning basal silty sandstones of P1 form a 20-80 m thick lowstand systems tract of Late Bajocian age (Figs 35, 36, 37A). It consists of heavily burrowed fine-to medium-grained sandstones, with bivalves, gastropods, belemnites, ammonites and the trace fossils Diplocraterion parallelum, Diplocraterion habichi and Planolites isp. Petrified wood occurs in large quantities. The sandstones are generally poorly cemented. The upper part of the lowstand systems tract consists of sandstones showing well-preserved small-and largescale wave ripples, indicating deposition in a shallow marine, wave-influenced environment, above fairweather wave base, and is interpreted as comprising aggradational and progradational shoreface and shallow marine near-shore deposits. The lower boundary of the lowstand systems tract is an erosion surface, with a relief of up to 0.3 m. The upper boundary is sharp and planar, and is covered by an abundance of belemnites, ammonites (C. borealis α), oysters and bivalves. Large numbers of Diplocraterion habichi descend from the surface. Overlying deposits consist of offshore siltstones of the Fossilbjerget Formation at localities 1 and 2 and silty sandstones of the Pelion Formation at localities 3 and 4 belonging to the transgressive systems tract. During the time span of the late lowstand and transgressive systems tracts, the active shoreface rapidly backstepped in a northwards direction. The sandstone volume of the lowstand systems tract is estimated at approximately 3 km 3 /km width in an E-W section. The complete width is not known, but a conservative estimate is 60-80 km, giving a total sandstone volume in the range of 180-240 km 3 (Fig. 36).

P1: Transgressive systems tract
The lowstand systems tract is capped by a marine erosion surface throughout southern and central Jameson Land, which forms the base of the transgressive systems tract. The transgressive systems tract is less than 6 m thick in south Jameson Land (Fig. 2, localities 1, 2), measured from the top of the lowstand deposits to the first occurrence of the C. borealis β faunal horizon (Fig. 35 Fig. 38. Palaeogeographic maps showing the large-scale facies distribution in the Jameson Land Basin. A: Late Bajocian, P1 time. Laterally widespread, sandy lowstand deposits characterise southern Jameson Land during early P1 times. Fluvial bypass probably prevailed throughout northern and central Jameson Land. Only a single outlier occurs in Liverpool Land; it shows sandy deposits of roughly this age, and localities in the easternmost part of the Jameson Land Basin show no indications of sediment influx from the east. Modified from Surlyk (1977b). The eastwards opening of the rifted seaway in SE Traill Ø is based on Carr (1998) and Vosgerau et al. (in press b). B: Late Bathonian, P5 time. Throughout the Bathonian, southern Jameson Land was characterised by offshore siltstones whereas central and northern Jameson Land was dominated by shoreface sandstones. C: Middle Callovian, P8 time. Southern, central and most of northern Jameson Land was dominated by offshore siltstones. Only the northernmost part of Jameson Land was characterised by shoreface sandstones. and consists of dark grey fossiliferous, phosphatic and calcareous siltstone. At localities 3 and 4, the transgressive systems tract is 30 m thick, contains the C. borealis α fauna throughout, and consists mainly of dark grey, calcareous and phosphatic, laminated offshore siltstones. Only minor vertical changes in texture characterise these deposits, suggesting that deposition kept pace with sea-level rise. An overall upwards increase in the density of fossils is seen in the systems tract at localities 3 and 4, suggesting a decrease in sedimentation rate, an increase in biological production or simply better preservation. A general high degree of carbonate cementation characterises the deposits, in very sharp contrast to the underlying lowstand and overlying highstand deposits. In northern Jameson Land, the transgressive systems tract is represented only by a transgressive surface of erosion, a thin transgressive lag, or in some cases a thin transgressive sand sheet.
The C. borealis α fauna is not found north of locality 4. At locality 5, the lower part of the Pelion Formation is characterised by the C. borealis β fauna. A presumed specimen of C. borealis β (a microconch) was found immediately above SB1 at locality 6, suggesting that the lack of the C. borealis α in the northern part of the study area is primary, reflecting the northwards onlap of the Pelion Formation. At localities 3 and 4, the transgressive systems tract is capped by a phosphatic, fossiliferous, calcareous siltstone bed, 0.2 m thick. The bed contains large numbers of belemnites, ammonites and bivalves, and is interpreted as a condensed unit, representing the time of maximum flooding (Fig. 30). The top surface of the bed is covered with C. borealis β. At localities 6, 6A and 7A, a heavily burrowed, calcareous siltstone bed is situated immediately above the basal SB1/TSE, and also represents the time of maximum flooding.

P1: Highstand systems tract
The highstand systems tract of P1 downlaps onto the upper condensed deposits of the transgressive systems tract. It contains C. borealis β at locality 6 in eastern central Jameson Land, and throughout southern Jameson Land (Fig. 36). The deposits change from proximal, wave-and current-influenced shoreface and tidal inlet deposits, c. 120 m thick in the north (Fig. 2, localities 5, 6, 6A, 7, 9-11), to a shallow offshore, storm-influenced coarsening-upwards siltstone and sandstone unit, 20-30 m thick, further south (localities 3 and 4). Most distally, at locality 1, the highstand deposits consist of a few metres of laminated offshore siltstones (Figs 35,   37A). At localities 3 and 4, the highstand systems tract is poorly cemented, and shows a significant upwards decrease in fossil content, in sharp contrast to the underlying deposits of the transgressive systems tract; the highstand systems tract is capped by a distinct marine erosion surface, covered with belemnites, ammonites and the bivalve Camptonectes broenlundi (Ravn 1911). The surface marks a major basinwards shift in facies, and is a sequence boundary, SB2. Diplocraterion habichi descends in large numbers from the surface, and the bivalve Modiolus strajeskianus (d'Orbigny 1845) is found in life position in high densities just below the surface, indicating an oxic, shallow marine environment (Fürsich 1984). Deposits of the highstand systems tract underlie the middle part of the Ugleelv Member at localities 3 and 4.
Throughout northern Jameson Land, the highstand systems tract includes four simple sequences (P1A-D), which form a forwards-stepping sequence set (Figs 6,35,37A). From locality 5 and northwards, at least as far as locality 11, the upper parts of the sequences show an increase in maximum grain size through P1A-D, reflecting the overall forestepping stacking order. In northern Jameson Land, the fourth order sequences are capped by coincident sequence boundaries and transgressive surfaces of erosion (SB/TSE), which are laterally most extensive and extend furthest offshore in sequence P1D. The maximum progradation point of shoreface units shifted more than 30 km towards the SSE during the time span covered by the highstand systems tract of P1 (from near locality 8 in northern central Jameson Land to south of locality 5 in central Jameson Land). The volume of the sandstones of the highstand systems tract in Jameson Land falls in the range of 1100-1400 km 3 (deposits may have extended further to the east and west than the present outcrop belt), and the total sandstone volume of the systems tract is estimated at 1600-1900 km 3 , assuming that sandy highstand deposits continue 120 km northwards into the Traill Ø -Geographical Society Ø area in an up to 100 m thick, 80 km wide, northwards tapering and thinning wedge (Fig. 36). In northern Geographical Society Ø, the stratigraphic interval equivalent to P1 is less than 30 m thick, from the basal onlap surface (SB1) to the first occurrence of Cranocephalites indistinctus which coincides with the base of P2 in Jameson Land. The section consists of a single unit coarsening-upwards from fine-to coarsegrained pebbly sandstone (A.G. Whitham, personal communication 1996).
P2: Basal sequence boundary, SB2, and lowstand systems tract The basal sequence boundary, SB2, is developed as a distinct surface at localities 3 and 4, and separates the C. borealis and C. indistinctus Chronozones. At localities 1 and 2, SB2 is a correlative conformity (Figs 35,37A). In northern Jameson Land, SB2 coincides with a transgressive surface of erosion (TSE), and is commonly overlain by a transgressive lag. At localities 3 and 4, SB2 is overlain by shallow marine fine-grained sandstones, followed by medium-to coarse-grained marine clinoform-bedded sandstones, in all 35-40 m thick. The sandstones are interpreted as a lowstand systems tract, spanning the C. indistinctus and lowermost C. pompeckji Chronozones (Figs 6, 27, 37A). The deposits form the Ugleelv Member at localities 3 and 4. A distinct transgressive surface of erosion caps the systems tract, and passes northwards into SB2/TSE (Fig. 35). The hiatus corresponding to SB2 in northern Jameson Land is documented at localities 6 and 6A, where P1 contains the C. borealis β fauna in the uppermost part, directly overlain by the C. carlsbergensis fauna of the C. pompeckji Chronozone (Callomon 1993), occurring in the basal transgressive lag of P2 (Figs 27, 37A). SB2 thus spans the C. indistinctus and lowermost C. pompeckji Chronozones in this area. The lowstand systems tract thins out rapidly just east of locality 3 and a few kilometres southeast of locality 4. The termination in other directions is not exposed. The sandstone volume in the wedge is estimated at approximately 1.4 km 3 /km width, in an E-W section. The complete width is not known, but is estimated to be 60-80 km, giving a total sandstone volume in the range of 84-112 km 3 (Fig. 36).

P2: Transgressive systems tract
The lowstand systems tract at localities 3 and 4, and SB2 in northern Jameson Land, are capped by a transgressive surface of erosion (TSE), which passes into a simple flooding surface in southern Jameson Land. The TSE may be present on southern Traill Ø, as a marine ero-sional surface overlain by the ammonite C. gracilis (A.G. Whitham, personal communication 1995). The TSE is overlain by large numbers of C. carlsbergensis at localities 6, 6A, 11-14. The occurrence of the C. gracilis fauna on the surface at localities 3 and 4, and of the slightly younger C. carlsbergensis fauna further north (except possibly in the Traill Ø region), may reflect diachronous onset of sedimentation on this surface. The surface was formed by erosional retreat of the shoreface depositional system over more than 200 km, from south of locality 5 to somewhere in the Traill Ø -Geographical Society Ø area, before the onset of renewed shoreline progradation, which ended at least 50 km north of the toe of the underlying lowstand systems tract of P2 (Figs 35, 37A). The TSE is overlain by a transgressive lag followed by thin offshore siltstones from locality 5 and northwards. It is directly overlain by offshore calcareous siltstones at localities 3 and 4. The total volume of the sandstone part of the transgressive systems tract is broadly estimated to equal the sandstone volume of the preceding highstand systems tract, in the range of 1600-1900 km 3 (Fig. 36).

P2: Highstand systems tract
The highstand systems tract of P2 is wedge-shaped and belongs to the upper part of the C. pompeckji Chronozone. It is up to 90 m thick in northern and central Jameson Land, and thins to less than 5 m in southern Jameson Land. It consists of four to five stacked simple sequences (Figs 35, 39), which form an aggradational to forwards-stepping sequence set (Fig. 35). In northern Jameson Land, the upper four sequences are generally amalgamated, with very minor or no offshore or lower shoreface deposits, suggesting a low rate of creation of new accommodation space. All sequences prograded to a position south of locality 5. The C. episcopalis fauna is found in the middle to upper part of the systems tract throughout northern Jameson Land (Fig.  37A). The sandstone volume of the systems tract is in the range of 700-900 km 3 in Jameson Land. The total sandstone volume, including deposits in the northernmost part of the basin is estimated at 1200-1400 km 3 , using the same assumption as for P1 (Fig. 36).
Sequence P3, Lower Bathonian (Figs 6,36,37B,39) Ammonite evidence suggests that P3 is of Early Bathonian age. Unpublished 87 Sr/ 86 Sr values from belemnites suggest an Early-Middle Bathonian age, by comparison with the strontium isotope curve of Jones et al. (1994). P3 contains the Arctocephalites arcticus fauna of the A. arcticus Chronozone throughout the study area. In south Jameson Land, the species A. delicatus of this zone is also found.

SB3: Basal sequence boundary and lowstand systems tract
The boundary between the C. pompeckji and the A. arcticus Chronozones coincides with a third order sequence boundary, SB3 (Fig. 37B). SB3 coalesces with a TSE from locality 5 and northwards. At locality 8, SB3 is interpreted locally to form the base of a minor incised valley, filled with estuarine deposits. SB3 passes into a correlative conformity within offshore deposits of the Fossilbjerget Formation south of locality 5, and marks a major shift in the lateral distribution of accommodation space at a composite sequence level. The depocentre of P3 is located in northern Jameson Land, and the thickness of P3 decreases both southwards and northwards of the depocentre (Fig. 37B). This contrasts with the underlying P2, which shows a tabular geometry throughout the northern localities southwards to locality 5, south of which it thins rapidly.
A single occurrence of estuarine deposits (locality 8), positioned immediately above SB3, is interpreted to form part of the lowstand systems tract. Lowstand deposits may have existed between localities 4 and 5, but if so, they have been removed by recent erosion.

P3: Transgressive systems tract
The transgressive systems tract is represented by a TSE overlain by lag deposits, which may be followed by thin, calcareous siltstones interpreted to have been deposited during maximum flooding. The upper part of the estuarine association of locality 8 may also belong to the transgressive systems tract. The total volume of the sandstone part of the transgressive systems tract is estimated at 1200-1400 km 3 , using the same assumptions as for P2 (Fig. 36).

P3: Highstand systems tract
The highstand systems tract volumetrically dominates P3 throughout central and northern Jameson Land. It is 42 m thick at locality 11, thickens to 50-60 m at locality 8 (the thickness is approximate, due to limited stratigraphic control), and thins to less than 15 m at locality 5. Sequence P3 is not clearly distinguishable in southern Jameson Land, but the stratigraphic interval corresponding to the sequence covers less than 8 m at localities 3 and 4. At localities 5 and 8, only the uppermost part of P3 is represented by shoreface deposits, whereas the lower part consists of offshore siltstones and fine-grained sandstones, reflecting the forwards-stepping nature of the sequence set (Fig. 37B). During highstand time, shoreface units stepped forwards over more than 30 km. The highstand systems tract is capped by a low order sequence boundary, SB4, which is developed as an unconformity and coincides with a transgressive surface of erosion from central Jameson Land and further north (Fig. 37B). The sandstone volume of the systems tract Fig. 39. Stacked shoreface and shallow, near-shore sand sheet units of P2 and P3 (Fig. 6). SB2/TSE and SB3/TSE are sequence boundaries, each coinciding with a transgressive surface of erosion, capping sequences P1 and P2, respectively, throughout northern Jameson Land. Tidal inlet channel sandstones (TC) of sequence P1 are seen in the lower part of the section. Sequence P2 is 90 m thick and consists of four shoreface units; sequence P3 is dominated by sand sheet deposits. The dark bands are horizons cemented with ankerite, dolomite, calcite and siderite. Pelion Formation, locality 7 (Fig. 2).
in Jameson Land is in the range of 400-500 km 3 , and the total volume of the sandstone part is estimated at 900-1000 km 3 , using the same assumptions as for P1 (Fig. 36).
A carbonate-cemented, fossiliferous, fully marine sandstone, c. 30 m thick, covers the stratigraphic level of P2 and P3 on northern Geographical Society Ø. The unit is overlain by deposits containing A. micrumbilicatus and is interpreted as a tidal channel fill overlain by transgressive sand sheet deposits (A.G. Whitham, personal communication 1996).
Sequence P4, Lower-Middle Bathonian (Figs 6,36,37B,38B) Ammonite evidence indicates an Early-Middle Bathonian age for sequence P4. Unpublished 87 Sr/ 86 Sr values from belemnites also suggest an Early to Middle Bathonian age, by comparison with the strontium isotope curve of Jones et al. (1994). P4 contains the A. micrumbilicatus and A. greenlandicus faunas of the A. greenlandicus Chronozone in the lower part, and A. harlandi and the A. ishmae α faunas of the A. ishmae Chronozone in the upper part of the sequence. The A. ishmae fauna is also found on Traill Ø.

SB4: Basal sequence boundary
The upper boundary of P3 is formed by a low order sequence boundary, SB4, which coincides with a TSE from locality 5 and northwards, except at a position between localities 10 and 11, where it locally forms the base of an incised channel fill, up to 30 m thick, capped by the TSE (Fig. 37B). South of locality 5, SB4 is developed as a correlative conformity, and the transgressive surface of erosion passes into a simple marine flooding surface.
It is suggested that the hiatus associated with SB4 covers the uppermost A. arcticus Chronozone in northern Jameson Land, separating the A. arcticus fauna of the A. arcticus Chronozone and the A. micrumbilicatus fauna of the A. greenlandicus Chronozone; the A. delicatus fauna of the A. arcticus Chronozone is absent. A. delicatus is only found in southern Jameson Land, where it occurs in the basal part of P4. At locality 5, an uncertain occurrence of this species is indicated, but this might instead be a specimen of A. arcticus (Callomon 1993). In any event, a considerable faunal hiatus is thought to separate the A. arcticus and A. delicatus faunas of the A. arcticus Chronozone in East Greenland.
The missing interval may be represented by the A. spathi, A. porcupinensis and A. arcticus faunas in part of the A. spathi and A. porcupinensis Chronozones known from the Yukon area, Canada (Callomon 1993). Lowstand systems tract deposits have not been identified in P4. Deposits of this systems tract may have been deposited in the area between localities 4 and 5 but, if so, have been removed by recent erosion.

P4: Transgressive systems tract
A significant transgression is interpreted to have occurred after SB4 time, leaving a transgressive lag throughout northern Jameson Land, and possibly further north. This lag is overlain by a thin sheet of offshore siltstones, locally rich in bivalves, belemnites and ammonites, interpreted as a condensed unit and representing the level of maximum flooding. The transgressive lag and the condensed offshore deposits contain the A. micrumbilicatus fauna of the lower A. greenlandicus Chronozone throughout Jameson Land, whereas the A. delicatus fauna is restricted to southern Jameson Land. The lower faunas of the A. greenlandicus Chronozone are found throughout Jameson Land. The volume of the sandstone part of the transgressive systems tract is estimated to be in the order of 900-1000 km 3 , including sandy deposits in the Traill Ø -Geographical Society Ø area, using previous assumptions (Fig. 36).

P4: Highstand systems tract
The highstand systems tract of P4 contains ammonites of the middle to upper A. greenlandicus and A. ishmae Zones (A. greenlandicus, A. freboldi, A. harlandi and A. ishmae α faunas). Sequence P4 is c. 60 m thick throughout northern and central Jameson Land, and is volumetrically dominated by a forwards-stepping set of simple sequences, P4A-D (Fig. 37B).
The thickness of the section which covers the stratigraphic interval of P2-4 on Geographical Society Ø is only 30 m (A.G. Whitham, personal communication 1995), compared to 250 m in north Jameson Land. This large difference is interpreted to be the result of a high degree of sedimentary bypass and erosion in the northern, proximal areas during times of falling sea level and lowstand. The sandstone volume of the systems tract in Jameson Land is in the order of 700-800 km 3 ; the total sandstone volume is estimated at 900-1000 km 3 (Fig. 36).

Sequence P5, Middle-Upper Bathonian (Figs 6, 36, 37B)
Sequence P5 is up to 75 m thick, and consists of an aggradational sequence set (P5A-E). The maximum southwards progradation distance of P5 is c. 25 km less than that of the underlying P4, marking the onset of the large-scale backstepping pattern of the composite sequences from P5 to P8 (Figs 6, 37B;Surlyk 1990bSurlyk , 1991. P5 spans the upper A. ishmae, A. cranocephaloide, C. variabile and C. calyx Chronozones indicating a Middle to Late Bathonian age-span for the sequence (Figs 6, 37B). Unpublished 87 Sr/ 86 Sr values from belemnites also indicate a Middle to Late Bathonian age, by comparison with the strontium isotope curve of Jones et al. (1994).
The A. ishmae β fauna of the A. ishmae Chronozone is one of the most common and widespread faunas in the Arctic. It occurs throughout Jameson Land, and has also been found on Traill Ø (Donovan 1953). At this level, the genus Oxycerites occurs; it is usually restricted to lower latitudes in the Tethyan Realm, and indicates a Late Bathonian age . The presence of Oxycerites suggests that the transgression that ended deposition of P4 was linked to a eustatic rise in sea level, permitting migration of ammonites between the Boreal and Tethyan Realms.

SB5: Basal sequence boundary
SB5 is positioned in the A. ishmae Chronozone, separating the A. ishmae α and β faunas. SB5 is developed as an SB/TSE in central Jameson Land (Fig. 2, locality 5) and further north. In central Jameson Land, SB5 tops the uppermost shoreface deposits of the Pelion Formation, and is overlain by offshore siltstones of the Fossilbjerget Formation. In northern Jameson Land, SB5 separates condensed sequences of P4 from the less condensed sequences of P5. Lowstand systems tract deposits have not been identified in P5, but may have existed in the area between localities 5 and 8, and if so, have been removed by recent erosion.

P5: Transgressive systems tract
The transgressive systems tract deposits are generally thin. In southern Jameson Land, the tract is represented by a marine flooding surface overlain by thin offshore siltstones, interpreted as a condensed unit. From locality 5 and northwards, it is represented by a transgressive surface of erosion, locally overlain by a conglomerate lag or sandstone sheet, up to 4 m thick, with abundant A. ishmae β. These deposits are overlain by thin, laminated offshore siltstones, interpreted to represent the level of maximum flooding. The total volume of the sandstone part of the transgressive systems tract is estimated at 900-1000 km 3 (Fig. 36).

P5: Highstand systems tract
The highstand systems tract of P5 contains Arcticoceras crassiplicatum of the A. ishmae Chronozone, and A. cranocephaloide, Kepplerites tychonis, K. rosenkrantzi, K. peramplus, K. vardekloeftensis and K. svalbardensis of the A. cranocephaloide, C. variabile and C. calyx Chronozones. In northern Jameson Land, the highstand systems tract of P5 is dominated by progradational shoreface units. The shorelines prograded southwards, at least as far south as locality 8 (Fig. 37B). At this locality, P5 consists of more than three coarsening-upwards offshore units of the Fossilbjerget Formation. At locality 5, the upper part of P5 contains K. peramplus and K. svalbardensis of the C. calyx Chronozone. In southern Jameson Land, the C. calyx Chronozone marks the onset of a significant increase in the degree of condensation of the offshore deposits of the Fossilbjerget Formation (Surlyk et al. 1973;Callomon 1993). The sandstone volume of the systems tract in Jameson Land is in the order of 400-500 km 3 , and the total sandstone volume is estimated at 700-800 km 3 (Fig. 36). Sandy, shallow marine deposits of the transgressive systems tract exist in the Traill Ø -Geographical Society Ø area, corresponding to the level of P5, although a precise biostratigraphic correlation has not yet been made.
Sequence P6, Upper Bathonian -Lower Callovian (Figs 6, 36, 37B) The composite sequence P6 spans the C. apertum and C. nordenskjoeldi Chronozones. The duration of P6 is about 1.5 Ma, according to the time-scale of Gradstein et al. (1994;Fig. 6). P6 is backstepping in the lower part and forestepping in the upper part. It has only been studied in detail at locality 9A.

SB6: Basal sequence boundary
SB6 coincides with a transgressive surface of erosion throughout northern Jameson Land. In this area, the hiatus at SB6 corresponds to the K. vardekloeftensis faunal horizon of the C. calyx Chronozone, and this fauna is restricted to southern Jameson Land ( Fig. 37B; Callomon 1993). The C. apertum α fauna of the C. apertum Chronozone is found immediately above SB6. At this stratigraphic level, biostratigraphic correlation with European ammonite faunas is again possible, and the C. apertum Chronozone correlates with the C. discus and part of the M. herveyi Chronozones (Callomon 1993). SB6 is situated close to the base of the Callovian in East Greenland, and forms a very prominent correlation surface throughout central and northern Jameson Land. A major northwards retreat of the depositional systems is recorded across the SB6/TSE (Fig. 6). Lowstand systems tract deposits have not been identified in sequence P6; if deposited, they are expected to occur south of locality 8.
In southern Jameson Land, P6 is represented by offshore siltstones, which form part of a condensed unit that spans most of the Lower Callovian (Figs 6, 37B; Surlyk et al. 1973;Birkelund 1975;Surlyk 1990bSurlyk , 1991Callomon 1993). The distal condensation reflects the overall large-scale backstepping of the third order sequences during this time interval.

P6: Transgressive systems tract
At locality 9A, the transgressive systems tract consists of a basal lag, overlain by offshore siltstones and very fine-grained sandstones, 22 m thick (level 1-23 m in Fig. 33). The deposits include a transgressive sand sheet, 5 m thick, overlain by a shoreface unit, 5 m thick, which is followed by an overall backstepping set of shallow offshore, storm-influenced coarsening-upwards units, each 1-1.5 m thick, representing the distal edges of shoreface units. At localities 8 and 11, similar deposits are found at the same stratigraphic level, and are interpreted as belonging to the transgressive systems tract. The total volume of the sandstone part of the transgressive systems tract is estimated at 700-800 km 3 , including sandy deposits in the Traill Ø -Geographical Society Ø area (Fig. 36).

P6: Highstand systems tract
At locality 9A, a change in stacking pattern, and the reappearance of shallow water sandstones in the section, marks the transition from the transgressive to the highstand systems tract. At locality 9A, the highstand systems tract of P6 is 31 m thick and consists of coarseningupwards offshore and shoreface units, separated by non-erosional or erosional marine flooding surfaces (23-54 m in Fig. 33). The units are stacked in a forwards-stepping pattern. The uppermost three units show intense burrowing by Diplocraterion habichi, Monocraterion tentaculatum, Ophiomorpha nodosa and Skolithos isp., suggesting very shallow water depths. A shallow water depth is also indicated by the occurrence of both small and large wave-ripples as well as swaley cross-stratification. The package comprising the three coarsening-upwards units forms the 'minor regressive cycle' of Heinberg & Birkelund (1984); this unit forms the Parnas Member of the Pelion Formation (Surlyk 2003, this volume, fig. 5). The deposits are interpreted as near-shore sand sheet and shoreface units. In northernmost Jameson Land, P6 consists of shoreface deposits only. The sandstone volume of the systems tract in Jameson Land is estimated at 200-300 km 3 , and the total sandstone volume is estimated at 400-500 km 3 (Fig. 36 Gradstein et al. (1994).

SB7: Basal sequence boundary
SB7 occurs near the boundary between the C. nordenskjoeldi and K. koenigi Chronozones. It marks the maximum progradation of highstand deposits of P6, which form the Parnas Member. In northern Jameson Land, SB7 is developed as an SB/TSE, whereas it is represented by a correlative conformity in central and southern Jameson Land.

The deposits of P7 and P8, Lower-Upper Callovian
The deposits of P7 and P8 are not subdivided into systems tracts, due to a lack of distinct depositional trends. The sequences form the uppermost part of the Pelion-Fossilbjerget couplet. Throughout south and central Jameson Land, the sequences are represented by offshore siltstones of the Fossilbjerget Formation, grading into shoreface sandstones of the Pelion Formation in northern Jameson Land (Fig. 37B).
A minor progradational unit, 3-4 m thick, is dated to the upper K. koenigi -lower S. calloviense Chronozones. It contains the K. galilaeii and S. calloviense faunas . In this unit, two sandstone sheets, together up to 3 m thick, separated by bioturbated siltstones, were deposited in the otherwise siltstone-dominated offshore environment (Fig. 37B, localities 9A, 11). The sandstone beds show hummocky cross-stratification, and Ophiomorpha nodosa burrows, which also occur in the interbedded siltstones. A rich fauna of ammonites, belemnites, bivalves, gastropods and brachiopods occurs in the beds. The trace fossils suggest a nearshore position, and the sandstone beds are interpreted as nearshore storm deposits, laid down above storm wave base. The upper bed is topped by a marine flooding surface, overlain by parallel, even laminated, offshore mudstones. The sandstones are interpreted as the basinwards limit of a forwards-stepping depositional unit, possibly forming the distal edge of lowstand deposits of P8. The top of the sandstones mark the Lower-Middle Callovian boundary in the area. Throughout Jameson Land, P8 forms an important condensed level, which caps the Pelion and Fossilbjerget Formations in the area, and which is downlapped by the Olympen Formation (Figs 6, 37B). In northern Jameson Land, shallow marine sandstones of the Pelion Formation correspond to the stratigraphic interval of P7 and P8 (Surlyk et al. 1973;Heinberg & Birkelund 1984). Condensation in south Jameson Land was initiated in P5 time, and in the upper part includes the Middle Callovian offshore Goniomyakløft Member of the Fossilbjerget Formation (Surlyk 2003, this volume, fig. 5), the 'wood beds' of Callomon (1993) containing Kosmoceras cf. or aff. jason of the K. jason Chronozone (Callomon 1961(Callomon , 1993Surlyk & Birkelund 1972;Surlyk et al. 1973Surlyk et al. , 1993Surlyk 1990bSurlyk , 1991. In central Jameson Land, Longaeviceras keyserlingi of the P. athleta Chronozone occurs c. 20 m below the Fossilbjerget Formation -Olympen Formation boundary (Larsen & Surlyk 2003, this volume). In northern Jameson land, a single specimen of Kosmoceras (Zugokosmokeras) cf. phaeinum (Buchman) or Kosmoceras (Zugokosmokeras) cf. proniae (Teisseyre) of the P. athleta Chronozone was found 2.8 m below the boundary. A fragment of Kosmoceras (Zugokosmokeras) cf. proniae was reported from 15 m above the boundary in north-west Jameson Land . The Goniomyakløft Member in southern Jameson Land thus represents the top of the Pelion-Fossilbjerget couplet and possibly overlaps with the basal part of the Olympen Formation to the north.

Regional implications
The couplet comprising the Pelion and Fossilbjerget Formations forms the lower half of a large-scale Middle Jurassic regressive-transgressive-regressive succession, and is approximately time-equivalent with the Brent Group of the Northern North Sea and with the Krossfjord and Fensfjord Formations and to some extent the Garn Formation on the Norwegian shelf. The depositional pattern of the Brent Group has been related to the uplift and subsequent deflation of a major volcanic dome (Sellwood & Hallam 1974;Whiteman et al. 1975;Hallam & Sellwood 1976;Ziegler 1988Ziegler , 1990Underhill & Partington 1993. The presence of a similar, roughly contemporaneous regional Early Jurassic uplift and subsequent subsidence in East Greenland was suggested by Surlyk (1977aSurlyk ( , 1978 and Surlyk et al. (1993) on stratigraphical grounds and corroborated by fission track thermochronology by Johnson & Gallagher (2000). The main East Greenland uplift was centred in northern East Greenland, and the eastern part of the uplift area is today probably located on the Norwegian shelf off Lofoten. Uplift of the East Greenland area probably commenced in the Early Jurassic, culminating in Toarcian-Aalenian times. The regional uplift is probably partly equivalent to the uplifted intra-rift area between Greenland and Norway of Doré (1991;Fig. 5).
Rifting began in the Late Bajocian, increased during the Bathonian-Kimmeridgian and culminated in Kimmeridgian -mid-Volgian times (Surlyk et al. 1981). Sequence P1 and the lower part of P2 of the Pelion and Fossilbjerget Formations show the development of shallow marine sandstones of Late Bajocian -Early Bathonian age in a basinal position, which are similar to time-equivalent deposits in the Northern North Sea and the Norwegian shelf described, for example, by Gjelberg et al. (1987), Helland-Hansen et al. (1992) and Mitchener et al. (1992). Major flooding events occurred both in the North Sea area and in Jameson Land near the Bajocian-Bathonian boundary, indicating the onset of an inter-regional transgression (Surlyk et al. 1973(Surlyk et al. , 1981Birkelund 1975;Surlyk 1990aSurlyk , b, 1991Surlyk , 2003Helland-Hansen et al. 1992;Mitchener et al. 1992;Steel 1993). The P3 and P4 sequences show a largescale progradational stacking pattern. SB5 at the base of P5 coincides with the lithostratigraphic top of the Pelion Formation in central Jameson Land, and marks a major shift from shoreface to offshore depositional environments. SB6 at the top of P5 roughly coincides with the Bathonian-Callovian boundary in Jameson Land, and forms the top of the Pelion Formation throughout northern Jameson Land, marking a major landwards shift in depositional environments. The P5-8 sequences show a large-scale backstepping pattern. The distance of overall large-scale shoreline backstepping from P1 to P5 is more than 100 km. Backstepping through P6-8 is about 50 km. In northern central Jameson Land, only the upper part of P8 forms part of the condensed succession, which in south Jameson Land covers most of the Callovian, and marks the culmination of backstepping (Surlyk 1977b(Surlyk , 1990b(Surlyk , 1991(Surlyk , 2003Surlyk et al. 1993;Alsen & Surlyk in press). Throughout central East Greenland, the condensed unit is characterised by a mixture of true Boreal and sub-Boreal ammonite faunas (Callomon 1993), supporting the sequence stratigraphic interpretation of the inter-regional character of the large-scale transgression. The transgression, which was initiated in the Late Bathonian (P5), and continued into the Early Oxfordian, was partly of eustatic origin according to Hallam (1988). Domal subsidence may also have caused a significant relative sea-level rise through this time span in the areas influenced by the domes, similar to the situation in the North Sea (for further discussion, see Surlyk 1990band Underhill & Partington 1994.

Summary
In Middle Jurassic times, a north-south elongate shallow marine embayment was formed in central East Greenland with a low gradient, without a marked shelfslope break. Throughout the East Greenland basin, the base of the Pelion Formation marks the onset of a new depositional cycle characterised by a major re-arrangement of drainage patterns, extensive transgressive onlap and the influx of large amounts of quartzose sand, interpreted as reflecting the onset of the important Middle-Late Jurassic rift phase which culminated in Kimmeridgian-Volgian times (Surlyk 1978(Surlyk , 1990a(Surlyk , b, 2003Surlyk & Clemmensen 1983;Surlyk & Noe-Nygaard 2000). The low axial gradient of the basin-floor resulted in the development of laterally extensive simple sequences, formed by predominantly axial shoreline progradation. The distribution and architecture of the sandstone units were controlled by changes in relative sea level. A total of 28 simple sequences are recognised. Detailed biostratigraphic correlations at the level of ammonite zones and faunal horizons show that the average duration of a simple sequence is about 360,000 years. They are the smallest-scale units which can be correlated over large distances and they are bounded by laterally extensive key surfaces. Of special importance for the sequence stratigraphic interpretation is the nature of transgressive marine lags, which form the basal deposits of most sequences. The presence of laterally widespread pebble lags, containing intra-and extra-formational clasts, mainly of larger sizes than those present in the underlying deposits, is interpreted to indicate that a modified sequence boundary coincides with the base of the lag deposits . The horizontal distribution of transgressive lag conglomerates directly reflects the original distribution of the former presence of foreshore, beach, and fluvial deposits.
The very extensive lateral distribution of the shallow marine sandstones of the Pelion Formation, over more than 20,000 km 2 , and the distribution of coarse pebbly sandstones and conglomerates over more than 10,000 km 2 indicate that major rivers continuously delivered coarse-grained sediments to the southwards prograding shorelines. The rivers entered the basin at its northern and western margin at relay zones between en echelon right-stepping border faults, as testified by palaeocurrent data and the large-scale textural and facies distribution (Surlyk et al. 1973(Surlyk et al. , 1981Surlyk 1977bSurlyk , 1990aSurlyk & Clemmensen 1983). The proportion of conglomerates and coarse-grained sandstones decreases southwards, indicating that the transport capacity of the rivers decreased as the floodplain became wider during progradation. Only one localised occurrence of terrestrial deposits is recognised in Jameson Land. This is most likely a consequence of transgressive marine erosion of floodplain, lagoonal and fluvial sediments of the underlying sequences.
The sequences generally consist of a thin transgressive systems tract, dominated by a sandstone or pebble lag overlain by fossiliferous, calcareous siltstones or mudstones representing a condensed unit, followed by sandy highstand, forced regressive and lowstand deposits (Fig. 34). Detached lowstand shoreface deposits were probably not developed during the high-order cycles because of a continuous, high sediment influx to the basin and a high sediment distribution rate. In proximal areas, the sequences are terminated upwards by coincident sequence boundaries and transgressive surfaces of erosion. In distal offshore areas, the correlative conformities are difficult to pinpoint.
Definition of low-order composite sequences is based on the stacking pattern of the high-order sequences, the nature and extent of marine transgressive lags, and a detailed biostratigraphical ammonite zonation based on faunal horizons. Eight composite sequences are recognised (P1-8), each with a duration of 1-2.5 Ma (Fig. 6). In proximal realms, the sequences are separated by subaerial erosion surfaces representing sequence boundaries, coincident with marine transgressive surfaces of erosion. More distally, the sequence boundaries are represented by surfaces marking significant basinwards shift in facies (Fig. 35). Low-order sequence boundaries mark major changes in the overall stacking pattern of the high-order sequences.
The composite sequences are subdivided into systems tracts, which in the study area are highly asymmetric, volumetrically dominated by highstand deposits (Fig. 35). These consist of aggradational to forwardsstepping sequence sets, generally made up of thin offshore siltstones overlain by progradational shoreface and shallow marine, near-shore sandstones and conglomerates, deposited in response to high-order sea-level fall (forced regressions) and lowstand. The sandy deposits of the low-order highstand systems tract downlap onto extensive condensed offshore deposits, deposited during maximum flooding. Two examples of low-order lowstand sandstones are documented, belonging to P1 and P2, while a third, belonging to P8, is less well documented (Figs 35,36). In the northern part of the study area, the transgressive systems tracts are mostly represented by a transgressive surface of erosion, commonly overlain by a thin coarse-grained sandstone or pebble lag or a thin sand sheet. A thicker transgressive systems tract has only been identified in P1, at localities 3 and 4, and in P6 at locality 9 in northern central Jameson Land. In each sequence, the transgressive systems tract consists of backstepping offshore to shoreface depositional units, reflecting fluctuations in relative sea level on a higher order scale (Fig. 33). Volumetrically large portions of P7 and P8 may also form part of transgressive systems tracts throughout north-central Jameson Land, but this has not been quantified due to lack of clear depositional trends. Distally, in southern Jameson Land, the transgressive systems tracts are represented by simple marine flooding surfaces, overlain by condensed offshore deposits. The volumetric distribution of the sandy parts of the low-order systems tracts are quantified based on values obtained from the study area and unpublished data from the Traill Ø -Geographical Society Ø area.