Archives - Page 2

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  Lithostratigraphy, geology and geochemistry of the volcanic rocks of the Vaigat Formation on Disko and Nuussuaq, Paleocene of West Greenland

  Vol. 39 (2017)

  ​Asger Ken Pedersen, Lotte Melchior Larsen and Gunver Krarup Pedersen

  The upper Cretaceous–Tertiary Nuussuaq Basin in West Greenland contains a many kilometres thick succession of siliciclastic sediments and overlying volcanic rocks. The first studies in the early 19th century centred on the coal and fossils in the sediments and the minerals in the volcanic rocks, including famous occurrences of native iron. The present focus of interest includes modern stratigraphic and volcanological studies to decipher the basin evolution and support hydrocarbon exploration.

  The Nuussuaq Basin is the only onshore analogue for the sedimentary and volcanic basins offshore West Greenland primarily known from seismic data. The excellently exposed volcanic rocks, in particular giant foreset-bedded hyaloclastite deposits, are of a size comparable to seismic sections and therefore directly applicable to their interpretation.

  This bulletin presents the lithostratigraphy, geology and geochemistry of the Paleocene volcanic rocks of the Vaigat Formation on Disko and the major part of the Nuussuaq peninsula. The Vaigat Formation in this area is up to 1600 m thick and composed mainly of olivine-rich picrites, with ten formally defined members and 20 informal units. The comprehensive descriptions and analyses of each member and unit represent a synthesis of many years of work and are intended to serve as a guide for future studies, including exploration for mineral deposits associated with some units of the formation.

  A companion bulletin on the volcanic rocks of the Maligât Formation overlying the Vaigat Formation was published in 2018.

   

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  Review of Survey activities 2016

  Vol. 38 (2017)

  Editors Adam A. Garde and Ole Bennike

  The 17 contributions in this Review of Survey activities reflect the wide range of activities currently performed by the Geological Survey of Denmark and Greenland, commonly in collaboration with external partners.

  Topics in and around Denmark include the important Danish potential for geothermal energy, a shale gas study, securing seismic exploration data from the North Sea for the public, new information on Cretaceous–Palaeogene chalk and limestone, the importance of GEUS’ Jupiter database for the national monitoring of groundwater resources, study of nitrate runoff into streams from agricultural fields, as well as high-precision mapping of contaminated landfill sites and location of sinkholes using digital elevation maps.

  Activities in Greenland are represented by a study of potential gold mineralisation sites in South-East Greenland using advanced statistical methods, delineation of potential petroleum reservoirs in the Nuussuaq Basin using modern hand-held photogrammetry and geophysical logging, and monitoring of the Greenland ice sheet including a new study around Camp Century. A final historical paper celebrates the pioneer Danish geophysicist Inge Lehmann and discusses political issues in connection with the installation of the first seismographs in Denmark and Greenland.

   

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  Biostratigraphic correlation of the western and eastern margins of the Labrador–Baffin Seaway and implications for the regional geology

  Vol. 37 (2017)

  Henrik Nøhr-Hansen, Graham L. Williams & Robert A. Fensome

  The Labrador–Baffin Seaway between Canada and Greenland is a key element in understanding the tectonic evolution of the North Atlantic region during late Mesozoic and Cenozoic times. The sedimentary rocks forming the continental margins on either side of this seaway represent a vast data source documenting the evolution of the region from the initial continental rifting to the formation of a strait linking the Atlantic and Arctic oceans. This sedimentary archive is important both for charting the geotectonic history and assessing the resource potential of the area. The study presented in Geological Survey of Denmark and Greenland Bulletins 36 and 37 is a major contribution to our understanding of the development of the Labrador–Baffin Seaway. It is based on new palynological analysis of samples from 13 offshore wells on the Canadian Margin and six wells from the Greenland Margin, and is the first comprehensive study to present an integrated, consistent and fully documented biostratigraphic correlation across both continental margins.

  This bulletin presents the palynostratigraphic framework that permits detailed correlation between the Canadian and Greenland continental margins; palynological-event charts are provided for the 19 offshore wells. The focus is on the stratigraphic evolution of the margins, particularly with respect to major unconformities that form the basis for published sequence and seismic stratigraphic schemes. The palynological data also contribute to our understanding of the significant environmental and climatic changes that occurred in the region from Early Cretaceous to late Neogene times.

   

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  Cretaceous and Cenozoic dinoflagellate cysts and other palynomorphs from the western and eastern margins of the Labrador–Baffin Seaway

  Vol. 36 (2016)

  Robert A. Fensome, Henrik Nøhr-Hansen & Graham L. Williams

  The Labrador–Baffin Seaway between Canada and Greenland is a key element in understanding the tectonic evolution of the North Atlantic region during late Mesozoic and Cenozoic times. The sedimentary rocks forming the continental margins on either side of this seaway represent a vast data source documenting the evolution of the region from the initial continental rifting to the formation of a strait linking the Atlantic and Arctic oceans. This sedimentary archive is important both for charting the geotectonic history and assessing the resource potential of the area. The study presented in Geological Survey of Denmark and Greenland Bulletins 36 and 37 is a major contribution to our understanding of the development of the Labrador–Baffin Seaway. It is based on new palynological analysis of samples from 13 offshore wells on the Canadian margin and six wells from the Greenland margin, and is the first comprehensive study to present an integrated, consistent and fully documented biostratigraphic correlation across both continental margins.

  This bulletin presents the formal taxonomy of the palynological record with illustrations of most taxa described herein. The systematic descriptions focus particularly on the dinoflagellate cysts: three new and five emended genera, 16 new species and six new combinations of species are proposed. A new acritarch species and a new miospore species are also described. This taxonomic documentation of the microflora forms the foundation both for detailed correlation across the Labrador–Baffin Seaway and for interpretation of changing environments and climatic conditions from Early Cretaceous to late Neogene times.

   

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  Review of Survey activities 2015

  Vol. 35 (2016)

  Editors Adam A. Garde, Ole Bennike, Kristine Thrane and W. Stuart Watt

  This issue of​ Review of Survey Activities presents a selection of 24 papers reflecting the wide spectrum of current activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level.

  The Survey’s activities in Denmark are illustrated by 11 papers covering widely different subjects including groundwater management, pesticide monitoring, 3D urban geology, the regional Danish potential for geothermal energy, Palaeozoic stratigraphy from borehole logs, enhancement of oil production by injection of ‘smart’ water and glacial geology.

  Activities in Greenland are illustrated by eight papers on Precambrian crustal evolution and mineralisation processes in South-East and northern West Greenland, fundamental magma processes in the Skaergaard intrusion, onshore and offshore seismological studies, and on long-term monitoring of the Greenland ice sheet and sea-ice variability.

  International studies by the Survey are represented by two papers describing a large Nordic CO2-storage project and a pilot study of burial and exhumation along the eastern passive margin of Labrador and Newfoundland using apatite fission track analysis.

  Finally, three papers describe new developments in the digital access to, and handling of Greenland-related geodata and presentation of a new smartphone- and tablet-based app for effective handling of geological and sample data during field work.

   

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  The ammonites of the Middle Jurassic Cranocephalites beds of East Greenland

  Vol. 34 (2015)

  John H. Callomon, Peter Alsen & Finn Surlyk

  The Mesozoic sedimentary succession of eastern Greenland is renowned for its Boreal Jurassic ammonite record. The marine Middle Jurassic deposits of the Jameson Land Basin in central East Greenland are particularly rich in ammonites and have been the subject of much detailed taxonomic and stratigraphic study since the first collections at the beginning of the 20th century. Over the last fifty years, much of the work on the Middle Jurassic ammonite faunas has been undertaken by John H. Callomon, working initially under Lauge Koch’s last expeditions and subsequently with the University of Copenhagen and the Geological Survey of Greenland (GGU, now GEUS).

  This bulletin presents the culmination of these endeavours, published after John H. Callomon’s death. It focusses on the so-called Cranocephalites beds of the Ugleelv area of Jameson Land where a detailed ammonite stratigraphy comprising thirty-four faunal horizons is established for the Borealis, Indistinctus and Pompeckji Standard Zones. The Pompeckji Zone is subdivided into four new subzones and four new species are described. This detailed taxonomic and stratigraphic analysis confirms the status of the Jameson Land succession as the key Boreal reference section for this time interval, and furthermore allows a high-resolution study of the evolution of the ammonites which on this time-scale appears to be continuous.

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  Review of Survey activities 2014

  Vol. 33 (2015)

  Editors Ole Bennike, Adam A. Garde and W. Stuart Watt

  This Review of Survey activities presents a selection of 20 papers reflecting the wide spectrum of activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level.

  The Survey’s activities in Denmark are illustrated by eight articles covering Palaeozoic stratigraphy, permeability of North Sea chalk, Quaternary geology, seismology, groundwater geology and an assessment of mineral raw materials.

  Activities in Greenland and the Faroe Islands are also covered by eight papers. One deals with the completed Continental Shelf Project, three with mineral resources and exploration and three papers describe the Survey’s monitoring of the Greenland ice sheet. One paper deals with applied glaciology in Kyrgyzstan, Greenland and Canada.

  The Survey’s international activities are the subject of three papers: two dealing with fingerprinting of heavy minerals in Labrador and Brazil and one dealing with carbon dioxide capture and storage in Europe.

  Finally, one paper describes a new method to develop digital models, e.g. for geological outcrops, based on images taken with a handheld camera.

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  A catalogue of Danian gastropods from the Baunekule facies, Faxe Formation, Denmark

  Vol. 32 (2014)

  Bodil W. Lauridsen and K.I. Schnetler

  Fossiliferous middle Danian limestones of the Faxe Formation, exposed in a large quarry on the Stevns peninsula, eastern Denmark, yield a detailed record of the complex ecosystem associated with cold-water coral mounds. A particular sedimentary–diagenetic facies, the Baunekule facies, preserves the faunal record in exceptional detail.

  This bulletin presents a catalogue of the gastropod fauna from the Baunekule facies, providing the taxonomic status of 194 taxa; one new species (Zaclys? nuetzeli) is introduced. The catalogue is fully illustrated with a combination of detailed drawings and photographs, the former produced in the 1960s by Erna Nordmann, Gunni Jørgensen and Betty Engholm under the direction of Professor Alfred Rosenkrantz. The bulletin documents the high diversity of the gastropod fauna and the overwhelming dominance of small (millimetre-sized) carnivorous forms that browsed on the coral substrate. Over 80% of this unusual fauna may be endemic to the Faxe Formation, probably reflecting the specialised nature of the cold-water coral mound ecosystem.

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  Review of Survey activities 2013

  Vol. 31 (2014)

  Edited by Ole Bennike, Adam A. Garde and W. Stuart Watt

  This Review of Survey activities presents a selection of 22 papers reflecting the wide spectrum of activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level.

  The Survey's activities in Denmark and surrounding areas are illustrated by 11 articles covering mapping of fractures in Precambrian rocks, shale gas investigations, chalk architecture, a new technique for CO2-flooding experiments of chalk, Cretaceous and Palaeogene biostratigraphy, groundwater geology, Quaternary geology, stormwater management and geothermal energy.

  Activities in Greenland are covered by nine papers, four of which deal with mineral and petroleum exploration. One paper deals with seismology, three papers describe the Survey's monitoring of the Greenland ice sheet and one paper deals with long-term changes of the Upernavik Isstrøm.

  The Survey's activities in the new Center for Minerals and Materials (MiMa) are the subject of one paper, and finally on the occasion of its 125th anniversary in 2013, the Survey's history is briefly described.

   

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  Stratigraphic landscape analysis, thermochronology and the episodic development of elevated, passive continental margins

  Vol. 30 (2013)

  Paul F. Green, Karna Lidmar-Bergström, Peter Japsen, Johan M. Bonow and James A. Chalmers

  The uplift histories of passive continental margins constitute an important area of research, first of all because of their worldwide economic importance. Uplift and exhumation control the maturation processes of petroleum in marginal sedimentary basins.

  The histories of subsidence and uplift of passive continental margins are challenging to study and not least to explain in satisfactory ways, and different approaches and schools of thought have developed among different research groups over time.

  The present volume applies stringent landscape analysis and state-of-the-art thermochronology to several passive continental margins around the world. The great importance of relict sedimentary covers in elevated and tilted continental margins is demonstrated, and the strengths and limitations of apatite fission track thermochronology are laid out in detail.

  The authors demonstrate with a pioneering study of the margin of West Greenland and several other case studies that elevated, passive continental margins are not the results of continuous denudation and slow uplift acting on permanent highs. Instead, many margins have experienced complex histories of repeated subsidence, deposition, uplift, tilting and erosion. The nature of these processes is not yet well understood, but the regional extent of the vertical movements documented here suggests a plate-scale control. 

   

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  Tectono-magmatic evolution of the younger Gardar southern rift, South Greenland

  Vol. 29 (2013)

  Brian G.J. Upton

  The Mesoproterozoic Gardar province in South Greenland comprises some of the Earth's best exposed and best preserved alkaline intrusive complexes. The province was formed by continental rifting and associated magmatism during a long interval (1300–1140 Ma). Of the two parallel Gardar rift zones, the southern zone underwent a separate evolution during the younger Gardar period (1185–1140 Ma). This bulletin describes this mega-volcanic system with rifting, magma generation, emplacement and crystallisation in giant dykes and central intrusions. The primitive basic magmas evolved by fractionation into extreme compositions, and some intrusions, in particular the famous Ilímaussaq complex, contain accumulations of rare and exotic elements such as zirconium, niobium, rare earths and uranium. Many rocks show spectacular features of igneous layering and accumulation of crystals which recount the processes in the magma chambers. A modern analogue to the Gardar system is the Kenya Rift.

  The author, Brian Upton, has worked with the Gardar province for more than 50 years. His knowledge is based on extensive field work, laboratory studies and comparative studies in other alkaline provinces.

   

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  Review of Survey activities 2012

  Vol. 28 (2013)

  Edited by Ole Bennike, Adam A. Garde and W. Stuart Watt

  This Review of Survey activities presents a selection of 17 papers reflecting the wide spectrum of activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level.

  The Survey's activities in Denmark and surrounding areas are illustrated by nine articles covering Miocene geology, groundwater geology, marine geology, geological mapping, seismology, disposal of radioactive waste and the use of satellite radar data to detect elevation changes.

  Activities in Greenland are covered by seven papers dealing with mineral and petroleum exploration. One paper describes lineament mapping and another describes the Survey's monitoring of the Greenland ice sheet. The Survey's international activities are the subject of a paper dealing with titanium minerals in Cameroon. 

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  Neoglacial and historical glacier changes around Kangersuneq fjord in southern West Greenland

  Vol. 27 (2012)

  Anker Weidick, Ole Bennike, Michele Citterio and Niels Nørgaard-Pedersen

  The Greenland ice sheet is losing mass at an accelerating rate due to climate change. Prediction of the future behaviour of the ice sheet depends on our understanding of the links between climatic variations and glacial fluctuations in the distant and recent past. This bulletin presents an overview of glacier fluctuations in south-western Greenland over the last 300 years, with particular focus on the inner parts of Nuup Kangerlua. The early record is based on written descriptions, paintings, photographs and maps of the area from the 1700s and 1800s, together with archaeological data from Norse ruins; aerial photographs and satellite images from the 1900s provide a link to the present.

  The lowland marine outlets from the Inland Ice in south-western Greenland were mainly characterised by large amplitude changes during the Late Holocene, as illustrated in this bulletin by the Kangiata Nunaata Sermia glacier system which has receded over 20 km during the last two centuries, demonstrating a marked response to climatic fluctuations during and since the Little Ice Age. Other examples of such behaviour are provided by the Eqalorutsit Killiit Sermiat glacier at the head of Nordre Sermilik fjord in southern Greenland, and by Jakobshavn Isbræ in Disko Bugt in central West Greenland. In contrast, where uplands and highlands extend below the marginal parts of the Inland Ice, the outlets have been advancing almost up to the present, so that the position of the glacier front around AD 2000 broadly coincides with the Little Ice Age maximum. It is notable, however, that the number of advancing outlets has decreased markedly in recent years.

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  Review of Survey activities 2011

  Vol. 26 (2012)

  Edited by Ole Bennike, Adam A. Garde and W. Stuart Watt

  This Review of Survey activities presents a selection of 20 papers reflecting the wide spectrum of activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level.

  The Survey's activities in Denmark and surrounding areas are illustrated by 11 articles covering petroleum geology, groundwater geology, geomorphology, marine geology, geothermal energy, seismology and monitoring of an underground gas storage.

  Activities in Greenland are covered by five papers dealing with mineral and petroleum exploration. Two other papers describe the Survey's monitoring of the Greenland ice sheet and the testing of an automatic earthquake detection method on data from Station Nord, North Greenland.

  The Survey's international activities are the subject of two papers: one dealing with petroleum geology in Vietnam, one with agrominerals in Tanzania.

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  Upper Cretaceous chalk facies and depositional history recorded in the Mona-1 core, Mona Ridge, Danish North Sea

  Vol. 25 (2011)

  ​Kresten Anderskouv and Finn Surlyk

  Upper Cretaceous – Danian chalks form important hydrocarbon reservoirs in the North Sea, contributing significantly to the national economies of Denmark, Norway and the United Kingdom. Understanding the process of chalk sedimentation thus has implications not only for charting the evolution of the Cretaceous chalk sea, but also for predicting the distribution and nature of potential reservoir chalks in the subsurface. In particular, North Sea chalk reservoirs commonly include a range of redeposited chalk facies types, yet rigorous documentation of such facies is scarce in the published literature.

  This bulletin presents a detailed analysis of chalk deposits from an exceptionally well-cored borehole (Mona-1) in the northern Danish Central Graben. Chalk sedimentation in this area in the Late Cretaceous was strongly influenced by active intrabasinal tectonics, controlling sea-floor morphology and the location of depocentres. Chalk ooze was commonly remobilised, creating a wide spectrum of chalk facies types that record processes ranging from suspension settling to slumping and debris flow.