bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary analysis of the hydrocarbon source rock potential of central and western North Greenland
Authors: Christiansen F.G , Nøhr-Hansen H , Rolle F , Wrang P
Published: June 2021

During the 1984 field season potential hydrocarbon source rocks were studied in central and western North Greenland. Samples from most lithostratigraphic units were collected from Freuchen Land in the north-east to Washington Land in the south-west. Preliminary results from LECO, Rock-Eval and palynofacies analyses suggest that some intervals in the Cambrian shelf sequence and in the Ordovician and Silurian trough sequence have enough organic matter to qualify as source rocks. Most of the trough sequence is, however, thermally postrnature with respect to oil generation and only the Cambrian Brønlund Fjord Group is expected to have been the source of the oil accumulations in the subsurface.
Til Knud Ellitsgaard-Rasmussen
Authors: Noe-Nygaard A
Published: June 2021

Kære Ellitsgaard. Seneetus est natura loquacior (Cicero). Som den længstlevende af GGUs første styrelse har jeg taget mig den frihed at opfatte mig selv som en slags bedstefar til den institution, du har bygget op. Som den gamle mand, jeg efterhånden også er, vil jeg ikke undlade ved denne lejlighed at berette lidt historie, der ellers nemt kan gå i glemmebogen.
Proterozoic basaltic magmatic periods in North-West Greenland: evidence from K/Ar ages
Authors: Dawes P.R , Rex D.C
Published: June 2021

This paper is the third of a series reporting on K/Ar whole rock ages of Proterozoic basaltic rocks of the Thule district, North-West Greenland. The dating programme is a co-operative venture between the Geological Survey of Greenland and The University, Leeds, V.K., and was set up in connection with a 1:500 000 mapping project of the region between 75°N and 78° 45'N (Melville Bugt - Inglefield Land, fig. 1). Field work by one of us (PRD) has shown that several episodes of unmetamorphosed Proterozoic basic igneous rocks can be distinguished stratigraphically in the region (see below). The routine K/Ar isotopic work, carried out concurrently with the field work, has aimed at dating these episodes, thereby providing minimum ages for deposition or consolidation of the host rocks. The two earlier reports (Dawes et al., 1973, 1982a) dealt with sills and dykes from the northern part of the region (Inglefield Land - Prudhoe Land); intrusions that have known or inferred stratigraphic relationships with the Proterozoic Thule Group. The present report gathers together all hitherto unpublished K/Ar dates - 18 in total on both extrusive and intrusive rocks - mainly from the central and southern parts of the region (Inglefield Bredning and Melville Bugt). Six of the samples represent cross-cutting intrusions in the Precambrian Shield that have uncertain age relationships with the overlying Thule Group.
Geophysical investigations at the Inland Ice margin of the Pâkitsoq basin, central West Greenland
Authors: Thorning L , Thomsen H.H , Hansen E
Published: June 2021

In recent years much effort has been directed towards investigation of the margin of the Inland Ice in connection with possible development of hydropower. The thickness of the ice and thus the subglacial relief has been difficult to determine. Electromagnetic reflection (EMR) techniques have been used over large parts of the Inland Ice with considerable success, but have so far not produced good results in the marginal areas of the Inland Ice. This note reports the successful application of EMR techniques to an area of the Inland Ice adjacent to the Piikitsoq basin near Jakobshavn, central West Greenland, together with a ground magnetic survey over a smaller part of the area. The field areas are shown in fig 1. The field work was carried out by LT and ER during a five week period in July-August 1985.
Exceptionally high ablation in 1985 at Qamanârssûp sermia, West Greenland
Authors: Braithwaite R.J
Published: June 2021

As part af the GGU programme of hydropower investigations in West Greenland, climatological and glaciological measurements were continued at Qamanârssiip sermia (inventory number lCH21(02) in 1985. The field programme was generally the same as in previous years (see Braithwaite, 1985a, b). The station was established in August 1979 so that records for six complete summers 1980-1985 are now available. Detailed summaries of results up to 1984 are given in Braithwaite (1985a, b) while the latest results will be presented in a Gletscher-hydrologiske Meddelelser in spring 1986.
Mellopegma (Mollusca) from the Middle Cambrian of North Greenland
Authors: Peel J.S
Published: June 2021

During the last decade, the resurgence of interest in the non-trilobite faunas of the Cambrian has resulted in the description of many new taxa of problematic molluscs. One such form is the laterally compressed helcionellacean Mellopegma, originally described from the Middle Cambrian of Australia by Runnegar & Jell (1976) but subsequently reported from the Lower Cambrian of China (Zhou & Xiao, 1984). Mellopegma has now been identified from the Middle Cambrian of central North Greenland where it occurs as phosphatised internal mouids preserved in a manner similar to that of the original Australian specimens from the Currant Bush Limestone of Queensland.
Silurian thelodont scales from North Greenland
Authors: Turner S , Peel J.S
Published: June 2021

Thelodont scales are recorded from samples of Silurian limestone from Hall Land, Washington Land and Peary Land, North Greenland. Faunas of probable Early Silurian age compare best with faunas from western Europe, while a fauna of Late Silurian (Pridoli) age from Hall Land can be compared with faunas from Arctic Canada and Tuva. The preoccupied names Logania Gross, 1967 and Katoporus Gross, 1967 are replaced by Loganella and Katoporodus, respectively.
Silurian ostracoderms from Washington Land (North Greenland), with comments on cyathaspid structure, systematics and phyletic position
Authors: Bendix-Almgreen S.E
Published: June 2021

The few detached dermal elements recorded here document a new ostracoderm fauna comprising undeterminable species of one anaspid, two cyathaspids and a heterostracan which might have its closest relatives among the pteraspids. This fauna is derived from marine deposits of ultimate Wenlock or possibly Early Ludlow age at the top of the Lafayette Bugt Formation in its type section, in Washington Land, western North Greenland. It is probably equivalent to one of the undescribed faunas known from the Monograptus testis - M. nilssoni sequence of the Cape Phillips Formation in the Canadian Arctic Archipelago. Comparative material from Norway and Spitsbergen is considered in this study which prompted general comments on cyathaspid squamation, vestigial fin structure, cyathaspid systematics, their phyletic position relative to the pteraspids, system of stability control in swimming, their habitats and diets.
Lithostratigraphy and structure of the North Greenland fold belt in Nansen Land
Authors: Bengaard H.-J , Davis N.C , Friderichsen J.D , Higgins A.K
Published: June 2021

Field work in Nansen Land and adjacent areas in 1985 has largely confirmed the provisional lithostratigraphy of the Paradisfjeld Group and Polkorridoren Group previously established; both are Lower Cambrian deep-water sequences. Some units of the Polkorridoren Group show marked thickness variations. Two major phases of Ellesmerian (Devonian-Carboniferous) deformation are recognised, whereas Eurekan (CretaceousTertiary) events are limited to relatively minor structures, and several phases of dyke intrusion.
Energy balance on outlet glaciers from the Inland Ice, West Greenland
Authors: Knudsen N.T , Ottosen O , Svendsen L.M
Published: June 2021

As part of the GGU programme of hydropower investigations in West Greenland, energy balance measurements were made on Qamanârssûp serrnia during the 1986 ablation season. The investigations are the continuation of a project in which Aarhus University has measured energy balances on Nordbogletscher, Johan Dahl Land, in 1981 and 1982 and on Qamanârssûp serrnia in 1984 in coIlaboration with P. Clement and R. J. Braithwaite, respectively (fig. 1). The main point of the programme was direct calculation of the ablation at the glacier surface from observations in the atmospheric boundary layer. Measured ablation was also used to calculate the residual part of the energy balance, as all elements were not determined. Lastly, the ablation was evaluated using variables chosen by correlation between easily measured climatic elements and the energy balance. The measurements in Johan Dahl Land were made by Jens Peter Jensen and Ole Ottosen as part of a student thesis project. Ole Bendixen undertook field measurements in 1984 on Qamanârssûp serrnia while Ole Ottosen and Lars Moeslund Svendsen carried out the field work in 1986.
A Balto-Scandian Middle Cambrian fauna from Peary Land, North Greenland
Authors: Fletcher T.P , Higgins A.K , Peel J.S
Published: June 2021

The first record of Middle Cambrian faunas of 'Atlantic' affinity from the Franklinian basin sequence of North Greenland was made by Poulsen (1969) who noted that previously described Greenland faunas were of 'Pacific' type. Field work by the Geological Survey of Greenland during the last decade has established that 'Atlantic' faunas are widespread in more outer shelfsequences along the northern coast of North Greenland while the 'Pacific' faunas occur within inner shelfsequences more to the south, near the margin of the Inland Ice. North Greenland preserves both faunas in dose geographical juxtaposition in only slightly tectonised geological settings. Thus, alatest Middle Cambrian trilobite fauna described by Robison (in press) from the Holm Dal Formation in an area some 40 km south of the presently discussed locality (and more inner shelf) includes a mixture of polymeroids characteristic of the Cedaria Zone of North America and agnostoids characteristic of the Lejopyge laevigata Zone of the Swedish standard zonation.
Silurian trilobites from Peary Land, central North Greenland
Authors: Lane P.D
Published: June 2021

Five species of trilobites are described from near the top of the Odins Fjord Formation in Peary Land: Opoa ostreata sp. nov., Encrinuroides palasso sp. nov. (for comparison with which the type series of Encrinuroides moderatus (Poulsen, 1934) is refigured), Distyrax peeli gen. et sp. nov. (Encrinuridae), Podowrinella christiei sp. nov. and Gaotania anoplos sp. nov. The age of the fauna and links with other faunas are discussed.
Review of the Survey's activities in 1987
Authors: Ghisler M
Published: June 2021

Over the past few years many functions of the Ministry for Greenland have been transferred to the Greenland Home Rule Administration. FolIowing the reorganisation of the government after the general election in September 1987 the Ministry for Greenland was abolished and its remaining functions transferred to other ministries. The Geological Survey of Greenland, together with the Greenland Mineral Resources Administration and the Greenland Environment Research Institute were transferred to the Danish Ministry of Energy. The Minister of Energy, Svend Erik Hovmand, visited GGU in October. The systematic geological investigation of Greenland and its mineral deposits and petroleum potential continl;led throughout 1987 - GGU's work comprised geologicaI mapping and reconnaissance surveys combined with more detailed studies in selected areas with emphasis on economic geology. The scientific and technical staff of 114 continues to be based in Copenhagen. A total of 92 participants were engaged in the field work in Greenland and carried out programmes in both East and West Greenland.
Progress in geochemical mapping of West Greenland
Authors: Steenfelt A
Published: June 2021

Geochemical mapping based on low density sampling and analysis ofstream sediment and stream water is part of the mineral resources evaluation programme undertaken by the Geological Survey of Greenland (Steenfelt 1987a, b). In the field season of 1986 two areas were sampled, the inner Disko Bugt region (1:250000 map sheet 69 V.2 and part of 70 V.2), and the Godthåb region (map sheets 64 V.1 and 64 V.2).
Application of seismo-stratigraphic interpretation techniques to offshore West Greenland
Authors: Chalmers J.A
Published: June 2021

A pilot study is being conducted to determine if the use of seismo-stratigraphic interpretation techniques can increase the understanding af the geology of offshore West Greenland in order to reassess the prospectivity of the area. During the period 1975 to 1979, a number of concessions offshore West Greenland were licensed to various consortia of oil companies to search for petroleum. Some 40 000 km of seismic data were acquired, all of which is now released. Five wells were drilled, all of them dry, and all concessions were relinquished by the industry by 1979. The regional geology of offshore West Greenland has been summarised by Manderscheid (1980) and Henderson et al. (1981). They show the West Greenland Basin to consist of fairly uniformly westward dipping sediments bordered near the shelf break by a basement ridge. These authors used what may be termed 'conventional' techniques of seismic interpretation. However, since that time the techniques of seismo-stratigraphy (Vail et al., 1977; Hubbard et al., 1985) have become established. They are now being applied to study seismic data acquired during the mid-1970s.
Detailed investigation of the niobium-tantalum distribution within the Motzfeldt Centre, South Greenland
Authors: Thomassen B , Tukiainen T , Secher K
Published: June 2021

A one year programme for detailed investigation of selected parts of the Nb-Ta-U-bearing pyrochlore mineralisation within the 'Motzfeldt Centre, South Greenland, was initiated in June 1987. The aim of the programme is to delineate areas with a potential for highgrade accumulation of Ta-enriched pyrochlore which is important if international exploration and mining activity is to be attracted. It is also important for official decisions in relation to any application for concessionary activity. The programme is carried out as a joint project between GGU and Nunaoil AJS under supervision of GGU, and a major part of the funding is granted by the Mineral Resources Administration for Greenland.
A preliminary study of the porosity and permeability of limestones and sandstones in the Jameson Land area, central East Greenland
Authors: Stemmerik L
Published: June 2021

The Upper Palaeozoic - Mesozoic sequence in the Jameson Land area (figs 1, 2) is well known from numerous studies carried out since GGU initiated mapping of the area in 1968 (e.g. Clemmensen, 1980a, b; Surlyk et al., 1973, 1984, 1986a; Surlyk, 1983, 1987; Heinberg & Birkelund, 1984). Based on these studies, Surlyk et al. (1986b) proposed that a number of Upper Permian - Cretaceous formations have a reservoir potential. Sandstone and limestone samples from these and a few additional formations (fig. 2) have been anaIysed for porosity and air-permeability. The analyses, all performed on surface samples or shallow cores, represent the first numerical approach to the evaluation of reservoir properties in the Jameson Land - Scoresby Land basin, and form a preliminary background for a more detailed reservoir study presently being undertaken by GGU. The analyses were carried out commercially by the Core Analysis Laboratory of the Geological Survey of Denmark (Haslund, 1985; Springer, 1986). Air-permeability, He-porosity and grain density were measured conventionally on uncleaned 1" x 1" plugs after humidity drying.
Surging glaciers in Greenland – a status
Authors: Weidick A
Published: June 2021

New wide-angle vertical aerial photography covering most of West and East Greenland were flown in the years 1981 and 1985 by Mark Hurd Corp., Minneapolis, Minnesota, for the Geodetic Institute, Copenhagen. The photographs are on a scale of approximately 1:150 000,so that single photographs cover a large area, and are valuable as bench marks for glacier changes. These photographs have been used for updating information on West Greenland glacier changes and the history of West Greenland glacier surges. Those covering East Greenland have been used for location of importantcentres of surging glaciers.
Test drilling with hot water jet at the Inland Ice margin, Pâkitsoq, central West Greenland
Authors: Olesen O.B , Clausen A
Published: June 2021

A new hot water jet driII was tested on the Inland Ice margin north-east of Jakobshavn. A total of 2436 m was driIled and data on drilling performance is presented together with the prelimiriary interpretation of borehole logging.
A new anorthosite/gabbro complex at Nûgssuaq, central West Greenland
Authors: Garde A.A , Steenfelt A
Published: June 2021

As part of the GGU activity in the Disko Bugt region, central West Greenland (Kalsbeek, 1989), the authors carried out helicopter-supported geological reconnaissance mapping and stream sediment sampling for geochemical mapping in the area between Jakobshavn Isfjord and Qarajaq Isfjord (fig. 1). A considerable part of the season was spent in the eastern part of the Nûgssuaq peninsula, partly to complete the stream sediment sampling initiated in 1986 (see Steenfelt, 1988) and also because previous geological field work in eastern Nûgssuaq was very limited. The existing geological map at a Rapp. Grønlands geol. Unders. 145. 16-20 (1989) scale of 1:500 000 covering Nûgssuaq is almost entirely based on interpretation of aerial photographs. During the field work large occurrences of hitherto unknown anorthosite/gabbro rocks and supracrustal sequences were discovered in the gneiss terrain. Both the anorthosite/gabbro and supracrustal units appear to be tectonically interleaved with strongly foliated, flat-Iying or shallowly south-dipping orthogneisses, which themselves contain numerous shear zones suggesting substantial subhorizontal movements.
New observations of marine trace fossils in delta plain sequences, southern Nûgssuaq, West Greenland
Authors: Pedersen G.K , Rasmussen B.F
Published: June 2021

During the 1988 field season new observations were made on the sediments of the Upper Cretaceous Atane Formation in southern Nûgssuaq. These observations indicate that the degree of bioturbation may be taken as an indicator of the degree of marine influence within the interdistributary delta plain environments. The field work was carried out during six days in July 1988 as part of a sedimentological research project supported by GGU and the Danish Natural Science Research Council.
New geological investigations in eastern Disko: redeposited volcanoclastic sediments with rhyolite from the Nordfjord Member
Authors: Larsen L.M , Pedersen A.K
Published: June 2021

During field work in 1988 in eastern Disko we encountered redeposited volcanoclastic sediments with acid rocks at several localities between Rensdyrdalen and Charles Polaris Dal within lava sequences from the Nordfjord Member of the Maligât Formation. Some of the sediments were only observed during helicopter reconnaissance of steep inaccessible walls and corries, while other sites provided detailed information and samples through field visits. Fig.1 shows the area with newly discovered acid volcanic rocks in eastern Disko. Localities 1 and 2 denote localities investigated in some detail. In north-western Disko peraluminous rhyolite tuffs and conglomerates with almandine-bearing rhyolite blocks occur as widespread but minor deposits in the Nordfjord Member (Pedersen, 1977; Hansen & Pedersen, 1985; Pedersen & Pedersen, 1987). The acid rocks contain graphite and scarce sediment xenoliths and they are associated with contaminated basalts, andesites and dacites, same af which carry nativc iran. The distribution af airfall rhyolite tuff shows that the aciel rocks were erupted somewhere in north-western Disko or in the present shallow sea west af this arca. No eruption sites are exposed at present.
Some observations on the structure of the early Proterozoic, Ammassalik mobile belt in the Ammassalik region, South-East Greenland
Authors: Chadwick B , Vasudev V.N
Published: June 2021

Ammassalikian deformation appears to have given rise in the first instance to a regional layer cake structure of tectonically interleaved sheets of the early Proterozoic Siportoq supracrustal association and Archaean quartzo-feldspathic orthogneisses, the latter containing locally abundant amphibolite dykes. Younger orthogneisses were emplaced magmatically in parts of the structure. The layer cake structure was progressively modified by fold nappes and later domes with steep intervening cusps. The early Ammassalikian structure is attributed to thrust stacking during ensialic crustal shortening with tectonic instability spreading from north to south. Some of the nappes and upright structures may be buoyancy phenomena which resulted from thermal instabilities generated at depth within the thrust pile.
Basic dykes of the southern Ammassalik region, South-East Greenland: preliminary mineralogical and geochemical results
Authors: Hall R.P , Hughes D.J , Joyner L
Published: June 2021

The Ammassalik mobile belt of South-East Greenland and the Archaean gneisses to the north and south are cut by abundant variably deformed and metamorphosed Proterozoic basic dykes. Undeformed and unaltered dolerite dykes in the southernmost part of the region retain fresh igneous subophitic textures and mineral assemblages, the pyroxenes of which preserve complex chemical variations with highly variable Ca, Mg and Fe contents. The ophitic pyroxenes in neighbouring dykes of supposed Tertiary age comprise more usual, compositionally uniform pigeonite-augite pairs. The contrast between these pyroxene assemblages probably resuIts largely from differences in the oxygen fugacity of their respective parental magmas. The investigated Proterozoic dykes have chemical and mineralogical similarities with dykes of the same general age in southern West Greenland and Scotland, and they pre-date the development of the Ammassalik mobile belt, rather than being directly related to it.
Studying the early history of life in Greenland
Authors: Peel J.S
Published: June 2021

Exceptionally preserved fossils of soft-bodied animals have always aroused particular interest within the geological community. Not only do they supply anatomical information not usually preserved, but they also provide insights into the structure of the living communities which are difficult to obtain from fossils preserved as hard skeletal elements alone. The importance of these soft-bodied or poorly skeletised forms is indicated by their dominance in present day environments where animals without hard parts make up more than two thirds of the number of species and individuals present (Conway Morris, 1986).
Caledonian and pre-Caledonian geology of Dronning Louise Land, North-East Greenland
Authors: Friderichsen J.D , Holdsworth R.E , Jepsen H.F , Strachan R.A
Published: June 2021

The western border of the East Greenland Caledonides is exposed in Dronning Louise Land, where it is marked by a N–S trending thrust Imbricate Zone. The autochthonous crystalline basement to the west of the Imbricate Zone is dominated by orthogneisses, and unconformably overlain by two metasedimentary sequences (Zebra Series and Trekant Series). These metasedimentary units can be recognised in the Caledonian thrust slices of the Imbricate Zone and also as folded inliers in the gneiss complexes to the east, and witness to a progressive increase in Caledonian deformation and metamorphism.
Ice drilling and mass balance at Pâkitsoq, Jakobshavn, central West Greenland
Authors: Thomsen H.H , Olesen O.B , Braithwaite R.J , Bøggild C.E
Published: June 2021

Hot water drilling and mass-balance measurements were made on the Inland Ice at Pakitsoq north-east of Jakobshavn. Two arrays of moderate and shallow-depth thermistor strings have been installed in the ice to map the englacial temperature from the ice margin to the equilibrium line. Water fluctuations were observed in a drill hole connecting to the ice bed. The measurements indicate a high subglacial water pressure dose to the ice overburden pressure.
The crystalline rocks of Germania Land, Nordmarken and adjacent areas, North-East Greenland
Authors: Friderichsen J.D , Gilotti J.A , Henriksen N , Higgins A.K , Hull J.M , Jepsen H.F , Kalsbeek F
Published: June 2021

The crystalline rocks of Germania Land, Nordmarken and adjacent areas are dominated by grey, migmatitic quartzo-feldspathic orthogneisses with a complex history of emplacement and deformation. Ultramafites, eclogites and metasedimentary rocks are preserved as inclusions or trails of enclaves within the migmatitic orthogneisses. Later intrusive suites include metadolerite dykes, alkali feldspar metaporphyries and metagabbros. All these crystalline rocks have suffered thorough metamorphism and deformation, and three fabric events are recognised. Three systems of late mylonite zones are found: west of the study area in Hertugen af Orleans Land, along the east side of Stormlandet and Germania Land, and in northern Store Koldewey and Lille Koldewey. The region lies within the East Greenland Caledonian fold belt. Available isotopic data suggest the crystalline rocks include Archaean and Early Proterozoic suites. These have undergone variable degrees of later reworking on several occasions. It is unclear how much of the deformation history is Caledonian and how much pre-Caledonian. The latest fault displacements are post-Caledonian, as shown by local preservation of fault bounded outcrops of Carboniferous and Jurassic sedimentary rocks.
Quaternary geology of western and central North Greenland
Authors: Kelly M , Bennike O
Published: June 2021

The earliest Quaternary event represented is the Kap Bryant glacial stade of probable Saalian age, in which an ice sheet covered the area out to the shelf. In contrast, in the Late Weichselian Kap Fulford stade, the area was only partly glaciated, with outlet lobes from an ice sheet occupying the outer fjords. There is some evidence of an earlier (Early Weichselian?) slightly more extensive glaciation (Kap Sumner stade). In the early Holocene, the ice margin had retreated to the middle regions of the fjords and extensive glacial lakes were formed in intervening areas. The Late Holocene Steensby stade produced a readvanee of the ice sheet at the head of the fjords and the growth of local ice caps. Reworked marine fossils in glacial sediments define the Hall Land marine event of Eemian and/or Early Weichselian age. The Late Weichselian/Holocene marine event (Nyeboe Land event) is abundantly represented by deposits whose distribution shows that the limit of transgression varied over the area, with a maximum at about 125 m above sea level. Regression from this limit occurred during the Holocene, initially at a slow rate. The fossil biota are described from the marine sediments and from a small number of terrestrial occurrences.
Degree-day factor, energy balance, and the increased melting of the Greenland ice sheet under a warmer climate
Authors: Braithwaite R.J
Published: June 2021

Ablation on the Greenland ice Sheet can be calculated either from the degree-day factor or by an energy balance model. Both approaches involve problems. i.e. the degree-day factor varies with time and space while the energy balance model requires data which are often not available. The solution is to understand, and possibly predict variations in degree-day factor. This can be attempted by (1) sensitivity experiments with the energy balance model, and (2) field samples of ablation under widely varying climatic conditions.
Review of the Survey's activities in 1992
Authors: Ghisler M
Published: June 2021

The activities of the Geological Survey of Greenland (Grønlands Geologiske Undersøgelse, GGU) in 1992 were strongly influenced by political initiatives to increase interest in the hydrocarbon and mineral resources of Greenland. GGU has supported the Mineral Resources Administration (MRA) with both an international promotion drive to present the investment potential of Greenland to the mining industry and with presentations in connection with a licensing round for hydrocarbon exploration and exploitation offshore West Greenland south of 66°N.
Measurements of firn density in the lower accumulation area of the Greenland ice sheet: EPOCH 1992
Authors: Braithwaite R.J , Laternser M
Published: June 2021

Groups from several countries are studying Greenland glaciers in connection with the 'greenhouse effect' (Braithwaite et al., 1992a). In particular, GGU is the Danish partner in a IO-nation two-year project (March 1991 to February 1993) on causes and effects of sea level changes which is funded by the European Community through the European Programme on Climatology and Natural Hazards (EPOCH). As its contribution to EPOCH, GGU is studying the effects of meltwater refreezing in the lower accumulation area of the Greenland ice sheet which may reduce, or at least delay, the expected sea level rise under warmer climate. Work done under EPOCH in 1991 was described by Braithwaite et al. (1992b) while the present note describes the most important results of the 1992 field work.
Lead isotope studies on mineral showings and ore deposits in East Greenland
Authors: Jensen S.M
Published: June 2021

Lead isotope studies indicate an age of 680 ± 65 Ma for syn-diagenetic stratiform copper mineralisation in the Upper Proterozoic Eleonore Bay Supergroup (EBS) sediments. Metals in EBS-hosted veins were remobilised from local host rocks, or derived from underlying Middle Proterozoic gneisses. Tungsten-arsenic skarns associated with Caledonian granites intruded into the EBS incorporated lead mobilised from the basement gneisses mixed with Caledonian granite lead. Isotopic compositions of trace lead in sparse sulphide occurrences in North-East Greenland point to Late Archaean – Early Proterozoic sources, comparable to the local basement gneisses. Base metal mineralisation in Upper Palaeozoic – Mesozoic rocks in central East Greenland shows a limited range. in lead isotope compositions, suggesting that a large, homogeneous crustal reservoir supplied the metals, or that metals from different sources were effectively mixed. Mineralisation in Tertiary igneous rocks in the Kangerdlugssuaq area of southern East Greenland shows lead isotope evidence for contamination by material from lower crustal Archaean sources.
Firn temperature and meltwater refreezing in the lower accumulation area of the Greenland ice sheet, Pâkitsoq, West Greenland
Authors: Braithwaite R.J
Published: June 2021

Firn temperatures and meltwater refreezing are studied in the lower accumulation area of the Greenland ice sheet as part of an international project on sea level changes. In the study area, 1440–1620 m a.s.l., meltwater penetrates several metres into the firn and refreezes, warming the firn by 5–7°C compared with annual air temperatures. This firn warming is closely related to surface melt which can be estimated by several methods. A relatively high degree-day factor is needed to account for the melt rates found.
Conditions of origin of kimberlites in West Greenland: new evidence from the Sarfartoq and Sukkertoppen regions
Authors: Larsen L.M , Rønsbo J
Published: June 2021

Minerals in a garnet lherzolite nodule from Sarfartoq and macrocrysts in a kimberlite from the Sukkertoppen region have been analysed by microprobe. Temperatures calculated for the Sarfartoq nodule lie in the range 1110–1137°C, and pressures are estimated at greater than 50 kbar. The calculated temperature for the Sukkertoppen macrocrysts is 1309°C. Temperatures recalculated from existing data for kimberlites in the Holsteinsborg region and in SW Greenland lie in the range 1034–1078°C (40-50 kbar). The temperature variations may reflect the setting of the kimberlites in Archaean and Proterozoic terrains. Assuming a common geotherm of 40mW/m2 all the kimberlites in West Greenland originated within the diamond stability field.
Discovery of live oil at Marraat, Nuussuaq: field work, drilling and logging
Authors: Christiansen F.G , Dam G , Pedersen A.K
Published: June 2021

Observations of oil seepage and bitumen impregnation at the surface are very important in an early evaluation of the exploration potential of a sedimentary basin, since they usually demonstrate the existence of an oil-prone source rock and that oil generation has taken place somewhere in the subsurface. Such evidence has been reported from most onshore sedimentary basins in Greenland, and solid bitumens have in many cases been correlated to a known source rock in the immediate vicinity, or in rare cases interpreted as long-distance migration from a known or an inferred source rock (see review by Christiansen, 1994).
Dinoflagellate cyst stratigraphy of the Barremian to Albian, Lower Cretaceous, North-East Greenland – a summary
Authors: Nøhr-Hansen H
Published: June 2021

As part of studies of the onshore hydrocarbon potential in East Greenland undertaken by the Geological Survey of Greenland (GGU), a project was initiated with the purpose of describing the dinoflagellate cyst stratigraphy of the Lower Cretaceous succession in East Greenland (72°76°N) and correlating the exposed sections throughout the region (Nøhr-Hansen, 1993). Based on the rather sporadic occurrence of macrofossils the Lower Cretaceous sediments of East Greenland was previously dated as Aptian to Albian (Spath, 1946; Maync, 1949; Donovan, 1953, 1955, 1957). Maync (1949) reported the total exposed thickness of the ‘Aptian-Albian series’ to be more than 2000 m, whereas Surlyk (1990) noted that the Lower Cretaceous shale succession reached a cumulative thickness or 1000 m. Furthermore, Donovan (1972) reported that Hauterivian and Barremian sediments were unknown in East Greenland. Dinoflagellate cysts recorded from 40 sections throughout the region have now dated the Lower Cretaceous sequence as Barremian to Albian, and correlation of sections yields a cumulative thickness of approximately 1500m (Nøhr-Hansen, 1993).
Greenland glaciers and the 'greenhouse effect', activities 1993
Authors: Braithwaite R.J , Olesen O.B , Reeh N , Weidick A
Published: June 2021

Possible global climate change caused by increased 'greenhouse effect' may lead to a warmer climate that will cause increased melting of the Greenland ice sheet, and a rise in world sea level. Climate warming may be apparent first and with greatest magnitude at high latitudes so that increased melting of the Greenland ice sheet could give early warning of global climate change. For these reasons, GGU and foreign organisations are studying Greenland glaciers in connection with the ‘greenhouse effect’ (Braithwaite et al. 1992).
A newly discovered mid-Carboniferous - ?early Permian reef complex in the Wandel Sea Basin, eastern North Greenland
Authors: Stemmerik L , Elvebakk G
Published: June 2021

Three types of carbonate build-ups occur in the mid-Carboniferous – ?early Permian (Moscovian–?Asselian) succession at Kap Jungersen, southern Amdrup Land, North Greenland: (1) Palaeoaplysina-dominated build-ups; (2) AIgae-dominated build-ups; and (3) Bryozoan-dominated build-ups. The build-ups are less than 15 m thick and up to a few hundred metres wide. They often coalesce to form laterally widespread, build-up dominated units and are locally stacked to form up to 100 m thick build-up dominated sections along platform margins.
Historical fluctuations of calving glaciers in South and West Greenland
Authors: Weidick A
Published: June 2021

Fluctuations of calf-ice producing outlets of the Julianehåb ice cap and other local glaciers in South Greenland, and outlets of the Inland Ice in South and West Greenland between latitudes 60° and 73°N from c. A.D. 1850 to the present time are reviewed. Seasonal variations of the fast running tidewater glaciers (ice streams) may veil long term trends, but in general it is concluded that the mode of activity (advance or retreat) is nearly synchronous for the outlets and their neighbouring land-based segments, whereas amplitude differs; topographical control is important for short-term fluctuations but should not be over-emphasised. The situation around 1990 is one of spreading readvance and the observed behavioural patterns fit with Huybrechts' model for the present dynamic situation of the ice cover. This model indicates that the ice sheet generally is expanding as a consequence of the climatic cooling since the Holocene climatic optimum but also locates areas with present thinning of the ice margin.
Geology of North-East Greenland (75°-78°N) – the 1988–90 mapping project
Authors: Henriksen N
Published: June 2021

The geological background for the 1988–90 mapping project in North-East Greenland is outlined. The principal geological units represented in the region between Grandjean Fjord and Jökelbugten include rocks of pre-Caledonian, Caledonian and post-Caledonian age. Particular reference is made to the articles resulting from the project which make up this Survey report.
Structure of the Eleonore Bay Supergroup at Ardencaple Fjord, North-East Greenland
Authors: Higgins A.K , Soper N.J
Published: June 2021

The Caledonian structures in the late Proterozoic Eleonore Bay Supergroup of the Ardencaple Fjord area were controlled by the position and shape of the contacts with older basement rocks. Those contacts that are not late faults are likely to have been extensional shear zones of Vendian age which were reactivated in compression during the Caledonian orogeny. This interpretation may aIso be applied to the other large tracts of low grade Eleonore Bay Supergroup sediments in East Greenland, and explains their preservation at the present erosion level, surrounded by Precambrian basement rocks.
Search for Archaean basement in the Caledonian fold belt of North-East Greenland
Authors: Nutman A.P , Kalsbeek F
Published: June 2021

SHRIMP U-Pb isotope data on zircon crystals from a gneiss sample near Danmarkshavn, where the presence of Archaean rocks has earlier been documented, show that the rock has undergone a complex history of igneous and metamorphic zircon growth. At least three generations of zircon are present with ages of c. 3000 Ma, c. 2725 Ma and 1967 ±8 Ma (2 α). Apparently the rock was formed from an Archaean protolith which underwent high grade metamorphism during the early Proterozoic. Another sample from the easternmost exposures of the Caledonian basement, collected further north, yielded only early Proterozoic zircons with an age of 1963 ± 6 Ma. Together with a SHRIMP U-Pb zircon age of 1974 ± 17 Ma reported earlier, these results give evidence of a major igneous and metamorphic event in North-East Greenland about 1965 Ma ago.
40Ar/39Ar mineral age constraints on the timing of deformation and metamorphism, North-East Greenland
Authors: Dallmeyer R.D , Strachan R.A
Published: June 2021

40Ar/39Ar mineral ages have been determined from basement gneisses and cover sequences exposed in the Caledonides of North-East Greenland. These range between c. 438 Ma and c. 370 Ma (Early Silurian – Middle Devonian). They are interpreted as dating cooling folIowing polyphase Caledonian metamorphism which completely rejuvenated intracrystalline argon systems within the (early Proterozoic) basement gneisses. The 40Ar/39Ar results indicate that thrust-related regional deformation.
Stratigraphy of the post-Caledonian sediments in the Germania Land area, North-East Greenland
Authors: Piasecki S , Stemmerik L , Friderichsen J.D , Higgins A.K
Published: June 2021

Sediment outliers in North-East Greenland are briefly described and dated on the basis of macro- and microscopic plant fossils. Conglomerates and sandstones at Depotnæsset are probably of Late Carboniferous age based on the content of poorly preserved spores and pollen together with Stigmaria molds. Conglomerates, sandstones and coals from localities west of Germania Land are of Early to Middle Jurassic age based on poorly preserved fossil leaves and sporomorphs. The sedimentary facies and the fossil content of the Upper Carboniferous sediments suggest that the transition between the continental Carboniferous basins of East Greenland and the marine basins of North Greenland was situated north of 78°N. The maturity of the sporomorphs suggests that the Upper Carboniferous basins subsided by 1.5–2 km in Late Carboniferous to Middle Jurassic time, whereas subsidence of the Jurassic basins was negligible.
Surge of Storstrømmen, a large outlet glacier from the Inland Ice of North-East Greenland
Authors: Reeh N , Bøggild C.E , Oerter H
Published: June 2021

During field work in 1989 it was noted that the front of Storstrømmen glacier, North-East Greenland, had advanced by more than 10 km as compared to its position in 1978. lnspection of satellite images shows that the advance took place in the period from 1978 to 1984. Scattered observations of frontal positions back to 1913 indicate a general retreat until 1978. During the advance after 1978, the ice discharge in the frontal region of Storstrømmen was as much as 10.8 km3 per year, which is about half the discharge from Jakobshavn Isbræ, West Greenland, the most productive calving glacier in Greenland. Observed surface-elevation and surface-velocity changes during a period overlapping that of the large frontal advance show all the characteristics associated with a surge.
Sinistral transpression and hydrothermal activity during emplacement of the Early Proterozoic Julianehåb batholith, Ketilidian orogenic belt, South Greenland
Authors: Chadwick B , Erfurt P , Frisch T , Frith R.A , Garde A.A , Schønwandt H.K , Stendal H , Thomassen B
Published: June 2021

The first systematic investigations of the central part of the Early Proterozoic Ketilidian orogen in the vicinity of Søndre Sermilik in the early 1960s suggested that this part of the orogen comprised a mixture of the Julianehåb granite, altered supracrustal rocks and older orthogneisses. Recent field work has shown that the area consists only of a variably deformed suite of granitic to dioritic plutonic rocks and a range of hornblende-bearing dykes of the appinite suite which all belong to the Julianehåb batholith. Steep to vertical shear zones with widths from a few centimetres to more than one kilometre are a significant element of the structure. The principal shear zones trend north-east and they are parallel to the schistosity and subhorizontal linear structures in the granitoid rocks. Kinematic indicators in many of the shear zones indicate sinistral transcurrent displacements. The relationships between granite fabrics, shear zones and mafic dykes suggest that the Julianehåb batholith was emplaced during subduction from the south towards the Archaean craton in the north-west in a sinistral transpressional system. Effects of hydrothermal alteration, mainly in the form of quartz veining, silicification, chloritisation, epidotisation and pyritisation, are common within and adjacent to the largest shear zones. These effects are believed to be related to late stages of the evolution of the batholith. Gold anomalies appear to be closely tied to the hydrothermal phenomena.
Re-appraisal of the Ikermit supracrustal suite of the Ketilidian border zone in South-East Greenland
Authors: Chadwick B , Erfurt P , Frith R.A , Nielsen T.F.D , Schønwandt H.K , Stendal H
Published: June 2021

Previous workers in the Ketilidian orogen of South-East Greenland reported extensive outcrops of acid vo1canic rocks and related gneisses which they described as the Ikermit supracrustal suite. The suite was regarded as a favourable host for sulphide mineralisation. New fjeld and petrographic data show that the 'acid volcanic rocks' from the type locality on Ikermit island are entirely Archaean orthogneisses with abundant, but local, mylonites. These gneisses and mylonites occur within the wide border zone between the Ketilidian orogen and the Archaean foreland to the north. The name 'Ikermit supracrustal suite' should be abandoned.
Shape and size of lacustrine deposited melanogen (opaque organic matter), Upper Carboniferous, East Greenland
Authors: Hoelstad T , Piasecki S , Stemmerik L
Published: June 2021

The content of opaque particles (melanogen) in eight kerogen concentrates from lacustrine sediments of the Upper Carboniferous of East Greenland are characterized with respect to shape and size by means of electronic image analysis. The method of electronic image analysis is briefly described and the applied sequence of image analysis functions is explained. The main items of the program sequence are shade and intensity correction, object discrimination and object selection. It is demonstrated that the method produces consistent results. Shape indices for circularity (4π × area/perimeter2) and elongation ((b/a)1/2) and the areas of the optical sections have been recorded. These parameters have a distinct relationship to the sedimentary environment; the melanogen particles in the clay-siltstone beds show increasing circularity, decreasing elongation and increasing areas up through the coarsening-upward sequences. Thus, the size and shape of the melanogen particles are not only tied to the sedimentary texture of the actual sample, but also to the overall textural characteristics of the section.
The Fylla structural complex: possible very large gas reserves offshore southern West Greenland
Authors: Bate K.J , Whittaker R.C , Chalmers J.A , Dahl-Jensen T
Published: June 2021

This paper outlines the evidence for the possible existence of very large gas reserves offshore southern West Greenland. It is a slightly modified version of a paper published in the Oil & Gas Journal, August 22nd 1994. Recent interpretation of new seismic data acquired off­shore southern West Greenland (Fig. 1) has identified a number of structural leads which may contain gas reserves with a cumulative volume of the order of 100 tcf. The presence of two flat-spots with clear Amplitude Versus Offset (AYO) effects overlying a possible oil column is the most direct indication of the occurrence of gas in the area.
The Melville Bay area, North-West Greenland – the first phase of petroleum exploration
Authors: Whittaker R.C , Hamann N.E
Published: June 2021

The first detailed interpretation of the structure and geological development of the Melville Bay area based on reflection seismic data was completed in June 1994 as part of the KANUMAS project (Larsen & Pulvertaft 1990). This marks the first step in the exploration for petroleum offshore North-West Greenland and has resulted in renewed optimism for the oil potential of the region.
Petroleum geology and thermal maturity of eastern North Greenland - a new energy research project
Authors: Stemmerik L , Dalhoff F , Nilsson I
Published: June 2021

Petroleum geological studies were initiated in eastern North Greenland in 1993 as part of a regional mapping programme carried out by the Geological Survey of Greenland (Henriksen, 1994, 1995; Stemmerik & Elvebakk, 1994). These activities continued in 1994, and a three-year research programme was initiated to generate data for basin modelling of the Phanerozoic sedimentary basins in the easternmost part of North Greenland. The basin modelling project is supported by the Danish Ministry of Environment and Energy and is a continuation of previous petroleum-related research programmes in the region (Christiansen, 1989; Hakansson & Stemmerik, this report). The aim of the project is to improve the understanding of the subsidence and uplift history of the adjacent shelf basins, and to evaluate the presence of pre-Carboniferous source rocks with adequate maturity in these areas.
A new airborne electromagnetic and magnetic survey of Inglefield Land, North-West Greenland: Project AEM Greenland 1994–1998
Authors: Stemp R.W , Thorning L
Published: June 2021

Late in 1993 the Greenland Home Rule Government decided to finance a five-year programme of airborne geo­physical surveying over selected regions of Greenland, project AEM GREENLAND 1994–1998, with approximately five million kroner per year. The primary objective is to stimulate mining exploration activity in Greenland over the short term. The secondary objective is to provide data, which will have a lasting effect in the interpretation of the geology in selected parts of Greenland. The Geological Survey of Greenland (GGU) manages the project, carries out interpretations of the data, and will maintain the acquired data in digital databases as a service to the public and mining companies (MINEX 1994a, b).