bluuebunny/crossref_metadata_2025 huggingface dataset:
Molluscan Faunas and Biostratigraphy of the Marine Younger Miocene Formations in Denmark. Part I: Geology and Biostratigraphy
Authors: Rasmussen Leif Banke
Published: June 2021

The result of biostratigraphical investigations into the marine Younger Miocene formations in Denmark on the basis of the molluscan faunas shows the presence of six assemblage zones, distributed by two on the older formation, viz. the Hodde Formation, and four on the younger formation, viz. the Gram Formation:Upper Miocene (Gram Formation):The Nassa slieswicia zone The Astarte reimersi - Nuculana pygmaea zone The Astarte reimersi - Goodallia esbjergensis zone The Astarte vetula zoneLate Middle Miocene (Hodde Formation):The Nassa fuchsi - Limopsis lamellata zone The Nassa cimbrica - Aquilofusus festivus zone.In Denmark all the zones have only been recorded from West and Central Jutland and North Slesvig. So far they all seem to be distributed over the same region, except for the Nassa slieswicia zone, which has so far been recorded only from the region farthest south, close to the Danish-German frontier.The marine Younger Miocene formations in Denmark include an unbroken, at least 35 m. thick series of clay, consisting at the bottom of Hodde Clay (belonging to the Hodde Formation), above that of Glauconite Clay, and at the top of Gram Clay (the last two belonging to the Gram Formation). Fairly homogeneous bottom conditions make it possible to follow the evolution of a few species from the Hodde Clay to the uppermost parts of the Gram Clay.The basis of the investigations is partly collected, partly sorted-out material from about 90 localities scattered over the whole area of distribution. The most important basis, however, is a borehole at Gram in North Slesvig, where the complete series of clay was penetrated, and a borehole at Sæd, also in North Slesvig. Most of the other localities have only yielded fossils from a few assemblage zones. The geological conditions in the main part of the localities show that the series of clay to a great extent has been glacially deformed in the Quaternary Period, which has to some degree complicated the stratigraphical investigations.It has been tried to substantiate the results mentioned through rather a detailed mention of the geological conditions in each locality and through analyses of the sampled and sorted-out fauna from each locality.
Differential pollen dispersion and the interpretation of pollen diagrams. With a contribution to the interpretation of the elm fall
Authors: Tauber Henrik
Published: June 2021

Pollen grains are liberated into the air in vast quantities. They are carried by air movements to the stigmas of the flowers, or eventually deposited on the ground and on lake surfaces. This transfer is a complex physical process, which can only be understood from a detailed knowledge of how and when pollen grains are released into the air, how they are transported by air currents in and above forests and over lakes and bogs, and how they finally settle out of the air and become incorporated in various deposits. Being dependent on transfer by air currents, the degree of dispersion will vary considerably with the size of the pollen grains, with the time of the year in which they are emitted, and with the physical structure of the vegetation. Pollen records preserved in lake and bog deposits must therefore be expected to give a more complex reflection of the vegetation around basins than is usually assumed in pollen analysis.
Brørup-Mosernes Lejringsforhold
Authors: Jessen Axel , Madsen Victor , Milthers V , Nordmann V
Published: June 2021

De i det sydlige Jylland, i større eller mindre Nærhed af Brørup Station beliggende, interglaciale Moser blev, efter at deres Tilstedeværelse var kommet til Geologernes Kundskab, i 1897 og de nærmest følgende Aar indgaaende undersøgte af N. Hartz, som publicerede sine Undersøgelser i 1909. Det er dog i første Række Mosernes Indhold af Fossiler, der har været Genstand for Hartz's Undersøgelser, hvorimod han kun giver forholdvis faa og lidet detaillerede Oplysinger angaaende deres Stratigrafi og Lejringsforhold til det omgivende, kvartære Jordarter.
Om Forekomster af Glacialflager af paleocæn Mergel paa Sjælland
Authors: Hansen Sigurd
Published: June 2021

Medens Forekomsten af store, løse Flager af Skrivekridt (brokket Kridt) i Istidsaflejringerne paa Sjælland har været kendt siden Bredsdorffs Dage, blev Tilstedeværelsen af lignende Glacialflager af den graa, paleocæne Mergel (Kertemindemergel) først paapeget Hundrede Aar senere af V. Milthers 1923 nemlig i Egnen Sydvest for Holbæk mellem Regstrup og Knabstrup. Fra to Mergelgrave ved Dorthealyst og Hanerup var der i Aarene 1919-1920 blevet indsendt et Antal Mergelprøver til Analysering i Danmarks geologiske Undersøgelses Laboratorium, og Resultaterne af Analyserne af dette graa, fede, stenfrie Ler viste meget høje Procenttal for kulsur Kalk, idet over Halvdelen af Analyserne angav mellem 60 og 75% kulsur Kalk i Tørstof. I Aaret 1921 undersøgtes Mergellejet ved Hanerup af Det danske Hedeselskabs Mergelvæsen, hvorved der paavistes ret udstrakte Mergellag af i det mindste 11 m Tykkelse og med et Indhold af kulsur Kalk paa henimod 70%.
The Influence of Prehistoric Man on Vegetation
Authors: Iversen Johs.
Published: June 2021

The present paper is a verbatim copy of the original manuscript used in a lecture, which was given at the University of Cambridge 14th Oct. 1946. The views expressed in the context are in all essentials the same as in a more detailed paper published in 1941, but the basis of my interpretations is considerably wider. Four of the diagrams given here are quite new, they are worked out with the definite object of throwing more light on some aspects of the influence of Neolithic man on vegetation. The diagram from Sækkedammen shows an especially early settlement of short duration (Atlantic time). The peculiar circumstances prevailing in the infertile Jutland heath plains, is illustrated in a diagram from Tinglev Sø. Finally there is a diagram from a district, which differs greatly, both as regards vegetation and Neolithic culture, namely Mogetorp mosse in Södermanland in the Swedish Midlands, known from Sten Florins archaeological and geological investigations of the Mogetorp-Vråculture. Also the presentation and discussion of the material diverges from that in my former paper, and so with some reluctance I have followed a request, that I should publish the lecture and the pollen diagrams.
Clay Mineralogy of some Lower Tertiary (Paleogene) Sediments from Denmark
Authors: Tank R. W
Published: June 2021

108 samples from the Paleogene rocks of Denrnark were examined by standard X-ray techniques and their clay suites form the basis of the present study. The X-ray data have permitted a three-fold mineralogical zonation of the Danish Paleogene.The oldest zone (Zone I) is characterized by a high montmorillonite content, minor or trace amounts of illite and segregated mixed-layer clay minerals and the absence of kaolinite. The boundaries of Zone I coincide with the Paleocene Series. The clay minerals are detrital and are derived from a carbonate terrain bordering the Fennoscandian massif. Diagenetic changes in the marine environment and segregation by sorting and floculation are important factors accounting for the high montmorillonite content.A middle zone (Zone Il) is characterized by the predominance of amorphous material. Minor amounts of montmorillonite, illite and kaolinite are present and represent alteration produets of volcanic ash. Zone II is restricted to the Mo Clay Formation.The youngest zone (Zone III) contains variable amounts of montmorillonite, illite, kaolinite and random mixed-layer montmorillonite-illite. The boundaries of Zone III appear to extend from the lower Eocene to the Miocene. The clay minerals of Zone III are products of the alteration of the volcanic material of the Fennoscandian massif. Changes in the conditions of the source area and the physical environment of deposition account for the mineralogical variations.
Ivy, Mistletoe and Elm Climate Indicators - Fodder Plants. A Contribution to The Interpretation of the Pollen Zone Border VII-VIII
Authors: Troels-Smith J
Published: June 2021

Knud Jessen (1935) fixed the border between his pollen zones VII-VIII which, broadly speaking, separates the Atlantic period from the Sub-Boreal period in Danish pollen diagrams, at the level "where the curve for the Oak Mixed Forest bends inwards, often because the frequency of the linden especially drops quickly".
Bornholms Geologi. Anden, omarbejdede Udgave
Authors: Milthers V
Published: June 2021

Nærværende anden Udgave af Bornholms Geologi er ligesom første Udgave i sine Hovedtræk blevet til paa Grundlag af »Beskrivelse til Geologisk Kort over Danmark (i Maalestok 1:00000). Kortbladet Bornholm ved K.A. Grönwall og V. Milthers. DGU Række I, Nr. 13. Kjøbenhavn 1916«. I Løbet af de 14 Aar, der er gaaet siden første Udgave fremkom, er der imidlertid udført adskillige Undersøgelser, som har uddybet Kendskabet til Bornholms geologiske Forhold i væsentlig Grad, og som der er taget Hensyn til i nærværende Udgave.
Review of the Survey's activities in 1979
Authors: Ellitsgaard-Rasmussen K
Published: June 2021

On the 1st of May 1979 Home Rule was introduced in Greenland. Under the new status the Danish Government and the Greenlandic Home Rule Authorities have equal powers when it comes to policy and important concrete resolutions within the field of mineral resources, including water resources for hydroelectric power.
Early Cambrian microfossils from the Portfjeld Formation, Peary Land, eastern North Greenland
Authors: Peel J.S
Published: June 2021

The Portfjeld Formation of eastern North Greenland is a dominantly carbonate sequence which, in its type area around Jørgen Brønlund Fjord, Peary Land, lies between the mainly clastic intervals of the Morænesø Formation, below, and the Buen Formation of early Cambrian age, above (Jepsen, 1971). In J. C. Christensen Land and Valdemar Glückstadt Land, to the east and south-east, the formation lies variously on sandstones of the Campanuladal Formation or dolomites of the Fyns Sø Formation (O'Connor, 1979). The age ofthe Portfjeld Formation has not previously been known with any degree of certainty, although its general occurrence between supposed tillites of the Morænesø Formation (Troelsen, 1956; Jepsen, 1971; Clemmensen, 1979) correlated with the Varanger sequence of Norway and the fossiliferous early Cambrian Buen Formation has caused most workers to suggest a late Precambrian - early Cambrian age. The term Eocambrian has often been applied.
Evidence of mid-Proterozoic granite formation in the Isua area
Authors: Kalsbeek F , Bridgwater D , Boak J.L
Published: June 2021

A 1.5-2 m wide fine-grained undeformed acid dyke, cutting the Early Archaean Isua supracrustal succession, was found in 1978 (D.B., J.B.). Preliminary Rb-Sr isotope measurements (F.K.) of small hand samples suggested an unexpected mid-Proterozoic age. Additional material was collected in 1979 (J.B.). Owing to weight restrictions in the helicopter, some of the samples are smaller (100-500 g) than we would normally use, but we feel justified in presenting the results since they suggest Proterozoic granitic activity in the area, which has implications for the later history of the Archaean block.
The South Greenland regional uranium exploration project
Authors: Armour-Brown A. B , Tukiainen T , Wallin B
Published: June 2021

The SYDURAN project completed the airborne gamma-spectrometer and geochemical sampling survey over some 14 000 km2 of south-west Greenland from the fjord Sermiligarssuk in the north-west to Kap Farvel in the south and up the east coast as far as the southern shore of Lindenows Fjord. This covered all the Ketilidian structural zones and a small area of Archaean as classified by Allaart (1976) (fig. 29). Geological field work and prospecting of a more detailed nature was carried out in five areas where previous work indicated possibie uranium mineralisation.
Mapping of Archaean, Mesozoic and Tertiary rocks between Watkins Bjerge and Angmagssalik (69°–65°50'N)
Authors: Myers J.S , Bridgwater D , Gill R.C.O
Published: June 2021

A light aircraft and helicopter were used between the 23rd and 29th July to complete the mapping of the 1:500000 geological map sheet 13 (fig. 2). Two reconnaissance flights were made from Iceland in a Piper Navajo aircraft on the 23rd and 24th July over the inland nunataks between Watkins Bjerge and Angmagssalik (fig. 30). The aim was to map the structure and distribution of Precambrian, Mesozoic and Tertiary rocks between Nansen Fjord and Watkins Bjerge, where there is no coverage by aerial photographs, and the structure and lithologies within the Precambrian gneiss complex on the inland nunataks to the south.
A marine geophysical survey of the East Greenland continental shelf between latitudes 60° and 70°N – Project DANA 79
Authors: Larsen B
Published: June 2021

Project DANA 79 is a part of GGU's geophysical investigations of the East Greenland shelf with special reference to the oil and gas potential of the continental margin. The programme also includes a regional aeromagnetic survey called EASTMAR (Larsen & Thorning, this report) and the planned deep seismic investigations (Risum, this report). Project DANA 79 was designed to provide knowledge of the geology of the sea floor and the shallow (0-300 m) subsurface. Special emphasis was put on the delineation of the basement and of the sedimentary basins on the shelf. The project was mainly sponsored as an energy related research programme by the Danish Ministry of Trade, Industry and Shipping, and was also supported by the Danish Natural Science Research Council.
Trilobites and gastropods from Silurian carbonate mounds in Valdemar Glückstadt Land, eastern North Greenland
Authors: Lane P.D , Peel J.S
Published: June 2021

Silurian carbonate mounds were reported from Valdemar Glückstadt Land, eastern North Greenland (lat. 82°N, long. 22°W) by Peel (1980) folIowing reconnaissance geological mapping in 1979. The localities were revisited during August 1980 when a complex of carbonate mounds and patch reefs rooted in bedded Silurian limestone and over/ain by black graptoliferous shales of latest Ear/y Silurian age, similar to those known elsewhere from eastern North Greenland (Christie & Peel, 1977; Lane & Thomas, 1979; Mabillard, 1980) was noted. Trilobites and gastropods are well represented in the mound faunas, together with stromatoporoids, favositid and rugose corais, pentamerid and other brachiopods, cephalopods and rare bivalves. Crinoid debris is abundant.
Thermal maturation of organic matter by a thick basaltic sill in Upper Cretaceous shales, Svartenhuk Halvø, central West Greenland
Authors: Schiener E.J , Perregaard J
Published: June 2021

Thermal effects of igneous intrusions on sedimentary organic matter indicate that organic compounds are more stable under geologically short but intense exposure to high temperature compared to those affected by slow burial. In the immediate contact zone a drastic reduction occurs in kerogen content, accompanied by high reflectance values. The presence in this zone of n-alkanes in the C15–C20 range suggests hydrogenation of kerogen. Heat effects are still recognisable at a distance of three times the thickness of the intrusive body.
Introduction to the Ilímaussaq intrusion with a summary of the reported investigations
Authors: Bailey J.C , Larsen L.M , Sørensen H
Published: June 2021

The Ilimaussaq intrusion belongs to the late Precambrian Gardar province of South Greenland (fig. 1). The province ean be regarded as a cratogenic rift province with similarities to the East African rift system and the Oslo igneous provinee (Upton, 1974; Emeleus & Upton, 1976). The provinee consists of continental sandstones, and a variety of volcanic and plutonic igneous rocks many of which are alkaline. An important series of faults have influenced the position of the plutonic centres and presumably facilitated the rise of magma into the upper erust. The alkaline roeks evolved towards Si-rich melts such as comendites and alkali granites, and towards Si-poar melts such as phonolites and nepheline syenites. Both types of evolution are present at Ilimaussaq (fig. 2).
Helvine from the Ilímaussaq intrusion
Authors: Johnsen O , Bohse H
Published: June 2021

Beryllium minerals are widespread in the Ilimaussaq intrusion. At present, 13 different beryllium minerals have been identified. These are bertrandite, gelbertrandite, spherobertrandite, beryllite, chkalovite, leucophane, epididymite, eudidymite, sorensenite, tugtupite, genthelvite (Semenov, 1969; Engell et a!., 1971), semenovite (Petersen & Rønsbo, 1972) and now helvine. While epididymite occurs as an accessory in the alkali granite (Hamilton, 1964), chkalovite in pegmatites and hydrothermal veins (Engell et al., 1971; Semenov, 1969), all the other recorded beryllium minerals have been found in hydrothermal veins and alteration zones. Engell et al. (1971) reported that leucophane occurs as an accessory in the naujaite referring to the original description of Bøggild (1905). However, this description does not indicate whether the leucophane occurs as an accessory in unaltered naujaite or ifit is related to veins cutting naujaite as recorded by Semenov (1969).
An experimental study of the decomposition of steenstrupine in Na2CO3 solution
Authors: Konnerup-Madsen J , Holm P.M , Rose-Hansen J
Published: June 2021

This study is part of a more detailed investigation of the stability and the natural decomposition process of steenstrupine, initiated to help delineate the conditions during the later stages of solidification of the Ilimaussaq rocks. Interest in steenstrupine also arises from the potential importance regarding Kvanefjeld as a uranium ore reserve, steenstrupine being the most important uranium-bearing mineral in the Kvanefjeld area (Sørensen et al., 1974; Makovicky, 1981). Major emphasis has been placed on the decomposition of steenstrupine in Na2CO3 solution in the 200° to 600°C range at pressures up to 1000 bars.
Radioactive albitites bordering the Ilímaussaq complex: Agpat and Søndre Siorarssuit
Authors: Nielsen B.L
Published: June 2021

In 1957, during the early uranium prospecting history in the Ilimaussaq intrusive complex, rich radioactive mineralisation was discovered at Agpat, on the south coast of Tunugdliarfik (Sørensen, 1957). The following year a number of radioactive samples were analysed at Risø and they proved to be mainly rich in thorium. A few of them, however, contained uranium in the order of 1000 ppm. In 1962 a 200 m deep hole was drilled in black lujavrite at the plateau 300 metres above sea level close to Agpat. The hole did not intersect radioactive mineralisation comparable to what was found at the coast, and the Agpat mineralisation attracted no further attention. During 1978 a field excursion for uranium geologists visited Agpat as an example of radioactive mineralisation at the border zone of the alkaline complex. The importance of the mineralisation was emphasised as it represents an epigenetic radioactive enrichment different from the refractory steenstrupine mineralisation in lujavrites. Transport of radioactive elements along the border of the complex mayaiso result in mineralisation in the surrounding supracrustal rocks, and the observations made at Agpat point to the sandstone and lava series of the Eriksfjord Formation as an important exploration target.
Isotopic studies in the East Greenland Caledonides
(72°–74°N) – Precambrian and Caledonian ages
Authors: Rex D.C , Gledhill A.R
Published: June 2021

Rb-Sr isotopic studies on crystalline rocks from different rock units of the East Greenland Caledonides have given a number of isochron and 'errorchron' ages, as well as sets of inconclusive data. All the results are presented here as an illustration of the problems encountered, though previously published data is given in summary form. Eleven collections from Archaean - early Proterozoic rock units have given seven early Proterozoic Rb-Sr whole rock isochrons, while one set of data points plot about a 2450 m.y. reference line. Seven collections from metasediments of presumed middle to late Proterozoic age produced only one 'errorchron' of c. 1245 m.y., but data points from all the collections plot about a 1250 m.y. reference line. Six collections from a suite of 'older' granites gave four isochron ages of 1080, 1000,765 and 650 m.y. Eight collections from Caledonian granites gave four isochron ages, three 'errorchrons' and one mineral-whole rock isochron; the ages fall in the range 377-550 m.y.
Chromium-rich sapphirine from the Bjørnesund area, southern West Greenland and its bearing on the conditions of crystallisation of the Fiskenæsset anorthosite complex
Authors: Friend C.R.L , Hughes D.J
Published: June 2021

Windley et al. (1973) have postulated that the Fiskenæsset anorthosite complex crystalIised under conditions of high water vapour pressure. This hypothesis readily explains several of the distinct characteristics of the complex. In particular, the late precipitation of chromitite layers towards the top of the complex in the anorthosite sensu stricto (Ghisler & Windley, 1967) is not normally expected in large layered intrusions (Wager & Brown, 1968), and is explained because the early precipitation of chromite is suppressed under such conditions (Shiraki, 1966). AIso, Windley et al. (1973) have suggested that chromium amphibole, rather than pyroxene, was precipitated in association with the chromite as a direct consequence of the enrichment of volatiles in the upper parts of the intrusion.
Geophysical investigations offshore East Greenland - Project NAD
Authors: Andersen M.S , Larsen H.C , Risum J.B , Thorning L
Published: June 2021

The objective of project NAD is to map the continental margin of East Greenland, using high sensitivity aeromagnetic surveys and multichannel seismic refIection and marine gravity and magnetic surveys, and to prepare a preliminary petroleum geological assessment of the region on the basis of all the available data. The aeromagnetic surveys were carried out during 1979 (Larsen & Thorning, 1980). Marine geophysical surveys are planned for 1980, 1981 and 1982 (Risum, 1980). During 1980 a total of 2610 km of marine geophysical data were collected and the processing and interpretation of the aeromagnetic data acquired in 1979 was continued.
Modelling glacier hydrology in West Greenland
Authors: Braithwaite R.J
Published: June 2021

There is great interest in the possibility of using runoff in West Greenland for the generation of hydroelectric power. However, there is still very little information about hydrological conditions in the country. For example, measurements of runoff and glacier mass balance were only started at a few sites in the late 1970s by the GTO and GGU, respectively. This means that the choice of any particular basin for possibie exploitation must be made initially in the absence of direct field data. However, a solution to the problem is to develop a runoff model which can be applied to ungauged basins, i.e. a model which does not require field calibration. Such a model should give, as a minimum, estimates of the long-term mean runoff and the likely year-to-year variability. These estimates can be used to calculate hydropower potential and reservoir size at the feasibility or preliminary design stage of any proposed project. Naturally, if it is decided that a particular project is feasible, field measurements will then be started on-site for as many years as possibie so that the final design of the project can be based upon a series of real data.
Preliminary Rb-Sr age determinations from the North Greenland fold belt, Johannes V Jensen Land, with comments on the metamorphic grade
Authors: Springer N
Published: June 2021

This report presents the first Rb-Sr age determinations obtained on low-grade metasediments within the eastern part of the North Greenland fold belt. Samples were collected during the 1979 field mapping in eastem Johannes V. Jensen Land, the results ofwhich have been published elsewhere (Soper et al., 1980). Material selected for this study was taken from moderately folded rocks of the Polkorridoren Group and from the northem part of the fold belt where deformation is intense and sedimentary structures are rarely preserved (fig. 23). The principles and methods of isotopic dating of sedimentary rocks applied in this study have been treated in a recent paper by Clauer (1979).
Collection of samples for a reconnaissance geochemical survey from the Peary Land - Kronprins Christian Land region, North Greenland
Authors: Henriksen N
Published: June 2021

The regional geochemical reconnaissance survey carried out in 1978 and 1979 (Ghisleret al., 1979; Henriksen, 1980) was continued in 1980 with coIlection of stream sediments. The purpose was to provide information for an evaluation of the mineral potential and to obtain general geochemical data. As a new aspect of this activity, moss and soil samples were coIlected this year with the aim of evaluating plant material as a meaningful sampling media for future investigations of similar type. A special report on the investigations of the plant material is given by P. Mølgaard and E. Håkansson (this report).
Notes on Lower Palaeozoic flysch trace fossils from Hall Land and Peary Land, North Greenland
Authors: Pickerill R.K , Hurst J.M , Surlyk F
Published: June 2021

Seven ichnospecies are recorded from the Cambrian to Silurian turbidite succession of North Greenland.Two specimens are of particular importance as they provide new data on the palaeoenvironmental and stratigraphic range of their contained traces. Protopaleodictyon sp. is recorded for the first time from the Cambrian. The occurrence ofRhizocorallium sp. in deep basinal turbidites extends its occurrence in such environments back to the Ordovician and emphasises that caution must be exercised when utilizing the trace as an environmental indicator.
Some rugose corals from the Upper Permian of East Greenland
Authors: Fedorowski J
Published: June 2021

Rugose corals are described from the Upper Permian Foldvik Creek Formation of Hold with Hope and Wegener Halvø, East Greenland. Specimens described from the same area by H. W. Fliigel in 1973 have been re-examined and revised. Among three species identified, Allotropiochisma birkenmajeri n.sp. belongs to a new genus, into which all Fliige!'s species of Amplexizaphrentis are inc1uded. All new species of Calophyllum introduced by Fliigel are synonymised with Calophyllum profundum (Geinitz, 1842). The new subgenus Groenlandophyllum introduced by Fliigel is not accepted. The life habits of corals and their adaptations to a muddy bottom are reconstructed and discussed.
The Kap Leiper basic dyke and the age of the dolerites of Inglefield Land, North-West Greenland
Authors: Dawes P.R , Peel J.S , Rex D.C
Published: June 2021

This note reports field observations (PRD and JSP) and K/Ar whole-rock dating work (DeR) on dolerite intrusions from south-western Inglefield Land. The stratigraphic relationships of the intrusions and the significance of the K/Ar ages are briefly discussed.
The Qârusuk dykes: post-Nûk, pre-Qôrqut granitoid magmatism in the Godthåb region, southern West Greenland
Authors: McGregor V.R , Bridgwater D , Nutman A.P
Published: June 2021

The Qarusuk dykes are minor intrusions of granitic and trondhjemitic gneiss emplaced in the Godthåb region between 2700 and 2600 Ma ago. They post-date the Nuk gneisses and their subsequent regional deformation and metamorphism but pre-date the essentiaUy post-tectonic Qôrqut granite complex. They are associated in time and commonly in place with intense ductile deformation concentrated in distinct belts along which there was considerable movement of fluids accompanied by retrogression of earlier mineral assemblages. Outside the Godthåb district dykes of similar character post-date the regional c. 2800 Ma granulite facies metamorphism. The dykes are siliceous with low Fet + Mg0 and high Na20 + K20. Variation in Na2O/K2O is at least in part attributed to exchange between magma and percolating fluids. Non-magmatic controls are thought to affect trace element (including REE) and isotopic compositions. The overall chemical character is consistent with derivation by partial melting of sialic rocks associated with the influx of hydrous fluids associated with shear belt formation.
Petrography and geochemistty of amphibolites from the Nordre Strømfjord area in the central part of the Nagssugtoqidian of West Greenland
Authors: Mengel F.C
Published: June 2021

The microstructures and general occurrence of orthopyroxene in the investigated amphibolites indicate that the rocks have been strongly deformed under granulite facies conditions. Microstructural features also suggest that high grade metamorphism in some cases outlasted deformation. The amphibolites show chemical resemblance to tholeiites from tectonic settings around active plate margins. Since chemical differentiation trends are not obvious, the results are insufficient to show that all the Nordre Strømfjord amphibolites originated in the same magmatic environment. The Nordre Strømfjord amphibolites may be Archaean or Proterozoic in age.
Processing and interpretation of aeromagnetic data in The Geological Survey of Greenland
Authors: Thorning L
Published: June 2021

This report gives a brief, general description of a system of computer programs for the processing, interpretation and presentation of mainly aeromagnetic data. The system consists of data bases for aeromagnetic and accessory data, programs for the correction and compilation of magnetic data, a contouring package with some special features and a package of interpretation programs.
Anatectic origin of mid-Proterozoic granite dyke in the Isukasia area, West Greenland Pb-Pb and Rb-Sr isotope evidence
Authors: Kalsbeek F , Taylor P.N
Published: June 2021

It was found some time ago on the evidence of mineral-isotope relations that the early Archaean gneisses of the Godthåbsfjord region in West Greenland were mildly reheated during the mid-Proterozoic at c. 1600-1700 Ma (Pankhurst et al., 1973; Baadsgaard et al., 1976). A Rb-Sr whole-rock isotope study of a fine-grained granitic dyke from the Isukasia area indicated that this dyke was formed 1610 ± 130 Ma ago by anatexis of early Archaean rocks (Kalsbeek et al., 1980). This suggested that temperatures not less than c. 650°C were reached at depth, at least locally, within the Archaean craton during the Proterozoic. We have made a Pb-Pb isotope study of this dyke to check and amplify this conclusion. The field relations, petrology and chemistry of the dyke have been described in the earlier paper.
Glaciology related to potential hydroelectric power for Greenland towns
Authors: Weidick A , Thomsen H.H
Published: June 2021

There is increasing interest in the possibility of supplying towns with hydroelectric power from neighbouring basins. To meet this interest the project 'Vandkraftundersøgelser for bynære bassiner' was carried out at the localities listed in Table 4 and shown in figure 37. The project has been in operation since 1980 as a joint project of Greenland Fisheries Investigations and the Greenland Technical Organization; in 1982 GGU commenced glaciological work on the project. The project is due to terminate in March 1984. The effect of glaciers upon the discharge from the individual basins must vary greatly according to glacier cover but it can rarely be neglected and is of paramount importance for basins receiving meltwater from the Inland Ice.
Glaciological activities in the Johan Dahl Land area, South Greenland, as a basis for mapping hydropower potential
Authors: Clement P
Published: June 2021

Along the margin of the Inland Ice several basins have been proposed as possibie areas for hydropower production (ACG/VBB, 1975). ane of the most promising localities was (and still is) the Nordbosø basin in Johan Dahl Land, South Greenland. With a mean annual runoff from Nordbosø of 140 million m3 and a powerhead of 640 m, an annual production of approximately 200 GWh would result (ACG/VBB, 1980). In the Nordbosø basin Nordbogletscher is the main water source, as ablation from the glacier contributes with 60-70% of the annual runoff. An understanding of the glaciological conditions including mass balance, glacier dynamics, drainage of ice-dammed lakes, and climate-ablation relationships, is essential for the whole project. In a joint project with the Greenland Fisheries Investigations (environmental studies) and the Greenland Technical Organization (engineering and hydrological studies), GGU is responsibie for the glaciological work, and in the 1983 field season the glaciological investigations were continued for the sixth year. The project is supported by the Danish Ministry of Energy.
Vendian stratigraphy and sedimentology of the East Greenland Caledonides
Authors: Hambrey M.J , Moncrieff A.C.M
Published: June 2021

The present two-year programme 1984-1985 on the Vendian Tillite Group in central East Greenland follows comprehensive investigations on similar sequences in eastern Svalbard. The project aims to establish through Vendian time the disposition of land masses and oceans in relation to the East Greenland depositional environment, and to erect detailed stratigraphic correlations with other parts of the North Atlantic - Arctic region. This is important for understanding the tectonic evolution of the region prior to the opening of the Iapetus Ocean. The work is a collaborative venture involving N. Abrahamsen (University of Aarhus, palaeomagnetism), G. Bylund (University of Lund, palaeomagnetism), A. H. Knoll (Harvard University, biostratigraphy), A. M. Spencer (Statoil, sedimentology), K. Swett (University of Iowa, sedimentology of bounding rock units) and G. Vidal (University of Lund, biostratigraphy). The authors were accompanied in the 1984 field season by Bylund and Vidal who undertook extensive sampling of the Late Proterozoic to Early Palaeozoic sequence.
Precambrian crystalline basement at the head of Victoria Fjord, North Greenland
Authors: Henriksen N , Jepsen H.F
Published: June 2021

Precambrian granites and gneisses outcrop below late Proterozoic and Lower Cambrian sediments in a small area at the margin of the Inland Ice. The exposed crystalline rocks comprise orthogneisses with scattered amphibolite bands, and occasional horizons of metasediments. The rocks are folded, somewhat migmatised and metamorphosed under amphibolite facies conditions. Samples for Rb-Sr whole rock and Zr isotopic age determinations have been collected.
Geology of central and eastern North Greenland
Authors: Higgins A.K
Published: June 2021

A historical review of geological research in North Greenland is followed by a summary of the main results of the 1978-80 GGU expeditions to the region. New outcrops of Archaean and early Proterozoic crystalline rocks are recorded only as xenoliths in dykes and volcanic centres. A revised stratigraphy is applied to the middle Proterozoic Independence Fjord Group sandstones, while petrographic and isotopic studies have been made of the cross-cutting Midsommersø dolerites and the overlying Zig-Zag Dal Basalt Formation. No convincing evidence has been found of a Carolinidian orogenic episode separating these units from succeeding late Proterozoic sedimentary sequences. Lower Palaeozoic sediments dominate North Greenland and are divided into southern shelf and northern trough successions; new or revised stratigraphies are now applied in both settings. The shelf-trough boundary can be shown to have moved south with time, and a major early Silurian expansion of the trough is related to shelf subsidence and a new phase of turbidite deposition derived from the rising East Greenland Caledonian mountains. Devonian - Middle Carboniferous (Ellesmerian) deformation brought deposition to a close and created the North Greenland fold belt, in which deformation intensity and metamorphic grade increase northwards. Thin-skinned thrusting in association with west or south-facing folds is important in southern areas; this is one of the main differences in interpretation compared to earlier work in the fold belt. New outcrops of post-ElIesmerian sediments (Wandel Sea Basin) have mainly been recorded as fault or thrust bounded sequences; a new stratigraphy is applied to the Wandel Sea Basin succession. Cretaceous - Tertiary events include a suite of volcanic centres, dyke swarms, the Kap Washington Group volcanics, and faults and thrusts of Tertiary (Eurekan) age; all have been studied anew, as have the Quaternary deposits.
Initiation of petroleum exploration in Jameson Land, East Greenland
Authors: Surlyk F , Piasecki S , Rolle F
Published: June 2021

Active petroleum exploration in East Greenland is of fairly recent date and was preceded by a much longer history of scientific work and mineral exploration. The discovery in 1948 of lead-zinc mineralisation at Mestersvig resulted in the formation of Nordisk Mineselskab AIS in 1952. In the beginning of the seventies Nordisk Mineselskab initiated cooperation with the American oil company Atlantic Richfield (ARCO) in order to undertake petroleum exploration in Jameson Land. The Jameson Land basin contains a very thick Upper Palaeozoic - Mesozoic sedimentary sequence. Important potential source rocks are Lower Permian lacustrine mudstone, Upper Permian black marine mudstone, Middle Triassic dark marine limestone, uppermost Triassic black marginal marine mudstone, Lower Jurassic black mudstone and Upper Jurassic deep shelf black mudstone. Tbe Upper Permian mudstone, which is the most promising source rock, is immature to weakly mature along the western basin margin and is expected to be in the oil or gas-generating zone when deeply buried in the central part of the basin. Potential reservoir rocks include Upper Permian bank and mound limestones, uppermost Permian fan delta sandstones, Lower Triassic aeolian and braided river sandstones, and Lower, Middle and Upper Jurassic sandstones. The most important trap types are expected to be stratigraphic, such as Upper Permian limestone bodies, or combination stratigraphic-structural such as uppermost Permian or Lower Triassic sandstones in Early Triassic tilted fault blocks. In the offshore areas additional play types are probably to be found in tilted Jurassic fault blocks containing thick Lower, Middle and Upper Jurassic sandstones and lowermost Cretaceous sandstones and conglomerates. The recognition of the potential of the Upper Permian in petroleum exploration in East Greenland has important implications for petroleum exploration on the Norwegian shelf.
A decade of geophysical surveying in Greenland
Authors: Thorning L
Published: June 2021

A review is given of aeromagnetic, radiometric, seismic and gravimetric surveys over Greenland and adjacent offshore waters carried out during the decade 1975-85. The determination by aeromagnetic surveys of major boundaries in the Precambrian craton in ice-free areas and under the Inland Ice is discussed.
The age of the Danmarks Fjord Member, eastern North Greenland
Authors: Smith M.P , Peel J.S
Published: June 2021

Conodonts of late Early Ordovician age (late Canadian, early-middle Arenigian) are identified from the Danmarks Fjord Member of the Wandel Valley Formation at its type locality near the head of Danmark Fjord, eastern North Greenland. The identifications confirm recent suggestions of an Early Ordovician age for the member made on lithostratigraphic grounds, and refute earlier opinions that the dolomite was probably of Early Cambrian age.
Notes on the trilobite faunas of the Henson Gletscher Formation (Lower and Middle Cambrian) of central North Greenland
Authors: Blaker M.R
Published: June 2021

Cambrian trilobite faunas collected from a 90 m section of the Henson Gletscher Formation in southern Freuchen Land are described. Nineteen species are discussed, six of which are new. Aspects of the ontogenies of two species of Ogygopsis Walcott, 1889 are outlined, and initial correlations of Ogygopsis made with North America and Siberia. The first occurrenees outside China of species assigned to Arthricocephalus Bergeron, 1889 and Changaspis Lee, 1963 are reported. Problems of ptychopariid classification for the early Cambrian are covered, and proposals for a new approach to understanding ptychopariid relationships are outlined.
Lithostratigraphy and depositional history of Upper Ordovician - Silurian shelf carbonates in central and western North Greenland
Authors: Sønderholm M , Harland T.L , Due P.H , Jørgensen L.N , Peel J.S
Published: June 2021

Field work in 1985 revealed that the Aleqatsiaq Fjord Formation (Ordovieian-Silurian) can be traced from Washington Land to westernmost Peary Land, and that a tripartite subdivision of the formation can be achieved throughout most of this area (units AFI-3). Five mapping units (WGI-5) were recognised within the overlying Washington Land Group of Silurian age between Hall Land and westernmost Peary Land. These are described and correlated with sequenees in Washington Land and elsewhere in Peary Land. Deposition was uniform in the lower part of the sequenee (units AFI-WG1) throughout the mapped area. Lateral lithologieal variation in the upper part (units WG2-5) refleets differential regional subsidenee, the presence of intrashelf mounds and the development of huge mound complexes along the shelf margin.
The Cambrian Henson Gletscher Formation: a mature to postmature hydrocarbon source rock sequence from North Greenland
Authors: Christiansen F.G , Nøhr-Hansen H , Nykjær O
Published: June 2021

During the 1985 field season the Cambrian Henson Gletscher Formation in central North Greenland was studied in detail with the aim of evaluating its potential as a hydrocarbon source rock. The formation contains organic rich shale and carbonate mudstone which are considered to be potential source rocks. These are sedimentologically coupled with a sequence of sandstones and coarse carbonates which might be potential reservoir rocks or migration conduits. Most of the rocks exposed on the surface are, however, thermally mature to postrnature with respect to hydrocarbon generation, leaving only few chances of finding trapped oil in the subsurface of the area studied in detail.
Archaean age and Proterozoic metamorphic overprinting of the crystalline basement at Victoria Fjord, North Greenland
Authors: Hansen B.T , Kalsbeek F , Holm P.M
Published: June 2021

Zircon U-Pb and Rb-Sr whole-rock isotope data show that the crystalline rocks at the head of Victoria Fjord, North Greenland, have Archaean ages (c. 3000 Ma), but that strong disturbance of the isotope systems has taken place later. K-Ar analyses on hornblende show that the area underwent a phase of high-grade metamorphism during the Proterozoic, probably around 1850 Ma.
Studies on the onshore hydrocarbon potential in East Greenland 1986-87: field work from 72° to 74°N
Authors: Marcussen C , Christiansen F.G , Larsen P.-H , Olsen H , Piasecki S , Stemmerik L , Bojesen-Koefoed J , Jepsen H.F , Nøhr-Hansen H
Published: June 2021

A study of the onshore hydrocarbon potential of central and northem East Greenland was initiated in 1986. Field work was carried out from early July to mid August covering the region between Kong Oscar Fjord and Kejser Franz Joseph Fjord (fig. 1). In 1987 field activities will continue further to the north, eventually reaching Danmarkshavn (77°N). The programme is a continuation of the 1982-83 investigations in Jameson Land (Surlyk, 1983; Surlyk et al., 1984a) and is part of a regional programme comprising petroleum geological studies of all sedimentary basins in Greenland (Larsen & Marcussen, 1985; Larsen, 1986). The aim of the two-year field study followed by laboratory analyses is: (1) to study the presence and distribution of potential hydrocarbon source rocks in the region; (2) to evaluate the thermal history and maturity pattern of the region including the thermal effect of Tertiary intrusions and volcanics; (3) to make a stratigraphic, sedimentological and tectonic study of the region with special emphasis on subsidence history, reservoir formation and potential hydrocarbon traps.
Continued glaciological work north-east of Jakobshavn, West Greenland
Authors: Thomsen H.H
Published: June 2021

Glaciological investigations were carried out on the Inland Ice north-east of Jakobshavn. The work is part of the hydropower investigations at Pâkitsoq on a drainage basin proposed for a local hydropower project. The work was started in 1982, when stakes for measuring mass balance were drilled into the ice. So far the investigations have included mass balance measurements, photogrammetric and satellite mapping, ice-thickness mapping, stable isotope studies, simulation of runoff and ice dynamics (Reeh, 1983; Thomsen, 1983, 1984, 1985; Braithwaite & Thomsen, 1984; Thomsen & Braithwaite, 1985; Thomsen & Reeh, 1986; Reeh & Thomsen, 1986a; Thorning et aL, 1986).
A new genus of nevadiid trilobite from the Buen Formation (Early Cambrian) of Peary Land, central North Greenland
Authors: Blaker M.R
Published: June 2021

A new genus of nevadiid trilobite is described from the Lower Cambrian of Peary Land, central North Greenland, from the same horizon and locality from which a non-skeletised fauna has been recently reported. The new genus, BuenelIus, is tentatively assigned to the Nevadiidae Hupe, 1953, and comparisons are made with the genera Nevadia Walcott, 1910, Nevadella Raw, 1936, Callavia Matthew, 1897, Holmia Matthew, 1890 and Kjerulfia Kiaer, 1917.
Geological photogrammetry using oblique aerial photographs
Authors: Dueholm K.S , Pedersen A.K
Published: June 2021

Large areas in Greenland are covered by oblique aerial photographs, taken with 23 x 23 cm2 photogrammetric cameras of the type 'EagIe' between 1948 and 1953. Though almost all of Greenland is now covered by modem vertical photographs, the oblique photographs still represent a valuable alternative source of geological information because of the perspective at right angles to the mountain side. So far, geologists have only been able to use the oblique photographs for visual interpretation. New photogrammetric instruments like the Kem DSR U/GPl Analyticai Plotter at the Institute of Surveying and Photogrammetry,the Teehnieal University of Denmark, make it possibie for geologists to map precisely from oblique photographs. This report deseribes an experiment where such photographs have been used for mapping of steep mountain sides for the production of geological maps, cross-seetions and perspective views. Earlier results are reported by Dueholm & Garde (1986) and Heinesen (1987).
Scheelite in Malene supracrustals of the Ivisârtoq area, southern West Greenland
Authors: Appel P.W.U
Published: June 2021

In 1982 the first traces of scheelite were found in the Godthåbsfjord area in heavy mineral concentrates from stream sediments. The same year the first in situ scheelite occurrences were found. In the folIowing year a stream-sediment sampling programme was carried out in the area and in the area to the south. This programme demonstrated that scheelite is a frequent constituent of the 3800 m.y. old Isua supracrustal rocks and in the 3300 to 3000 m.y. old Malene supracrustals, whereas the gneisses in the Nuuk/Godthåb area are barren. The Malene supracrustal rocks, which form extensive outcrops, are the larger of the two supracrustal belts, and outcrops are found scattered over an area of at least 35000 km2. During the field season of 1986 stream sediment samples were collected in the Ivisârtoq area of the inner Godthåbsfjord region, and they proved to contain high amounts of scheelite. It was thus decided to carry out field work with ultra-violet light, but early snow precipitation prevented any field work. During the field season the folIowing year, another attempt was made to carry out field work with ultra-violet light in the lvisârtoq area.