scholarly journals The stratigraphy of the marine Quaternary deposits in West Greenland

1950 ◽  
Vol 2 ◽  
pp. 1-142
Author(s):  
D Laursen

The present report deals with the Quaternary marine deposits in West Greenland. The area in question extends from Kugssineq, Svartenhuk peninsula, in the north to the settlement of Sukkertoppen in the south. The field investigations for the paper have been made partly in 1939, partly in 1946, last-mentioned year under the auspices of Grønlands Geologiske Undersøgelse (abb. G.G.U., i. e. Geological Survey of Greenland). All localities visited are described with added lists of the collected shells. On the basis of the investigations made it will be demonstrated that the stratigraphy of the layers at Orpigsôq drawn up by Jensen and Harder in 1910 (30) is applicable to all the area investigated. Furthermore a detailed examination is made of the petrographic structure, the content af shells, and the levels of the various horizons, a discussion of a few errors, and ultimately an attempt at a correllation of the Quaternary marine layers of Greenland with the corresponding postglacial layers of Iceland, Norway, and Denmark.

1983 ◽  
Vol 115 ◽  
pp. 49-56
Author(s):  
B Chadwick ◽  
M.A Crewe ◽  
J.F.W Park

The programme of field investigations in the north of the Ivisartoq region begun in 1981 by Chadwick & Crewe (1982) was continued in 1982. Julia Park began mapping the Taserssuaq granodiorite, its host rocks and the Ataneq fault in the north-west. Dur team was joined by D. Bellur, Geological Survey of India, nominally as an assistant. In this report we present only summary notes of new findings relevant to the interpretation of the geometry and chronology of this segment of the Archaean crust in southern West Greenland. We use the established terminology for the Archaean rocks of the Godthåbsfjord region.


Author(s):  
Niels Henriksen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Henriksen, N. (1998). North-East Greenland 1997–1998: a new 1:500 000 mapping project in the Caledonian fold belt (72°–75°N). Geology of Greenland Survey Bulletin, 180, 119-127. https://doi.org/10.34194/ggub.v180.5095 _______________ The Geological Survey of Denmark and Greenland (GEUS) continued in 1997 the systematic geological mapping programme for the 1:500 000 regional map series, with initiation of field work on sheet no. 11, which covers part of North-East Greenland. Of the 14 planned map sheets at 1:500 000 which will cover all of Greenland, 11 have been published, and one additional sheet for which field work has been completed is under compilation. Only two areas of Greenland are not yet covered by map sheets of this series: part of North-West Greenland (sheet no 6) and the target for the present project in North-East Greenland (sheet no. 11). The field work for the latter sheet is planned for two seasons, with the first season completed in 1997 and the second and final season to follow in 1998. The map sheet (no. 11) covers the region between Kong Oscar Fjord and the Stauning Alper in the south (72°N) and Kuhn Ø and Grandjean Fjord in the north (75°N, Fig. 1). The western part of this region is dominated by crystalline complexes of the East Greenland Caledonian fold belt. A post-Caledonian sequence of Upper Palaeozoic and Mesozoic sediments and Tertiary plateau basalts and intrusions covers the eastern part of the region. This article focuses on the Caledonian geology, whereas results from the work in the post-Caledonian sediments are described in the article by Stemmerik et al. (1998, this volume). The new Survey work for map sheet 11 represents a reinvestigation of areas extensively studied by geologists of Lauge Koch’s expeditions to East Greenland (1926–58), the principal results of which were compiled by John Haller for the 1:250 000 map sheets covering the region 72°–76°N (Koch & Haller 1971) and incorporated into an impressive regional description of the East Greenland Caledonides (Haller 1971). The Scoresby Sund region to the south of latitude 72°N and the Dove Bugt region to the north of latitude 75°N have already been investigated by the Geological Survey of Greenland (Henriksen 1986, 1997; Higgins 1994) as part of the present ongoing 1:500 000 regional mapping programme. The 1997–1998 mapping project will fill the last remaining gap in the Survey’s 1:500 000 coverage of North-East Greenland. All of North-East Greenland is covered by a set of wide angle black and white vertical aerial photographs taken in the period 1978–87 from an altitude of c. 14 km. On the basis of these aerial photographs and ground control points established by Kort- og Matrikelstyrelsen (National Survey and Cadastre – formerly the Geodetic Institute), new topographical maps of the entire region 72°–75°N, at a scale of 1:100 000, with 100 m contours, are being drawn at the Survey and will serve as a basis for the field investigations and the subsequent geological map compilations. Drawing of the topographic maps in the Survey´s photogrammetric laboratory is combined with photogeological interpretation both prior to and following the field investigations. In addition to establishing a general overview of the regional geology, the project includes activities aimed at supplementing knowledge of the economic potential of the region, in respect to both minerals (Harpøth et al. 1986) and hydrocarbons (Christiansen et al. 1992; Stemmerik et al. 1997). The field work co-ordinated by the Survey included co-operation with a geophysicist from the Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven, who undertook rock magnetic investigations to facilitate interpretation of an AWI aeromagnetic survey, and four Norwegian sedimentologists from Saga Petroleum whose work was integrated with a Survey group working with Mesozoic sediments (Stemmerik et al. 1998, this volume). Logistic support was also given to three groups of geologists from the University of Oslo and three geologists from Massachussetts Institute of Technology, with whom agreements on scientific co-operation had been arranged in advance. Some aspects of the project are based on funding from the Danish National Science Foundation and Carlsberg Foundation, with support for special research topics concerning the pre-Caledonian basement terrain, Caledonian metamorphism, and studies of Upper Proterozoic carbonate sediments. The field investigations in 1997 were carried out during a seven week field season between early July and late August with participation of a total of 38 persons, including 32 geologists (Henriksen 1998). The work was supported by two helicopters and a small, fixed wing, Twin Otter aircraft, which operated from Mestersvig, a former airport which is kept open for limited special operations by the military sledge patrol Sirius. The GEUS group benefitted substantially from base facilities at Mestersvig, organised and manned by the Danish Polar Center (DPC). Transport between Mestersvig and Denmark was carried out by the Royal Danish Air Force (RDAF) using a C-130 Hercules aircraft.


1981 ◽  
Vol 140 ◽  
pp. 1-107
Author(s):  
L.A Símonarson

Field relations and the composition of the Quaternary molluscan and barnacle faunas at Pátorfik, Kûtsiaq and Sarfâgfik on the north coast of Nûgssuaq, West Greenland, are described. The marine Quaternary deposits at Pátorfik are older than 35 000 years. The lower part of the deposits seems to represent a prodelta environment, whereas the middle and upper parts apparently correspond to a delta slope. The rich fauna and the field relations differ essentially from what we know from other localities in Greenland where Late Wisconsian or Holocene marine fossiliferous deposits have been found. The faunal composition indicates prevailing water temperatures during deposition similar to those at the boundary between the arctic and boreal faunal regions today and somewhat higher than those in Umanak Fjord at present. It is suggested that the Pátorfik deposits were formed during the last interglacial stage (Sangamon/Eemian). The marine beds at Kûtsiaq and Sarfâgfik are of Early Holocene ages and apparently represent delta deposits.


Author(s):  
Feiko Kalsbeek ◽  
Lilian Skjernaa

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kalsbeek, F., & Skjernaa, L. (1999). The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 103-112. https://doi.org/10.34194/ggub.v181.5118 _______________ The 2800 Ma Atâ intrusive complex (elsewhere referred to as ‘Atâ granite’ or ‘Atâ tonalite’), which occupies an area of c. 400 km2 in the area north-east of Disko Bugt, was emplaced into grey migmatitic gneisses and supracrustal rocks. At its southern border the Atâ complex is cut by younger granites. The complex is divided by a belt of supracrustal rocks into a western, mainly tonalitic part, and an eastern part consisting mainly of granodiorite and trondhjemite. The ‘eastern complex’ is a classical pluton. It is little deformed in its central part, displaying well-preserved igneous layering and local orbicular textures. Near its intrusive contact with the overlying supracrustal rocks the rocks become foliated, with foliation parallel to the contact. The Atâ intrusive complex has escaped much of the later Archaean and early Proterozoic deformation and metamorphism that characterises the gneisses to the north and to the south; it belongs to the best-preserved Archaean tonalite-trondhjemite-granodiorite intrusions in Greenland.


1889 ◽  
Vol 6 (9) ◽  
pp. 425-427
Author(s):  
Alexander Somervail

On De La Beche's Geological Survey Map of Cornwall are three colours representing the associated rocks at, and on each side of the Manacle Point. The Point itself and for a considerable distance south of it is represented as a greenstone. Partially encased in the greenstone and to the south of it is gabbro, which forms the main mass of this rock in the Lizard district. On the north side of the greenstone which forms the extreme south wall of Porthonstock Cove is hornblende-schist, which with some serpentine and other rocks terminates against the killas, or slates near Porthalla.Several observers with seeming good reason have drawn attention to the fact that the greenstone as represented on the map is made to cover much too large an area to the south, and that any one walking from this direction, or the reverse, finds gabbro where the former rock was expected to occur.


1985 ◽  
Vol 24 (95) ◽  
pp. 327-340
Author(s):  
Francis Thompson

The Irish land act of 1881, it is generally agreed, was a victory for the Land League and Parnell, and nationalist policy with regard to the act and the attitude of southern tenants towards it have been many times subjected to detailed examination by historians of this period. In these analyses of the events of 1880–81, however, little reference is normally made to the part played by the different parties and interests in the north of the country. It is often assumed, for example, that the Ulster tenants held aloof from the campaign for reform, lending no more than occasional vocal support to the agitational efforts of tenants in the south and west. Indeed, they were later excoriated by William O'Brien, Michael Davitt and others not only for giving no support to the land movement but also for sabotaging Parnell's policy of testing the 1881 act by precipitately rushing into the land courts to take advantage of the new legislation: ‘that hard-fisted body of men, having done nothing themselves to win the act, thought of nothing but turning it to their own immediate use, and repudiating any solidarity with the southern and western rebels to whom they really owed it’. If, however, northern tenants were harshly judged by nationalist politicians in the years after 1881, the part played by the northern political parties in the history of the land bill has been either ignored or misunderstood by historians since that time. The Ulster liberals, for example, are rarely mentioned, the implication being that they made no contribution to the act even though it implemented almost exactly the programme on which they had been campaigning for much of the previous decade. The northern conservatives, on the other hand, are commonly seen as leading opponents of the bill, more intransigent than their party colleagues in the south, ‘quick to denounce any weakening of the opposition’ to reform, and ‘determined to keep the tory party up to the mark in defending the landlord interest’


1879 ◽  
Vol 6 (4) ◽  
pp. 154-160
Author(s):  
J. Nolan

The rocks I propose to describe in this paper belong to that great metamorphic series which occupies so large a portion of the north of Ireland, extending over most of the counties Tyrone, Londonderry, and Donegal. For the present I shall confine, my observations principally to that portion of them situated about the central parts of Tyrone, from the vicinity of Omagh eastwards and north-eastwards towards Slieve Gallion. This district has “Geological Report on Londonderry and parts of Tyrone and Fermanagh”; but as, during the progress of my work for the Geological Survey, I have had opportunities for a very detailed examination of it, I beg, briefly, to offer some further remarks and conclusions.


1970 ◽  
Vol 28 ◽  
pp. 23-25
Author(s):  
A Weidick ◽  
N.W Ten Brink

The area investigated during 1969 is located approximate1y between 66° 10' and 67° 30' N, and 50° and 52° W, the eastem half of the West Greenland ice-free land area transected by Søndre Strømfjord. The principal objectives of the work were to map and describe the glacial and emerged marine deposits for a Quatemary map at 1:500 000 scale, and to collect material for establishing a radiometric chronology of former ice-margin positions and sea levels. In order to study as large an area as possible, the investigations north of Søndre Strømfjord and Sondrestrom Airbase were conducted by A. Weidick, the area south of this by N. W. Ten Brink.


2008 ◽  
Vol 54 (184) ◽  
pp. 131-144 ◽  
Author(s):  
Bea Csatho ◽  
Toni Schenk ◽  
C.J. Van Der Veen ◽  
William B. Krabill

AbstractRapid thinning and velocity increase on major Greenland outlet glaciers during the last two decades may indicate that these glaciers became unstable as a consequence of the Jakobshavn effect (Hughes, 1986), with terminus retreat leading to increased discharge from the interior and consequent further thinning and retreat. To assess whether recent trends deviate from longer-term behavior, we measured glacier surface elevations and terminus positions for Jakobshavn Isbræ, West Greenland, using historical photographs acquired in 1944, 1953, 1959, 1964 and 1985. These results were combined with data from historical records, aerial photographs, ground surveys, airborne laser altimetry and field mapping of lateral moraines and trimlines, to reconstruct the history of changes since the Little Ice Age (LIA). We identified three periods of rapid thinning since the LIA: 1902–13, 1930–59 and 1999–present. During the first half of the 20th century, the calving front appears to have been grounded and it started to float during the late 1940s. The south and north tributaries exhibit different behavior. For example, the north tributary was thinning between 1959 and 1985 during a period when the calving front was stationary and the south tributary was in balance. The record of intermittent thinning, combined with changes in ice-marginal extent and position of the calving front, together with changes in velocity, imply that the behavior of the lower parts of this glacier represents a complex ice-dynamical response to local climate forcings and interactions with drainage from the interior.


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