Note “Paleocene” or “Palaeocene”

There seems to be some doubt as to which of the spellings “Paleocene” or “Palaeocene” should be used in manuscripts submitted for publication in Europe, while in North America the spelling “Paleocene” is standard. The latter is not surprising, as in North America the prefix paleo- is also used in terms such as Paleozoic, paleomagnetism, etc. In Europe, however, the prefix derived from the Greek palaios (= ancient, old) is generally spelt “palaeo-”, as for example in palaeontology...................</jats:p

The Eqaloqarfia layered dyke, Nunarssuit, South Greenland

The layering in the Eqaloqarfia dyke defines a synform running parallel to the length of the dyke, with a maximum inward dip of the limbs of 36°. The layering is developed in the lower part of a trough of feldspar-phyric gabbro in an otherwise normal dolerite. Homogeneous dolerite both underlies and forms a border to the gabbro. A perpendicular feldspar layer occurs in places at the border between the dolerite and the gabbro: in this layer unzoned plagioclase laths have grown at steep angles to the margin of the dolerite. The gabbro is characterised by platy feldspars up to 2 cm wide which are set in a doleritic matrix. The cores of the plates have a composition in the range An57-64 and constitute an early generation of plagioclase which crystallised at depth. The second generation of plagioclase, forming the shells of these plates and the smaller crystals in the matrix, began crystallising with a composition An69-75, zoning down to An30-40 at the margins of crystals. The layering comprises olivine-rich horizons alternating with layers of the feldspar-phyric gabbro. There is no graded bedding in the olivine-rich layers, nor is there any lamination or packing of the feldspar plates in the gabbro. Intermittent settling of olivine during the early slow crystallisation in the gabbro trough is regarded as the cause of the layering. A slight cryptic variation is shown by the second generation of plagioclase. In view of the lack of evidence for either magmatic currents or feldspar settling, it is thought that diffusion can contribute more to differentiation than is usually allowed. Diffusion is also required to explain the lack of zoning in the plagioclase laths of the perpendicular feldspar layer.</jats:p

Mapping in the Umanak district, central West Greenland

Publication of 1:100000 geological maps from central West Greenland has reached a stage when five maps have been issued, and a sixth is in an advanced stage of preparation. However, until the summer of 1978, one of the most readily accessibie areas in this part of Greenland - that around and east of Umanak - had not been mapped in greater detail than required for the production of the 1:500000 sheet Søndre Strømfjord - Nfigssuaq. Consequently it was decided that the writer, together with a group of senior students from the Institute of General Geology, Copenhagen University, should remap the area over a period of three seasons with a view to preparation of the 1:100000 sheet 70 V.2 Nord - Agpat. This work was started in the 1978 field season when in all four geologists, each with an assistant, were in the fieid. The areas in which the individual geologists worked are shown in fig. 9. Mapping was carried out on enlargements of vertical aerial photographs provided by the Geodetic Institute, the 1:50000 topographic sheets being unsuitable for detailed mapping. Logistic support was provided by the GGU cutter N. V. Ussing, with Flemming Nielsen as skipper.</jats:p

Reinvestigation of the Cretaceous boundary fault in Sarqaqdalen, Nûgssuaq, central West Greenland

A reinvestigation of the major fauIt in Sarqaqdalen was undertaken in 1988 in response to a renewed interest in the style and timing of the whole fault system that marks the easterly limit of Cretaceous sediments in central West Greenland. This interest stems in turn from the reinterpretation ofseismic lines from the 1970s that has recently been initiated in GGU (Chalmers, 1988; 1989). Dating of seismic sequences isinfiuenced greatly by what ean be learnt from the nearest onshore outcrops, for example proven unconformities in onshore sequences, and demonstrable relationships between sedimentation and fauIt movements.</jats:p

The Puklen intrusion, Nunarssuit, SW Greenland, a preliminary account of a new Gardar intrusion

The Puklen Intrusion is a small elongate complex situated in Nunarssuit, SW Greenland. It was emplaced in Ketilidian basement, and cut off and hornfelsed Gardar dolerites. The four component members of the intrusion are augite syenite, quartz syenite, soda granite and granophyre, emplaced in that order. It seems that these components represent a differentiation sequence from augite syenite. This is of interest owing to the widespread occurrence of augite syenite (with fayalite) in the Gardar province of SW. Greenland.</jats:p

The development of thin thrust sheets and basement-cover sandwiches in the southern part of the Rinkian belt, Umanak district, West Greenland

At the southern margin of the Rinkian belt, West Greenland, it can be demonstrated that the Lower Proterozoic Marmorilik Marble Formation, which was deposited unconformably on a gneiss basement, has been squeezed and stretched into a thin recumbent syneline and overridden by the basement over an area of more than 1000 km2. Aseeond supracrustal cover unit, seen now as a thin mylonitic biotite schist horizon, occurs at a slightly higher structural level, and marks the site of another thrust along which the gneiss basement has overridden its supracrustal cover. The demonstration that a superficially simple sequence consisting of concordant layers of different gneiss types and supracrustal rocks is in faet a pile ofthrust sheets, has important implications for the interpretation of both West Greenland and other Precambrian areas.</jats:p

1990 – a year of change in hydrocarbon-geological activities at the Geological Survey of Greenland

The background for the Geological Survey of Greenland's (GGU's) hydrocarbon-geological activities was briefly outlined in the Report of Activities for 1989 (Stemmerik et al., 1990a). In that report it was intimated that a shift of emphasis in hydrocarbon-geological activities was under way, not only from onshore to offshore but also from East to West Greenland (Fig. 1). 1990 saw this shift take more concrete form. Thus field work in East Greenland was limited to minor projects that focus on diagenesis and reservoir properties of siliciclastic sediments. All other projects onshore East Greenland have reached or are entering into final report stage</jats:p

The Precambrian rocks of the Upernavik-Kraulshavn area (72°-74°15'N), West Greenland

In an attempt to complete the mapping of sheet IV of the 1 :500 000 map series, a reconnaissance was carried out of the coastal region of West Greenland between 72° and 74° 15'N in the period 30.6 to 24.8.1967.</jats:p

New mapping on Svartenhuk peninsula

Svartenhuk, although petrographically the best known of the West Greenland basalt areas, was until now the least satisfactonly mapped. The accounts of Rosenkrantz et al. (1942) and Noe-Nygaard (1942) were written before either accurate topographical maps or aerial photographs of the area were available and thus the accompanymg geological maps are of a very generalised nature. Therefore, in order that the area could be satisfactorily represented on the Survey 1:500 000 sheets, it was necessary to remap it on new photogrammetric topographical maps, making full use of aerial photographs. This was our first task.</jats:p