scholarly journals Reconnaissance dating of Archaean rocks from South-East Greenland

1986 ◽  
Vol 130 ◽  
pp. 90-95
Author(s):  
J.C Escher ◽  
F Kalsbeek ◽  
O Larsen ◽  
T.F.D Nielsen ◽  
P.N Taylor
Keyword(s):  
Mobile Belt ◽  
East Greenland ◽  
Geological Map ◽  
Map Series ◽  
Major Project ◽  
Age Determinations

A major project of geological investigations in South-East Greenland is planned for 1986 and 1987 with the aim of producing sheet 14 of the 1:500000 geological map series covering Greenland. The northern part of the map sheet is occupied by the Nagssugtoqidian mobile belt, and the southern part consists mainly of Archaean rocks. Because of difficulties of access, the Archaean part of the area is poorly known. Geological reconnaissance has been carried out by Bridgwater & Gormsen (1969), and, as a preparation for the 1986 and 1987 expeditions, by Escher & Nielsen (1982, 1983) and Nielsen & Escher (1985). This report presents reconnaissance Rb-Sr and Pb-Pb whole-rock age determinations from the Archaean part of the map sheet.

Explanatory notes to the Geological map of Greenland, 1:500 000, Humboldt Gletscher, Sheet 6

2004 ◽  
pp. 1-48
Author(s):  
Peter R. Dawes
Keyword(s):  
Coarse Grained ◽  
Mobile Belt ◽  
Nares Strait ◽  
General Terms ◽  
Mineral Occurrence ◽  
North Eastern ◽  
Copper Gold ◽  
High Grade Metamorphism ◽  
Geological Map ◽  
Map Series

NOTE: This Map Description was published in a former series of GEUS Bulletin. Please use the original series name when citing this series, for example: Dawes, P. R. (2004). Explanatory notes to the Geological map of Greenland, 1:500 000, Humboldt Gletscher, Sheet 6. Geological Survey of Denmark and Greenland Map Series 1, 48 pp. + map. https://doi.org/10.34194/geusm.v1.4615  _______________ These explanatory notes cover the map region bounded by latitudes 78°N and 81°N and longitudes 56°W and 74°W, with geology shown on the land areas between Nares Strait - the seaway between Greenland and Ellesmere Island, Canada - and the Inland Ice. The bedrock geology is composed of Precambrian and Lower Palaeozoic provinces that continue across Nares Strait into Canada. Map units and mineral occurrences are described in general terms and are proceeded by sections on physical environment, logistics, data sources and geoscientific research. The notes are aimed at the practical user and a guide for further reading. The bedrock is composed of three provinces separated by unconformities, each representing a hiatus of c. 500 Ma during which basic dykes were emplaced. The Palaeoproterozoic Inglefield mobile belt, forming the crystalline shield, is an E-W-trending belt of deposition and orogeny characterised by polyphase magmatism, deformation and high-grade metamorphism. Clastic deposition, with magmatism at c. 1985 Ma, are the oldest events recorded, followed by the accumulation of the Etah Group (carbonate, pelitic and psammitic sediments with supposedly coeval mafic and ultramafic rocks) between 1980 and 1950 Ma ago. These rocks were intruded 1950 to 1915 Ma ago by the Etah meta-igneous complex, that records polyphase plutonism (intermediate to felsic, with some basic and magnetite-rich rocks), followed by deformation and partial melting producing granites 1785 to 1740 Ma ago. The Mesoproterozoic Thule Basin, defined by the unmetamorphosed and little deformed Thule Supergroup, records sedimentation and basaltic volcanism at least as old as 1270 Ma. The faulted, north-eastern basin margin shown on the map preserves the passage from the basinal sequence to a relatively thin platform succession invaded by basic sills. The Palaeozoic Franklinian Basin is represented by a homoclinal Cambrian to Silurian shelf carbonate succession and a major Silurian reef complex, with coeval siliciclastic slope deposits. The map region includes the classical area for Franklinian stratigraphy, now composed of 29 formations and four groups - Ryder Gletscher, Morris Bugt, Washington Land and Peary Land Groups. The only younger units preserved in the map region are widespread Quaternary deposits, an isolated outcrop of coarse-grained fluvial deposits (Bjørnehiet Formation) and non-carbonised wood erratics of Neogene age. Five mineral occurrence types are shown on the map: in lithologies of the Inglefield mobile belt, sulphide-graphite rust zones, a magnetite deposit and copper-gold mineralisation and in the Franklinian Basin, commercially drilled, zinc-lead-silver and zinc-lead-barium mineralisations. The basic ingredients of a petroleum model exist in the Franklinian Basin but prospectivity is low.

scholarly journals The Skjoldungen map sheet: completion of the 1:500 000 geological mapping of South-East Greenland

1991 ◽  
Vol 152 ◽  
pp. 30-31
Author(s):  
J.C Escher
Keyword(s):  
Geological Mapping ◽  
The Other ◽  
Geological Survey ◽  
East Greenland ◽  
Metamorphic Development ◽  
Geological Map ◽  
Map Series

The publication of the 1:500 000 Skjoldungen map sheet (Escher, 1990; Fig. 1) marks the completion of the Geological Survey of Greenland's (GGU's) reconnaissance mapping activities in South-East Greenland. A descriptive text to the map is under preparation. All of South-East Greenland between Kap Farvel (59° 00´N) and Mesters Vig (72° 00´N) is now covered by sheets of the 1:500 000 geological map series of Greenland. Five sheets in the series (nos 5,6,9, 10 and 11) remain to be published (Fig. 1); the Thule map sheet (sheet 5) will be printed in the course of 1991, and sheet 10 is under compilation. The presentation of the Skjoldungen map is somewhat different from that of the other 1:500 000 maps inthe series. In addition to traditional lithological information, an effort has been made to show the tectonic/metamorphic development of the region during the Archaean and Proterozoic.

scholarly journals Explanatory notes to the Geological map of Greenland, 1:500 000, Humboldt Gletscher, Sheet 6

2004 ◽  
pp. 1-48 ◽  
Author(s):  
Peter R. Dawes
Keyword(s):  
Coarse Grained ◽  
Mobile Belt ◽  
Nares Strait ◽  
General Terms ◽  
Mineral Occurrence ◽  
North Eastern ◽  
Copper Gold ◽  
High Grade Metamorphism ◽  
Geological Map ◽  
Map Series

Dawes, P.R. 2004: Explanatory notes to the Geological map of Greenland, 1:500 000, Humboldt Gletscher, Sheet 6. Geological Survey of Denmark and Greenland Map Series 1, 48 pp. + map. These explanatory notes cover the map region bounded by latitudes 78°N and 81°N and longitudes 56°W and 74°W, with geology shown on the land areas between Nares Strait - the seaway between Greenland and Ellesmere Island, Canada - and the Inland Ice. The bedrock geology is composed of Precambrian and Lower Palaeozoic provinces that continue across Nares Strait into Canada. Map units and mineral occurrences are described in general terms and are proceeded by sections on physical environment, logistics, data sources and geoscientific research. The notes are aimed at the practical user and a guide for further reading.The bedrock is composed of three provinces separated by unconformities, each representing a hiatus of c. 500 Ma during which basic dykes were emplaced. The Palaeoproterozoic Inglefield mobile belt, forming the crystalline shield, is an E-W-trending belt of deposition and orogeny characterised by polyphase magmatism, deformation and high-grade metamorphism. Clastic deposition, with magmatism at c. 1985 Ma, are the oldest events recorded, followed by the accumulation of the Etah Group (carbonate, pelitic and psammitic sediments with supposedly coeval mafic and ultramafic rocks) between 1980 and 1950 Ma ago. These rocks were intruded 1950 to 1915 Ma ago by the Etah meta-igneous complex, that records polyphase plutonism (intermediate to felsic, with some basic and magnetite-rich rocks), followed by deformation and partial melting producing granites 1785 to 1740 Ma ago. The Mesoproterozoic Thule Basin, defined by the unmetamorphosed and little deformed Thule Supergroup, records sedimentation and basaltic volcanism at least as old as 1270 Ma. The faulted, north-eastern basin margin shown on the map preserves the passage from the basinal sequence to a relatively thin platform succession invaded by basic sills. The Palaeozoic Franklinian Basin is represented by a homoclinal Cambrian to Silurian shelf carbonate succession and a major Silurian reef complex, with coeval siliciclastic slope deposits. The map region includes the classical area for Franklinian stratigraphy, now composed of 29 formations and four groups - Ryder Gletscher, Morris Bugt, Washington Land and Peary Land Groups.The only younger units preserved in the map region are widespread Quaternary deposits, an isolated outcrop of coarse-grained fluvial deposits (Bjørnehiet Formation) and non-carbonised wood erratics of Neogene age.Five mineral occurrence types are shown on the map: in lithologies of the Inglefield mobile belt, sulphide-graphite rust zones, a magnetite deposit and copper-gold mineralisation and in the Franklinian Basin, commercially drilled, zinc-lead-silver and zinc-lead-barium mineralisations. The basic ingredients of a petroleum model exist in the Franklinian Basin but prospectivity is low.

scholarly journals C14 dating of Survey material carried out in 1976

1977 ◽  
Vol 85 ◽  
pp. 127-129
Author(s):  
A Weidick
Keyword(s):  
Field Work ◽  
Geological Survey ◽  
National Museum ◽  
East Greenland ◽  
Radiocarbon Age ◽  
Carbon 14 ◽  
Geodetic Institute ◽  
Map Series ◽  
North Greenland ◽  
Age Determinations

Twenty-two radiocarbon age determinations of shell samples (18), wood (3) and gyttja (1) from North and East Greenland are summarised below. All the material was collected during GGU field work. The samples have been dated at the Geological Survey of Canada, Ottawa (marked GSC); Isotopes Inc., Westwood, New Jersey, USA (marked I) and at the Carbon-14 Dating Laboratory of the Geological Survey of Denmark and the National Museum, Copenhagen (marked K). The samples in East Greenland are located by coordinates taken from the Danish Geodetic Institute 1:250000 map series; in North Greenland from the U.S.A.F. World AeronauticaI Chart 1: 1000000, 5th edition.

scholarly journals Rb/Sr whole rock isochron age determinations on metamorphosed acid volcanic rocks and granitic gneisses from the Ketilidian mobile belt, South-East Greenland

1974 ◽  
Vol 66 ◽  
pp. 12-20
Author(s):  
S Pedersen ◽  
O Larsen ◽  
D Bridgwater ◽  
J Watterson
Keyword(s):  
Volcanic Rocks ◽  
Mobile Belt ◽  
High Grade ◽  
East Greenland ◽  
Volcanic Material ◽  
Grade Metamorphism ◽  
The North ◽  
Acid Volcanic ◽  
High Grade Metamorphism ◽  
Age Determinations

The metamorphosed supracrustal rocks and paragneisses studied were collected during a reconnaissance traverse across the trend of the Ketilidian mobile belt in South-Bast Greenland (Andrews et al., 1971, 1973). All the samples are taken from gneisses regarded as derived from supracrustal material which was originally composed of acid volcanic material deposited as lavas, ignimbrites or sediments with a large volcanic component. Sample localities are shown in fig. 2. All the rocks have been affected by at least one metamorphic episode during the formation of the Ketilidian mobile belt. All are regarded as deposited after the end of regional high grade metamorphism in the Archaean block to the north (which has yielded a U/Pb zircon diffusion age of 2808 m.y.) and are intruded by a variety of synto late tectonic granites within the Ketilidian mobile belt which have yielded U/Pb diffusion and concordia ages between 1850 and 1770 m.y. in this area (Gulson & Krogh, 1972).

scholarly journals Reconnaissance investigations in the Skjoldungen region, South-East Greenland

1988 ◽  
Vol 140 ◽  
pp. 72-76
Author(s):  
T.F.D Nielsen ◽  
J.C Escher
Keyword(s):  
Coastal Areas ◽  
East Greenland ◽  
Geological Map ◽  
Map Series ◽  
Supported Work

From 1 July to 25 August 1987 a GGU expedition made reconnaissance investigations between 62°N and 64°20'N in South-East Greenland. The programme was a continuation of the investigations in the Ammassalikl Angmagssalik distriet in 1986 (Kalsbeek & Nielsen, 1987) and the completion of the fieldwork describing areas in East Greenland between 62°30'N and 65°45'N for the planned map sheet (no. 14) in the 1:500 000 geological map series. The Skjoldungen district was known mainly from previous boat-supported work in the coastal areas as described by Bridgwater & Gormsen, 1969; Andrews et al., 1971, 1973; Bridgwater et al., 1976; Escher & Nielsen, 1982, 1983; Nielsen & Escher 1985 and Escher et al., 1986.

Episodic tectono-thermal activity in the southern part of the East Greenland Caledonides

2000 ◽  
pp. 42-49 ◽  
Author(s):  
A. Graham Leslie ◽  
Allen P. Nutman
Keyword(s):  
Thermal Activity ◽  
Isotopic Data ◽  
Zircon Age ◽  
East Greenland ◽  
Original Series ◽  
Age Determinations

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Leslie, A. G., & Nutman, A. P. (2000). Episodic tectono-thermal activity in the southern part of the East Greenland Caledonides. Geology of Greenland Survey Bulletin, 186, 42-49. https://doi.org/10.34194/ggub.v186.5214 _______________ Isotopic data from the Renland augen granites of the Scoresby Sund region (Figs 1, 2) provided some of the first convincing support for relicts of potentially Grenvillian tectono-thermal activity within the East Greenland Caledonides. In Renland, Chadwick (1975) showed the presence of major bodies of augen granite (Fig. 2) interpreted by Steiger et al. (1979), on the basis of Rb–Sr whole rock and U–Pb zircon age determinations, to have been emplaced about 1000 Ma ago.

scholarly journals Isotopic age dating in Liverpool Land, East Greenland

1987 ◽  
Vol 134 ◽  
pp. 25-37
Author(s):  
B.T Hansen ◽  
J.D Friderichsen
Keyword(s):  
Age Dating ◽  
Isotopic Age ◽  
Pb Isotope ◽  
East Greenland ◽  
Isotope Age ◽  
Caledonian Orogeny ◽  
Plutonic Rocks ◽  
Age Determinations ◽  
Late Part

In Liverpool Land in the eastern part of the Scoresby Sund region gneisses and migmatites were intruded by a number of intermediate plutonites and by younger granites. A number of K-Ar, Rb-Sr and U-Pb isotope age determinations indicate that: 1) the gneisses have a pre-CaIedonian as well as a CaIedonian history, 2) the migmatites were thoroughly reworked during the late part of the Caledonian orogeny, while 3) the plutonic rocks all seem to have been intruded during the Caledonian orogeny.

scholarly journals Reconnaissance P,T studies of Proterozoic crustal evolution of the Ammassalik area, East Greenland

1989 ◽  
Vol 146 ◽  
pp. 48-53
Author(s):  
A.P Nutman ◽  
C.R.L Friend
Keyword(s):  
Regional Metamorphism ◽  
Crustal Thickening ◽  
Mobile Belt ◽  
Crustal Evolution ◽  
Intrusive Complex ◽  
East Greenland ◽  
Early Proterozoic ◽  
Northern Half

The Ammassalik area of East Greenland lies in the centre of a 300 km wide early Proterozoic mobile belt, dominated by Archaean gneisses and early Proterozoic metasediments. Regional Proterozoic synkinematic metamorphism was associated with crustal thickening by southerly-directed thrusting and isoclinal folding. Maximum P, T conditions recorded during the regional metamorphism are found in the northern half of the mobile belt and are 9.5 kbar (equivalent to 30 km burial) and c. 700°C. Following some erosion and uplift, the late kinematic 1885 Ma Ammassalik Intrusive Complex (AIC) was intruded at pressures of c. 7 kbar (equivalent to a depth of 20 km). Temperatures in the metamorphic aureole of the AIC reached 800°C. Following further erosion and uplift, post kinematic, c. 1575 Ma granite-diorite-gabbro complexes were intruded, under pressures of 2.5 kbar (equivalent to a depth of 8 km).

scholarly journals Regional geology and 1:500 000 mapping in North-East Greenland

1990 ◽  
Vol 148 ◽  
pp. 16-20
Author(s):  
N Henriksen
Keyword(s):  
Geological Mapping ◽  
Fold Belt ◽  
East Greenland ◽  
Regional Geology ◽  
Field Mapping ◽  
North East ◽  
General Geology ◽  
Geological Map

A three-year field mapping programme was initiated in 1988 aiming at regional geological studies and geological mapping in North-East Greenland between latitudes 75° and 78°N. This region encompasses relatively little known parts of the Caledonian fold belt and the overlying post-Caledonian sequences, which lie north of the better known regions of central East Greenland (Henriksen, 1989). Major aims of the programme include compilation a 1:500 000 geological map, and an understanding of the general geology of the region.

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