Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas.
A 2 km succession of upper Middle and Upper Devonian fluvial conglomerates and sandstones outcrops along a north-south distance of 160 km, and forms the western sequence of the Devonian outcrop area of East Greenland. The thickness of the conglomerates varies considerably along the western margin, a...
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Kommissionen for Videnskabelige Undersøgelser i Grønland
1978
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ftsbaarhusojs:oai:ojs.tidsskrift.dk:article/141446 2024-09-09T19:38:42+00:00 Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. Yeats, A. K. Friend, P. F. 1978-01-01 application/pdf https://tidsskrift.dk/meddrgroenland/article/view/141446 eng eng Kommissionen for Videnskabelige Undersøgelser i Grønland https://tidsskrift.dk/meddrgroenland/article/view/141446/185279 https://tidsskrift.dk/meddrgroenland/article/view/141446 Copyright (c) 1978 Copyright for all papers published by Kommisionen for videnskagelige Undersøgelser i Grønland is vested in the Commission. Those who aske for permission to reproduce material from the Commission's publications are, however, informed that the author's permission must also be obtained if he is still alive. Meddelelser om Grønland; Vol. 206 No. 4 (1978): Meddelelser om Grønland; 112 pp. Meddelelser om Grønland; Årg. 206 Nr. 4 (1978): Meddelelser om Grønland; 112 pp. 2794-6827 0025-6676 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Fagfællebedømt artikel 1978 ftsbaarhusojs 2024-06-18T14:24:43Z A 2 km succession of upper Middle and Upper Devonian fluvial conglomerates and sandstones outcrops along a north-south distance of 160 km, and forms the western sequence of the Devonian outcrop area of East Greenland. The thickness of the conglomerates varies considerably along the western margin, and this appears to represent the growth of distinct coarse grained fans. These coarse fluvial deposits range up to 1000 m in thickness. Breccias are locally present on the basal unconformity, sometimes including clasts up to 15 m long, that appear to have slipped and rolled from nearby outcrops of basement (pre-Devonian) sediment. Although some of the breccias were certainly deposited from water, others may have accumulated from debris flows. A number of ravines and valleys eroded in the basement, are preserved with plugs of breccia or conglomerate. Thin limestone and siltstone units occur, also close to the unconformity, and are thought to have formed in lake hollows between the highgradient alluvial deposits and the basement topography. Most of the outcrops of the area are of rather similar sandstone sequences. These have been analysed, particularly using our multivariate analytical technique, described in number 1 of this volume. Palaeocurrents and lithology show the presence of a number of distinct sandstone bodies, hundreds of metres thick, and kilometres in lateral extent. These distinctive bodies were deposited by broadly eastward flowing river fan systems at the margin of the Devonian outcrop area. A southward flowing (axial) river system deposited sands further east, in the centre of the basin. The fan sandstone bodies are characterised by cycles, 20 to 100 m thick. In the central parts of the fans, these cycles consist of an upwards increase in the proportion of flat bedding to cross-bedding, although the medium sand grade is relatively constant. The edges of the fan bodies are marked by very-fine sand grade accumulations, interpreted as the fills of hollows between fans, or between a fan and the basement ... Article in Journal/Newspaper East Greenland Greenland Aarhus University: OJS at The State and University Library Greenland Kap ENVELOPE(23.567,23.567,65.533,65.533) Kap Kolthoff ENVELOPE(-24.041,-24.041,73.725,73.725) |
institution |
Open Polar |
collection |
Aarhus University: OJS at The State and University Library |
op_collection_id |
ftsbaarhusojs |
language |
English |
description |
A 2 km succession of upper Middle and Upper Devonian fluvial conglomerates and sandstones outcrops along a north-south distance of 160 km, and forms the western sequence of the Devonian outcrop area of East Greenland. The thickness of the conglomerates varies considerably along the western margin, and this appears to represent the growth of distinct coarse grained fans. These coarse fluvial deposits range up to 1000 m in thickness. Breccias are locally present on the basal unconformity, sometimes including clasts up to 15 m long, that appear to have slipped and rolled from nearby outcrops of basement (pre-Devonian) sediment. Although some of the breccias were certainly deposited from water, others may have accumulated from debris flows. A number of ravines and valleys eroded in the basement, are preserved with plugs of breccia or conglomerate. Thin limestone and siltstone units occur, also close to the unconformity, and are thought to have formed in lake hollows between the highgradient alluvial deposits and the basement topography. Most of the outcrops of the area are of rather similar sandstone sequences. These have been analysed, particularly using our multivariate analytical technique, described in number 1 of this volume. Palaeocurrents and lithology show the presence of a number of distinct sandstone bodies, hundreds of metres thick, and kilometres in lateral extent. These distinctive bodies were deposited by broadly eastward flowing river fan systems at the margin of the Devonian outcrop area. A southward flowing (axial) river system deposited sands further east, in the centre of the basin. The fan sandstone bodies are characterised by cycles, 20 to 100 m thick. In the central parts of the fans, these cycles consist of an upwards increase in the proportion of flat bedding to cross-bedding, although the medium sand grade is relatively constant. The edges of the fan bodies are marked by very-fine sand grade accumulations, interpreted as the fills of hollows between fans, or between a fan and the basement ... |
format |
Article in Journal/Newspaper |
author |
Yeats, A. K. Friend, P. F. |
spellingShingle |
Yeats, A. K. Friend, P. F. Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. |
author_facet |
Yeats, A. K. Friend, P. F. |
author_sort |
Yeats, A. K. |
title |
Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. |
title_short |
Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. |
title_full |
Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. |
title_fullStr |
Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. |
title_full_unstemmed |
Devonian Sediments of East Greenland IV. The Western Sequence, Kap Kolthoff Supergroup of the Western Areas. |
title_sort |
devonian sediments of east greenland iv. the western sequence, kap kolthoff supergroup of the western areas. |
publisher |
Kommissionen for Videnskabelige Undersøgelser i Grønland |
publishDate |
1978 |
url |
https://tidsskrift.dk/meddrgroenland/article/view/141446 |
long_lat |
ENVELOPE(23.567,23.567,65.533,65.533) ENVELOPE(-24.041,-24.041,73.725,73.725) |
geographic |
Greenland Kap Kap Kolthoff |
geographic_facet |
Greenland Kap Kap Kolthoff |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_source |
Meddelelser om Grønland; Vol. 206 No. 4 (1978): Meddelelser om Grønland; 112 pp. Meddelelser om Grønland; Årg. 206 Nr. 4 (1978): Meddelelser om Grønland; 112 pp. 2794-6827 0025-6676 |
op_relation |
https://tidsskrift.dk/meddrgroenland/article/view/141446/185279 https://tidsskrift.dk/meddrgroenland/article/view/141446 |
op_rights |
Copyright (c) 1978 Copyright for all papers published by Kommisionen for videnskagelige Undersøgelser i Grønland is vested in the Commission. Those who aske for permission to reproduce material from the Commission's publications are, however, informed that the author's permission must also be obtained if he is still alive. |
_version_ |
1809907603724042240 |