Structural and Climatic Controls on Fluvial Depositional Systems: Devonian, North-East Greenland
- M. Marzo and
- C. Puigdefábregas
Published Online: 14 APR 2009
Copyright © 1993 The International Association of Sedimentologists
How to Cite
Olsen, H. and Larsen, P.-H. (1993) Structural and Climatic Controls on Fluvial Depositional Systems: Devonian, North-East Greenland, in Alluvial Sedimentation (eds M. Marzo and C. Puigdefábregas), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303995.ch26
- Published Online: 14 APR 2009
- Published Print: 16 SEP 1993
Print ISBN: 9780632035458
Online ISBN: 9781444303995
- Structural and climatic controls on fluvial depositional systems;
- Vertical and lateral facies changes;
- a cross-bedded facies association (most common) and a flat-bedded facies association;
- Zoologdalen Formation;
- Andersson Land Formation
Depositional system analysis of continental Devonian deposits in North-East Greenland unravels the complex simultaneous controls of tectonism and climate. The analysis is a combination of sedimentological and structural investigations. Sediment bodies are defined as depositional systems on sedimentological criteria, and mapped by a combination of field mapping and computer assisted stereoscopic studies of vertical aerial photographs. Vertical and lateral facies changes and thickness variations of the sediment bodies are related to the geological structures exposed in the present-day outcrops.
The Upper Devonian Kap Graah and Celsius Bjerg Groups exposed in Gunnar Andersson Land in North-East Greenland are subdivided into three well defined units, termed chronosomes, separated by event-stratigraphic horizons. The chronosome boundaries define times of major palaeogeographic reorganization.
Chronosome I reflects fluvial systems transverse to the basin margins that are separated by a huge aeolian sand sea or erg occupying the basin. This palaeogeography was controlled by a climatic shift towards drier conditions, compared with pre-chronosome I conditions. Chronosome II also reflects two transverse fluvial systems, but the erg was replaced by a longitudinal southward flowing meandering river. This palaeogeography was controlled by tectonic activity both within and outside the basin. The latter caused an increase in relief of the source terrain and thus increased local precipitation. Chronosome III reflects a broad alluvial plain draining towards the north, i.e. in the opposite direction compared with chronosome II. This dramatic change was controlled by tectonic uplift of the southern part of the basin.