The fossilised desert: recent developments in our understanding of the Lower Cretaceous deposits in the Huab Basin, NW Namibia.

Jerram DA, Mountney N, Howell J, Stollhofen H (2000)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2000

Journal

Communications - Geological Survey of Namibia Ministry of Mines and Energy, Geological Survey of Nambia

Pages Range: 269-278

Journal Issue: 12

Abstract

The Lower Cretaceous deposits in the Huab Basin, NW Namibia, comprise fluvial and aeolian sandstones, lava flows and associated intrusions of the Etendeka Group. The sandstones formed part of a major aeolian sand sea (erg) system that was active across large tracts of the Paraná-Huab Basin during Lower Cretaceous times (133-132 Ma). This erg system was progressively engulfed and subsequently preserved beneath and between lava flows of the Paraná-Etendeka Flood Basalt Province. Burial of this erg by flood basalts has resulted in the preservation of a variety of intact aeolian bed forms. Preserved bed forms vary in type and scale from 1 km wavelength compound transverse draa to isolated barchan dunes with downwind wavelengths of < 100 m. Due to the present-day preferential erosion of the lava flows, preserved aeolian dunes are now exposed in 3-D in the position in which they were migrating ~133 Ma ago. A relatively non-destructive eruption style of inflated pahoehoe flows preserved the bed form geomorphology. These first pahoehoe flow fields, comprising olivine-phyric Tafelkop lavas, define a shallow shield-like volcanic feature. This volcanic feature centres around the Doros igneous centre marking this as the likely source for the lavas. Early lava flows followed low topography between dune build-ups, ponding in the interdune areas. Striations left on the sand surface by the lavas indicate the localised flow directions of the lava. Numerous sediment interlayers, preserved between the lava flows, record a change in palaeowind direction during volcanism. This change in climate may have been driven by the ongoing break-up of the West-Gondwana supercontinent or may be a direct result of the widespread volcanism.

Authors with CRIS profile

Harald Stollhofen Lehrstuhl für Geologie (Exogene Dynamik)

Involved external institutions

University of Oslo NO Norway (NO) The University of Liverpool GB United Kingdom (GB) University of Keele GB United Kingdom (GB)

How to cite

APA:

Jerram, D.A., Mountney, N., Howell, J., & Stollhofen, H. (2000). The fossilised desert: recent developments in our understanding of the Lower Cretaceous deposits in the Huab Basin, NW Namibia. Communications - Geological Survey of Namibia, 12, 269-278.

MLA:

Jerram, Dougal A., et al. "The fossilised desert: recent developments in our understanding of the Lower Cretaceous deposits in the Huab Basin, NW Namibia." Communications - Geological Survey of Namibia 12 (2000): 269-278.

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