Pleistocene to Recent rejuvenation of the Hebron Fault, south-western Namibia.

White S, Stollhofen H, Stanistreet IG, Lorenz V (2009)


Publication Language: English

Publication Type: Book chapter / Article in edited volumes

Publication year: 2009

Publisher: Geol. Soc. London

Edited Volumes: Palaeoseismology: Historical and prehistorical records of earthquake ground effects for seismic hazard assessment

Series: Geol. Soc. Spec. Publ.

City/Town: London

Book Volume: 316

Pages Range: 293-317

DOI: 10.1144/SP316.18

Abstract

The Hebron Fault in SW Namibia is associated with a ,1 m to 9.6 m high scarp
displacing Proterozoic basement and Middle to Late Pliocene crystalline conglomerates. The
young age of strata exposed in the fault scarp together with evidence for displacement of
aeolian dunes, post-dating the Middle Stone Age, suggests that latest fault displacements occurred during the Late Pleistocene to recent. Recorded historical seismic events show that the fault zone is still active. Latest movements of the fault are recorded by: down-to-the-SW offset of calcretecemented conglomerate; fluvially modified, asymmetric hanging wall, graben-like structures; at least two left-stepping jogs in the fault trace and structural data from basement rocks in which late-stage crush zones overprint earlier cataclasite. These features provide consistent evidence that the present scarp formed predominantly by normal dip-slip displacement on a NW-striking, steeply SW-dipping master fault with only a minor dextral strike-slip component. Strongly
veined cataclastic fault rocks adjacent to the scarp in basement most probably originated at
depths of 4–10 km. The conclusion is therefore that recent fault activity has reactivated a preexisting, much older fault.
Aerial photographic lineaments and similar fault scarps identifiedNWand SE of the present study
area are interpreted as extensions of the same fault structure. Hence the total length of the Hebron Fault is at least 300 km subparallel to the Atlantic margin of southern Africa. Our observations confirm that the Hebron Fault is a neotectonic feature of regional significance that may relate to late Cenozoic and particularly Quaternary neotectonic activity in NE Namibia and NW Botswana.

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How to cite

APA:

White, S., Stollhofen, H., Stanistreet, I.G., & Lorenz, V. (2009). Pleistocene to Recent rejuvenation of the Hebron Fault, south-western Namibia. In Reicherter, K., Michetti A.M., Silva, P.G. (Eds.), Palaeoseismology: Historical and prehistorical records of earthquake ground effects for seismic hazard assessment. (pp. 293-317). London: Geol. Soc. London.

MLA:

White, Stephen, et al. "Pleistocene to Recent rejuvenation of the Hebron Fault, south-western Namibia." Palaeoseismology: Historical and prehistorical records of earthquake ground effects for seismic hazard assessment. Ed. Reicherter, K., Michetti A.M., Silva, P.G., London: Geol. Soc. London, 2009. 293-317.

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