Sea-level change in southern Africa since the Last Glacial Maximum

QUATERNARY SCIENCE REVIEWS

卷:201

Article

Cooper, J. A. G.^1,2  Green, A. N.²  Compton, J. S.³ 

[1] Univ Ulster, Cromore Rd, Coleraine, Londonderry, North Ireland

[2] Univ KwaZulu Natal, Westville, South Africa

[3] Univ Cape Town, Rondebosch, South Africa

关键词: Holocene;    Sea-level indicators;    Southern Africa;    Shelf bathymetry;    Termination I;    Glacial isostatic adjustment;   

DOI  :  10.1016/j.quascirev.2018.10.013

来源: Elsevier

【 摘 要 】

Sea-level change around southern Africa (southern Namibia, South Africa, southern Mozambique) since Termination I has been quantified using a variety of indicators. Existing and new data are reviewed to provide a baseline for future studies and identify key research needs and opportunities in the region. While the southern African records broadly agree with other far-field records, detailed Holocene records present as-yet unresolved discrepancies with glacial isostatic adjustment (GIA) model predictions. Two domains, the west coast and east coast are considered. Radiocarbon dated saltmarsh fades and marine shells in life position provide the basis for the west coast sea-level curve back to 9 ka BP. Given the age and elevation uncertainties, a Mid-Holocene highstand of +2 to +4 m is suggested between 7.3 and 6 ka BP, as are several Late Holocene oscillations of <1 m amplitude. On the east coast, fewer data are available for the Mid to Late Holocene (post 7 ka BP) compared to the west, but many submerged indicators are available back to 13 ka BP. Reappraisal of existing data suggests a sea-level curve similar to that of the west coast. In both instances, the resolution of existing sea-level index points is neither sufficient to accurately constrain the magnitude and timing of the peak highstand nor the existence of minor inferred subsequent oscillations. Between 13 and 7 cal ka BP chronological and geomorphological evidence (submerged shoreline complexes) suggest several alternating periods of slow and rapid sea-level change. Despite abundant data, the indicator resolution to quantify these changes remains elusive. (C) 2018 Elsevier Ltd. All rights reserved.

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