Variations in Isochore Thickness of the Ecca Sediments in the Eastern Cape Province of South Africa,as Deduced from Gravity Models  

作　　者：Christopher BAIYEGUNHI Oswald GWAVAVA 

机构地区：[1]School of Computational Sciences,Faculty of Science and Agriculture,University of Fort Hare

出　　处：《Acta Geologica Sinica(English Edition)》2016年第5期1699-1712,共14页地质学报（英文版）

基　　金：the National Research Foundation(NRF)(Grant UID:101980);Govan Mbeki Research and Development Centre(GMRDC),University of Fort Hare for financial support

摘　　要：Gravity modelling was carried out along five profiles that traverse the Eastern Cape Province of South Africa in order to determine the depositional surface and isochore thickness of the Ecca sediments.Gravity models of the subsurface rock density reveal that the Ecca Group has a maximum vertical thickness of about 3215 ± 160 m.The maximum depositional surface（elevation）above sea level for the Ecca sediments is about 500 m,whilst the depth below sea level reaches about10000 m.Correlation of the isochore thickness maps with the depositional surfaces shows that the sediments in the basement highs were subsided,deformed,eroded and deposited in the basement lows.The basement highs served as the source area（s） for the sediments in the basement lows,thus basement highs are characterized with thin sediment cover whilst the lows have thick sediment cover.Gravity modelling was carried out along five profiles that traverse the Eastern Cape Province of South Africa in order to determine the depositional surface and isochore thickness of the Ecca sediments.Gravity models of the subsurface rock density reveal that the Ecca Group has a maximum vertical thickness of about 3215 ± 160 m.The maximum depositional surface（elevation）above sea level for the Ecca sediments is about 500 m,whilst the depth below sea level reaches about10000 m.Correlation of the isochore thickness maps with the depositional surfaces shows that the sediments in the basement highs were subsided,deformed,eroded and deposited in the basement lows.The basement highs served as the source area（s） for the sediments in the basement lows,thus basement highs are characterized with thin sediment cover whilst the lows have thick sediment cover.

关 键 词：ediment isochore thickness depositional surface Ecca Group basement highs and lows 

分 类 号：P512.2[天文地球—地质学]