The Mesozoic East African and Madagascan Conjugate Continental Margins: Stratigraphy and Tectonics

• Main Authors: Coffin, MF, Rabinowitz, PD
• Format: Book Part
• Language: English
• Published: American Association of Petroleum Geologists 1992
• Subjects: Earth Sciences; Geology; Marine Geoscience; Antarc*; Antarctica
• Online Access: http://www.aapg.org/pubs.cfm; http://ecite.utas.edu.au/73911

The continental margin of East Africa began forming in the PermoCarboniferouswith the development of rift basins, and extensionoccurred intermittently over 150 million years until the LateJurassic initiation of sea floor spreading. The margin developedby a combination of extensional and transform tectonics thatseparated plates containing Africa, Madagascar-Greater India,South America, and Antarctica. A salient aspect of the pre-breakupstratigraphy of the rift basins is salt in isolated Tanzanian grabens,in the Somali Coastal Basin, and in offshore Madagascan basins.At the initiation of sea floor spreading, sedimentary facies changedthroughout the rift and pull-apart basins from dominantlycontinental to marine. Volcanic activity and faulting occurred atthe same time. Sea floor spreading ceased in the Western SomaliBasin in the Early Cretaceous. Vigorous abyssal circulation alongthe East African margin probably commenced in the midCretaceous,and widespread regional volcanism occurred in theLate Cretaceous. Middle Jurassic through Holocene sedimentthicknesses exceed 8 km in places along the margin.