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Reconstruction of Madagascar and Africa: evidence from the Davie Fracture Zone and Western Somali Basin

Citation

Coffin, MF and Rabinowitz, PD, Reconstruction of Madagascar and Africa: evidence from the Davie Fracture Zone and Western Somali Basin, Journal of Geophysical Research-Solid Earth, 92, (B9) pp. 9385-9406. ISSN 0148-0227 (1987) [Refereed Article]


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Copyright Statement

Copyright 1987 American Geophysical Union.

DOI: doi:10.1029/JB092iB09p09385

Abstract

New seismic reflection, gravity, and magnetic data from offshore East Africa allow the Davie Fracture Zone to be traced from 11S to its intersection with the Kenyan coast at 2S, constraining the relative motion of Madagascar and Africa. Seasat-derived free air gravity anomalies and slope/rise positive magnetic anomalies observed in shipboard data help to locate the continent-ocean boundaries (COB) off the shore of East Africa and Madagascar. Seismic reflection data further document a diapirprovince off Madagascar, presumably conjugate to that observed off Kenya and Somalia. The Dhow and Very Large Crude Carrier (VLCC) basement ridges are complex features and do not appear to be simple fracture zones owing their existence entirely to the separation of Madagascar and Africa. From these data we determine a predrift fit of Madagascar and Africa involving a 14.2 rotation of Madagascar to Africa about a pole at 10N, 150E. The geometry of the reconstruction adheres to seismic and potential field data indicating the oceanic nature and extent of the Comoros Basin and of the Somali Basin between Kenya and the Seychelles, and it does not conflict with onshore or offshore stratigraphy. Timing of the opening of the Western Somali Basin is constrained by Mesozoic marine magnetic anomalies and extrapolation to the interpreted COB and occurred between approximately 165 and 130 Ma.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geology
Research Field:Marine Geoscience
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Coffin, MF (Professor Mike Coffin)
ID Code:73860
Year Published:1987
Web of Science® Times Cited:90
Deposited By:Research Division
Deposited On:2011-10-27
Last Modified:2011-11-04
Downloads:5 View Download Statistics

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