Late Oligocene volcanism and extension in the southern Red Sea Hills, Sudan

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doi: 10.1144/jgs.158.2.285
Authors:Kenea, N. H.; Ebinger, C. J.; Rex, D. C.
Author Affiliations:Primary:
Free University of Berlin, Institute of Geology, Geophysics and Geoinformatics, Berlin, Federal Republic of Germany
University of London, United Kingdom
University of Leeds, United Kingdom
Volume Title:Journal of the Geological Society of London
Source:Journal of the Geological Society of London, Vol.158(Part 2), p.285-294. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0016-7649
Publication Date:2001
Note:In English. 41 refs.; illus., incl. 3 tables, geol. sketch map
Summary:The temporal and spatial relationships between Cenozoic extension in the Red Sea and flood basalt volcanism in the Ethiopian plateau region were poorly understood along the Red Sea Hills region of Sudan. Rift basins in the Red Sea area developed in terranes accreted in Pan-African time, and it is believed that some of these ancient sutures controlled later Red Sea rifting. The objectives of field, remote sensing and geochronological studies of the southern Red Sea Hills near the Sudan-Eritrea border were to constrain the geometry and kinematics of extension, the timing of volcanism, and the structural relationship between Cenozoic and Pan-African faults. Basaltic volcanism began at about 31 Ma in the Derudeb region, coincident with the widespread flood basaltic volcanism in Ethiopia and Yemen associated with the Afar plume, suggesting a causal link. Felsic lavas erupted onto a faulted erosional surface at about 29 Ma, based on 40Ar/39Ar step heating results on feldspar separates. The original form of these basins has been modified by subsequent faulting, Red Sea rift flank uplift, and erosion. Structural patterns indicate that extension increases eastward toward the Red Sea, with stratal dips of up to 35° in the Adar Ribad region, but most of this fault block rotation post-dates the rhyolite eruptions. The location of the Odi and Adar Ribad basins, and the reactivation of segments of Pan-African shear zones of the Baraka suture suggest that the development of these basins was influenced by pre-existing crustal shear zones, although some faults and dykes cross-cut other basement structures.
Subsections:Igneous petrology
Subjects:Absolute age; Ar/Ar; Basalts; Cenozoic; Dates; Extension tectonics; Flood basalts; Igneous rocks; Oligocene; Paleogene; Tectonics; Tertiary; Upper Oligocene; Volcanic rocks; Volcanism; Africa; East Africa; Red Sea Hills; Sudan
Coordinates:N170000 N180000 E0373000 E0363000
Abstract Numbers:01M/3327
Record ID:2001026528
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom
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