African lithospheric structure, volcanism, and topography

Saved in:
Online Access: Get full text
doi: 10.1016/0012-821X(89)90119-2
Authors:Ashwal, Lewis D.; Burke, Kevin
Author Affiliations:Primary:
Lunar and Planet. Inst., Houston, TX, United States
Volume Title:Earth and Planetary Science Letters
Source:Earth and Planetary Science Letters, 96(1-2), p.8-14. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X
Publication Date:1989
Note:In English. Lunar and Planet. Inst., Contrib. No. 721. 42 refs.; sects., geol. sketch map
Summary:The virtual absence of volumetrically minor, mid-plate volcanic rocks of Cainozoic age from cratonic areas in Africa, and their concentration in areas affected by Pan-African crustal reactivation, is interpreted as indicating that the latter are underlain by fertile lithospheric mantle and the former by depleted lithospheric mantle. A model is proposed to explain the distribution of volcanism and the two kinds of African mantle lithosphere: 1) cratons were formed by the convergence of island arcs and so are underlain by depleted, sub-oceanic-type mantle lithosphere; 2) similar depleted mantle lithosphere has been scraped from beneath areas thickened during continental collision and replaced by fertile material which now forms the lithospheric mantle below reactivated crust; 3) when the African plate came to rest approx 30 m.y. ago, heating from below extracted magmas from the fertile but not from the depleted mantle lithosphere, and 4) as a result of 30 m.y. of interactions with an underlying convective pattern, Pan-African reactivated areas display both Neogene elevations and volcanism but cratonic areas display only elevations. [R.E.S.]
Subjects:African Plate; Cenozoic; Continental crust; Cratons; Crust; Geomorphology; Landform evolution; Lithosphere; Magmas; Mantle; Mechanism; Orogeny; Pan-African Orogeny; Plate tectonics; Precambrian; Proterozoic; Reactivation; Tectonophysics; Topography; Upper mantle; Upper Precambrian; Volcanism; Volcanology; Africa; Evolution; Intraplate tectonics
Abstract Numbers:90M/3414
Record ID:1990016391
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
Tags: Add Tag
No Tags, Be the first to tag this record!

Similar Items