Isotopic and geochemical evidence for a heterogeneous mantle plume origin of the Virunga volcanics, Western rift, East African Rift system
نویسندگان
چکیده
Article history: Virunga volcanics in the we Received 20 May 2008 Received in revised form 7 November 2008 Accepted 17 November 2008
منابع مشابه
Trace element and Sr-Nd-Pb isotope geochemistry of Rungwe Volcanic Province, Tanzania: implications for a Superplume source for East Africa Rift magmatism
*Correspondence: Paterno R. Castillo, Geosciences Research Division, Scripps Institution of Oceanography, University of California, San Diego, 8615 Kennel Way, La Jolla, CA 92037, USA e-mail: [email protected] †Present address: Sæmundur A. Halldórsson, Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland The recently-discovered high, plume-like 3...
متن کاملRe-Os systematics of mantle xenoliths from the East African Rift: Age, structure, and history of the Tanzanian craton
In order to understand the effects of contractional and extensional tectonics on thick, mantle roots, we have undertaken a systematic study of mantle xenoliths from the Labait volcano, which lies within the East African Rift on the eastern boundary of the Archean Tanzanian craton. The Re-Os systematics of the Labait xenoliths show that ancient, refractory lithosphere is present to depths of ;14...
متن کاملInitiation of the western branch of the East African Rift coeval with the eastern branch
The East African Rift System transects the anomalously high-elevation Ethiopian and East African plateaux that together form part of the 6,000-km-long African superswell structure. Rifting putatively developed as a result of mantle plume activity that initiated under eastern Africa. The mantle activity has caused topographic uplift that has been connected to African Cenozoic climate change and ...
متن کاملHelium isotopes at Rungwe Volcanic Province, Tanzania, and the origin of East African Plateaux
[1] We report helium isotope ratios (He/He) of lavas and tephra of the Rungwe Volcanic Province (RVP) in southern Tanzania. Values as high as 15RA (RA = air He/He) far exceed typical upper mantle values, and are the first observation of plume‐like ratios south of the Turkana Depression which separates the topographic highs of the Ethiopia and Kenya domes. The African Superplume ‐ a tilted low‐v...
متن کاملOs-Hf isotopic insight into mantle plume dynamics beneath the East African Rift System
a Department of Geosciences, 333 Deike Building, Pennsylvania State University, University Park, PA 16802, United States b Department of Geological Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, MI 48109, United States c Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Rd., NW, Washington, D.C. 20015, United States d Departme...
متن کامل