Age of Betain Gneiss; implication for Late Precambrian crustal evolution in Souteastem Desert, Egypt

Ghoneim Mohamed Ahmed F. and Aly S. M. and El Baraga M. H.: Age of Betain Gneiss; implication for Late Precambrian crustal evolution in Souteastem Desert, Egypt. In: Acta mineralogica-petrographica, (34). pp. 41-50. (1993)

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Abstract

The gneiss-migmatite rocks pf Hodein area, which represents the southeastern extension of Beitan Gneisses, cover about 98 km and trend NW-SE. These rocks are overthrusted by supracrustal cover mainly arc-ophiolite assemblage and granitic rocks. Petrologically, the rocks are divided into biotite-gneisses, hornblende-gneisses, biotite-hornblende-gneisses, gamet-biotite-hornblende-gneisses ana augen-biotite-gneisses. The whole rock Sm-Nd isochron age of the Beitan gneisses yield 889±8 Ma (MSWD=8.5) which is consistent with Rb-Sr age (863±15 Ma, MSWD=9). This rock has initial £Nd and e'sr-values (-8.6 and +9.5, respectively) which reveals the age of early Pan-African. Moreover, the Nd-model age (TDM) of these rocks range from 1.46 to 2.65 Ga, negative ElNd and low e'sr-values reveal the existence of early Pan-African continental crust. The data are tested against mantlecrust mixing model. It is suggested that these rocks were derived throughout assimilation of about 35—50% Nd-enriched, sligntly Sr-depleted lower crust component by a mildly depleted subcontinental mantle source.

Item Type: Article
Journal or Publication Title: Acta mineralogica-petrographica
Date: 1993
Volume: 34
ISSN: 0365-8066
Page Range: pp. 41-50
Language: English
Publisher: University of Szeged, Department of Mineralogy, Geochemistry and Petrology
Place of Publication: Szeged
Related URLs: http://acta.bibl.u-szeged.hu/39412/
Uncontrolled Keywords: Kőzettan, Ásványtan, Földtan, Geokémia
Additional Information: Bibliogr.: p. 49-50. ; ill. ; összefoglalás angol nyelven
Subjects: 01. Natural sciences
01. Natural sciences > 01.05. Earth and related environmental sciences
Date Deposited: 2016. Oct. 17. 09:25
Last Modified: 2022. Jul. 27. 10:12
URI: http://acta.bibl.u-szeged.hu/id/eprint/24808

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