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image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Mineralogy and Petro...arrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
Mineralogy and Petrology
Article . 2002 . Peer-reviewed
License: Springer TDM
Data sources: Crossref
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Petrology and geochemistry of Pan-African granitoids, Kab Amiri area, Egypt - implications for tectonomagmatic stages in the Nubian Shield evolution

Authors: A. M. Moghazi;

Petrology and geochemistry of Pan-African granitoids, Kab Amiri area, Egypt - implications for tectonomagmatic stages in the Nubian Shield evolution

Abstract

Three distinctive metaluminous granitic suites have been identified from the Pan-African belt of the Kab Amiri area, Eastern Desert, Egypt. These are: 1) a trondhjemite-tonalite suite, 2) a calc-alkaline granodiorite suite, and 3) an alkali leucogranite suite. The trondhjemite-tonalite and the granodiorite suites resemble I-type granitoids whereas the alkali leucogranites display A-type characteristics. Geochemical attributes and field aspects indicate that three independent magmas, at different tectonic stages of the Pan-African crustal growth, are required to explain the origin of these granitoid suites. Rocks of the trondhjemite-tonalite suite correspond to granites of the arc stage and possess a narrow range of SiO2 with low K2O, Sr, Rb, Ba, Nb and Zr. Its composition is consistent with 20–30% partial melting of a primitive low-K tholeiitic source, similar to the early formed tholeiitic metavolcanics of the Egyptian basement. The granodiorite suite belongs to the collision stage and displays higher K2O, Rb, Ba, and Sr. Its magma was derived by 30–40% partial melting of LILE-enriched mafic island arc crust. The presence of abundant microdiorite enclaves in the trondhjemite-tonalite and the granodiorite suites suggests that mantle-derived mafic magma played an important role in their petrogenesis, acting as a heat source for melting via underplating and/or intrusion. The A-type leucogranites are post-collision highly fractionated granites. They exhibit low Al2O3, MgO, CaO, TiO2, Sr, and Ba and high Rb, Nb, Y. The wide chemical variations within this suite are consistent with its evolution by fractional crystallization of plagioclase, K-feldspar, amphibole, Fe–Ti oxides, and apatite from a mafic magma. The parent magma was originated in the upper mantle due to crustal attenuation associated with extension in the late stage of the Pan-African crustal evolution.

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selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
71
Top 10%
Top 10%
Average
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