气候变化领域集成服务门户(CCPortal): Petrogenesis and tectonic implications of the Maladob ring complex in the South Eastern Desert; Egypt: new insights from mineral chemistry and whole-rock geochemistry

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DOI	10.1007/s00531-020-01937-2
	Petrogenesis and tectonic implications of the Maladob ring complex in the South Eastern Desert; Egypt: new insights from mineral chemistry and whole-rock geochemistry
	Abdel-Karim A.-A.; Azer M.; Sami M.
发表日期	2020
ISSN	14373254
英文摘要	Alkaline ring complexes are widely distributed in the south Eastern Desert (SED) of Egypt, but their petrogenesis and geodynamic settings are a matter of many discussions. In this contribution, mineral chemistry, and whole-rock geochemical data of the Maladob intrusive rocks were used to investigate their petrogenesis. The Maladob ring complex is a small alkaline intrusion in the SED of Egypt, composed of oversaturated syenite, quartz syenites and peralkaline granite. The rocks consist of K-feldspar (Or94–97) and albite (An0-1), alkali amphiboles (arfvedsonite and ferro-katophorite), sodic pyroxene (aegirine), with accessory aenigmatite, zircon, apatite, ilmenite, magnetite and titanite. Geochemically, the rocks are peralkaline, show distinctive geochemical characteristics such as low contents of CaO, MgO, Sr and high contents of alkalis, Rb, Nb, Y, and REE, typical of A-type granites. The rocks are weakly to moderately fractionated with a general enrichment in LREE [(La/Sm)N = 2.96–3.64]. Typically, the Maladob rocks are classified as within plate granites and exhibit A1 subtype characteristics. We suggest that the Maladob rocks were formed from a similar OIB-like mafic magma by fractional crystallization. The fractionation of feldspars and mafic minerals play a significant role during magma evolution. During the Mesozoic intraplate magmatism, the upwelling of asthenosphere causes underplating of lithospheric OIB-like magma which was subjected to prolonged fractional crystallization to produce the Maladob syenites and peralkaline granite. © 2020, Geologische Vereinigung e.V. (GV).
英文关键词	Alkaline ring complex; Egypt; Fractional crystallization; Nubian Shield; Peralkaline granite; Syenite
语种	英语
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147755
作者单位	Geology Department, Faculty of Science, Zagazig University, Zagazig, Egypt; Geological Sciences Department, National Research Centre, Cairo, Egypt; Geology Department, Faculty of Science, Minia University, El-Minia, 61519, Egypt
推荐引用方式 GB/T 7714	Abdel-Karim A.-A.,Azer M.,Sami M.. Petrogenesis and tectonic implications of the Maladob ring complex in the South Eastern Desert; Egypt: new insights from mineral chemistry and whole-rock geochemistry[J],2020.
APA	Abdel-Karim A.-A.,Azer M.,&Sami M..(2020).Petrogenesis and tectonic implications of the Maladob ring complex in the South Eastern Desert; Egypt: new insights from mineral chemistry and whole-rock geochemistry.International Journal of Earth Sciences.
MLA	Abdel-Karim A.-A.,et al."Petrogenesis and tectonic implications of the Maladob ring complex in the South Eastern Desert; Egypt: new insights from mineral chemistry and whole-rock geochemistry".International Journal of Earth Sciences (2020).