干旱区生态环境知识资源中心(Arid): THE KABR EL-BONAYA PERIDOTITES, SOUTHEASTERN SINAI, EGYPT: PETROLOGY, GEOCHEMISTRY, AND METAMORPHISM OF NEOPROTEROZOIC ARC ULTRAMAFIC CUMULATES

Arid

DOI	10.2475/10.2021.02
	THE KABR EL-BONAYA PERIDOTITES, SOUTHEASTERN SINAI, EGYPT: PETROLOGY, GEOCHEMISTRY, AND METAMORPHISM OF NEOPROTEROZOIC ARC ULTRAMAFIC CUMULATES
	Maurice, Ayman E.; Azer, Mokhles K.; Asimow, Paul D.; Basta, Fawzy F.; Helmy, Hassan M.; Shibata, Tomoyuki
通讯作者	Maurice, AE (corresponding author), Helwan Univ, Fac Sci, Peol Dept, Cairo 11790, Egypt.
来源期刊	AMERICAN JOURNAL OF SCIENCE
ISSN	0002-9599
EISSN	1945-452X
出版年	2021
卷号	321 期号:10 页码:1445-1496
英文摘要	Two small, isolated ultramafic masses in the northeastern part of the Wadi Kid arca, southeast Sinai, arc composed of variably serpentinized harzburgite and lherzolite with minor talc-anthophyllite rock. The primary phases are dominantly olivine, orthopyroxene and Cr-spinel; clinopyroxene, amphibole, and phlogopite are also found in Iherzolite samples. The whole-rock Mg# of harzburgite samples (89-91) is higher than that of lherzolite (average 82). The harzburgite samples contain olivine with higher Mg and Ni contents, orthopyroxene with higher Mg#, and Cr-spinel with higher Cr content than do the lherzolite samples. The REE patterns of clinopyroxene and amphibole in Iherzolite are most consistent with a cumulate origin. Although several compositional characteristics of the harzburgites resemble those of residual mantle, in detail the Cr2O3 and Al2O3 contents of fresh Cr-spinel in harzburgite are different from those found in mantle samples or in any of the Neoproterozoic ophiolitic peridotites throughout the Arabian-Nubian Shield. Thus, all the ultramafic rocks at Kabr El-Bonaya are best explained as ultramafic cumulates, with harzburgite consisting of early-formed cumulate phases and Iherzolite containing later-formed cumulate phases with higher REE abundances, primary hydrous minerals, evolved primary silicates, and high TiO2 (0.77 wt.%) and Al2O3 (18 wt.%) contents in Cr-spinel. The trace-element characteristics of the rocks indicate a subduction-related parental magma: whole-rock chondrite-normalized REE patterns are LREE-enriched; calculated integral O-2 values are elevated (+2.47 to +3.39 log units above the fayalite-magnetitequartz buffer); and computed N-MOR13-normalized trace element patterns for melts in equilibrium with clinopyroxene and amphibole have negative Nb-Ta anomalies and enrichment in large-ion lithophile elements. The low Al2O3/SiO2 ratios (0.007-0.040) of harzburgite samples and the low TiO2 contents and high Cr# of their Cr-spinel indicate derivation from a mantle source that experienced high-degree partial melting. From these characteristics, we infer a boninitic parental melt for the harzburgite. We offer an illustrative quantitative fractionation model that can explain the successive derivation of harzburgite and lherzolite cumulates along a single equilibrium, polybaric cooling path. We conclude that the Kabr El-Bonaya ultramafic cumulates represent the exposed roots of a Neoproterozoic island arc that was caught in the collision between East and West Gondwana.
英文关键词	Neoproterozoic Island Arcs Ultramafic cumulates Arabian-Nubian Shield Sinai
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000734021200002
WOS关键词	SOUTH EASTERN DESERT ; ALASKAN-TYPE COMPLEX ; MARIANA FORE-ARC ; ARABIAN-NUBIAN SHIELD ; MINERAL CHEMISTRY ; UPPER-MANTLE ; ISLAND-ARC ; TRACE-ELEMENTS ; ABYSSAL PERIDOTITES ; POSTCOLLISIONAL MAGMATISM
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/373954
作者单位	[Maurice, Ayman E.] Helwan Univ, Fac Sci, Peol Dept, Cairo 11790, Egypt; [Azer, Mokhles K.] Natl Res Ctr, Geol Sci Dept, Cairo 12622, Egypt; [Asimow, Paul D.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA; [Basta, Fawzy F.] Cairo Univ, Fac Sci, Geol Dept, Giza 12613, Egypt; [Helmy, Hassan M.] Minia Univ, Fac Sci, Geol Dept, Al Minya 61519, Egypt; [Shibata, Tomoyuki] Hiroshima Univ, Grad Sch Adv Sci & Engn, Hiroshima, Japan
推荐引用方式 GB/T 7714	Maurice, Ayman E.,Azer, Mokhles K.,Asimow, Paul D.,et al. THE KABR EL-BONAYA PERIDOTITES, SOUTHEASTERN SINAI, EGYPT: PETROLOGY, GEOCHEMISTRY, AND METAMORPHISM OF NEOPROTEROZOIC ARC ULTRAMAFIC CUMULATES[J],2021,321(10):1445-1496.
APA	Maurice, Ayman E.,Azer, Mokhles K.,Asimow, Paul D.,Basta, Fawzy F.,Helmy, Hassan M.,&Shibata, Tomoyuki.(2021).THE KABR EL-BONAYA PERIDOTITES, SOUTHEASTERN SINAI, EGYPT: PETROLOGY, GEOCHEMISTRY, AND METAMORPHISM OF NEOPROTEROZOIC ARC ULTRAMAFIC CUMULATES.AMERICAN JOURNAL OF SCIENCE,321(10),1445-1496.
MLA	Maurice, Ayman E.,et al."THE KABR EL-BONAYA PERIDOTITES, SOUTHEASTERN SINAI, EGYPT: PETROLOGY, GEOCHEMISTRY, AND METAMORPHISM OF NEOPROTEROZOIC ARC ULTRAMAFIC CUMULATES".AMERICAN JOURNAL OF SCIENCE 321.10(2021):1445-1496.