干旱区生态环境知识资源中心(Arid): Petrological characteristics of the Neoproterozoic Ess ophiolite mantle section, Arabian Shield, Saudi Arabia: a mineral chemistry perspective

Arid

DOI	10.1007/s00531-019-01799-3
	Petrological characteristics of the Neoproterozoic Ess ophiolite mantle section, Arabian Shield, Saudi Arabia: a mineral chemistry perspective
	Gahlan, Hisham A.1,2; Azer, Mokhles K.3; Asimow, Paul D.4; Mubarak, Heba S.3; Al-Kahtany, Khalid M.5
通讯作者	Azer, Mokhles K.
来源期刊	INTERNATIONAL JOURNAL OF EARTH SCIENCES
ISSN	1437-3254
EISSN	1437-3262
出版年	2020
卷号	109 期号:1 页码:239-251
英文摘要	The Ess ophiolite, one of the most important ophiolitic massifs of the Arabian Shield, consists of a lower succession of serpentinized mantle rocks overlain by an ultramafic cumulate sequence, layered and isotropic gabbros, sheeted dykes, pillow lavas and pelagic sediments. The Ess mantle section is composed mainly of serpentinized peridotites with chromitite pods, dunite, wehrlite and pyroxenite. Extensive metasomatism and alteration has transformed the ultramafic rocks to talc-carbonates, magnesite deposits and listvenite, especially along shear zones and fault planes. Nevertheless, relics of primary chromian spinel, olivine and pyroxenes are observed. Both primary and metamorphic olivines can be recognized in dunite; the latter is marked by very high forsterite content (97-98), low NiO content (< 0.2 wt%) and wide variations in MnO content (0.03-1.3 wt%). The mesh and bastite textures of the serpentine suggest that protoliths were mainly harzburgite with minor dunite. Some fresh cores of Cr-spinel are rimmed by ferritchromite and Cr-magnetite, indicating prograde metamorphism at lower amphibolite facies under oxidizing conditions. The high Cr# (> 0.6) and low TiO2 content (< 0.14 wt%) of fresh Cr-spinel and the high forsterite (0.90-0.93) and NiO contents (0.4-0.5 wt%) of fresh olivine are all consistent with residual mantle rocks that experienced high degrees of partial melt extraction. Orthopyroxene and clinopyroxene in the Ess peridotites have low CaO, Al2O3 and TiO2 contents resembling those typically found in depleted harzburgites from fore-arcs. Consequently, we propose that the Ess mantle peridotites formed in a forearc setting during subduction initiation that developed as a result of northwest subduction due to the convergence between East and West Gondwana, leading eventually to closure of the Mozambique Ocean during the Pan-African orogeny.
英文关键词	Ess ophiolite Serpentinized peridotite Fore-arc Supra-subduction zone Arabian shield
类型	Article
语种	英语
国家	Saudi Arabia ; Egypt ; USA
收录类别	SCI-E
WOS记录号	WOS:000501229900002
WOS关键词	SOUTH EASTERN DESERT ; MAFIC-ULTRAMAFIC INTRUSION ; CHROMIAN SPINEL ; NUBIAN SHIELD ; ALASKAN-TYPE ; EGYPT IMPLICATIONS ; AFRICAN OROGEN ; COMPLEX ; PERIDOTITES ; GEOCHEMISTRY
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
EI主题词	2019-12-03
来源机构	King Saud University
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/311546
作者单位	1.King Saud Univ, Dept Geol & Geophys, Riyadh 11451, Saudi Arabia; 2.Assiut Univ, Dept Geol, Assiut 71516, Egypt; 3.Natl Res Ctr, Dept Geol Sci, Cairo, Egypt; 4.CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA; 5.King Saud Univ, Coll Sci, Seism Studies Ctr, Riyadh 11451, Saudi Arabia
推荐引用方式 GB/T 7714	Gahlan, Hisham A.,Azer, Mokhles K.,Asimow, Paul D.,et al. Petrological characteristics of the Neoproterozoic Ess ophiolite mantle section, Arabian Shield, Saudi Arabia: a mineral chemistry perspective[J]. King Saud University,2020,109(1):239-251.
APA	Gahlan, Hisham A.,Azer, Mokhles K.,Asimow, Paul D.,Mubarak, Heba S.,&Al-Kahtany, Khalid M..(2020).Petrological characteristics of the Neoproterozoic Ess ophiolite mantle section, Arabian Shield, Saudi Arabia: a mineral chemistry perspective.INTERNATIONAL JOURNAL OF EARTH SCIENCES,109(1),239-251.
MLA	Gahlan, Hisham A.,et al."Petrological characteristics of the Neoproterozoic Ess ophiolite mantle section, Arabian Shield, Saudi Arabia: a mineral chemistry perspective".INTERNATIONAL JOURNAL OF EARTH SCIENCES 109.1(2020):239-251.