干旱区生态环境知识资源中心(Arid): Field, textural, geochemical, and isotopic constraints on the origin and evolution of the magmatic microgranular enclaves from the Gharib Granitoid Complex, North Eastern Desert, Egypt

Arid

DOI	10.1016/j.precamres.2021.106380
	Field, textural, geochemical, and isotopic constraints on the origin and evolution of the magmatic microgranular enclaves from the Gharib Granitoid Complex, North Eastern Desert, Egypt
	Eliwa, H. A.; Deevsalar, R.; Mahdy, N. M.; Kumar, S.; El-Gameel, Kh; Zafar, T.; Khalaf, I. M.; Murata, M.; Ozawa, H.; Andresen, A.; Chew, D.; Fawzy, M. M.; Afandy, A.; Kato, Y.; Fujinaga, K.
通讯作者	Eliwa, HA (corresponding author), Menoufia Univ, Fac Sci, Geol Dept, Shibin Al Kawm, Egypt.
来源期刊	PRECAMBRIAN RESEARCH
ISSN	0301-9268
EISSN	1872-7433
出版年	2021
卷号	365
英文摘要	The Neoproterozoic Gharib Granitoid Complex (GGC), in the North Eastern Desert (NED) of Egypt, is characterized by the occurrence of varieties of granitoids. Monzogranite, the most abundant granite variety, contains abundant magmatic microgranular enclaves (MMEs) of mafic to intermediate composition. The MMEs are more mafic than their host and marked by a greater amount of amphibole and biotite. They are finer grained and have porphyritic/poikilitic textures. The sharp, crenulated, and fine-grained quenched contacts of the elongated, rounded, and ellipsoid form of the MMEs with their felsic host indicate rapid cooling during a magma mixing/mingling event. Micro-textural evidence supports the mechanical transfer of minerals that crystallized in felsic magma to the mafic melt (e.g., feldspar phenocrysts cross-cutting the MME-host boundaries, stubby apatite, quartz ocelli, and poikilitic outermost rims of K-feldspar phenocrysts), supercooling/quenching process (e.g., acicular apatite and elongated hornblende and biotite crystals), and disequilibrium growth (e.g., hornblende-biotite clots replaced early crystallized clinopyroxene), which also favour a magma mingling/mixing origin. Linear to curvilinear chemical variations of the MMEs and the host monzogranites on Harker diagrams, highly similar trace element contents, and Sr-Nd isotopic systematics together with mineral-chemical features also support mixing/mingling as the main process in magma genesis and strongly suggest that the MMEs were supercooled hybrid globules within cooler, partially crystallized host felsic magma. The crust-like geochemical signatures (i.e., SiO2 content, metaluminous nature, and lack of upper crustal xenoliths and typical peraluminous minerals), along with low [MMEs: (Sr-87/Sr-86)(initial) = 0.70136-0.70373; monzogranites: (Sr-87/Sr-86)(initial) = 0.70202-0.70320)] along with zircon and apatite U-Pb age data indicate the possible involvement of juvenile lower continental crust (LCC) of the Arabian-Nubian Shield (ANS) in their genesis. The medium- to high-K calc-alkaline affinity, the LILE enrichment, and the HFSE depletion along with low Nb/La ratios and positive eNd( t) (MMEs = +4.01 - +5.62, monzogranites = +2.29 - +6.03) indicate the contribution of depleted lithospheric mantle in the magma genesis, whereas the low delta Eu and fairly high delta Ce values, stable La/Sm, and variable Sr/Th ratios in apatites from the monzogranites and MMEs indicate the contribution of volatile/fluids from the remnants of the oceanic slab in facilitating melting in the source region. The genesis of the monzogranites and MMEs started with asthenosphere upwelling, followed by melting of the remnants of lithospheric mantle, and underplating of mantle magma, which led to partial melting of the LCC. Multi-element modelling postulates that the low degree mixing between partially crystallized mantle magma and LCC-derived felsic melt (F-mix similar to 0.1) could produce the parent magma for the monzogranites. Further mixing/mingling of the crystal-charged monzogranite parent magma with new pulses of mafic melts (F-mix similar to 0.25) developed a hybrid zone and formed the hybrid MMEs. Thus, the final episode of the ANS evolution was associated with a complex post-collisional interplay between asthenosphere, litho-spheric mantle, and the LCC caused by the removal of delaminated lithospheric root and dense lower crust following the collision between East and West Gondwana in the Neoproterozoic time.
英文关键词	Arabian Nubian Shield Geochemistry Sr-Nd isotopes Microgranular Enclaves Granites Magma mixing
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000703586700004
WOS关键词	ARABIAN-NUBIAN SHIELD ; PALAEOPROTEROZOIC MALANJKHAND GRANITOIDS ; ZIRCON U-PB ; CALC-ALKALINE ; NEOPROTEROZOIC GRANITOIDS ; CRUSTAL EVOLUTION ; CONTINENTAL LITHOSPHERE ; NORTHEASTERN DESERT ; CHAOTIC DYNAMICS ; VOLCANIC-ROCKS
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/2XILL650/364412
作者单位	[Eliwa, H. A.; El-Gameel, Kh; Khalaf, I. M.] Menoufia Univ, Fac Sci, Geol Dept, Shibin Al Kawm, Egypt; [Deevsalar, R.] Univ Ryukyus, Dept Phys & Earth Sci, Nishihara, Okinawa 9030213, Japan; [Mahdy, N. M.; Fawzy, M. M.; Afandy, A.] Nucl Mat Author, PO 530, Cairo, Egypt; [Kumar, S.] Kumaun Univ, Dept Geol, Naini Tal 263002, India; [Zafar, T.] Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China; [Murata, M.; Ozawa, H.] Natl Univ Corp, Naruto Univ Educ, Fac Sci Naruto, Dept Geosci, Tokushima 7728502, Japan; [Andresen, A.] Univ Oslo, Dept Geosci, Oslo, Norway; [Chew, D.] Trinity Coll Dublin, Sch Nat Sci, Dept Geol, Dublin 2, Ireland; [Kato, Y.; Fujinaga, K.] Univ Tokyo, Sch Engn, Dept Geosyst Engn, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan
推荐引用方式 GB/T 7714	Eliwa, H. A.,Deevsalar, R.,Mahdy, N. M.,et al. Field, textural, geochemical, and isotopic constraints on the origin and evolution of the magmatic microgranular enclaves from the Gharib Granitoid Complex, North Eastern Desert, Egypt[J],2021,365.
APA	Eliwa, H. A..,Deevsalar, R..,Mahdy, N. M..,Kumar, S..,El-Gameel, Kh.,...&Fujinaga, K..(2021).Field, textural, geochemical, and isotopic constraints on the origin and evolution of the magmatic microgranular enclaves from the Gharib Granitoid Complex, North Eastern Desert, Egypt.PRECAMBRIAN RESEARCH,365.
MLA	Eliwa, H. A.,et al."Field, textural, geochemical, and isotopic constraints on the origin and evolution of the magmatic microgranular enclaves from the Gharib Granitoid Complex, North Eastern Desert, Egypt".PRECAMBRIAN RESEARCH 365(2021).