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DOI | 10.1007/s005310050304 |
Geochemistry, petrogenesis and tectonic setting of late Neoproterozoic Dokhan-type volcanic rocks in the Fatira area, eastern Egypt | |
Mohamed, FH; Moghazi, AM; Hassanen, MA | |
通讯作者 | Mohamed, FH |
来源期刊 | INTERNATIONAL JOURNAL OF EARTH SCIENCES
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ISSN | 1437-3254 |
出版年 | 2000 |
卷号 | 88期号:4页码:764-777 |
英文摘要 | The Neoproterozoic Dokhan volcanics of the Fatira area in eastern Egypt comprise two main rock suites: (a) an intermediate volcanic suite, consisting of basaltic andesite, andesite, dacite, and their associated pyroclastic rocks; and (b) a felsic volcanic suite composed of rhyolite and rhyolitic tuffs. The two suites display well-defined major and trace element trends and a continuum in composition with wide ranges in sie, (54-76%), CaO (8.19-0.14%), MgO (6.96-0.04%), Sr (983-7 ppm), Zr (328-95 ppm), Cr (297-1 ppm), and Ni (72-1 ppm). They are enriched in LILEs (Rb, Ba, K, Th, Ce) relative to high field strength elements (Nb, Zr, P, Ti) and show strong affinity to calc-alkaline subduction-related rocks. However, their undeformed character, their emplacement temporally and spatially with post-orogenic A-type granite, and their high Zr/Y values suggest that their emplacement follow the cessation of subduction in eastern Egypt in an extensional-related within-plate setting. Major and trace element variations in the intermediate volcanics are consistent with their formation via partial melting of an enriched subcontinental lithospheric mantle source followed by a limited low-pressure fractional crystallization of olivine and pyroxene before emplacement. The LILE enrichment relative to HFSE is attributed to the inheritance of a subduction component from mantle material which constituted the mantle wedge during previous subduction events in eastern Egypt. The evolution of the whole volcanic spectrum was governed mainly by crystal/melt fractionation of amphibole, plagioclase, titanomagnetite, and apatite in the intermediate varieties and plagioclase, amphibole, biotite, Fe-Ti oxides, apatite. and zircon in the felsic varieties. At each stage of evolution, crystal fractionation was accompanied by variable degrees of crustal contamination. |
英文关键词 | Neoproterozoic Dokhan volcanics Egypt geochemistry petrogenesis |
类型 | Article |
语种 | 英语 |
国家 | Egypt |
收录类别 | SCI-E |
WOS记录号 | WOS:000088003200016 |
WOS关键词 | NORTHERN NUBIAN SHIELD ; RARE-EARTH ELEMENTS ; A-TYPE GRANITES ; ISOTOPIC CONSTRAINTS ; CRUSTAL EVOLUTION ; SOUTHERN ISRAEL ; ISLAND-ARC ; DESERT ; ORIGIN ; MAGMA |
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/2XILL650/139154 |
作者单位 | (1)Univ Alexandria, Fac Sci, Dept Geol, Alexandria, Egypt |
推荐引用方式 GB/T 7714 | Mohamed, FH,Moghazi, AM,Hassanen, MA. Geochemistry, petrogenesis and tectonic setting of late Neoproterozoic Dokhan-type volcanic rocks in the Fatira area, eastern Egypt[J],2000,88(4):764-777. |
APA | Mohamed, FH,Moghazi, AM,&Hassanen, MA.(2000).Geochemistry, petrogenesis and tectonic setting of late Neoproterozoic Dokhan-type volcanic rocks in the Fatira area, eastern Egypt.INTERNATIONAL JOURNAL OF EARTH SCIENCES,88(4),764-777. |
MLA | Mohamed, FH,et al."Geochemistry, petrogenesis and tectonic setting of late Neoproterozoic Dokhan-type volcanic rocks in the Fatira area, eastern Egypt".INTERNATIONAL JOURNAL OF EARTH SCIENCES 88.4(2000):764-777. |
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