Arid
DOI10.1127/0077-7757/2002/0177-0321
Neoproterozoic volcanism at Um Shilman-Um Dubr area, Southeast Aswan, Egypt: Geology, geochemistry and tectonic environment of the Dokhan Volcanic Formation
Saleh, GM
通讯作者Saleh, GM
来源期刊NEUES JAHRBUCH FUR MINERALOGIE-ABHANDLUNGEN
ISSN0077-7757
出版年2002
卷号177期号:3页码:321-347
英文摘要

The volcanic history of the Neoproterozoic belt in the Eastern Desert of Egypt encompasses two major magmatic episodes. An earlier episode (950-750 Ma) produced the Shadli metavolcanic assemblages, and a younger episode (680-550 Ma) produced the Dokhan volcanic rocks. The Dokhan volcanics (DV) at Urn Shilman-Um Dubr, situated in the Southeast Aswan of Egypt, range in composition from basalt-andesite-dacite to rhyodacite-rhyolite. The latter unit is made up largely of ash flow tuffs and ignimbrites that are locally interstratified with basalt and andesite lava flows. Field, petrological and petrochemical investigations reveal that the rocks, which were previously mapped as island arc metavolcanics, are composed mainly of a thick sequence of volcaniclastics and flows that were subjected to low-pressure metamorphism. Geochemically, the Dokhan volcanics (DV) form a continuum in composition with a wide range of SiO2 (47.94-76.94 wt.%), CaO (0.14-8.85 wt.%), Sr (80905 ppm), Zr (72-340 ppm), U (1.4-13.1 ppm), Th (3.4-16.8 ppm) and are moderately enriched incompatible elements, including REE. The fractionation index (FeO*/MgO) increases gradually from the basalts through basaltic andesites to rhyolites (0.74, 0.92 and 1.59 respectively). The high Zr/Y ratio in the investigated volcanics characterizes rocks that evolved in continental arc setting and suggests involvement of subcontinental lithosphere in magma genesis. The relatively well-defined geochemical trends obtained for the Dokhan volcanic suite, along with the progressive increase in Euanomalies toward more-evolved compositions, combined with results of the geochemical modelling, support the idea that a fractional crystallization process has played a major role during the evolution of the Dokhan volcanic magma series. The enrichment of LILE (Sr, K, Rb and Ba) and the relative depletion of HFSE (Zr, P, Y and Ti) seem to be inherited from the mantle source. It is a typical calc-alkaline orogenic suites and exhibits mineralogical-geochemical traits of arc-related volcanism. A subduction-related tectonic setting for the emplacement of the investigated suite is indicated by the


英文关键词Dokhan volcanics petrography geochemistry petrogenesis incompatible trace element rave earth elements fractionation modelling
类型Article
语种英语
国家Egypt
收录类别SCI-E
WOS记录号WOS:000178036800006
WOS关键词CENTRAL EASTERN DESERT ; CRUSTAL EVOLUTION ; ROCKS ; COMPLEX ; ARC ; CLASSIFICATION ; DISCRIMINATION ; FRACTIONATION ; PETROGENESIS ; PETROLOGY
WOS类目Mineralogy
WOS研究方向Mineralogy
资源类型期刊论文
条目标识符http://119.78.100.177/qdio/handle/2XILL650/143445
作者单位(1)Nucl Mat Author, Cairo, Egypt
推荐引用方式
GB/T 7714
Saleh, GM. Neoproterozoic volcanism at Um Shilman-Um Dubr area, Southeast Aswan, Egypt: Geology, geochemistry and tectonic environment of the Dokhan Volcanic Formation[J],2002,177(3):321-347.
APA Saleh, GM.(2002).Neoproterozoic volcanism at Um Shilman-Um Dubr area, Southeast Aswan, Egypt: Geology, geochemistry and tectonic environment of the Dokhan Volcanic Formation.NEUES JAHRBUCH FUR MINERALOGIE-ABHANDLUNGEN,177(3),321-347.
MLA Saleh, GM."Neoproterozoic volcanism at Um Shilman-Um Dubr area, Southeast Aswan, Egypt: Geology, geochemistry and tectonic environment of the Dokhan Volcanic Formation".NEUES JAHRBUCH FUR MINERALOGIE-ABHANDLUNGEN 177.3(2002):321-347.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[Saleh, GM]的文章
百度学术
百度学术中相似的文章
[Saleh, GM]的文章
必应学术
必应学术中相似的文章
[Saleh, GM]的文章
相关权益政策
暂无数据
收藏/分享

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。