Composition and origin of black shales from Quseir area, Red Sea, Egypt
Composition and origin of black shales from Quseir area, Red Sea, Egypt
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埃及红海库塞尔地区黑色页岩成分及成因
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
M. El
中科院分区：
文献类型：
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作者：
A. El;M. Darwish;G. Philip;M. El
本文报道了库希尔地区达赫拉组和杜威组中的黑色页岩。它们富含有机物。它们可描述为沥青钙质有孔虫粘土岩至沥青泥质灰岩。在一些地方，黑色页岩异常富含钒(0.8%V{sub2}O{sub5})和其他重金属，最明显的是在与杜威组接触的附近。钒的含量似乎不受普遍风化的影响。黑色页岩由无序的结晶不良的高岭石、蒙脱石、亲有机蒙脱石、混层蒙皂石-伊利石、石英、方解石、铁粉白云石、碳酸盐氟磷灰石、石膏、硬石膏、黄铁矿和有机化合物(最不饱和分子)组成。微量元素含量可划分为陆源组合，Y、La、Ce主要由生物成因碎屑堆积而成：碎屑矿物中的Ti、Zr，高岭石中的Sc、Ga、Nb，而Co主要存在于蒙脱石中，包括铅、锶、锰的碳酸盐组合和含Cd、Be、Zn、V、U的有机组合。U、Th平衡常数表明无二次放射性富集。
This paper reports on black shales occurring within the Dakhla and Duwi Formations in the Quseir area. They are rich in organic matter. They can be described as bituminous calcareous foraminiferal claystone to bituminous argillaceous limestone. In places, the black shales are abnormally enriched in vanadium (0.8% V{sub 2}O{sub 5}) and other heavy metals, most markedly so near the contact with the Duwi Formation. The content of vanadium appears to be unaffected by the prevailing weathering. The black shales are composed of disordered poorly crystalline kaolinite, smectite, organophilic smectite, mixed-layer smectite-illite, quartz, calcite, ferroan dolomite, carbonate fluorapatite, gypsum, anhydrite, pyrite and organic compounds (most unsaturated molecules). The trace element content is classified into a terrigenous association where Y, La and Ce are accumulated by clastic of biogenic origin: Ti and Zr in detrital minerals; Sc, Ga and Nb in kaolinite, while Co is mostly in smectite, a carbonate association, including Pb, Sr and Mn, and an organic association which includes Cd, Be, Zn, V and U. The U and Th equilibrium constants suggest no secondary radioactive enrichment.