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Marine sedimentary phosphorites of Eocene age (Upper Ypresian) are exposed in the extreme west of Iraq within the Dammam Formation. They are associated with limestone and chert, and their deposition seems to have taken place in a shallow marine environment within a structurally controlled basin open to the sea from the northern and western sides only.The studied phosphorites are granular in texture, coarse-grained and cemented by calcite which is occasionally silicified. Bone fragments are present in small amounts. Carbonate-fluorapatite is the only phosphate mineral detected in these phosphorites, with relatively high amounts of the components SO4?2, CO3?2, F?1, H3O1 and Na1 substituting in the crystal structure.The Lower Eocene phosphorites of Iraq are part of the Tethyan phosphorite province, and are comparable in many aspects with those of Paleocene and Upper Cretaceous age in the Western Desert of the country.  相似文献   
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