الفهرس | Only 14 pages are availabe for public view |
Abstract Cenozoic subsurface sediments from Tarif well-2A, Nile Delta were studied with special reference t o the clay mineralogy, geochemistry and micropaleontology of the sediments. X-ray diffraction analysis of the clay minerals has revealed t h a t , smectite, kaolinite, illite and mixedlayer illite/smectite clays dominate the fine fraction of the sediments. Besides these clay minerals, other detrital non-clay minerals such as quartz, feldspar as well as c a l c i t e and dolomite were identified on the diffractograms. Chemical analysis of the major elements showed variations closely linked t o lithological changes and the elemental association has clarified some of the sedimentological processes influencing sedimentation in t h a t p a r t of the delta. The great aridity, entensive erosion and chemical weathering of non-stable materials were thought t o be responsible for the deposition of large amount of mature sands during the Quaternary. On the other hand, the wet climate, good mat of vegetation, little surface erosion and intense chemical weathering, prevailed during most of the Cenozoic and prior t o the Pleistocene, were probably responsible for the contribution of clay minerals and other detrital material during the Oligocene, Miocene and Pliocene times. |