الفهرس | Only 14 pages are availabe for public view |
Abstract Fourteen wells distributed along three SW-NE flow lines located north of Al-Ain city and covering the stratigraphic interval Quaternary - Upper Tertiary were selected for the present study. About 900 samples of rock cuttings representing the rock units: Quaternary, Pliocene Post Pars Formation, Miocene Upper and Lower Pars formations, Oligocene Asmari Formation, and Tertiary Pre Asmari Formation were recovered from these wells. Most of these samples were subjected to grain-size analysis, separation and semi-quantitative identification of acid-insoluble residues, microscopic examination of thin sections, X-ray diffractometry and chemical analyses for the major and trace elements. In addition, geophysical logs including: caliper, resistivity, neutron porosity, gamma ray, density and sonic were recorded in nine of the selected wells. Correlation between the penetrated sequences in each flow line as well as between the three lines revealed remarkable lateral and vertical variations in thicknesses and lithofacies characteristics of the various rock units. Sediments of the Quaternary and the underlying formations consist mainly of varying proportions of sands and gravels which are composed predominantly of carbonates and ophiolites. The concentrations of the determined major elements and some of the trace elements vary widely and are closely related to the relative proportions of the dominant mineral components. Evidently, the Quaternary sediments were derived primarily from the Oman Mountains and Jebel Hafit through river and aeolian processes. The relative contributions from these two sources varied remarkably in space . |