DETAILED DIAGENETIC STUDY AND ITS IMPLICATIONS ON THE RESERVOIR CHARACTERIZATION OF THE CAMBRIAN SIRBAN DOLOMITES IN THE VICINITY OF THE ABBOTABAD CITY, KHYBER PAKHTUNKHWA, PAKISTAN

Abstract

Study of dolomite is very important because of its economic importance. Majority of world oil and gas reservoirs rests in dolomites (Dunham et al., 1980). Dolomite is a complex mineral and several questions are still to be answered with respect to its formation and distribution throughout the geological record, as the mineral of dolomite cannot be prepared in the Laboratory (Land, 1998). Modern sea water is much more supersaturated but still it lacks the capability to form dolomite. The main reason is that of Kinetics which resists the formation of Dolomite in the water of modern oceans. Lack of the modern counterpart of ancient dolomite has created what is known by the “Dolomite problem” (Zenger, 1972), that how the old dolomites were formed by studying modern dolomites (Chilingar, 1956; Ronov, 1964). Lippmann in 1973 declared that in the precipitation of dolomite one of the main factor in kinetic is hydration shell which has to be controlled. These controlling factors include heating, cooling, dilution, concentration of oceanic water. Lowering level of sulphate contributes much in controlling kinetic problem (Lippmann, 1982). As the abundance of dolomite decreases with time so the “present is a key to past” is not working properly in some aspect of sedimentological studies