Mineralogical correlation between primary and replacement dolomites

Primary dolostones occur in the Upper Sinian Dengying Formation. Based on mineralogical study the indicators for correlation between the primary dolomites which are not influenced by the diagenesis and the replacement dolomites of different periods have been obtained. It is shown that the primary dolomites are characterized by crystal forms precipitated and deposited directly from sea water, stable and homogeneous distribution of Mg and Ca, ideal chemical composition, regular modulated microstructures, low positive δ¹³C and low negative δ¹⁸O. Project supported by the “85–102” Chinese National Key Science and Technology Project.