Determining of dolomitization age and depth of Mardin Group based on clumped isotopes and 1D basin model in SE Anatolia (SE Turkey)

Abstract

The widespread Cretaceous aged Mardin Group is shallow marine carbonates and is the most proliferous section in SE Anatolia (SE Turkey). Clumped isotope temperatures were measured for Mardin dolomites between 92oC and 125oC. Using 1D basin model, clumped isotopes temperatures were converted to a depth and time for dolomitization from 2200 m (22 Ma) to 3420 m (14 Ma). Both the range of paleotemperature and burial depth reflects different degree of recrystalization event as a result of burial event. The oxygen isotopic composition of dolomitizing fluid varied between 3.32‰ and 6.31‰ which is significantly heavier than Cretaceous marine waters. The results indicates that late dolomitization are present in the study area and that a deeply buried dolomitizing pore fluid with high T has a negative influence on porosity system of the Mardin Group Reservoir.