Transformation mechanism of muddy carbonate rock by the coupling of bioturbation and diagenesis: A case study of the Cretaceous of the Mesopotamia Basin in the Middle East

YE Yu,LI Fengfeng,SONG Xinmin,GUO Rui

Fig. 7. Photos of diagenetic environmental indicators of Cretaceous Mishrif Formation in Mesopotamia Basin. (a) H oilfield, Well M316, Mishrif Formation, 2951.20 m, single polarized light, undyed, cast thin section. Bioclasts are selectively dissolved to form moldic pores. (b) M oilfield, Well M-46, Mishrif Formation, 2888.15 m, single polarized light, undyed, cast thin section. Non-selective dissolution forms dissolution pores and vugs. (c) W oilfield, Well W-17, Mishrif Formation, 2436.50 m, single polarized light, undyed, cast thin section, geopetal crystal siltstone. (d) H oilfield, Well M316, Mishrif Formation, 2941.20 m, single polarized light, undyed, cast thin section. Fine-crystal dolomite is developed in sutures. (e) H oilfield, Well M316, Mishrif Formation, 2943.20 m, single polarized light, undyed, cast thin section. The burrows are filled with coarse-crystal ferric calcite. (f) H oilfield, Well M316, Mishrif Formation, 2967.20 m, single polarized light, undyed, cast thin section. There are automorphic fine-crystal dolomite and coarse-crystal ferric calcite in burrows.