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. 3. Photos of infillings in biological burrows. (a) A oilfield, Well A16, 2665.40 m, single polarized light, dyed, cast thin section. The matrix is muddy psammitic limestone, and the burrows are filled with psammitic granular limestone. (b) W oilfield, Well W-17, 2470.70 m, single polarized light, dyed, cast thin section. The matrix and burrows are clastizoic marl. (c) M oilfield, Well M-46, 2939.26 m, single polarized light, undyed, cast thin section. The matrix is clastizoic micrite, and burrows are filled with bioclastic micrite. (d) M oilfield, Well M-46, 2981.32 m, single polarized light, undyed, cast thin section. The matrix is clastizoic micrite, and burrows are filled with micritic bioclastic limestone. (e) M oilfield, Well M-46, 2937.65 m, single polarized light, dyed, cast thin section. The matrix is clastizoic mudstone, and the burrows are filled with micritic bioclastic limestone. (f) M oilfield, Well M-46, 2938.15 m, single polarized light, dyed, cast thin section. The matrix is clastizoic micrite, and the burrows are filled with calcsparite bioclastic limestone. (g) H oilfield, Well M31, 2914.13 m, single polarized light, dyed, cast thin section. The matrix is clastizoic mudstone, and the burrows are filled with calcite. (h) W oilfield, Well W-17, 2438.59 m, single polarized light, dyed, cast thin section. The matrix is bioclastic micrite, and the burrows are filled with clastizoic micrite. (i) W oilfield, Well W-2, 2234.55 m, single polarized light, dyed, cast thin section. The matrix is clastizoic micrite, and the burrows are filled with clastizoic limy dolomite. (j) M oilfield, Well M-46, 2876.84 m, single polarized light, undyed, cast thin section. The dissolution zones of the burrows are fine-crystal dolomite, and the non-dissolution zones are muddy fine-crystal dolomite. (k) M oilfield, Well M-46, 2875.39 m, single polarized light, undyed, cast thin section. The matrix is micritic bioclastic limestone, and burrows are filled with fine-crystal dolomite; (l) M oilfield, Well M-46, 2969.75 m, single polarized light, dyed, cast thin section. The matrix is clastizoic mudstone, and the burrows are filled with mosaic fine-crystal dolomite.