Hydrothermal Dissolution of Deeply Buried Cambrian Dolomite Rocks and Porosity Generation: Integrated with Geological Studies and Reactive Transport Modeling in the Tarim Basin, China

Figure 7

Photomicrographs showing different types of dolomites in Cambrian strata in well TS1. (a) Dark-brown to black, organic-rich laminated microbial dolomite (Md1), 7690 m. (b) Photomicrographs of microbial boundstones in platform margin reefs. Note the well-preserved original microbial fabric (Md2), 7875.7 m. (c) Photomicrographs of fabric-retentive dolomite (ooidal grainstone) (Md2) cemented with thin fibrous (or bladed) and equant dolomite crystals, 7710 m. (d) Very finely crystalline, fabric-retentive micrite (dolomicrite) (Md1) with medium-crystalline fabric-obliterative dolomite (Md2), 8030 m. (e) Medium to coarse crystalline fabric-obliterative dolomite (Md2), 7155 m. (f) Photomicrograph showing cement dolomites in the vug developed in the matrix dolomite: the initial medium-crystalline planar-s (subhedral) dolomites (Cd1) and subsequent coarse crystalline saddle dolomites (Cd2) which are characterized by curved crystal faces and undulose extinction. 7875 m. Note the relict pore space in vug center (blue resin).

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