Micro- and Nanoscale Pore Structure Characterization of Carbonates from the Xiaoerbulake Formation in the Tarim Basin, Northwest China

Figure 3

Thin sections of outcrop samples from different sections of the Xiaoerbulake Formation, Tarim Basin; observed by optical microscopy under a polarized light: (a) fine-medium grained dolomite, no evidence of pores, SHY 5-107-3; (b) doloarenite, fine-grained dolomite cementing the space between grains, SGT 6-56-2; (c) microbial dolomite (spongy layered dolomite), multigeneration, and multistage dolomite filling the dissolution pores, SHY 6-133-1; (d) micritic dolomite, bitumen filling some dissolution pores, SGT 4-30-E; (e) micritic dolomite, calcite filling the microfracture, SHY 3-041-3; (f) fine grained dolomite, few fabric dissolution pores filled by bitumen, SHY 3-041-3; (g) fine-medium grained dolomite, intragranular pores and microfractures (red arrows) in the grain, intergranular pores in the matrix dolomite (yellow arrow), SGT 5-47-A; (h) intergranular pores in the dissolved dolomite (yellow arrow) and intercrystalline pores (green arrow), SHY 4-091-D; (i) intercrystalline dissolution pores (green arrow) in the filling dolomite, SHY 5-108-3.

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