Sedimentary environment and petrological features of organic-rich fine sediments in shallow water overlapping deposits: A case study of Cambrian Yuertus Formation in northwestern Tarim Basin, NW China

JIN Zhimin,TAN Xiucheng,TANG Hao,SHEN Anjiang,QIAO Zhanfeng,ZHENG Jianfeng,LI Fei,ZHANG Shixuan,CHEN Lei,ZHOU Chenggang

Fig. 4. Macroscopic and microscopic characteristics of diamictic grainstone. (a) Thin shale and siliceous rock interbeds + terrigenous diamictic grainstone, Sugaite section; (b) Macroscopic photo of diamictic grainstone outcrop, showing a flat bottom and a convex top; (c, d) Dolomitic fine sandstone (Q: quartz, P: apatite, C: rock cuttings; Fig. 4c is under plane-polarized light, and Fig. 4d is under orthogonally-polarized light); (e. f) Sandy dolomite; Fig. 4e is under plane-polarized light, and Fig. 4f is under orthogonally-polarized light); (g, h) Residual granular phantom of the crystalline dolomite (Fig. 4h is the plane-polarized photomicrograph of thin section on a piece of 70g A4 paper); (i) Wave-built cross-bedding above the diamictic grainstone.