Understanding microbial carbonate is one of the most challenging issues in the field of carbonate sedimentology and reservoir. The biotic and abiotic processes that control microbial carbonate precipitation are becoming more established, but the influence of subsequent diagenesis on microbial carbonate reservoirs has not been adequately studied. Here, we describe microbial carbonate from the lower Cambrian Qingxudong Formation in southeastern Sichuan Basin to assess their formation, textures and subsequent diagenesis. Six stages of calcite cementation (Calcite-1 to Calcite-6) and four stages of dissolution (Dis-1 to Dis-4) were identified in microbialites of the Qingxudong Formation. Stromatolites and thrombolites have a different porosity evolution. Sedimentary processes are the fundamental controlling factors of creating pre-existing pores in stromatolites. For thrombolites, the formation of pre-existing pores is attributed to island dissolution and dolomitization in near-surface processes. Microbial metabolic activities contribute more to the dissolution and dolomitization than mixing water. Meteoric water dissolution (Dis-1) in synsedimentary processes and microbial dissolution (Dis-2) in near-surface processes are the fundamental control factors of porosity creation in microbial carbonate of Qingxudong Formation. Thermochemical sulfate reduction (TSR) is a double-edged sword for the porosity development. The destructive effect of TSR on microbial carbonate reservoirs is greater than the constructive effect. The microbial carbonate reservoirs, especially the fabric-destructive dolomite (Dol-2) evolved by thrombolites, have great potential for gas exploration in the Qingxudong Formation. This study is especially useful for further understanding deeply buried microbialite reservoir formation and development, and deep hydrocarbon exploration in this basin and elsewhere worldwide.

了解碳酸盐微生物是碳酸盐沉积学和储层领域最具挑战性的问题之一。控制微生物碳酸盐沉淀的生物和非生物过程变得越来越成熟，但是随后的成岩作用对微生物碳酸盐储层的影响尚未得到充分研究。在这里，我们描述了四川盆地东南部下寒武统清徐洞组的微生物碳酸盐，以评估其形成，质地和随后的成岩作用。在清徐洞组的微辉长岩中，确定了方解石胶结作用的六个阶段（方解石1至方解石6）和溶解的四个阶段（Dis-1至Dis-4）。基质岩和血栓岩具有不同的孔隙度演化。沉积过程是在叠层石中形成预先存在的孔的基本控制因素。对于血栓石，先前存在的孔的形成归因于近地表过程中的岛屿溶解和白云石化。与混合水相比，微生物的代谢活动对溶解和白云石化的贡献更大。沉积过程中的流星水溶解度（Dis-1）和近地表过程中的微生物溶解度（Dis-2）是清徐洞组微生物碳酸盐岩孔隙形成的基本控制因素。减少硫酸盐热化学反应（TSR）是开发孔隙率的双刃剑。TSR对微生物碳酸盐储层的破坏作用大于建设性作用。微生物碳酸盐储层，尤其是由凝块形成的破坏织物的白云岩（Dol-2），在清徐洞组天然气勘探方面具有很大的潜力。这项研究对于进一步了解深埋的微辉石储层的形成和发育，以及对该盆地和世界其他地区的深层油气勘探尤其有用。