微生物碳酸盐岩同生⁃早成岩阶段有机质降解示踪：以四川盆地灯影组四段为例

游杰,胡广,张玺华,沈安江,彭瀚霖,田兴旺,赵东方

Geochemical tracing of organic matter degradation in microbial carbonates during syngenetic⁃early diagenesis: A case study from the Member IV of Dengying Formation,Sichuan Basin

Jie You,Guang Hu,Xihua Zhang,Anjiang Shen,Hanlin Peng,Xingwang Tian,Dongfang Zhao

图3 灯影组四段微生物碳酸盐岩特征 (a)凝块云岩宏观照，可见格架状凝块结构，灯四段，许家嘴剖面；(b)格架状凝块岩，格架间孔隙被二期胶结物充填，第一期为纤状白云石胶结，第二期为自形程度较高的粒状白云石；(c)分散斑块状凝块岩，单个凝块大小介于0.2~1.5 mm，凝块结构边界呈弥散状；(d)密集丛状凝块岩，凝块结构较小，分布较为密集；(e)分散状凝块岩，凝块空腔内见泥微晶沉积物充填在凝块结构和亮晶白云石之间；(f)丘状叠层石宏观照，灯四段，胡家坝剖面；(g)丘状叠层石微观特征，纹层呈波状起伏，亮纹层厚度(约为0.5 mm)较暗纹层(约0.2 mm)大；(h)具平直纹层的叠层石，灯四段，胡家坝剖面;(i)平直状叠层石，纹层较为平直，纹层横向连续

Fig.3 The lithology of microbial carbonates, Member IV of Dengying Formation