引用本文：梅冥相,Khalid Latif,孟庆芬,胡媛.2019.寒武系张夏组鲕粒滩中微生物碳酸盐岩主导的生物丘：以河北秦皇岛驻操营剖面为例[J].地质学报,93(1):227-251. MEI Mingxiang,KHALID Latif,MENG Qingfen,HU Yuan.2019.Cambrian bioherms dominated by microbial carbonate within the oolitic grainstone bank, Zhangxia Formation of the Miaolingian, Zhucaoying section in Qinhuangdao City of Hebei Province[J].Acta Geologica Sinica,93(1):227-251.
Abstract:The Cambrian Miaolingian of the North- China Platform is chieflyconstituted by the Maozhuang, the Xuzhang, the Zhangxia and the Gushan Formations, and these Formations respectively make up the corresponding third- order depositional sequences. The time- specific facies represented by oolitic grainstones of the carbonate bank that is commonly makes up the forced- regressive system tract for each third- order depositional sequence also marks a special type of carbonate platform dominated by ooids, which is characteristic of the large- scale distribution with large acreage of oolitic- grainstone bank with the growth of bioherm dominated by microbial bioherms. Carbonate bioherms within the oolitic- grainstone bank at the Zhucaoying section in Qinhuangdao city of Hebei province can be considered as a typical example. Although similar deposits have described as the deposit of the “algal falt” deposit within the oolitic graonstone bank as well as grouped into the microbial reef, following features not only characterize the bioherm within the oolitic graonstone bank at the Zhucaoying section in Qinhuangdao city of Hebei province but also represent a grand sedimentological phenomenon: ① massive and thick- bedded carbonate bioherms of the column stromatolite with the alteration of massive and thick- bedded oolitic grainstons of the carbonate bank are developed in the low part of the forced regressive system tract; ② carbonate bioherms dominated by leiolites and dendralites are centralized in the top part of the Zhangxia Formation; ③ within column stromatolites are observed particular fossils of calcified cyanobacterias, i.e. the fossils belonging to the Lithocodium- Bacinella group; ④ several varieties of calcified cyanobacterias, such as the fossils of filamental cyanobacterias, the Hedstroemia and the Epiphyton, are found within the carbonate bioherms dominated by leiolites and dendralites. Lithocodium and Bacinella are now extinct, shallow marine life forms of unknown taxonomic origin, which are frequently described in the Mesozoic strata. No examples of modern leiolite have been published, and a few examples are described in ancient stratigraphical records. More importantly, the depositional fabric that is similar to the Lithocodium or the Lithocodium- like fabric is commonly interpreted as “the network of silicious sponge spiculas” or “the skeleton fibre of non- spicula keratose demosponges” during the study on the microbial carbonate of the Palaeozoic. Therefore, the bioherm dominated by microbial carbonates enriched with many varieties
of fossils of calcified cyanobacterias in the upper part of the Zhangxia Formation at the ZHucaoying section is an important example for the further understanding of microbial carbonates resulted from the sophisticated calcification of microbial mats or biofilms.