Morphology Characteristics And Environmental Significance Of The Cambrian Stromatolite In The Middle Of Taihang Mountain

Stromatolite is a kind of biological sedimentary structure formed by microorganism groups such as cyanobacteria,which capture,adhere and preciPitate the extraneous sediments.The stromatolites are widely developed in the Cambrian and Precambrian carbonates and are distributed in various geological periods.There are many forms of stromatolite.His monomers are horizontally wavy,monolithic,dendritic,and finger-like.There are monomers that grow independently,and there are also meshes or braids that are connected to each other.The stromatolite often appears in the state of a reef,and its form is mainly layered,layered,globular,tunnel-like,and irregularly shaped.There are still some paleontologists insisting on the early stromatolite research that different forms of stromatolite are the expression of algae in different eras,and have the significance of the age of biological evolution.The sedimentary scientists have shown through a large number of research results that the morphology of the stromatolite is related to the sedimentary hydrodynamic conditions.Cambrian stromatolites are particularly developed and are often found in Late Cambrian strata.The stromatolite is widely distributed in the Cambrian of the Zhangxia Formation in North China.Through field observations,we found that the Cambrian stromatolite reef has a spherical shape,a tunnel shape and an irregular tower shape in addition to the layered shape.The relationship between these reef morphology and sedimentary environment,hydrodynamic conditions,and microbial types has drawn my attention.In this paper,the study of the stromatolite in the middle part of taihang mountain was conducted by combining the field investigation and indoor research,and combined with the knowledge of sedimentology,paleontology and sedimentary facies.In the upper oolitic limestone and gushan bioclastic limestone of the zhangxia formation,stratified stromatolite reefs,cocked-shaped stromatolite reefs,sphericalcolumnar stromatolite reefs were developed,and stratified stromatolite,columnar stromatolite and cone-columnar stromatolite were developed inside the reef body.In the bottom of the zhangxia formation,irregular stromatolite reefs,algal stucco and nucleoid-shaped rocks were developed.Stratified stromatolite and finger stromatolite,dendritic stromatolite,columnar stromatolite and cone columnar stromatolite developed in the tidal flat environment,respectively.Algal stucco and nucleoid stone are developed in the high tide zone.The classification of the stromatolite monomers inside the reef body has made a certain understanding of the changes of the external environment in the reef body code.Cyanobacteria,pueraria,bioclasts and some minerals were found in the laminates.Then the sedimentary environment of stromatolite was studied systematically.This study provides references for the comprehensive study of growth conditions and genetic environment of stromatolites.