Manganese carbonate stromatolites of the Ediacaran Doushantuo Formation in Chengkou,northern Yangtze Craton,China  

作　　者：Yi Zhang Jian Li Long Chen Yi Wei Qiang Shi Dong-Ge Wang Qing-Ming Wu Liao-Yuan Song Meng Tian Hong-Wei Kuang Yong-Qing Liu Kaarel Mänd Hua-Qing Bai Zi-Liang Liu Yu-Chong Wang Da-Wei Qiao Wen-Jun Zhu 

机构地区：[1]No.205 Geological Team,Chongqing Bureau of Geology and Minerals Exploration,Chongqing 402160,China [2]Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [3]Department of Earth and Atmospheric Sciences,University of Alberta,Edmonton,Alberta T6G 2E8,Canada [4]Department of Geology,University of Tartu,Tartu 50411,Estonia [5]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,Sichuan Province,China [6]PetroChina Xinjiang Oilfield Company,Karamay 834099,Xinjiang Uygur Autonomous Region,China

出　　处：《Journal of Palaeogeography》2021年第3期356-381,共26页古地理学报（英文版）

基　　金：supported by the International Innovation Resources Cooperation Project“The Precambrian last glaciation and the evolution of paleoenvironment and life on Earth”from Beijing Science and Technology Committee(Grant No.Z201100008320007);the National Natural Science Foundation of China(Grant No.42072135);the National Key Research and Development Program of China(Grant No.2016YFC601001);the China Geological Survey Project(Grant Nos.DD20190002 and DD20190005);the second-level sub-project of“Prospecting prediction and technology application demonstration in integrated exploration area”from the China Geological Survey;the mineral investigation and prospecting prediction of integrated manganese exploration area in Chengkou,Chongqing(Grant No.121201004000150017-91);the mineral geological survey of Chengkou manganese ore concentration area in Chongqing(Grant No.DD20190166-18);the integrated exploration projects in Chengkou manganese mine integrated exploration area from the Chongqing Planning and Natural Resources Bureau。

摘　　要：The origin process of manganese ores remains unsolved worldwide.Exploring the origins of stromatolites that contain manganese may be a key to deciphering the sedimentary environments and metallogenic processes of these deposits.However,only a few manganese stromatolites have been discovered and described until now.Microbialites are well developed in the manganese deposits,located near the top of the Ediacaran Doushantuo Formation in Chengkou area of Chongqing,northern Yangtze Craton,but has not been explicitly studied;and whether they are true stromatolites or Epiphyton microbialites remains controversial.Based on field and core observations and thin section microscopy,the characteristics of five types of manganese stromatolites and their growth modes are described in detail in this study.The results show that these stromatolites grew in a biostrome in shoal and lagoon environments and were syngenetic with oncolites and oolites on a carbonate ramp behind the shoal.Manganese stromatolites can be categorized into three forms:(1)stratiform;(2)columnar,which includes branched and columnar types;and(3)stratiform-columnar,which is a transitional type.Based on a criterion that the diameter is less than or greater than 1 mm,columnar stromatolites are further divided into micro-columnar(<1 mm)and columnar(>1 mm)columns,which display synchronous growth and are similar to Pseudogymnosolenaceae.Their shapes are mainly controlled by water depths and hydrodynamic strengths.The greater the water depth,the more columnar the columns tend to be.Excessively strong hydrodynamic conditions decrease the growth rate of stromatolites,and they even stopped growth due to wave damage.Furthermore,pillared laminar textures(not Epiphyton),which consist of dendritic,micro-branched and microcolumnar stromatolites,are a common feature of the larger stratiform,stratiform-columnar and columnar stromatolites.The alternations of laminae with different internal textures record subtle fluctuations in water depths and hydrodynamic strengths,which indic

关 键 词：MICROBIALITES Manganese stromatolites EDIACARAN Doushantuo Formation Yangtze Craton Growth mode 

分 类 号：P618.32[天文地球—矿床学]