寒武纪苗岭世特别的光养碳酸盐岩工厂:以江苏徐州贾旺剖面张夏组为例  

A particular photozoan factory of carbonate rock of the Cambrian Miaolingian: a case study of the Zhangxia Formation at the Jiawang section in Xuzhou City of Jiangsu Province

作　　者：梅冥相[1,2] MEI Mingxiang(School of Earth Sciences and Natural Resources,China University of Geosciences,Beijing 100083,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质大学(北京)生物地质与环境地质国家重点实验室,北京100083

出　　处：《地质学报》2022年第3期744-768,共25页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号41472090,40472065,49802012)联合资助的成果。

摘　　要：碳酸盐岩工厂,即碳酸盐生产作用体系,是指那些表明了以下特征的底栖碳酸盐岩组合,这些特征包括主导性沉淀作用样式、矿物构成、生产作用以及生长潜力的深度变化范围;如果将浮游碳酸盐工厂作为第四个体系的话,再排除渗漏和陆相工厂(与流体相关的工厂),那么,在地质学尺度范围内,基于海相碳酸盐沉淀作用的三种基本的模式(非生物的(或者是准非生物的)、生物诱发的、以及生物控制的),这些沉淀作用综合在一起,就形成三个碳酸盐生产体系即形象化的三重划分的碳酸盐岩工厂:(1) T-工厂,T蕴含着热带的和水柱顶部的涵义;(2) C-工厂,C代表着冷水或受到控制的沉淀作用的基本涵义;(3) M-工厂,M代表着微生物、泥晶或泥丘的基本内涵。作为显生宙的第一个纪,寒武纪明显具有一个承前启后的特点,在较高的大气圈氧气含量下得到进化的生物矿化作用表征的寒武纪后生动物大爆发、与显生宙最高的大气圈二氧化碳含量下得到复苏的有机矿化作用主导的微生物礁相耦合,从而在寒武纪方解石海中形成一个蓝细菌繁荣所主导的光养T-工厂和M-工厂;光养T-工厂则以光合作用生物膜诱发的放射鲕粒为特征,光养M-工厂不但占据着T-工厂的位置而且以蓝细菌微生物席所主导的微生物礁所表征的碳酸盐泥丘为特征。所以说,这两个特别的碳酸盐工厂均指向一个光合作用新陈代谢的基本特征。这样的浅水光养T-工厂和光养M-工厂的典型实例,来自于江苏徐州贾旺剖面的张夏组,表现在张夏组构成的三级沉积层序中组成强迫型海退体系域的一个特别的沉积序列,即从一套31 m厚的光合作用生物膜诱发的放射鲕粒滩相灰岩向上变化为一套厚度为82 m的均一石和树形石主导的微生物礁灰岩,体现出了一个从光养-T工厂变化为光养M-工厂的变化序列。由于M-工厂在现代世界之中没有�Carbonate factories or production systems, are benthic carbonate associations that show variations in their dominant precipitation mode, mineral composition, and depth range of production as well as growth potential. If the planktonic carbonate factory is termed as a fourth system and the seep and continental carbonates(fluid-related factory) that are not included within this conceptual scheme, a threefold subdivision of the benthic carbonate production systems enriched with knowledge derived from the carbonate factory principle has been proposed on a geologic scale, i.e.(1) T-factory, in which the T is derived from tropical or “top-of-the-water-column”;(2) the C-factory, in which the C stands for cool-water or controlled precipitation;(3) the M-factory, in which M represents microbial, micrite, or mud-mound. As the first period of the Phanerozoic Eon that inherited the past and will usher in the future, the Cambrian is characteristic of the evolution of biomineralization marking the ‘Cambrian explosion’ that is coupled with increase in microbial carbonates predominated by organomineralization, the former might have benefited from the relatively high content of oxygen within the atmosphere and the latter might be genetically related to the highest content of CO;within the atmosphere, which led to the formation of the photozoan T-and M-factories in a calcite sea that was tied to the cyanobacterial bloom. This photozoan T-factory is marked by widespread distribution of radial ooids induced by photosynthetic biofilms and the photozoan M-factory occupied the shallow environments normally filled by the tropical factory, both of which point to the photosynthetic mechanism. An excellent example for these photozoan T-and M-factories are from the Zhangxia Formation of the Cambrian Miaolingian at the Jiawang section in Xuzhou City of Jiangsu Province of the southern North-China Platform. A set of oolites with a thickness of about 31 m that are predominated by radial ooids induced by photosynthetic biofilms as well

关 键 词：光养碳酸盐岩工厂 张夏组 寒武系苗岭统 江苏徐州贾旺剖面 华北地台 

分 类 号：P618.13[天文地球—矿床学]