华南石炭纪中期白云岩地层分布及其形成模式  

Distribution and causes of Mid-Carboniferous dolomitization in South China

作　　者：宋英凡 王向东 李莹 史宇坤[1] 胡科毅 黄兴 盛青怡 要乐 SONG Yingfan;WANG Xiangdong;LI Ying;SHI Yukun;HU Keyi;HUANG Xing;SHENG Qingyi;YAO Le(State Key Laboratory for Mineral Deposits Research,Frontiers Science Center for Critical Earth Material Cycling,School of Earth Sciences and Engineering,Nanjing University,Nanjing,Jiangsu 210023,China;State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Science,Nanjing,Jiangsu 210008,China)

机构地区：[1]内生金属矿床成矿机制研究国家重点实验室,关键地球物质循环前沿科学中心,南京大学地球科学与工程学院,江苏南京210023 [2]现代古生物学和地层学国家重点实验室,中国科学院南京地质古生物研究所,江苏南京210008

出　　处：《地质学报》2024年第2期346-362,共17页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号91955201);第二次青藏高原综合科学考察研究(编号2019QZKK0706)联合资助的成果。

摘　　要：石炭纪是地质演化历史上重要的时期,发生了全球规模的海西造山运动,晚古生代大冰期(LPIA)达到峰值,全球海平面频繁波动,导致古气候和古环境的剧烈变化。在华南,石炭纪中期,浅水碳酸盐岩台地相区广泛发育一套白云岩沉积。本文系统总结华南3个主要碳酸盐台地内白云岩的厚度及时代,识别出白云岩时空分布的差异性。结合石炭纪中期全球气候环境特征,认为冰期兴盛引发了全球海平面下降,导致华南各沉积盆地形成利于白云岩化的环境,白云岩得以发育。而白云岩时空分布的差异性可能与各沉积盆地独特的构造演化以及不同成岩模式有关。中下扬子碳酸盐岩台地白云岩的形成模式主要为萨勃哈模式和成岩早期浅埋藏的渗透回流模式,形成相对较薄的白云岩沉积;中南部和西南部碳酸盐岩台地白云岩的形成模式为渗透回流模式,成岩规模较大,沉积较厚。Carboniferous is an important period in the geological history when the Hercynian Orogeny occurred and the Late Paleozoic ice age(LPIA)reached its peak,which resulted in frequent fluctuations of eustatic sea level and dramatic changes in palaeoclimate and palaeoenvironment.At the Mid-Carboniferous boundary interval,a vast shallow platform dolomitization occurs widely in South China.This paper summarizes the thickness and age of dolostones in three major carbonate platforms in South China,and further clarifies their temporal and spatial distribution.In terms of characteristics of global climate and environment in this interval,we propose that the maximum glaciation could be the cause of eustatic sealevel fall which resulted in the widespread dolomitization in South China.The different temporal distributions of dolostones among sedimentary basins in South China might be related to their independent developing history of basins and different diagenetic patterns.The dolomitization in the Middle-Lower Yangtze Carbonate Platform could be the Sabkha pattern and the seepage-reflux pattern in the early burial stage,therefore,forming relatively thin-bedded dolostone deposits.The thick-bedded dolostones in the Central-southern Carbonate Platform and the southwestern Carbonate Platform could have been formed in the seepage-reflux pattern.

关 键 词：石炭纪中期 白云岩 时空分布 古环境 白云岩化模式 

分 类 号：P618.13[天文地球—矿床学]