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 sea- level 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.
SONG Yingfan, WANG Xiangdong, LI Ying, SHI Yukun, HU Keyi, HUANG Xing, SHENG Qingyi, YAO Le.2024. Distribution and causes of Mid- Carboniferous dolomitization in South China[J]. Acta Geologica Sinica,98(2):346-362.