二叠纪末期至中三叠世海洋碳酸盐工厂工作机制的转换：以华南地区为例

Carbonate factory (CF) is the most efficient production of carbonate in oceans. It includes three mechanisms: calcification of calcium-shelled metazoans, microbial calcification and abiotic chemical reaction. These CF types change from time to time during the Phanerozoic. The changes are particularly pronounced during the Permian-Triassic transition, which witnessed the greatest mass extinction of Earth life. The proposed study attempt to conduct detailed microfacies analysis, geomicrobiologic study and biomarker analysis on the continuous, up to 1000 m thick carbonate successions of latest Permian to Middle Triassic age exposed in the Upper Yangtze Platform and Great Bank of Guizhou in the Nanpenjiang basin, South China. Hopefully, all types of CFs preserved in these carbonate succession can be recognized, with emphasis on the benthic automicrite factory, which is very common in Earth Triassic. Meanwhile, these unusual deposits such as giant oolitic limestone, vermicular limestone and flat-pebble limestone will be multidiciplinarily analyzed to indicate their CF types. Based on the published high-resolution biostratigraphic and chronostratigraphic frameworks, evolutionary successions of all CF types are reconstructed, and their replacement models and possible mechanism across the Permian-Triassic boundary and Early-Middle Triassic transition will be discussed. Possible effects of paleoceanographic conditions (i.e., redox conditions) and extreme climatic regimes on carbonate factories are also evaluated by integrating the published carbon, sulfur isotopic data and newly obtained biomarker results.

碳酸盐工厂是海洋中生产碳酸盐最有效的方式，通常有钙质壳生物的分泌作用、微菌藻类钙化作用和非生物成因三种机制。这些工作机制在地质历史时期不断变化，特别是在二叠纪-三叠纪大转折时期表现很明显。本项目拟对华南上扬子地台和南盆江盆地的大贵州滩地区连续沉积达上千米厚的晚二叠世至中三叠世碳酸盐地层进行详细的沉积微相分析、地质微生物学研究和生物地球化学（Biomarker）分析，识别出大绝灭前和早、中三叠世所有碳酸盐工厂类型，对早三叠世常见的底栖自生微晶碳酸盐工厂进行深入研究，同时探讨鲕粒灰岩、蠕虫灰岩和扁平砾石灰岩各代表的碳酸盐工厂类型。结合前人发表的高精度生物年代地层格架恢复研究剖面上各类碳酸盐工厂的时间序列，分析它们在大绝灭前后和早-中三叠世之间的更替模式和规律；配合已发表的同位素地球化学资料和新获得的生标分析结果探讨古海洋环境和极端气候条件对碳酸盐工厂的制约机制。

本项目对华南上扬子地台和南盆江盆地的大贵州滩地区连续沉积达上千米厚的晚二叠世至中三叠世碳酸盐地层进行详细的沉积微相分析、地质微生物学研究和生物地球化学（Biomarker）分析，识别出大绝灭前和早、中三叠世所有碳酸盐工厂类型，对早三叠世常见的底栖自生微晶碳酸盐工厂进行深入研究，同时探讨鲕粒灰岩、蠕虫灰岩和扁平砾石灰岩各代表的碳酸盐工厂类型。结合前人发表的高精度生物年代地层格架恢复研究剖面上各类碳酸盐工厂的时间序列，分析它们在大绝灭前后和早-中三叠世之间的更替模式和规律；配合已发表的同位素地球化学资料和新获得的生标分析结果探讨古海洋环境和极端气候条件对碳酸盐工厂的制约机制。完成项目计划工作同时，以项目为依托完成Earth-Science Reviews专辑1次和Palaeogeography, Palaeoclimatology, Palaeoecology专辑2次，发表SCI论文20篇，均为T2以上文章.