大别山构造带东段杨山组煤的变质演化

采用地史分析与数值模拟相结合的研究方法,对下石炭统杨山组煤的变质演化历程进行了定性和定量研究。结果表明:杨山组煤的变质作用经历了海西旋回中期和燕山旋回中-晚期两个演化阶段,煤级在第一阶段异常低热古地热场中深成变质作用下达到焦煤,第二阶段却在异常高热古地热场导致的热变质作用下剧增至超无烟煤。在包括研究区在内的大别山构造带北麓,海西旋回中期可能具有冷盆的特征,而燕山旋回中-晚期却表现出热盆的性质。 

COALIFICATION HISTORY OF THE YANGSHAN COAL-BEARING FORMATIONIN THE EASTERN DABIESHAN TECTONIC ZONE

The metamorphism history of the coals in the Lower Carboniferous Yangshan coalbearing formation is investigated comprehensively using the methods of the geological history analysis and EASY% Ro numerical modeling.It is shown that the coalification of the Yangshan coals was completed during two geological history stages,i.e.,the middle Hercynian tectonic cycle and the middlelate Yanshanian one.The rank of coking coal was achieved at the end of the first stage under the deep burial coalification derived from the lower palaogeothermal current,and the metaanthracite was acquired at the end of the secondary stage through the thermal metamorphism led by the higher palaogeothermal current.In the northern Dabieshan tectonic zone,a cooling basin seemed to occur during the middle Hercynian cycle and a heating basin might be developed during the middlelate Yanshanian one.