贵州省晚三叠世含煤地层特征及对比

Late Triassic Coal-bearing Strata Characteristics and Correlation in Guizhou Province

贵州省晚三叠世地层分布在罗甸—贵阳—遵义—正安一线以西地区,主要为一套陆相或海陆相互相碎屑含煤沉积,厚87～2 400m。地层岩性、厚度变化较大,含煤性差异明显。通过对岩性、岩相、古生物和地层发育特征等分析研究,将全省晚三叠世地层划分为3个区:①黔西南区,地层出露较为齐全,地层厚度最大;②黔中南区,缺失了赖石科组和火把冲组,把南组相变为三桥组;③黔西北区,地层缺失较多,仅保存二桥组。在综合分析各分区地层岩性组合及地层相变与缺失规律的基础上,对该区含煤地层进行了对比。

To the west of Luodian-Guiyang-Zunyi-Zhengan line in the Guizhou Province, the Late Triassic strata is a set of limnic or limnic-marine alternating clastic coal-bearing deposits with thickness 87-2400m. Ethology and thickness of strata changing greatly, and coal-bearing properties differentiate obviously. Through lithology, lithofacies, paleontologic and stratigrahpic development features analyses, Late Triassic strata in the province can be divided into three districts： （1） Southeast Guizhou district, with rather complete strata outcropping, biggest strata thickness; （2） Central-South Guizhou district, absented Laishike and Huobachong formations and Banan Formation transformed into Sanqiao Formation; （3） Northwest Guizhou district, more stratigraphic hiatuses, only Erqiao Formation keeps. Based on lithologic assemblage, strata facies transformation and hiatus regulation integrated analyses, coal-bearing strata in the area have correlated.