摘要
基于湖南晚二叠世含煤岩系层序地层分析,研究了聚煤期古地理及其与聚煤作用的关系.结果表明:层序Ⅰ(龙潭组上段下部)受同沉积断裂的控制,主要分布于龙山隆起以南的龙潭组南型"沉积区,煤层形成于三角洲、潮坪古地理单元,并在衡阳-郴州一带形成南北向展布的富煤带;层序Ⅱ(龙潭组上段中上部)分布在江南隆起两侧的湘中南及湘西北地区,煤层主要形成于潮坪、泻湖和三角洲古地理单元,在湘中南的龙潭组"北型"沉积区形成北东向展布的邵阳—长沙—浏阳富煤带;层序Ⅲ(龙潭组上段顶部和长兴组)在整个湖南省广泛分布,但是仅在海侵体系域初期发育一层薄且不稳定的煤层.从层序Ⅰ到层序Ⅲ,聚煤中心在湘中南有从东南向西北迁移现象,聚煤作用有从弱(层序Ⅰ)到强(层序Ⅱ)再到弱(层序Ⅲ)的变化规律.
The relationships between paleogeography and coal accumulation of the Late Permian in Hunan were studied based on analysis of the sequence stratigraphy.The results show that sequence Ⅰ（lower upper member of Longtan formation） is mainly distributed in the ＂southern type＂ area of the Longtan formation which is adjacent to the south of the Longshan uplift.The coal was accumulated in the deltaic and tidal flat paleogeographical units,which formed a Hengyang-Chenzhou coal-rich zone with a south-north distribution trend.Sequence Ⅱ（middle upper member of Longtan formation） is distributed widely in central-southern and northwestern Hunan except the Jiangnan uplift.The coal was accumulated in the tidal flat,lagoon and deltaic paleogeographic units which formed a Shaoyang-Changsha-Liuyang coal-rich zone with a NW-NE distribution trend in the ＂northern type＂ area of the Longtan formation.Sequence Ⅲ（the upper upper member of Longtan formation and the Changxing formation）,was developed in the whole Hunan province but only one thin and unstable coal was developed in the early transgressive systems tract,indicating a weak coal accumulation.From sequence I through sequence Ⅲ,the coal-accumulation center migrated northwestward in the central-southern Hunan,and coal accumulation varied from weak（sequence Ⅰ）,strong（sequence Ⅱ） to weak（sequence Ⅲ）.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2011年第1期103-110,共8页
Journal of China University of Mining & Technology
基金
国家重点基础研究发展计划(973)项目(2006CB202202)
国土资源大调查项目(1212010633901)
国家自然科学基金项目(40672103)
关键词
岩相古地理
聚煤作用
层序地层
晚二叠世
湖南
lithofacies palaeogeography
coal accumulation
sequence stratigraphy
Late Permian
Hunan
