古地理学报2017，Vol.19Issue(6)：965-986,22.DOI:10.7605/gdlxb.2017.06.075
大巴山地区早古生代黑色岩系岩相古地理及页岩气地质意义
Lithofacies palaeogeography of the Early Paleozoic black rock series in Dabashan region and their shale-gas geological significance
摘要
Abstract
Two suites of black rock series of the Lower Cambrian Shuijingtuo Formation (the Bashan Formation to the Lujiaping Formation) and the Upper Ordovician Wufeng Formation to the Lower Silurian Longmaxi Formation were developed in the Dabashan region in the Early Paleozoic.Sedimentological research reveals that the black rock series were deposited in a passive continental margin basin in the northern margin of the Yangtze Plate.Their sedimentary environments were mainly a deep shelf due to rapid transgression during the earlier period and gradually changed into the shallow shelf with sea-level decline during the later period with some local reefs and shoals.The Early Cambrian and Late Ordovician to Early Silurian basements of the passive continental margin basin in the study area were not flat,which would result in the multi-island obstructively palaeogeographical pattern in continental margin.But their formation mechanisms are totally different.The Early Cambrian palaeogeographic pattern was inherited from grabenhorst pattern of the Doushantuo Stage,and local uplift or submerged uplift remained in garben;but foreland uplift during the Late Ordovician to Early Silurian developed in passive continental margin basin in the northern margin of Yangtze Plate was related to Yangtze Plate subduction to North China Plate.The restricted stagnant ocean is more conducive to high-quality shale formation with heavy thickness,high TOC (2％ ～6％) and high content of brittle mineral (40％ ～ 65％),which are usually sweet target layers for shale-gas exploration,but it is necessary to enforce structural research of preservation conditions.关键词
大巴山地区/黑色岩系/古地理格局/前陆隆起/页岩气勘探Key words
Dabashan region/black rock series/palaeogeography pattern/foreland uplift/shale-gas exploration分类
天文与地球科学引用本文复制引用
熊国庆,王剑,李园园,余谦,门玉澎,周小琳,熊小辉,周业鑫,杨潇..大巴山地区早古生代黑色岩系岩相古地理及页岩气地质意义[J].古地理学报,2017,19(6):965-986,22.基金项目
国家自然科学基金项目(编号:41672112,41372124)资助.[Financially supported by the National Natural Science Foundation of China (Nos.41672112,41372124)] （编号:41672112,41372124）
