摘要
运用陆相层序地层理论,采用露头、钻孔和地震剖面相结合的手段,在"岩性-岩相-相序"研究基础上,对鄂尔多斯盆地东北缘中—下侏罗统延安组、直罗组进行了层序地层划分。研究表明,延安组可以划分为5个层序、直罗组4个层序,每个层序由低可容空间体系域和高可容空间体系域组成。根据煤层、铀矿赋存特征,及其在层序地层格架中的位置,指出延安组煤层主要赋存在层序高可容纳空间体系域的三角洲平原泥炭沼泽环境中,直罗组含铀岩系主要发育在直罗组下部辫状河沉积岩段,铀矿赋存在低可容纳空间体系域中。结合地质、地球化学、古生物资料,探讨了古气候、构造对煤、铀矿成矿的制约。
Based on outcrop, drilling data and seismic sections, and along with the study of lithology, lithofacies and facies sequence, this study defined the sequence stratigraphy of the Middle-Lower Jurassic Yan＇ an Formation and Zhiluo Formation in the northeastern Ordos Basin. Five sequences have been recognized in the Yan＇an Formation and four in the Zhiluo Formation. Each sequence is composed of low accommodation systems tract and high accommodation systems tract. Occurrence features of coal sequences and uranium ore deposits and their positions in the sequence column, it can be deduced that the ~：oal of the Yan ~ an Formation occurs mainly in peat swamp environment of delta plain and the uranium of the Lower Zhiluo Formation occurs mainly in braid river deposit, which respectively represent the high accommodation systems tract and low accommodation systems tract, according to the characteristics and the position in sequence stratigraphic framework of Coal-Uranium distribution. In combination to geological, geochemical and paleontological data, the paper also discussed restriction of pale-climate and structure on coal-uranium mineralization.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2016年第12期3424-3440,共17页
Acta Geologica Sinica
基金
国家973项目(编号2015CB453000)
中国地质调查局项目(编号DD20160127
12120115013701)联合资助的成果
关键词
中-下侏罗统
层序地层
古气候
煤铀赋存规律
鄂尔多斯盆地东北缘
Middle-Lower Jurassic
sequence stratigraphy
paleoclimate
occurrence regularity of coal-uranium
Northeastern Ordos Basin
