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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 the theory of terrestrial sequence stratigraphy and using the combination of outcrops, boreholes and seismic profiles, based on the study of lithology-lithofacies-facies sequence, Group, Zhiluo group stratigraphic stratigraphic division. The research shows that the Yan’an Formation can be divided into five sequences and four sequences in Zhiluo Formation, each of which consists of a low-tolerant space system tract and a high-tolerant space system tract. According to the characteristics of coal seam and uranium deposit and its position in the sequence stratigraphic framework, it is pointed out that the Yan’an Formation coal seam mainly exists in the delta plains peat swamp environment with high sequence space system tract, It is mainly developed in the lower braided river sedimentary rock section of Zhiluo Formation, and the uranium deposit exists in the low-capacity space system tract. Combined with geology, geochemistry and paleontology data, the paper discussed the palaeoclimate and tectonic constraints on mineralization of coal and uranium deposits.