鄂尔多斯克拉通盆地寒武纪古构造与岩相古地理再认识

发布时间：2018-06-22 22:36

本文选题：岩相古地理 + 拗拉槽　；参考：《石油与天然气地质》2017年02期

【摘要】：依据野外露头、钻井和地震等资料,对鄂尔多斯盆地寒武纪古构造和岩相古地理开展研究。厚度图法研究表明,寒武纪的沉积格局与中新元古代的沉积格局具有继承性,古构造整体呈现"三槽二陆一洼"的特征。以此为指导,运用碳酸盐岩沉积学,将鄂尔多斯寒武系划分为滨岸、碳酸盐岩开阔台地、陆棚缓坡和海槽四大沉积体系,编制了5张鄂尔多斯地区寒武纪岩相古地理图。岩相古地理总体特征表现为古陆之外为滨岸,滨岸之外为台地,台地内部有洼地,台地外部为缓坡,缓坡边缘见海槽。鄂尔多斯地区在寒武纪经历了一个完整的海进—海退的演化过程。早寒武世表现为广大地区仍为古陆,仅在西南缘环陆发育了一套滨岸和开阔台地相沉积;中寒武世海侵扩大,古陆面积缩小,并被分割成3个独立的古陆,至张夏期吕梁古陆消失,中东部广大地区表现为广阔的开阔台地相沉积,西南缘为陆棚缓坡和海槽相沉积;晚寒武世,海退开始,鄂尔多斯古陆呈南北向条带状分布于鄂尔多斯中部地区。
[Abstract]:The Cambrian paleotectonics and lithofacies paleogeography in Ordos Basin were studied based on outcrop drilling and seismic data. The study of thickness map shows that the sedimentary pattern of Cambrian and the sedimentary pattern of MesoNeoproterozoic are inherited, and the paleotectonics are characterized by "three troughs, two continents and one depression" as a whole. Under the guidance of carbonate sedimentology, the Cambrian in Ordos is divided into four sedimentary systems: shore, open platform of carbonate rock, gentle slope of shelf and trough, and 5 lithofacies paleogeography maps of Cambrian in Ordos area are compiled. The general characteristics of lithofacies and paleogeography are that the coast is offshore and the offshore is platform outside the paleofacies and paleogeography, there are depressions in the interior of the platform, and the outer side of the platform is a gentle slope with a trough on the edge of the gentle slope. During the Cambrian period, Ordos area experienced a complete evolution process. The early Cambrian showed that the vast area was still ancient land, only developed a set of shoreline and open platform facies deposits in the southwestern margin, and the Middle Cambrian transgression expanded, the ancient land area was reduced, and was divided into three independent ancient continents. During the period of Zhangxia, the Lv Liang paleocontinent disappeared, and the vast area in the central and eastern part of China was characterized by broad open platform facies deposition, the southwest margin of which was composed of shelf gentle slope and trough facies, and the late Cambrian period, when the sea retreated. The ancient land of Ordos distributes in the central area of Ordos in the north-south direction.
【作者单位】：中国石油勘探开发研究院廊坊分院;中国石油天然气集团公司天然气成藏与开发重点实验室;中国石油青海油田分公司采油一厂;
【基金】：国家科技重大专项(2016ZX05007-002) 中国石油天然气股份有限公司科技攻关项目(2011B-0602)
【分类号】：P534.41;P618.13

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