地学前缘 ›› 2013, Vol. 20 ›› Issue (2): 10-18.

• 论文 • 上一篇    下一篇

鄂尔多斯盆地西南缘上三叠统延长组物源与沉积体系特征

 杨华, 刘自亮, 朱筱敏, 邓秀芹, 张忠义, 齐亚林   

  1. 1. 中国石油 长庆油田分公司, 陕西 西安 710018
    2. 成都理工大学 能源学院, 四川 成都 610059
    3. 中国石油大学(北京) 地球科学学院, 北京 102249
    4. 中国石油大学(北京) 油气资源与探测国家重点实验室, 北京 102249
  • 收稿日期:2012-12-24 修回日期:2013-01-22 出版日期:2013-03-15 发布日期:2013-03-15
  • 作者简介:杨华(1963—),男,教授级高级工程师,主要从事油气勘探及地质综合研究。E-mail:yh_cq@petrochina.com.cn
  • 基金资助:

    国家重大专项“大型油气田及煤层气开发”鄂尔多斯盆地大型岩性地层油气藏勘探开发示范工程(2008ZX05044 132)和“大型油气田及煤层气开发”项目专题(2011ZX05009002)

Provenance and depositional systems of the Upper Triassic Yanchang Formation in the southwestern Ordos Basin, China.

  1. 1. PetroChina Changqing Oilfield Company, Xian 710018, China
    2. College of Energy Resources, Chengdu University of Technology, Chengdu 610059, China
    3. College of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China
    4. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China
  • Received:2012-12-24 Revised:2013-01-22 Online:2013-03-15 Published:2013-03-15

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摘要：

以鄂尔多斯盆地西南缘延长组为例,通过对野外露头沉积特征、骨架颗粒、重矿物组合等分析,讨论了研究区物源与沉积体系特征。研究表明:早期沉积物源主要来自盆地西南方向,南部也有贡献。中、晚期沉积物源除来自西南方向和南部物源外,还受到来自盆地北东方向次要物源的影响。延长组长8之上与之下物源性质发生明显变化。延长组长8砂岩的岩屑以变质岩为主,少量沉积岩和火成岩;而延长组长6砂岩岩屑则以沉积岩为主, 少量变质岩和火成岩,这表明长6沉积期盆地周缘、特别是盆地西缘抬升加剧,地层的剥蚀更强烈,致使大量较年轻的地层被剥蚀并加入源区母岩中。鄂尔多斯盆地延长期湖盆为北西南东向展布,西南区主要发育辫状河和辫状河三角洲沉积体系，东北区主要发育曲流河三角洲沉积体系，在深湖区发育浊积扇沉积体系。

关键词: 重矿物, 物源方向, 延长组, 鄂尔多斯盆地西南缘

Abstract:

Taking the Yanchang Formation in the southwestern Ordos Basin as an example, based on the studies of petrology, sedimentary characteristics, measurements of paleocurrent directions shown by outcrops, as well as framework grains and minerals in sandstones and their distribution characteristics, the paper studied the provenance and depositional characteristics of the research area. The study shown that early sediment source was mainly from the southwest of the basin with some contribution from the south. This was followed by subsequent deposition of sediments sourced from the southwestern and southern areas with some contribution from the northeast of the basin. Debris of the Chang 8 sandstone is dominated by metamorphic rocks, small amount of sedimentary and volcanic rocks. Debris of the Chang 6 sandstone is dominated by sedimentary rocks, and a small amount of metamorphic rock and volcanic rocks. The presence of more felsic materials of the late Archean in the Chang 6 sandstone suggested that the western margin of the basin uplift had undergone intensive erosion, resulting in a large number of younger strata eroded and added to the source rocks. The distribution of the Yanchang Lake basin was along northwestsoutheast. It mainly developed braided fluvial and braided delta depositional systems in the southwestern slope, meandering river delta depositional system in northeastern terrainrelief and turbidite fan deposits in the deep lake systems.

Key words: heavy mineral, provenance direction, Yanchang Formation, southwestern Ordos Basin

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