鄂尔多斯盆地西缘晚三叠世构造—沉积环境分析
- 低渗透油气田勘探开发国家工程实验室 西安 710018
- 收稿日期:
1900-01-01
- 修回日期:
1900-01-01
- 刊出日期:
2011-06-10
摘要: 鄂尔多斯盆地西缘长期以来是地质学家所关注的热点，特别是晚三叠世的物源和形成构造—沉积环境颇具争议。砂岩碎屑组成、碎屑重矿物、地球化学成分、砾岩组成、古水流以及构造变形研究表明，晚三叠世西缘不同地区的物源和构造—沉积环境具有一定的差异性。北部贺兰山地区晚三叠世沉积主要形成于克拉通边缘，巴彦浩特地区为其主要物源区，阿拉善地块为次一级物源区，古流向以由西向东为主，沉积环境由扇三角洲向湖泊环境过渡，该时期为区域挤压背景下的裂谷盆地发育阶段；中部石沟驿地区上三叠统延长组沉积厚度达3 000 m左右，砂岩以长石岩屑砂岩为主，物源区以阿拉善地块为主，古流向由北西向南东，沉积环境为辫状河三角洲沉积环境，构造背景较为复杂，为整体挤压背景下的断陷盆地；南部平凉地区物源主要来自下伏地层和秦祁造山带，古水流主体由南西向北东方向，主体为冲积扇沉积环境，为前陆盆地发育阶段。可见，盆地西缘晚三叠世不同地区具有不同物源属性与构造—沉积环境，并非统一的“类”前陆盆地发育阶段。
Analysis of Tectonic Sedimentory Setting in Middle and Upper Triassic in the West Margin of the Ordos Basin
- National Engineering Laboratory for Exploration and Development of Low Permeability Oil & Gas Field, Xi'an 70018
- Received Date:
1900-01-01
- Rev Recd Date:
1900-01-01
- Publish Date:
2011-06-10
Abstract: Many geologists have paid attention to the west margin of Ordos basin for a long time, the provenance and tectonicsedimenary setting are still controversial. Based on the data analysis of sandstone detrital fragments, heavy mineral assemblages, geochemistry, composition of conglomerates, paleocurrent and tectonic deformation, it is indicated that the provenance and tectonicsediment setting is different in different areas in the west margin of Ordos basin. The deposition of the Upper Triassic in Helan Moutain occurred in craton, and its source areas belonged to the Alxa massif and Bayanhaote Basin, paleocurrent was from west to east, sedimentary setting is from fandelt to lake setting and Helan Moutain was rift basin in the Upper Triassic. The Upper Triassic sedimentation is tremendous, about 3 000 m in Shigouyi area.There are mainly feldspathic sandstone of this sedimentation, the provenance belonged to the Alxa massif, and paleocurrent was from northwest to southeast and Shigouyi area, and sedimentary setting was braidedriver setting. Shigouyi was downfaulted basin in Upper Triassic. The provenance belonged to QinlingQilianshan orogenic zone and stratum in CedipoHuating area, paleocurrent was from southwest to northeast, sedimentary setting was alluvial fan. CedipoHuating area was foreland basin in Upper Triassic. Based on the comprehensive analysis, it is suggested that the provenance and tectonicsedimentation was different in different areas in the west margin of Ordos basin, and being not uniform foreland basin simply.
杨 华. 鄂尔多斯盆地西缘晚三叠世构造—沉积环境分析[J]. 沉积学报, 2011, 29(3): 427-439.
| 引用本文: |
杨 华. 鄂尔多斯盆地西缘晚三叠世构造—沉积环境分析[J]. 沉积学报, 2011, 29(3): 427-439.
|
YANG Hua. Analysis of Tectonic Sedimentory Setting in Middle and Upper Triassic in the West Margin of the Ordos Basin[J]. Acta Sedimentologica Sinica, 2011, 29(3): 427-439.
| Citation: |
YANG Hua. Analysis of Tectonic Sedimentory Setting in Middle and Upper Triassic in the West Margin of the Ordos Basin[J]. Acta Sedimentologica Sinica, 2011, 29(3): 427-439.
|
点击查看大图
下载:
