| 摘要: |
| 北羌塘坳陷冬曲地区上三叠统巴贡组为一套碎屑岩沉积,在垂向上具有两个向上变粗的充填序列。根据沉积体产出形态和叠置序列、岩石组合与结构、沉积构造及流体性质等沉积特征,确定该套沉积体为扇三角洲相沉积,进而可划分出扇头、扇中、扇尾3个亚相。发育底冲刷构造、粒序层理、平行层理、交错层理等,表明其流体性质既有重力流又有牵引流特征。通过该套扇三角洲沉积体的认识,对研究该区古构造背景、沉积环境及油气地质条件等具有重要意义。 |
| 关键词: 巴贡组 扇三角洲 底冲刷构造 羌塘盆地 |
| DOI： |
| 附件 |
| 投稿时间：2018-03-30修订日期：2018-06-15 |
| 基金项目:中国地质调查局羌塘盆地金星湖－隆鄂尼地区油气资源调查项目(DD20160159) |
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| Sedimentary characteristics of the fan delta deposits from the Upper Triassic Bagong Formation in the Dongqu area, northern Qiangtang depression |
| CHEN Hao, SUN Wei, ZHAN Wang-zhong, HE Lei |
(1. Chengdu Center, China Geological Survey, Chengdu 610081, Sichuan, China;
2. Key Laboratory of Sedimentary Basins and Oil and Gas Resources, Ministry of Natural Resources, Chengdu 610081, Sichuan, China) |
| Abstract: |
| The Upper Triassic Bagong Formation in the Dongqu area, northern Qiangtang depression is made up of a succession of clastic deposits with two coarsening-upward depositional-filling sequences. According to the stacking patterns, rock associations and fabrics, sedimentary structures, and flow regimes, these clastic deposits belong to the fan delta deposits which may be subdivided into the proximal fan, mid-fan and distal fan subfacies. Sedimentary structures are common, including the basal scour structures, graded beddings, parallel beddings and crossbeddings generated by the gravity flows and tractional flows. The study of the fan delta deposits may assist in the understanding of palaeotectonic settings, sedimentary environments, and oil and gas accumulation in the study area. |
| Key words: Bagong Formation fan delta basal scour structure Qiangtang Basin |
