地震地质 ›› 2022, Vol. 44 ›› Issue (1): 76-97.DOI: 10.3969/j.issn.0253-4967.2022.01.006

• 研究论文 • 上一篇    下一篇

武威盆地第四纪沉积过程及其构造意义

何翔1),2),3)(), 杜星星1),*(), 刘健1), 李艺豪1), 李群3)   

  1. 1)中国地质科学院地质力学研究所, 自然资源部古地磁与古构造重建重点实验室, 北京 100081
    2)中国石油化工股份有限公司西北油田分公司勘探开发研究院, 乌鲁木齐 830011
    3)中南大学地球科学与信息物理学院, 长沙 410083
  • 收稿日期:2021-01-06 修回日期:2021-07-21 出版日期:2022-02-20 发布日期:2022-04-20
  • 通讯作者: 杜星星
  • 作者简介:何翔, 男, 1995年生, 2021年于中南大学获地质资源地质工程专业硕士学位, 主要从事沉积盆地分析方面的研究, 电话: 18232182424, E-mail: 1593496879@qq.com
  • 基金资助:
    中国地质调查局项目(DD20190018);中国地质调查局项目(DD20221644)

SEDIMENTARY PROCESS AND TECTONIC SIGNIFICANCE OF WUWEI BASIN DURING THE QUATERNARY

HE Xiang1),2),3)(), DU Xing-xing1),*(), LIU Jian1), LI Yi-hao1), LI Qun3)   

  1. 1) MNR Key Laboratory of Paleomagnetism and Tectonic Reconstruction, Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China
    2) Institute of Exploration and Development of Northwest Branch, SINOPEC, Urumqi 830011, China
    3) School of Geosciences and Info-Physics, Central South University, Changsha 410083, China
  • Received:2021-01-06 Revised:2021-07-21 Online:2022-02-20 Published:2022-04-20
  • Contact: DU Xing-xing

摘要:

为查明第四纪以来武威盆地沉积过程和青藏高原东北缘隆升扩展特征, 文中采用沉积地层学和地层年代学方法, 对武威盆地的第四纪沉积地层进行研究。第四纪期间, 武威盆地沉积了下更新统玉门砾岩、 中更新统酒泉砾石层和上更新统—全新统戈壁砾石层。早更新世, 玉门砾岩来源于祁连山, 沉积于武威盆地南部走廊南山区; 中更新世, 酒泉砾石来源于走廊南山区和武威盆地西北缘坟门山, 沉积于武威盆地北部断陷盆地沉积区; 晚更新世以来, 戈壁砾石来源于走廊南山区、 坟门山和龙首山, 沉积于物源区周边地区。武威盆地及周边第四系的物源区和沉积区均呈现出自南向北发展的特征, 揭示了青藏高原东北缘隆升和向N扩展, 隆升时间南早北晚, 隆升强度南强北弱、 西强东弱。

关键词: 武威盆地, 青藏高原东北缘, 第四纪, 砾石, 沉积过程, 高原隆升

Abstract:

The Wuwei Basin is located in the eastern part of the Hexi Corridor Basin group. It belongs to the frontier of uplift and expansion of the northeastern margin of the Qinghai-Tibet Plateau. The Quaternary sedimentary strata in the Wuwei Basin are hundreds of meters thick, which records the geological information of uplift and expansion of the northeastern margin of the Qinghai-Tibet Plateau during the Quaternary period. In order to study the sedimentary process of the Wuwei Basin since Quaternary and the characteristics of the uplift and extension of the northeastern margin of the Qinghai-Tibet Plateau, the sedimentary stratigraphy and stratigraphic chronology methods are applied to analyze the Quaternary sedimentary strata in the Wuwei Basin. Firstly, the Quaternary sedimentary sequence of the Wuwei Basin is established by studying the stratum characteristics and OSL ages of the Quaternary sedimentary strata. Secondly, through the analysis of the paleocurrent direction and zircon U-Pb isotopic age of the sedimentary gravel, the paleocurrent direction of different deposition periods and sediment source are restored. Finally, based on the above analysis, the sedimentary process of Quaternary strata in the Wuwei Basin and its response to the uplift and extension of the Qinghai-Tibet Plateau are discussed.
The Quaternary sedimentary strata in the Wuwei Basin are the lower Pleistocene Yumen conglomerate, the middle Pleistocene Jiuquan gravel bed and the Upper Pleistocene-Holocene Gobi gravel bed from bottom to top. The Gobi gravel bed can be subdivided into the Upper Pleistocene gravel bed, the Upper Pleistocene-Holocene loess layer and the Holocene gravel bed. In the early Pleistocene, the Yumen conglomerate’s source material is mainly Mesozoic and Paleozoic rocks. The main provenance area of the Yumen conglomerate is located in the Qilian Mountains south to the Wuwei Basin. The main sedimentary area of the Yumen conglomerate is located in the Zoulang Nan Shan located in the southern part of the Wuwei Basin and the southern part of the northern fault basin. In the middle Pleistocene, the Jiuquan gravel bed’s source material is mainly Cenozoic and Mesozoic rocks. In the early sedimentary stage of the Jiuquan gravel bed, the main provenance area is located in the Zoulang Nan Shan and the main sedimentary area is located in the northern part of Wuwei Basin. In the late sedimentary stage, the main provenance area of the Jiuquan gravel bed is located in the Zoulang Nan Shan and the Fenmen Mountain located in the northwestern margin of the Wuwei Basin, and the main sedimentary area is located in most of the northern fault basin and the surrounding area of the Fenmen Mountain. Since late Pleistocene, the Gobi gravel bed’s source material is mainly early Paleozoic rocks. The main provenance area of the Gobi gravel bed is located in the Zoulang Nan Shan, the Fenmen Mountain and the Longshou Mountain, and the main sedimentary area is located around the source area.
The uplift boundary of the northeastern margin of the Qinghai-Tibet Plateau continued to expand towards the northeast direction. The uplift boundary was located in the Qilian Mountains south to the Wuwei Basin in the early Pleistocene. It extended northward to the Zoulang Nan Shan and the Fenmen Mountain in the middle Pleistocene, and reached the Longshou Mountain north to the Wuwei Basin in the late Pleistocene. The main provenance and sedimentary areas of the Quaternary sediments in the Wuwei Basin show the migration characteristics from south to north, which indicates the uplift and expansion of the northeastern margin of the Qinghai-Tibet Plateau. The uplift time was early in the south and late in the north, and the uplift intensity was strong in the south and west and weak in the north and east.

Key words: Wuwei Basin, northeastern Qinghai-Tibet Plateau, Quaternary, gravel, sedimentary process, plateau growth

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