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。
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
作者
何翔
杜星星
刘健
李艺豪
李群
HE Xiang;DU Xing-xing;LIU Jian;LI Yi-hao;LI Qun(MNR Key Laboratory of Paleomagnetism and Tectonic Reconstruction,Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Institute of Exploration and Development of Northwest Branch,SINOPEC,Urumqi 830011,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China)
出处
《地震地质》
EI
CSCD
北大核心
2022年第1期76-97,共22页
Seismology and Geology
基金
中国地质调查局项目(DD20190018,DD20221644)资助。
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
Wuwei Basin
northeastern Qinghai-Tibet Plateau
Quaternary
gravel
sedimentary process
plateau growth
