Petrography,geochemistry and provenance of the sediments of the Early Cretaceous Yanguoxia Formation,Lanzhou-Minhe Basin,Northwest China

作     者：DU Ding-ding MUGHAL Muhammad Saleem ZHANG Cheng-jun 

作者机构：School of Earth Sciences and Mineral ResourcesLanzhou UniversityLanzhou 730000China Key Laboratory of Western China's Mineral Resources of Gansu ProvinceLanzhou 730000China Institute of GeologyUniversity of Azad Jammu and KashmirMuzaffarabad 13100Pakistan 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2018年第15卷第9期

页      面：2068-2088页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 0303[法学-社会学] 070903[理学-古生物学与地层学(含：古人类学)] 0708[理学-地球物理学] 0818[工学-地质资源与地质工程] 0705[理学-地理学] 0815[工学-水利工程] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0813[工学-建筑学] 0704[理学-天文学] 0833[工学-城乡规划学] 0713[理学-生态学] 0834[工学-风景园林学（可授工学、农学学位）] 

基　　金：Funds for the Central Universities(Grant No.862457) the Natural Science Foundation of China(Grant No.41571177) Gansu Youth Science and Technology Fund(1506RJYA094) 

主　　题：沉积岩石 早白垩纪 起源地 地球化学 岩相学 中国 西北 构造活动 

摘      要：Lanzhou-Minhe Basin is situated on the middle Qilian orogenic belt. Yanguoxia Formation contains abundance of maroon siltstones, mudstones and red sandstones of the lake facies. These sedimentary rocks recorded the process of the tectonic uplift of Qilian Mountains during the Early Cretaceous. We discovered plentiful dinosaur footprints, worm burrows, bird footprints, worm tracks-trails, ripple marks and cross lamination in the Yanguoxia site. Integrated petrographic studies classified sandstones of Yanguoxia Formation as feldspathic litharenite. All plots in the QFL(Q or Qt, total quartz; F, feldspar; L, lithic grains) and Qm FLt(Qm, monocrystalline quartz; Lt, lithic grains plus polycrystalline quartz) diagrams fall in the recycled orogen provenance field and quartzose recycled field, respectively, implying the source occurred the tectonic activity. Furthermore, geochemical study indicates that the Yanguoxia standstone was formed in an unstable continental setting due to the northwards movement of Indian Plate triggered the collision between the Qilian fold belt and the Qinlingfold belt. These sediments were derived from a mixed source and then deposited in the Lanzhou-Minhe Basin. Most of the felsic components were derived from the granitoid rocks of the Qilian Mountains due to the rapid and intense uplift during the Early Cretaceous while the mafic components were contributed by the basic and ultrabasic rocks of the rapidly rising ophiolite in the Qilian Mountain area. Bivariant log-log plot of Qp/(F+L)(Qp, polycrystalline quartz) against Q/(F+L) shows that Yanguoxia Formation was deposited in the semihumid and semi-arid. Moreover, the pollen also exhibits that the environmental condition during the deposition of Yanguoxia Formation was warm and wet, which affirm such environment was benefit to dinosaur survival. Geochemical study also infers that the Yanguoxia Formation was deposited under the oxidizing condition in a shallow marine environment. The minerals id