Element Geochemical Characteristics and Provenance Conditions of the 1st Member of Jurassic Zhongjiangou Formation in Wudun Sag, Dunhuang Basin

Applied Sciences

卷:12

Ling Feng¹  Wen Yin¹  Xianli Zou¹  Tao Xu¹  Yarong Wang¹  Jinpeng Wei² 

[1] Faculty of Petroleum, China University of Petroleum-Beijing at Karamay, Karamay 834000, China;

[2] The State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum-Beijing, Beijing 102249, China;

关键词: Wudun sag;    element geochemistry;    provenance;    tectonic background;    weathering degree;   

DOI  :  10.3390/app12094110

来源: DOAJ

【 摘 要 】

In order to clarify the provenance of the 1st member of the Zhongjiangou formation in Wudun sag, Dunhuang basin, the structural attributes, weathering and sedimentary characteristics of the provenance area were analyzed by means of element geochemistry, so as to determine the differences of sediment sources in different well areas. The results show that the higher the Al₂O₃ and K₂O contents, the higher the enrichment of large ion lithophile elements and high field strength elements, while the iron and magnesium elements are relatively deficient, and there are characteristics of medium degree differentiation of light and heavy rare earth elements in Well XC1 and Well D2. The lower the Al₂O₃ content and the higher the SiO₂ content, a loss of large ion lithophile elements and high field strength elements are observed, while the ferrophilic magnesium elements show serious loss, as shown in the characteristics of the high degree of differentiation of light and heavy rare earth elements in Well D1. In the UCC-normalized element spidergrams, the trend of Well XC1 and Well D2 is similar, which is different from that of well D1, indicating that the sediments of Well XC1 and Well D2 come from the same provenance area, while the sediment of Well D1 comes from a different provenance area. The provenance area of Well XC1 and Well D2 shows strong tectonic activity and strong weathering, while the provenance area of well D1 exhibits relatively weak tectonic activity and weathering. Combined with previous research results, Wudun sag is mainly characterized by a faulted lacustrine basin controlled by the southern boundary fault in the Jurassic layer. Therefore, the sediments of Well XC1 and Well D2 mainly come from the southern Sanweishan uplift provenance area, with strong tectonic activity; the sediments of Well D1 mainly come from the northern Beishan provenance area, with relatively weak tectonic activity.

【 授权许可】

Unknown