柴达木盆地古近系沉积相研究

综合利用野外露头剖面、钻井剖面、岩心以及测井、地震等多种资料,采用单因素分析多因素综合作图的定量岩相古地理研究方法,以三级层序为单元对柴达木盆地古近系沉积相进行综合研究。结果表明:柴达木盆地古近系发育冲积扇、辫状河、洪泛平原、扇三角洲、辫状河三角洲、湖泊和浊积扇7种沉积相类型;受盆地构造演化作用的控制,柴达木盆地古近系沉积经历了水体由浅变深的演化过程;阿尔金山西段的山前陡坡带主要发育扇三角洲-浊积扇-湖泊沉积体系,阿尔金山中段的山前缓坡带主要发育冲积扇-辫状河-辫状河三角洲-湖泊沉积体系,柴北缘及柴东地区主要发育辫状河-洪泛平原沉积体系。

Sedimentary facies of the Paleogene in Qaidam Basin

Based on integrated analysis of outcrop section, drilling profiles, cores, well logging and seismic data, according to the quantitative lithofacies paleogeography, i.e. single factor analysis and multifactor comprehensive mapping method, the sedimentary facies of the Paleogene in Qaidam Basin were comprehensively studied by the third-order sequence as the unit. The results show that there are seven types of sedimentary facies in this region, including alluvial fan, braided river, floodplain, fan delta, braided river delta, lake and turbidite fan. Under the control of the structural evolution function, the sedimentary water of the Paleogene in Qaidam Basin experienced the evolution process from shallow to deep. The sedimentary facies were respectively fan delta-turbidite fan-lake sedimentary system in piedmont steep slope zone of the western Altun Mountains, the alluvial fan-braided river-braided river delta-lake sedimentary system in piedmont gentle slope zone of the middle section of the Altun Mountains, and the braided river-floodplain sedimentary system in the east and northern margin of Qaidam Basin.