柴达木盆地北缘结绿素—红山地区古新统至中新统沉积相

Sedimentary facies of the Paleocene-Miocene in Jielüsu-Hongshan area in north margin of Qaidam Basin

根据柴达木盆地北缘露头剖面、钻井剖面的地层学和岩石学研究所取得的各种定量及定性资料,采用冯增昭教授倡导的单因素分析多因素综合作图法,编制了柴达木盆地北缘结绿素—红山地区古新统—始新统、渐新统和中新统的各种单因素图和沉积相图。这是首次将定量的沉积相研究方法应用于柴达木盆地的古新统至中新统。结绿素—红山地区古新统至中新统发育2种沉积相类型,即冲积扇和辫状河。其中辫状河可划分为砾质辫状河和砂质辫状河。古新世—始新世发育冲积扇—辫状河—湖泊沉积体系,渐新世—中新世发育辫状河—湖泊沉积体系。从古新世到中新世,柴达木盆地北缘经历了由大规模冲积扇沉积到辫状河沉积的演化过程。

On the basis of all kinds of stratigraphic and petrologic data of outcrop and well sections, the maps of single factors and sedimentary facies of the Paleocene-Eocene, Oligocene and Miocene were compiled with the single factor analysis and multifactor comprehensive mapping method proposed by Professor Feng Zengzhao. It is the first time to apply this method to study sedimentary facies of the Paleocene-Miocene in the Qaidam Basin.There are two types of sedimentary facies in this region： the alluvial fan and the braided fluvial river. The latter is further sub-divided into gravelly and sandy braided fluvial facies. The sedimentary systems were alluvial fan-braided fluvial river-lacustrine depositional systems during the Paleocene-Eocene, and braided fluvial river-lacustrine depositional systems during the Oligocene-Miocene. From Paleocene to Miocene, the sedimentary facies evolved from the extensive alluvial fan to the braided fluvial river environment.