Material Differentiation and Its Response to thePETMEvents in Continental Fault Lake during the Early Paleogene Period:A Case Study of Kongdian Formation in Jiyang Depression
Paleocene Eocene climate(PETM)events in Early Paleogene period on the Earth had serious impact on the global carbon cycle process and the terrestrial and marine ecological environment system.In this paper,on the basis of general thinsections, elemental analysis,carbon isotope,TOC et al.,the impact of Paleocene Eocene lake environment of Jiyang rifted basin, Bohai bay on the temporal and spatial variation and response ofPETMis studied,and it is found Jiyang basin experienced early multicycle evolution processes,detrital material and chemical differentiation occurred at the same time in lacustrine basin,and terrestrial weathering and chemical sedimentary differentiation indicates the change of extreme climate.In this perod,the lake water experienced gradual salinization characterized by the spatial zoning and time-evolution stage,which is a direct response to the occurrence of hot climate events.Time-space evolution of the lake was subject toPETMevents.The lake was not fully salty in the early events with prosperous plankton.Early phytoplankton absorption of 12 CO_2 led to the higher productivity in the ancient Lake,which dropped to a minimum with the lake turning increasingly salty and more difficult for the survival. delta~(13) C of lacustrine sedimentary records are in obvious negative bias due to excessive 12 C absorption and precipitation,resulting in,a maximum of 5.It is confirmed that globalPETMevents affected the time-space evolution and differentiation process of material in Jiyang depression during Paleocene-Eocene.