The Characteristics Of Provenance Systems And Sedimentary Systems Of Yingcheng Formation In Lishu Fault Depression

The structure of Lishu Fault Depression is in the southeast of Song Liao Basin uplift areas, since the development of late Jurassic, it experienced many structural movements and eventually form the break of the features for depression. This paper mainly based on the region’s seismic data, drilling core data, supplemented by logging, logging and a variety of analysis and test data, the sedimentology theoretical and mathematical geology, the systematically studied pear Fault Depression Yingcheng Sedimentary provenance system characteristics and the sedimentary system of the period, mainly to obtain the results and understandings as follows:(1)The integrated seismic data, logging data, and light and heavy mineral testing a variety of analysis and test data, together with qualitative and quantitative methods, summing up there are four provenance in Lishu Fault Depression the trap of Yingcheng Formation are northwest source area, the eastern slopes of the source area(Nationwide raised Kungchuling raised), the northern slope source area(the Yang dachengzi Uplift) and the basin of the northwest corner of Pacific ditch protruding parts of the source region. These four provenance systems in the vertical inheritance of the characteristics of the development is manifested in the horizontal coexistence of multi-source, source differences between the characteristics of the mixed-source deposition.(2)Marked by the sedimentary facies, the comprehensive analysis of logging phase signs and seismic facies indicators, the camp during the period of deposition terrain elevation Lishu Fault Depression lake basin deeper water, the region develops fan delta sedimentary facies. During the deposition of the eastern terrain further steep northern slope slows, the lake basin in eastern fan delta is developed, braided fluvial delta deposits in the lake basin in northern, north-west development contiguous; three sections of the camp and the camp, Sec deposition period, the lake basin uplift, with shallow water, the region formed braided river delta sedimentary facies. Due to the frequent diversion of underwater distributary’s channel, coupled with lake waves scour sand body of the study area with contiguous development on a flat surface, the characteristics of the mixed-source deposition; in the longitudinal direction, this depositional system has a continuing nature, inheritance and similar characteristics.What’s more, Provenance Systems control the distribution characteristics and parent rock feature of different depositional system.(3)In integrated the Yingcheng Formation of the Lishu Fault Depression during the deposition of sedimentary background, on the basis of system characteristics of provenance and sedimentary facies characteristics, namely establish a gentle slope-type fan delta and braided river delta depositional model. In the early deposition of each layer, the lake water retrograded into the sand body from the bottom of the thinning of sand bodies and increased mud, showing a positive graded characteristics; in the late of deposition, the lake water recede, with progradational sand body plot, the number of single sand body thickness increases from the bottom showing the reverse grading of characteristics.