Sedimentary System And Coal Accumulating Pattern Study Of Carboniferous-Permian In Zhengcun Exploration Area

The study area is located in the north of Xinan coal field, the southern margin of North China coal basin. Regional structure is relatively simple, the basic structure is a monoclinic structure to form a nearly EW, tend to close S , and the formation dip normally 7 ~ 11°, the faults are mainly NW-SE or near EW , they are a group of tensile fracture . The development of formation over the whole, the coal-bearing of the late Paleozoic Carboniferous - Permian are rich, and the strata is the main article in the study.Through the comprehensive analysis of section on field measurements, well logging, seismic, particle size analysis and the application of sedimentological analysis, based on the lithological characteristics, logging curves, particle size distribution characteristics and seismic facies analysis, identified tidal flat, delta, river and lake sedimentary systems from the Carboniferous - Permian strata in the study area . On this basis, then further discusses the characteristics of various types of sedimentary features of all Sedimentary systems, and discusses on the formation of different thickness, lithology and coal formation control.With the use of high resolution sequence stratigraphy of the basic principles and methods, established the sequence stratigraphic framework of the exploration area of the Late Paleozoic coal-bearing rocks of Carboniferous-Permian according to changes of sedimentary base level, combined with its adjacent areas in North China basin research in the outcrops, well logs and seismic data, analysis and comparison of integrated analysis, through research in this area in the Carboniferous-Permian coal-bearing sedimentary rocks filling sequence, due to relatively stable tectonic activity, the dominant factor in base-level change, creating a cycle of clear, obvious characteristics of the multi-level sub-base level cycles. Since the base-level rise in the Carboniferous, the occurrence of transgression, the maximum Late Carboniferous to Early Permian base level dropped, water withdrawal basin, into the late Permian continental deposits in the sequence, form a complete cycle, long base level cycle, in which it can be further divided into three long cycles, 8 Periodic cycles; with the deposition characteristics of different periods, respectively analysis the characteristics of different levels of.the cycles.Based on the changes in depositional base level units with response characteristics of the sequence and combined with the analysis of basin evolution with reference to base level change, summarizes the relationship between the different evolutionary stages of the sedimentary system and coal forming activities in the basin. Datum frequent movements constitute the sea several times alternately, several peat swamp development, the formation of multiple coal seams of the zone groups; one of all, Permian Shanxi Formation in shallow water delta developed in the shallow water delta slope in the basin over the slow, shallow body of water more stable, well-developed delta plain, a larger scale, delta plain distributary development between the peat swamps in the shallow water, forming thick and distribution stable coal seam in this area, and it is a coal seam with industrial exploitation of its value .