Northeast Of The Ordos Basin Jurassic, Zhiluo, - The Period Of The Original Deposition Of The Face And Post-transformation

Effected by the intensity and asymmetry deudation reconstructive later, the stratum distributing of Zhiluo-Anding period in Ordos Basin and the neighbour area's synchronal stratum disintegrated entirety, or with parts missing partly. It shows thicker in the west and thin east entirety.Based on the analysis of great deal of outcrop and well logging data, take the cycle compare as the main method, combine to the regional marker bed and the characteristic of lithology and color, the Zhiluo group in headquarters of the basin is divided into upper and lower sections. Through the analysis of the well sedimentary faces, regional section compare, and combine to the other methods, such as lithology identify, grain size analysis and geochemical, such sedimentary system types as the braid river face, meandering river face, delta face, and lake face are been identified in Zhiluo-An'ding group of today's basin.Provenance analysis is the important reference that background of geostructure, distribute of precipitation facies, primary basin resume. Through actual measurement the paleocurrent direction outdoors, optical mode statistics, heavy mineral distributed, athodeluminescence characteristic, rare earth, trait and principal quantum element analysis, use these means analyse the provenance of Zhiluo-Anding in Northeastern part of Ordos basin,and judged that the provenance come form the northern horseback in northern of Yulin and the mother rock is igh grade rock the Eozoic mmixture the granitic irruptive rock.Region of interest in southern of Yulin controlled by the northern provenance,and affected by volcanic provenance in eastern of region of interest.Through the provenance analysis, precipitation facies distributed on the plane and precipitation facies evolved on the plane section, resumed primary sedimentary features of Zhiluo-Anding in Northeastern part of Ordos basin.On base of resuming primary sedimentary features of Zhiluo-Anding,the late-reformations can be inquired. After the stratum deposited,the eastern uplift and the western subsidence,it suffered strong and unequal exfoliation.At Late Jurassic,the metamorphic rock basement stratum of Hetao area thrust-motion form north to south,it result that the stratum curtated and deformed to the provenance at the compression.The provenance supplied the abundant high grade rock cuttings and granitic cuttings,it offered material safegrardguarantee. Simultaneously,at the process of the stratum suffered late-reformations,the northern and the southern uplifted caused the eastern stratum exfoliated entirety,it offered favor structural setting for uranium deposits concentrated at later stage.