Research On The Type And Evolution Feature Of Buried Hill In Jizhong Depression

The material of buried hill is based primarily on pre-Tertiary strata in Jizhong depression. We think that the whole strata of middle to Upper Proterozoic trend in the NW and NE by the preparation of pre-Tertiary geological map, concentrateing in the mid-west area of the depression; All of the paleozoic group stratum has the distribution except the middle-north of Raoyang depression ,the north of the slope of Lixian, the north of the low uplift of Goyang and the western areas of Niutuo; The mesozoic mainly distributes in the northeast and northwest.of Jizhong depression by the influence of the tectonic movement of Yanshan and Himalayan.The controlling factor of'the growth of the buried hills are the extensional structures which are formed by the extension strength and the mantle arches in the Tertiary Period The strike-slip component in the process of stretching is second modification to the hill .Based on the difference of fault nature and mechanical properties, we have delimited three structural systems_the extensional fault, the taper slide structure and the reverse structure .Through the analysis of the spatial mop and combination rule of the fault, we can study easily the three-dimensional space distribution.According to the hills and its growth position of hill belts in Jizhong depression, buried hill can be divide into the bulge hill belt, the steep slope hill belt, the hollow hill belt, the central uplift hill belt and the pitch hill belt,then we make the concrete analysis in the light of the types of hill which they grow.Through comparative analyseing the similarities and differences of the hills of Raoyang sug, Baxian sug ,Langgu sug and Wuqing sug, I summe up the distribution rules of the various depression hill.Hill and the' formation of hill belt, the mop, the transformation as well as the oil-gas migration of hill and so on are controlled and affacted by the transfer zone in different degree.Transfer zone can be devided into five types in Jizhong depression,such as the accommodation zone of synthetic approach type,the accommodation zone of synthetic overlap type,the accommodation zone of Synthetic collateral type,the accommodation zone of convergent collateral type and the accommodation zone of convergent approach type, using Structural Map,The Fault Development History And The Formation Isopach map.Analyzeing Transfer zone's characteristic and the regular change in two aspects of the structural geometry and kinematics, so that we can figure out the conversion relationship in the hill belts and summe up the effects that the migration of the oil and gas is affected by transfer zone.we use the technology of balanced cross-section and analysize the feature of tectonic evolution of the different buried hill in Raoyang sag to determine the formation process of the different hills and the dissolution and transformation effect .according to the time orde of the formation, buried and stereotypeof the hills,The buried hill can be divided into five kinds of evolution types: (1) early formation, later buried, later stereotypes(early-later-later type); (2) early formation, later buried, early stereotypes(early-later-early type); (3) early formation, early buried, later stereotypes(early- early-later-type); (4) early formation, early buried, early stereotypes(early-early-early type); (5) later formation, early buried, later stereotypes(early-early-later type). By analyzing the period of the formation buried hill,we can find that the first type buried hill belt are the best for for hydrocarbon accumulation.the second is the second type.