| Guojuzi sag is one of sag within the of CheZheng depression of Jiyang depression.it's northern Chengnan hanging-wall block is a typical of half garben sedimentary characteristics, and develop various types of reservoir and transporting system from the fault zone to slope, and has a good reservoir conditions. According to the third resource evaluation, the prospective reserve of Guojuzi sag has 1.8×108 tons of geological oil reserves. At present, only 5.96 million tons of geological oil reserves were proved and the density of exploration well is only 0.05 well/km2. Hereby, Guojuzi sag has a larger exploration potential. Because the impact from the activity of Chengnan fault, The sediment in Paleogene from Chengkouzhi uplift were accumulated along Chengnan fault and a series of alluvial fan, fan delta, inshore underwater fan, fluxoturbidite fan was growed in Guojuzi sag. And Guojuzi sag is a type region for studing the controlling of extension faulting on the development of sedimentary fan.Based on the large number of rock core observation, well logging, logging data analysis, and interpretation of seismic profiles, The dissertation studies the process of structural deformation in Guojuzi sag and the controlling of extension faulting on the development of sedimentation of Shahejie formation in Paleogene. The dissertation acquires the following innovations:1. Guojuzi sag has experienced three stages of evolution. From Shahejie fourth to third phase, The sag was controlled by faulting, and fault activity was very intense, and the block was tilted by fault movement. Shahejie second phase to Dongying phase, the sag was controlled by faulting and thermal subsidence. In this phase, the width of garben was stability, but the sag was enlarge with the expanding of water area, the separation between uplift and depression is relative weakening. From Neogene to Quaternary, the sag was controlled by thermal subsidence and the whole sag subsidenced. From Shahejie fourth phase to Shahejie first phase, the rolling half graben developed which controlled by the boundary listric fault. In Dongying phase, the sag was a complex half-graben, and a series of normal fault with same dipping was develop in upper layer.2. The dissertation has discussed quantity of extension in horizontal and fault displacement in vertical and has also analyzed their spatial and temporal change rule.In Paleocene, the quantity of extension of sag in direction of north-south is reducing gradually from west to east, and the total quantity of extension between north-south section and west-east section is close and is about 3000m. The ratio of extension, are reach to 40% in the north-south section, however, it is 17% in the east-west section. The extension during Paleocene have two intense period. The first period from Shahejie fourth phase to middle stage of Shahejie third phase is the intense extension period, and the extension ratio is 30%. The second period form Shahejie second phase to Dongying phase, the fault movement is also intense. The dissertation also found that the extension in different area is different. In the central of the sag, the time of intense extension is from Shahejie fourth phase to lower period of Shahejie third phase, but in the west part and the east part,The time which happen intense extension was from lower to middle period of Shahejie third phase. In contrast, secondary extension happen early at east and west part which began at Shahejie second phase, but in the central part, the extension happened until Dongying formation. The analysis of vertical displacement of faulting indicated that the fast tectonic subsidence happened in Shahejie fourth phase, lower-middle period of Shahejie third phase and Dongying formation. The subsidence center has happened westward migration from Shahejie fourth phase to Shahejie third phase. Moreover, the subsidence in north part of sag is about 10 times in south part of sag.3.The dissertation has put forward that the stratum of Guojuzi Sag has been tilted in the process of faulting and the spatial and temporal change of tilting. The measurement of the three north-south profiles indicates that tilting is most obvious in Chengnan fault, especially in the lower period of Shahejie third phase, angles of tilting are 5 to 10 degrees in general, but the biggest angle of tilting can reach to 15 degrees where the concordant adjustment-fault developed. In the South gentle slope which is away from the Chengnan fault, angles of tilting are 1 to 3 degrees and the biggest angle is 4 degrees.4.The dissertation has put forward the sedimentary evolution of Guojuzi Sag. In Upper period of Shahejie forth phase, Guojuzi Sag is shallow lacustrine sedimentation, water of overall Sag is shallow. Owing to small height difference between provenance and sediment trap, small size striatus subsea apron developed. In Shahejie third phase, since the intense movement of fault in the margin of sag, sag came into the stage of fault depression deposition. The depocenter of sag is near the side of fault and structure is half-graben. The main provenances is the Cambro-ordovician strata in the north Chengzikou uplift and scondary is the Permain-Carboniferous and Mesozoic strata. Owing to the obvious height difference between provenance and sediment trap, In the north part and eastern adjustment-fault belt, multi-phase, multi-series underwater fan developed, and fan was connected between each other. In central of sag, lake bed fan developed. In the east, the canyon developed in the margin of lake was formed and a certain of scale turbidities fan developed in end of the canyon in middle period of Shahejie third phase. In the middle peroid of Shahejie third phase, faulting became weak, the climate changed to be dry environment. Since height difference between provenance and sediment trap was gradually decreased, the size of northern subsea apron is turn to be smaller. In this period, the central of sag is still semi-deep lake, and there develop deltaic deposit in South slope. In Shahejie second phase, the controlling of faulting is gradually weakened. The strata are main show lenticular which is thicker in the central of sag and is gradually thinning in north and south part, and sag was controlled by the faulting and thermal subsidence. In Shahejie first phase to Dongying phase, the climate is rainy and humid, the lake sinking once again and biology became prosperous again. Fan delta and semi-deep lake sediments are develop in the steep slopes (fault zone), and southern gentle slope developed delta deposition system.5.The dissertation has also put forward that the tectonic deformed process of Sag is play a impotrant role on controling of depositional process of sag. The deformation process of sag not only controlled the migration of subsidencecenter, but also control distribution of sedimentary facieses and the distribution of sand bodies. Guojuzi sag was mainly controlled by Chengnan fault.In Shahejie fourth phase to Shahejie third phase, owing to the activity of Chengnan fault was migrated to west, the subsidence center was also migrated to west. Hence, the extension has resulted into the increase of height difference between provenance and sediment trap. The rocks of provenance was denuded and were continuously carried into lake by rapid stream, and multi-phase, multi-series underwater fan were developed in the lake. The subsea aprons are develop from west to east in upper peroid of Shahejie fourth phase to lower Shahejie third phase, such as Da35, Guo 4, Guo6 and Guol which are controlled by faulting. Every early stage of rapid tectonic subsidence are mostly the development of great suit of offshore sand gravel, such as sand gravel in upper Shahejie fourth phase and lower Shahejie third phase has large thickness, coarse granularity, and develop in offshore.The research results of this dissertation not only has important significance for guiding exploration activity of Guojuzi sag, but also has important reference for the research of tectonic control on depositional system of fault basin in Eastern China.
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