| The Huizhou depression is a confirmed depression with rich hydrocarbons, which is a major producing area of the Pearl River mouth basin. The Dongsha Massif is a important hydrocarbon accumulation adjacent with the Huizhou depression. Because mass hydrocarbon reservoirs and pay structures has been found in the Dongsha Massif and the transitionally peripheral uplift and depression area, the prevailing hydrocarbons source has displayed in the Huizhou depression, the Dongsha Massif is profitable hydrocarbon potential ranges in the range of petroleum system, the Huizhou depression. The study on the Dongsha Massif architecture, structure and evolvement is weak dimension, especially the joint study methods of uplift and depression is lack and little. The fundamental purpose is reinforced study on the relation with the Huizhou depression and the Dongsha Massif by analyzing the upwarping-downwarping pattern of the basin, the structural feature, the joint evolution and the hydrocarbon reservoir forming, taking the modern oil geological theory and basin-mountain coupling as a guide, taking integration of uplift and depression as a breakthrough point, taking the comprehensive analysis of the multiple dates, the methods and the modeling as new measures. It's enriching exploration targets.(1)Huizhou Depression and Dongsha Massif coupling exists at the same tectonic stress field and they have certain response relationship and differences to each other. Huizhou depression formed the complex structure with the Massif alternating with the low-lying; however, Dongsha Massif losted the Wenchang and Enping strata because of continuing uplift at that time, only some small faults developed partially during the Enping period, and the structure of the Dongsha Massif is relatively simple. Several low-lyings exsist as the structural style of combined controlling by the faults and upthrusts in the internal of the depression as well as multi-level uplift structure. Fault system also has different levels and the role of controls, respectively, concave control, low-lying control and regulation. Faults are divided into three types:the NE or NEE, NW or NWW and near EW directions which are consistent with the Dongsha Massif and this is the just reflection of the controlling of the unified stress field. Huizhou Depression and Dongsha Massif are controlled by the pre-exsisting structure significantly:in the Dongsha Massif it register as structures morpha of "three terrace- two ridges -one transition" and the structure character of ground layer overlap; Huizhou depression is shown as substrate controlling the deposition filling and composite half-graben structure characteristics. In the extensional stress field, the structural styles of Huizhou depression shows as mainly for the tension block, with the presence of the twist factor, shear type of block companied, wherefore Buried Hills anticline, the tilting off block, reverse tilted fault block, half base drape structures, horst structure, fault-related fold, traction slip fault characteristics such as composition of several typical structures can be identified.(2)Being established in the tectonic location of the Pearl River Mouth Basin, the study area consequents upon the following factors, the pressing and collision between the India plate and Eurasian plate, the subduction belt of Pacific plate. And those factors control its forming and complex evolution. Coupling upwarding and depression presents multiphase and couple mechanism under the multiphase tectonic setting. Huizhou depression is a classic faulted basin, and with integral evolution of faulted depression. Huizhou depression and the Dongsha massif are coupling on the tectonic feature during the evolution. The paper establishes in the structural history, palaeostructure maps, and classifies the evolution of study area into four phases. The followings:â‘ Late Crataceous-Palaeocene, strong block movement, formed the initial frame of upwarding and depressionging;â‘¡late Eocene-early Oligocene, strong tectonic movement, coupling the fast denude on uplifting and the uplift of depression;â‘¢late Oligocene-early Miocene, depression in the predominant, the uplift coupling with depression on duration subsidence;â‘£Middle Miocene-Pliocene, block activization, coupling the elevation and subsidence of uplift with the subsidence and elevation of depression. Huizhou depression during late Eocene-early Oligocene has the complex evolution; however, Dongsha massif displays the fast uplifting.(3)For discussing the relationship between tectonic evolution and accumulation, this paper selects two typical oil and gas reservoir of HZ27-3 and LH11-1 to autopsy. The anatomical analysis of Hz27-3 oil-bearing structures suggest that Hz27-3 has the features of enough source rocks, complex migration path of faults or stratum, composite multi-trap style and reservoir near the source. The analysis of LH11-1 suggest that LH11-1 characters with a large reef trap, high porosity sandstone transmission conductor of Zhuhai formation, and verify the existence of long-distance oil migration in the Huizhou Depression and east Sharon along the structural ridge. We have the conclusions that tectonic evolution plays an important role in the construction and transformation of reservoir of different periods and late Oligocene to early Miocene is an important period for the formation of structural ridge, making outstanding contributions for the LH11-1 oil and gas accumulation, engendering the dominant migration pathway of "boundary fracture-sandstone transmission conductor of Zhuhai formation-unconformity-structural ridge-reef reservoir ". This paper revealed that the different stages of tectonic evolution in East Sharon built different types of traps, and suggest the character of "rock hill-drape anticline-reef-stratum or rock" traps configuration relations in cross, and the overlap of stratum relations and lithology distribution in horizontal, which control the overlap trap, sand lens and the tilting wipe out an important factor in traps.
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