Mesozoic And Paleozoic Structural Style And Trap Evaluation In The East Margin Of Eastern Yangtze Plate

The study area is located in northeastern Middle Yangzi Region, is located in a composite basin-mountain system which combined by two basin mountain system, the east of Qinling Mountains and Jiangnan-Xuefeng orogenic belt, regional tectonic evolution possess the characteristics of multi-stage tectonic movement, Tectonic stress of multiple and multi-layered structural deformation, has the "two mountains and one folder basin" of regional geological structure, integral with hedge interference, north-south belt, vertically stacked structure. Based on2D seismic data interpretation and research area, improve the formation layer structure feature study, deepen the structural evolution and deformation characteristic analysis through balanced cross section, analyse control effect of tectonic evolution on the area of local structure distribution and hydrocarbon accumulationThesis mainly using2d seismic data, in combination with drilling and well logging data layer, through the more Wells synthetic seismic records, VSP horizon calibration, the three regional seismic geology structure anatomy and tectonic evolution, forming structure interpretation skeleton, at the conclusion of the tectonic style, and on the basis of the detailed interpretation of the structure of the develop, implement the geological structure and structural form. Around the Middle East of jianghan plain Mesozoic and Paleozoic Marine stratum launched research, through a large number of the seismic tectonic geology explain, and combining previous large outcrops structural geology material and its know than of study area, detailed analyse Northern and southern hedge drape fold structure system by the formation mechanism, structure trellis, structure combination and composite, the structure types and tectonic style and its formation and evolution stages.Take structure and the basin evolution analysis as the main line, application of mountain-basin coupling balance profile and other modern theory and method, and carried out the of research of kinematics, dynamics and geometry, from mountain-basin system structure origin and structure types Angle to afresh the tectonic units and divide the work area into four secondary structure., namely the Dahong mountain thrust and nappe tectonics,the back, ramp thrust structural area, to flush the interference range, the south of Yangzi River snowy peak to/the back counter to flush the nappe1area, the south of Yangzi River snowy peak counter to flush the nappe2areas; And further division6third-level tectonic units,14four level of tectonic units.. Promulgates according to the earthquake, and referred with formerly the geophysics material confirmation, thought that had three types, the scale by the basis to the deposition cap rock to vary the Watt formation, the overall has the deep source to open the characteristic which slid together to the surface impetus shallow layer slip plane, by the depth metamorphic rock between and the basis surface slip plane, deposition cap rock multiple Watt pushed primarily duplicate, the stratum multiple way superposition’s structural system was the work area characteristic.Three kind of slip planes are:1) the basis inside story opens to the surface:The late proterozoic era shallow deterioration rock layer and the15th of10th lunar month ancient, between the antique generation of kata-metamorphism rock layer opens to the surface, by the south, north is gradually shallow the orogenic zone to the research area interior burying depth fluctuation, in washes away under the belt of folded strata the duplicate existence giant basis to open to the zone of fracture (mouth), forms the structure with the cap rock to have the causes and effects origin relations, mainly distributes south the north orogenic zone the reason.2) cap rock and basis surface slip plane:On the Sinian system cap rock with the under Sinian system shallow metamorphic rock basis between the slip plane, has in the nappe to slide to be away from a big way, to flushes the belt for to wash away the slip fold surface.3) deposits the cap rock slip plane:The silurian series lower segment, the Devonian system base, three packs are the base are three cap rock interior slip planes, the main distribution and the nappe frontal zone and bring, reduces by the depth to the shallow Watt scale. By the orogenic zone to the basin, transforms gradually by the thick skin structure to the pellicle structure, and form the bountiful structure combination and the style. According to the structure distortion dislodgement characteristic, has divided the local structure type and the style, and has analyzed its distributed rule. May divide into the extrusion structure, sway from side to side the structure, the extension structure, the magmatic rock to construct four kind and the composite construction type. The extrusion contraction structure including the before and after exhibition imbricate structure, flushes the structure, the recoil structure to/the back and dual counter flushes the structure, the bamboo to divide the structure and so on local structure distortion style; The extension structure including the rift valley (half rift valley), the horst, breaks structure styles and so on step, buried hill; Sways from side to side the structure to walk by the writing from right to left work area slides the efflorescent fault both sides to sway from side to side the structure, constructs including the plus and minus efflorescent structure; The magmatic rock invasion mainly distributes nearby the later period Cretaceous system master control fault. Because the research area has experienced many phase of distortion transformations, many display partially for the composite construction characteristic, like the early time extrudes counter flushes later period extends slides, the early time folds the tile to wash away reverse later period counter flushes and so on, causes the structure complex shape to be changeable.Through the region, the work area structure evolve and construct the combination compound forming process the research, has pointed out east the Jianghan plain since the Indo-Chinese time, because receives many kinds of stress field functions and the multi-boundary condition limit, the areal structure evolution has characteristics and so on multi-level which the structure stress field’s multiplicity, structure activity’s many issues, the structure distort. Has experienced east Gary, Heisey successively Indo-China, early Yanshan movement, the late Yanshan movement-early Himalayan movement, late the Himalayas and so on five sedimentary structure evolutionary phase, the Yanshan movement time extrudes the structure main distortion time early for the Yangzi east, late Yanshan movement-the Himalayas time for transformation time. By the orogenic zone to the trough, the tectonic stress weakens gradually, slides the duplicate distance and the structure reduction quantity reduces gradually, the structure style is involved in by the basis flushes supinely-> dual counter flushes the structure-> to fold the tile to flush the structure-> cap rock Watt nappe structure-> to flush (back only to flush) constructs transits gradually, its Watt opens to the surface by the basis to the cap rock multi-wrap slip plane transition, the vanguard reverse triangle cuneate faulted structure is obvious, and has "Shan Xiehuo the multi-wedges split the bamboo" the structure style. Because pushes the duplicate principal stress direction not to be inconsistent, north causes the home court to construct east walks toward left slides the transformation, the research area has "middle the basis to break slides-the cap rock to flush, the north and south to push duplicate Watt, the writing from right to left to walk the slippery pressure turns, the longitudinal multiple superposition" the structureAccording to the research in the area of Marine medieval born tectonic deformation styles and tectonic evolution, the union formerly the Yangzi area oil gas became the Accumulation background and becomes the Accumulation environment, has analyzed the possible deformational trap type and the combination way. Thought after this area has male the material base, the intense many phase of transformations and the complex hot system, had decided this area many issues live the hydrocarbon, many phase of migration, the multi-loop system, to expect success Tibet and the many phase of transformation detachment conditions, stressed that many issues live the hydrocarbon and the later period Cheng Cang validity. After marine facies in paleozoic group many phase of transformations the tax saves the integrity and the tax save the way, the early thermal evolution degree, the later period buries the warming function deeply, the schedules to gather the condition and the preserved condition, proposed research area "north strong in middle, middle strong in south" the overall judge advice, lower part the Cretaceous system under the plane of unconformity the inside story structure, the buried hill low fault block, under the silurian slip plane the enveloping in-situ body and dual counter covers pushes sets constructs the body, the nappe interior relatively weak distortion anticline and breaks the anticline is may supply the choice the oil-gas exploration domain.