| The South China Plate was under an extensional tectonic setting and was mainly characterized by intraplate movements during the Hercynian stage. A series of extensional rift basins or sinistral pull-apart rift basins were developed in it. Especially in Permian, an intenser extension was developed and extended to inner part of the basin, called Emei Taphrogenesis, which led to the formation of some deep-water basins in different places in the South China Plate. So the paleogeographic pattern presented as basins alternated with platforms, basins in platforms, and platforms in basins. As we know, reefs developed on the margin of platform-basins are good reservoirs of oil and gas, such as Puguang Gas Field and Longgang Gas field. Therefore, it is very meaningful to study the sequence filling and sediment distribution of Permian in the South China Plate.This dissertation was primarily focused on the Permian in eastern Sichuan basin. Base on the field outcrops and a large of logging data, and seismic materials, this paper studied the Permian cherts and their implications with multiple methods. The principle of Sedimentology, Sequence Stratigraphy, Geochemistry, Paleontology, Geophysics and Tectonics and some other traditional geology theories were used as the instructions of this paper. Besides, the characters of deposition system, sequence filling, and regional tectonic setting were analyzed. With regarding sequence or sequence systems tract, we drew the sequence-based lithofacies paleogeography map more scientifically, isochronously, continuously, and precisely. At the same time, we described and inferred the sediment distribution, and the characteristics and evolution of Permian sedimentary basin in eastern Sichuan basin as well as the evolution of the Permian Upper Yangtze Plate. According to the results, we obtained the findings as following:(1) The petrology, and distribution of major and minor elements, REE, and SiandO-isotopic geochemistry indicated that the Middle Permian Maokou Formation and the Upper Permian Wujiaping Formation consist of hydrothermal silicates in Lengshui Stream of Shizhu, Chongqing and they were deposited in inter-platform basins.①The contents of SiO2 in the Maokou and Wujiaping Formation are relatively high, and the value is 80.09%-97.91% and 65.52%-97.76% respectively. The ratio of Al/(Al+Fe+Mn) is regarded as a helpful criterion for identifying hydrothermal silicates from other silicates. The average ratios are 0.30 and 0.4599 in the Maokou and Wujiaping Formation. In addition, along with the projection in Fe-Mn- (Cu+Co+Ni) ternary diagram, SiO2-Al2O3, SiO2-Fe2O3, and U-Th relative diagram, most of the Maokou and Wujiaping Formations' silicate samples fall into the hydrothermal field. Only a few of them were not originated from hydrothermal.②In the Maokou and Wujiaping Formation, the REE contents of silicate are low (7.509×10-6 and 38.540×10-6), with mid enrichment of HREE and negative anomaly of Ce. Eu has not evident anomaly. These features suggest that the silicates are hydrothermal genetic.③The Silicon (δ30Si) and Oxygen (δ18O) isotope compositions are similar to hydrothermal origin. Based on the Oxygen isotope fractionation equation of chert and water, the paleotemperatures of the silicates in the Formations are 34.45-80.77℃and 43.28-93.61℃.④The well preserved remains of radiolarians, thin-shell brachiopoda, ammonites, and spongy spicules were recorded in the silicates. Moreover, slumps and limestone gravels were found in the silicates. These petrology characters indicate that the Maokou and Wujiaping Formations' silicates were deposited in inter-platform basins. This conclusion was supported by the geochemical data of the silicates, whch are the values of MnO/TiO2, Al2O3/(Al2O3+Fe2O3), 8Ce andδ30Si.(2) There were many syndepositional faults and volcanisms of Permian in eastern Sichuan basin. And the heat source responsible for hydrothermal convection is presented in study area. Two factors constrained the formation of hydrothermal silicates in the Maokou Formation and Wujiaping Formation:①Extensions along with the faults of the interior plate which lead to the crust being permeable, thus the sea water leaked into deep crust and was heated; Therefore, the circulation occurred and hot fluid upwelled.②Studied section is located near the Qiyaoshan fault, which could be the pass of hot liquid from deep crust. At that time, sea water encountered and was heated with magmatic liquid, and then dissolved much SiO2 and other elements. Final, the warmer sea water with dissolved SiO2 sprayed out from the faults, which made sea water be near the fault and contain much more SiO2. At the same time, biota of radiolarian and sponge which enrich in SiO2 grew much better and led to biogenic silicate deposition.(3) Four types of depositional system of the Permian developed in eastern Sichuan basin, which are coast-tidal flat depositional system, carbonate ramp depositional system, carbonate platform depositional system, and inter-platform basins depositional system. Because of the rapid development of reef-building, the paleoenvironment of the study area was changed from carbonate ramp depositional system to carbonate platform depositional system during Changxing.(4)In the strata, 6 kinds of sequence boundary characters were recognized, which are weathering crust, action surface of ancient karst, action surface of volcano event, flooding transgressive surface, transition surface of rock character and facies, erosion surface of turbidity flow in basin. Four kinds of contributing factor related to basin evolution are identified: orogenic erosional unconformity, uplift erosional sequence unconformity, transgressive onlap sequence unconformity, exposed sequence unconformity. Base on these, the Permian were divided into 12 third-order sequences in the study area, and different characters in different facies was discussed and correlated regionally in detail. Meanwhile, sequence stratigraphy filling models from PSQ1 to PSQ12 were establish in eastern Sichuan basin as well. In general, every sequence was dominantly controlled by the tectonic movements, global sea level change, sediments supply and paleoclimate.(5)According to the division of third-order sequences or third-order sequence systems, fourteen sequence-based lithofacies-paleogeography maps were figured out (PSQ1, PSQ2, PSQ3, PSQ4, PSQ5,PSQ6, PSQ7,PSQ8LST, PSQ8TST,PSQ8HST,0 PSQ9,PSQ10, PSQ11 and PSQ12). These maps revealed the features of sediment distribution and basin evolution. The reconstructed paleogeography showed that: 1) fine siltstones and shales with coal-line of coast deposited in the Liangshan period (PSQ1); 2) With sea-level rising, bioclastic limestones and bioclastic micrites intercalated with chert belts, shales or chert concretions were deposited on open platform in the Middle Permian Qixia Formaiton and Maokou Formation (PSQ2-PSQ6); 3) An inter-platform basin was developed in Shizhu area in PSQ7, although the other areas were still open platform; 4) In PSQ8LST, the sediments were characterized by shales, bauxitic shales, brown siltstones, and argillaceous siltstones with coal-line of coast environment. But basalts were developed in Liangping in the north of study area; 5) In PSQ8TST-PSQ12, sediments of carbonate ramps were accumulated in the study area. However, there was an inter-platform basin with silicates in PSQ9-PSQ12 in Shizhu, Chongqing; 6) The paleoenvironments of the study area were changed from carbonate ramp depositional system to carbonate platform depositional system during PSQ11-PSQ12. Two inter-platform basins with argillaceous limestone were developed in Liangping and Shizhu.(6) The eruption of Emei basalt was a process of continental rift evolution, which started in Maokou period in the early of Late Permian, and ended in Changxin period. The eructation of Emei basalt could be divided into five phases:①In the early of Maokou Period(PSQ5, PSQ6), magma in mantle started to be active, which made overlain crust updoming and made sea floor be fluctuated slightly. Under the influence of a variety of above factors, slides of incomplete consolidated marine sediments happened, therefore, the Maokou Formation nodular limestone deposited. Hydrothermal fluid enriched in SiO2 went into sea floor and permeated into the marine sediments, which deposited as chert nodules or bands in diagenesis.②In the late of Maokou period (PSQ7), the upwelling of magma made overlain crust become dome. Extensional faulting could be easily happened in the center of the dome, which led to the formation of rift basins, in which silicates deposited, such as Shizhu inter-platform basin of the Maokou period.③In the latest Maokou period, when the basalt wast close to eruption, the crust of Sichuan basin rose rapidly because of the upwelling of magma, which resulted in the domes being above the sea level. Therefore, a parallel unconformity developed between the Middle and Upper Permian named the Dongwu Movement.④In the early of Wujiaping period (PSQ8LST), Emei basalt erupted out of the ground comprehensively. In the center of the dome, eruption was continental and abundant basaltic cleavages were developed in the basalt. Eruptions occurred in the surrounding sea too, and the pillow structures were found in the basal. Because magma effused out of ground on a large scale, basement of adjacent area subsided to fill up the magma chamber. Shizhu inter-platform basin was developed under this background and led to the accumulation of the Wujiaping Formation's silicates.⑤Volcanism finished in Changxing period. Sichuan basin overall was extensional and subsided. Most part of the basin evolved to depositional area. "Kaijiang-Liangping" inter-platform basin with argillaceous limestones began to form along with "Shizhu" inter-platform basin.
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