To predict the large-scale source rock and reservoir distribution in Cambrian subsalt formations(Upper Sinian to Mid-Cambrian)in the Tarim Basin,more than 502D seismic lines and 3D data volume acquired latest,22 wells...To predict the large-scale source rock and reservoir distribution in Cambrian subsalt formations(Upper Sinian to Mid-Cambrian)in the Tarim Basin,more than 502D seismic lines and 3D data volume acquired latest,22 wells and some out-crops around this area were used to study the tectonic-lithofacies paleogeography,define the distribution of large scale source rocks and reservoirs,and sort out favorable zones.(1)The basin experienced evolution from ramp to deep-water mud-rich ramp,low-gradient slope,weak rimmed to strong rimmed platform,and the differentiation in the platform was controlled by pre-Cambrian palaeo-rifts.(2)The Luonan-Yubei ancient rift controlled the distribution of source rocks in the Lower Cambrian Yuertusi Formation,and this rift together with the northern depression are the main source rock area.(3)There are three sets of large-scale reservoirs,the Upper Sinian Qigebulake Formation,the Lower Cambrian Xiaorbulake Formation and the Wu-songger Formation,and shoal-mounds,early dolomitization and multi-levels of unconformities controlled reservoir develop-ment.(4)Four favorable zones,the north slope of Tazhong,upper slope of Maigaiti area,Keping-Wensu periphery,and south slope of Tabei,were evaluated.Of them,the north slope of Tazhong is most likely to have exploration breakthrough;the south slope of Tabei is the best area for exploring the Upper Sinian large scale weathering crust dolomite;Maigaiti slope and Kep-ing-Wensu periphery area improved in exploration potentials significantly,and are worth prospecting faster.展开更多
During July 2015 to June 2016, two permanent sampling sites were established in Scirpus mariqueter salt marsh and its adjacent mudflat on the intertidal zone of Chongming-Dongtan in the Yangtze Estuary. Based on month...During July 2015 to June 2016, two permanent sampling sites were established in Scirpus mariqueter salt marsh and its adjacent mudflat on the intertidal zone of Chongming-Dongtan in the Yangtze Estuary. Based on monthly trap net surveys of fishes, the characteristics of the fish assemblages in the different subhabitats, including the salt marsh and mudflat, and the monthly variations were analyzed. A total of 19 species of fishes were found belong to 12 Families. The characteristics including the dominant fish species were different in these two subhabitats. 18 species of fish were recorded in the mudflat, of which the dominant species were the Coilia ectenes, Pelteobagrus nitidus and Lateolabrax maculatus. Ten species of fish were recorded in the salt marsh of which the dominant species were the Coilia ectenes, Saurogobio dumerili, Liza haematocheila, Lateolabrax maculatus and Acanthogobius ommaturus. Pelteobagrus nitidus prefers to use the mudflat, while Lateolabrax maculatus and Liza haematocheila prefer to use the salt marsh. There was a significant difference in the monthly variation of fish abundance between the fish abundance of salt marsh and mudflat, while there was no significant difference in fish biomass. The Simpson index of the fish of the mudflat was significantly higher than that of the salt marsh, while the Margalef index and the Pielou index were lower than the salt marsh. The community can be divided into two groups: winter-spring (A) and summer-autumn (B). The abundance of fish in the mudflat and the salt marsh show a very significant correlation with the water temperature (r = 0.773, 0.830, respectively) and a significant correlation with the water salinity(r = 0.654, 0.648, respectively). The abundance of fish in mudflat and salt marsh are both significantly correlated with water temperature and salinity. The abundance of fish of the mudflat (r = 0.470, P > 0.05) is more related to the highest submerged depth than of the salt marsh (r = 0.087, P > 0.05).展开更多
There are abundant and highly varied trace fossils in the Sinian-Cambrian boundary beds in eastern Yunnan. Collections from 27 sections and their study give altogether 45 ichnogenera and 87 ichnospecies. Among them, 2...There are abundant and highly varied trace fossils in the Sinian-Cambrian boundary beds in eastern Yunnan. Collections from 27 sections and their study give altogether 45 ichnogenera and 87 ichnospecies. Among them, 2 ichnogenera and 7 ichnospecies are new, and 31 known ichnogenera and 38 known ichnospecies first found in the region. According to their order of appearance in the boundary beds and their assemblage features, the trace fossils in the Sinian-Cambrian boundary beds in the region may fall into 4 trace fossil assemblage zones in ascending order. In the paper they are correlated with those in the equivalent horizons abroad and their geological significance is discussed preliminarily.展开更多
基金Supported by the China National Science and Technology Major Project(2016ZX05004-002)PetroChina Science and Technology Major Project(2021DJ0501)。
文摘To predict the large-scale source rock and reservoir distribution in Cambrian subsalt formations(Upper Sinian to Mid-Cambrian)in the Tarim Basin,more than 502D seismic lines and 3D data volume acquired latest,22 wells and some out-crops around this area were used to study the tectonic-lithofacies paleogeography,define the distribution of large scale source rocks and reservoirs,and sort out favorable zones.(1)The basin experienced evolution from ramp to deep-water mud-rich ramp,low-gradient slope,weak rimmed to strong rimmed platform,and the differentiation in the platform was controlled by pre-Cambrian palaeo-rifts.(2)The Luonan-Yubei ancient rift controlled the distribution of source rocks in the Lower Cambrian Yuertusi Formation,and this rift together with the northern depression are the main source rock area.(3)There are three sets of large-scale reservoirs,the Upper Sinian Qigebulake Formation,the Lower Cambrian Xiaorbulake Formation and the Wu-songger Formation,and shoal-mounds,early dolomitization and multi-levels of unconformities controlled reservoir develop-ment.(4)Four favorable zones,the north slope of Tazhong,upper slope of Maigaiti area,Keping-Wensu periphery,and south slope of Tabei,were evaluated.Of them,the north slope of Tazhong is most likely to have exploration breakthrough;the south slope of Tabei is the best area for exploring the Upper Sinian large scale weathering crust dolomite;Maigaiti slope and Kep-ing-Wensu periphery area improved in exploration potentials significantly,and are worth prospecting faster.
文摘During July 2015 to June 2016, two permanent sampling sites were established in Scirpus mariqueter salt marsh and its adjacent mudflat on the intertidal zone of Chongming-Dongtan in the Yangtze Estuary. Based on monthly trap net surveys of fishes, the characteristics of the fish assemblages in the different subhabitats, including the salt marsh and mudflat, and the monthly variations were analyzed. A total of 19 species of fishes were found belong to 12 Families. The characteristics including the dominant fish species were different in these two subhabitats. 18 species of fish were recorded in the mudflat, of which the dominant species were the Coilia ectenes, Pelteobagrus nitidus and Lateolabrax maculatus. Ten species of fish were recorded in the salt marsh of which the dominant species were the Coilia ectenes, Saurogobio dumerili, Liza haematocheila, Lateolabrax maculatus and Acanthogobius ommaturus. Pelteobagrus nitidus prefers to use the mudflat, while Lateolabrax maculatus and Liza haematocheila prefer to use the salt marsh. There was a significant difference in the monthly variation of fish abundance between the fish abundance of salt marsh and mudflat, while there was no significant difference in fish biomass. The Simpson index of the fish of the mudflat was significantly higher than that of the salt marsh, while the Margalef index and the Pielou index were lower than the salt marsh. The community can be divided into two groups: winter-spring (A) and summer-autumn (B). The abundance of fish in the mudflat and the salt marsh show a very significant correlation with the water temperature (r = 0.773, 0.830, respectively) and a significant correlation with the water salinity(r = 0.654, 0.648, respectively). The abundance of fish in mudflat and salt marsh are both significantly correlated with water temperature and salinity. The abundance of fish of the mudflat (r = 0.470, P > 0.05) is more related to the highest submerged depth than of the salt marsh (r = 0.087, P > 0.05).
基金This research was a project (No. 4870087) supported by the National Natural Science Foundation of China.
文摘There are abundant and highly varied trace fossils in the Sinian-Cambrian boundary beds in eastern Yunnan. Collections from 27 sections and their study give altogether 45 ichnogenera and 87 ichnospecies. Among them, 2 ichnogenera and 7 ichnospecies are new, and 31 known ichnogenera and 38 known ichnospecies first found in the region. According to their order of appearance in the boundary beds and their assemblage features, the trace fossils in the Sinian-Cambrian boundary beds in the region may fall into 4 trace fossil assemblage zones in ascending order. In the paper they are correlated with those in the equivalent horizons abroad and their geological significance is discussed preliminarily.
