The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structur...The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structure and the Jiannan gas field, were selected to analyze biomarker parameters in marine strata and to examine various types of natural gas and hydrocarbon sources. Fluid inclusions; carbon, oxygen, and strontium isotopic characteristics; organic geochemical analysis and simulation of hydrocarbon generation and expulsion history of source rocks were used for tracing fluid migration paths in marine strata of the study area. The Carboniferous-Triassic reservoirs in three typical structures all experienced at least two stages of fluid accumulation. All marine strata above the early Permian were shown to have fluids originating in the Permian rocks, which differed from the late stage fluids. The fluids accumulated in the late Permian reservoirs of the Xinchang structure were Cambrian fluids, while those in the late Carboniferous reservoirs were sourced from a combination of Silurian and Cambrian fluids. A long-distance and large-scale cross-formational flow of fluids destroyed the preservation conditions of earlier accumulated hydrocarbons. A short-distance cross-formational accumulation of Silurian fluids was shown in the late Permian reservoirs of the Longjuba structure with favorable hydrocarbon preservation conditions. The fluid accumulation in the Carboniferous reservoirs of the Jiannan structure mainly originated from neighboring Silurian strata with a small amount from the Cambrian strata. As a result, the Jiannan structure was determined to have the best preservation conditions of the three. Comparative analysis of fluid migration paths in the three structures revealed that the zone with a weaker late tectonism and no superimposition and modification of the Upper and Lower Paleozoic fluids or the Upper Paleozoic zone with the fluid charging from the Lower Paleozoic in the western Hubei-easteru Chongqing area are important target areas for future exploration.展开更多
Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristic...Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristics and paleoenvironment in western Hubei.The lithology at the bottom of Lower Silurian Longmaxi Formationn in this study area is mainly dark carbonaceous shale,the mineral composition is mostly clay minerals,quartz and feldspar,the content of illite and kaolinite is high,but also contains a minor amount of strawberry pyrite and graptolite fossils.The test and analysishow that the total organic carbon content(TOC)of the source rock is 0.8-6.32%,the average value is 3.42%,and the vitrinite reflectance(Ro)is 1.57-2.95%.The type of organic matter is mainly typeⅡ2.The overall abundance of organic matter is high,and the degree of thermal evolution has reached the stage of high maturity and over maturity.All these have become the good material basis and conditions for the formation of shale gas.The paleoenvironment of the source rocks indicates that the organic matter is a mixed source of planktonic algae and bacteria material.The large amount of hopane also indicates that the bacterial activity is strong during the deposition of organic matter;The water of the ancient lake is almost freshwater and brackishwater in some parts;The redox property of the water is in a strong reduction environment and with a stable stratification,which is also conducive to the preservation of organic matter.The above research results will provide the application of shale gas exploration in western Hubei.展开更多
The Yutangba Se deposit is a rare high-Se deposit in the world and it is well known for its high contents of Se, which reach 8590×10+{-6} . The ore-hosted rocks are dominated by cherts that have been well develop...The Yutangba Se deposit is a rare high-Se deposit in the world and it is well known for its high contents of Se, which reach 8590×10+{-6} . The ore-hosted rocks are dominated by cherts that have been well developed. Enrichment of selenium in Se-rich ores is obviously controlled by stratigraphic position and lithological character. The closer the rocks are to the Maokou Formation cherts, the more they contain selenium, but in case the stratigraphic horizons are close to one another, the enrichment of selenium would be controlled by lithological character. In the Se ores and abandoned stone coal pile at the Yutangba Se deposit there have been found large amounts of independent Se minerals, for instance, achavalite and a variety of forms of native selenium. Native selenium minerals present in the abandoned stone coal pile are the outcome of a combination of natural factors and anthropologic activities. For example, lime making will create a closed environment favoring the growth of native selenium, and the reduction of selenium will lead to its secondary enrichment. Starting with the study of ore-forming fluids. Systematic studies have been conducted on fluid inclusions separated from the main ore veins in the mining district for their homogenization temperatures, salinities and density, and the results show that fluid inclusions contained in ores from the Yutangba Se deposit are large in number and diverse in form, dominated by primary ones. The homogenization temperatures of two types of fluid inclusions are within the range of {173.2}-{247.5℃}, individually up to 300℃ or even higher; the salinities of fluids in fluid inclusions in quartz and calcite are {5.9%}-{10.1%} and {3.9%}-{4.5%}, respectively; their densities vary from {0.79}-{0.93} g/cm+3. Extensive discovery of Se minerals due to secondary enrichment of selenium in the stone coal provides important clues to the improvements on the metallurgical and recovery technologies for selenium in the black shale series of China, and also is of great significance in expanding selenium reserves and relax the situation of lacking selenium resources on a global scale.展开更多
Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and ...Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.展开更多
During the seven years revolution in the Western Hunan Hubei revolutionary base,currency experienced four stages of construction and development,and became the economic tool of revolutionary regime,and made considerab...During the seven years revolution in the Western Hunan Hubei revolutionary base,currency experienced four stages of construction and development,and became the economic tool of revolutionary regime,and made considerable contribution;however,the importance of politics to financial work is obvious here.Due to the mistakes caused by the left leaning in the revolutionary work,the monetary work in the revolutionary base area in Western Hunan and Hubei has been seriously affected the final result of the influence is to withdraw from the circulation field with the transfer of the main body of the revolutionary team.展开更多
Chitinozoans collected from upper Tremadocian to lower Floian strata of Chenjiahe section, Yichang, western Hubei, China comprise six species belonging respectively to the genera Euconochitina including a new species,...Chitinozoans collected from upper Tremadocian to lower Floian strata of Chenjiahe section, Yichang, western Hubei, China comprise six species belonging respectively to the genera Euconochitina including a new species, Euconochitina fenxiangensis, Lagenochitina and Bursachitina, together with Desmochitina sp. and Eremochitina sp. The chitinozoan succession across the interval is correlated with relevant conodont and chitinozoan biozones and two new regional chitinozoan biozones, the Lagenochitina destombesi Biozone and the Euconochitina symmetrica Biozone are proposed based on their stratigraphic ranges in the Fenxiang to Honghuayuan formations in the Chenjiahe section.展开更多
基金sponsored by National Programs for Fundamental Research and Development (973 Program,2012CB214805)the National Natural Science Foundation (40930424)
文摘The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structure and the Jiannan gas field, were selected to analyze biomarker parameters in marine strata and to examine various types of natural gas and hydrocarbon sources. Fluid inclusions; carbon, oxygen, and strontium isotopic characteristics; organic geochemical analysis and simulation of hydrocarbon generation and expulsion history of source rocks were used for tracing fluid migration paths in marine strata of the study area. The Carboniferous-Triassic reservoirs in three typical structures all experienced at least two stages of fluid accumulation. All marine strata above the early Permian were shown to have fluids originating in the Permian rocks, which differed from the late stage fluids. The fluids accumulated in the late Permian reservoirs of the Xinchang structure were Cambrian fluids, while those in the late Carboniferous reservoirs were sourced from a combination of Silurian and Cambrian fluids. A long-distance and large-scale cross-formational flow of fluids destroyed the preservation conditions of earlier accumulated hydrocarbons. A short-distance cross-formational accumulation of Silurian fluids was shown in the late Permian reservoirs of the Longjuba structure with favorable hydrocarbon preservation conditions. The fluid accumulation in the Carboniferous reservoirs of the Jiannan structure mainly originated from neighboring Silurian strata with a small amount from the Cambrian strata. As a result, the Jiannan structure was determined to have the best preservation conditions of the three. Comparative analysis of fluid migration paths in the three structures revealed that the zone with a weaker late tectonism and no superimposition and modification of the Upper and Lower Paleozoic fluids or the Upper Paleozoic zone with the fluid charging from the Lower Paleozoic in the western Hubei-easteru Chongqing area are important target areas for future exploration.
基金Supported by project of National Natural Science Foundation of China(NSFC)(No.42072122).
文摘Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristics and paleoenvironment in western Hubei.The lithology at the bottom of Lower Silurian Longmaxi Formationn in this study area is mainly dark carbonaceous shale,the mineral composition is mostly clay minerals,quartz and feldspar,the content of illite and kaolinite is high,but also contains a minor amount of strawberry pyrite and graptolite fossils.The test and analysishow that the total organic carbon content(TOC)of the source rock is 0.8-6.32%,the average value is 3.42%,and the vitrinite reflectance(Ro)is 1.57-2.95%.The type of organic matter is mainly typeⅡ2.The overall abundance of organic matter is high,and the degree of thermal evolution has reached the stage of high maturity and over maturity.All these have become the good material basis and conditions for the formation of shale gas.The paleoenvironment of the source rocks indicates that the organic matter is a mixed source of planktonic algae and bacteria material.The large amount of hopane also indicates that the bacterial activity is strong during the deposition of organic matter;The water of the ancient lake is almost freshwater and brackishwater in some parts;The redox property of the water is in a strong reduction environment and with a stable stratification,which is also conducive to the preservation of organic matter.The above research results will provide the application of shale gas exploration in western Hubei.
文摘The Yutangba Se deposit is a rare high-Se deposit in the world and it is well known for its high contents of Se, which reach 8590×10+{-6} . The ore-hosted rocks are dominated by cherts that have been well developed. Enrichment of selenium in Se-rich ores is obviously controlled by stratigraphic position and lithological character. The closer the rocks are to the Maokou Formation cherts, the more they contain selenium, but in case the stratigraphic horizons are close to one another, the enrichment of selenium would be controlled by lithological character. In the Se ores and abandoned stone coal pile at the Yutangba Se deposit there have been found large amounts of independent Se minerals, for instance, achavalite and a variety of forms of native selenium. Native selenium minerals present in the abandoned stone coal pile are the outcome of a combination of natural factors and anthropologic activities. For example, lime making will create a closed environment favoring the growth of native selenium, and the reduction of selenium will lead to its secondary enrichment. Starting with the study of ore-forming fluids. Systematic studies have been conducted on fluid inclusions separated from the main ore veins in the mining district for their homogenization temperatures, salinities and density, and the results show that fluid inclusions contained in ores from the Yutangba Se deposit are large in number and diverse in form, dominated by primary ones. The homogenization temperatures of two types of fluid inclusions are within the range of {173.2}-{247.5℃}, individually up to 300℃ or even higher; the salinities of fluids in fluid inclusions in quartz and calcite are {5.9%}-{10.1%} and {3.9%}-{4.5%}, respectively; their densities vary from {0.79}-{0.93} g/cm+3. Extensive discovery of Se minerals due to secondary enrichment of selenium in the stone coal provides important clues to the improvements on the metallurgical and recovery technologies for selenium in the black shale series of China, and also is of great significance in expanding selenium reserves and relax the situation of lacking selenium resources on a global scale.
基金National Natural Science Foundation of China,No.71804168。
文摘Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.
文摘During the seven years revolution in the Western Hunan Hubei revolutionary base,currency experienced four stages of construction and development,and became the economic tool of revolutionary regime,and made considerable contribution;however,the importance of politics to financial work is obvious here.Due to the mistakes caused by the left leaning in the revolutionary work,the monetary work in the revolutionary base area in Western Hunan and Hubei has been seriously affected the final result of the influence is to withdraw from the circulation field with the transfer of the main body of the revolutionary team.
文摘Chitinozoans collected from upper Tremadocian to lower Floian strata of Chenjiahe section, Yichang, western Hubei, China comprise six species belonging respectively to the genera Euconochitina including a new species, Euconochitina fenxiangensis, Lagenochitina and Bursachitina, together with Desmochitina sp. and Eremochitina sp. The chitinozoan succession across the interval is correlated with relevant conodont and chitinozoan biozones and two new regional chitinozoan biozones, the Lagenochitina destombesi Biozone and the Euconochitina symmetrica Biozone are proposed based on their stratigraphic ranges in the Fenxiang to Honghuayuan formations in the Chenjiahe section.
