The Lower Triassic Feixianguan Formation in the Daxian-Xuanhan region, northeastern Sicbuan is interpreted to be a carbonate platform intermediate between the West Hubei-East Cbongqing marine basin and Guangyuan-Wangc...The Lower Triassic Feixianguan Formation in the Daxian-Xuanhan region, northeastern Sicbuan is interpreted to be a carbonate platform intermediate between the West Hubei-East Cbongqing marine basin and Guangyuan-Wangcang marine basin. Outcrops, well logs and seismic data have disclosed that three sedimentary facies can be identified for the formation： open platform, platform exposed shoal and restricted platform facies. During the early stage of deposition of the Feixianguan Formation, there existed a sedimentary framework all the same as the Late Permian one： open platform in the west, and platform exposed shoal, restricted platform and open platform eastwards. The gradual increase of the shoal area permitted eastward migration of the shoal facies. During the deposition of the third member of the Feixianguan Formation, the study area was invaded by temporary transgressions. Till the deposition of the fourth member of the formation, the study area was prevailed over the unified restricted platform deposits, as indicated by the sedimentary model for the typical carbonate platform shoal deposits. The reservoir rocks in the Feixianguan Formation consist mostly of solution opening dolostone, and the rock types are assembled by oolitic dolostone, residual oolitic dolostone and sucrosic residual oolitic medium- to coarse-grained dolostone. The deep and shallow dual laterologs show relatively high resistivity, clear amplitude differences and time difference saltation of acoustic waves in some intervals. The seismic responses are indicated by low-frequency and highly variable amplitudes and chaotic reflection configurations. The reservoir rocks are characterized by high porosity-high permeability and medium porosity-medium permeability, showing a marked correlation between porosity and permeability. Solution openings are extremely developed in the reservoir rocks, including cast pores, intergranular solution openings, intercrystal pores, intercrystal solution openings, solution openings （caves） and minute fissures. Macropores and coarse pore throats are common. The reservoir rocks are apparently controlled by sedimentary facies in distribution patterns. Vertically, they occur dominantly in the second and first members of the Feixianguan Formation, and laterally in the platform exposed shoals and restricted platforms, where good natural gas potential is expected.展开更多
There are different opinions about the Permian/Triassic boundary and its correlation in the Daxian-Xuanhan area because of lacking typical lithological symbols and fossil criterions. Especially, it is very hard to det...There are different opinions about the Permian/Triassic boundary and its correlation in the Daxian-Xuanhan area because of lacking typical lithological symbols and fossil criterions. Especially, it is very hard to determine the Permian/Triassic boundary in the Daxian-Xuanhan buried areas. This brings many difficulties to geological research and oil and gas exploration. Based on field investigation and studies of well cores, newly found fossils, lithological characteristics and well log analyses, the authors discussed the Permian/Triassic boundary in the Daxian-Xuanhan area and brought forward a specific scheme for its determination and regional correlation.展开更多
This paper analyzes the actual situation and bottleneck problems in the development of beef cattle industry in Xuanhan County.In view of the existing problems,this paper puts forward reasonable suggestions,with a view...This paper analyzes the actual situation and bottleneck problems in the development of beef cattle industry in Xuanhan County.In view of the existing problems,this paper puts forward reasonable suggestions,with a view to better exploring the development model of characteristic beef cattle industry in Xuanhan County based on the unique cattle resources of Xuanhan County,and effectively promoting the implementation of the strategy of rural revitalization.展开更多
为了全面评估宣汉县地质灾害的易发性,选取坡度、工程地质岩组、斜坡结构等7个与地质灾害密切相关的因子构建了评价指标体系。通过信息量模型结合层次分析法,利用GIS平台的空间分析与栅格计算功能,辅以一定的数学模型,将研究区地质灾害...为了全面评估宣汉县地质灾害的易发性,选取坡度、工程地质岩组、斜坡结构等7个与地质灾害密切相关的因子构建了评价指标体系。通过信息量模型结合层次分析法,利用GIS平台的空间分析与栅格计算功能,辅以一定的数学模型,将研究区地质灾害易发性划分为高、中、低3个易发等级。其中,高易发区较为分散,面积为372.98 km 2,占比为8.71%;中、低易发区面积与占比分别为2278.18 km 2、1629.48 km 2与53.22%、38.07%。通过与野外调查情况验证,认为评价结果较为合理,可为研究区的地灾防治和国土空间规划提供理论指导和技术支撑。展开更多
文摘The Lower Triassic Feixianguan Formation in the Daxian-Xuanhan region, northeastern Sicbuan is interpreted to be a carbonate platform intermediate between the West Hubei-East Cbongqing marine basin and Guangyuan-Wangcang marine basin. Outcrops, well logs and seismic data have disclosed that three sedimentary facies can be identified for the formation： open platform, platform exposed shoal and restricted platform facies. During the early stage of deposition of the Feixianguan Formation, there existed a sedimentary framework all the same as the Late Permian one： open platform in the west, and platform exposed shoal, restricted platform and open platform eastwards. The gradual increase of the shoal area permitted eastward migration of the shoal facies. During the deposition of the third member of the Feixianguan Formation, the study area was invaded by temporary transgressions. Till the deposition of the fourth member of the formation, the study area was prevailed over the unified restricted platform deposits, as indicated by the sedimentary model for the typical carbonate platform shoal deposits. The reservoir rocks in the Feixianguan Formation consist mostly of solution opening dolostone, and the rock types are assembled by oolitic dolostone, residual oolitic dolostone and sucrosic residual oolitic medium- to coarse-grained dolostone. The deep and shallow dual laterologs show relatively high resistivity, clear amplitude differences and time difference saltation of acoustic waves in some intervals. The seismic responses are indicated by low-frequency and highly variable amplitudes and chaotic reflection configurations. The reservoir rocks are characterized by high porosity-high permeability and medium porosity-medium permeability, showing a marked correlation between porosity and permeability. Solution openings are extremely developed in the reservoir rocks, including cast pores, intergranular solution openings, intercrystal pores, intercrystal solution openings, solution openings （caves） and minute fissures. Macropores and coarse pore throats are common. The reservoir rocks are apparently controlled by sedimentary facies in distribution patterns. Vertically, they occur dominantly in the second and first members of the Feixianguan Formation, and laterally in the platform exposed shoals and restricted platforms, where good natural gas potential is expected.
文摘There are different opinions about the Permian/Triassic boundary and its correlation in the Daxian-Xuanhan area because of lacking typical lithological symbols and fossil criterions. Especially, it is very hard to determine the Permian/Triassic boundary in the Daxian-Xuanhan buried areas. This brings many difficulties to geological research and oil and gas exploration. Based on field investigation and studies of well cores, newly found fossils, lithological characteristics and well log analyses, the authors discussed the Permian/Triassic boundary in the Daxian-Xuanhan area and brought forward a specific scheme for its determination and regional correlation.
基金National Key R&D Program(2018YFD0501705)Key R&D Project of Sichuan Science and Technology Program(18ZDYF3215)Sichuan Beef Cattle Innovation Team of Modern Agricultural Industrial Technology System(sccxtd-2020-13).
文摘This paper analyzes the actual situation and bottleneck problems in the development of beef cattle industry in Xuanhan County.In view of the existing problems,this paper puts forward reasonable suggestions,with a view to better exploring the development model of characteristic beef cattle industry in Xuanhan County based on the unique cattle resources of Xuanhan County,and effectively promoting the implementation of the strategy of rural revitalization.
文摘为了全面评估宣汉县地质灾害的易发性,选取坡度、工程地质岩组、斜坡结构等7个与地质灾害密切相关的因子构建了评价指标体系。通过信息量模型结合层次分析法,利用GIS平台的空间分析与栅格计算功能,辅以一定的数学模型,将研究区地质灾害易发性划分为高、中、低3个易发等级。其中,高易发区较为分散,面积为372.98 km 2,占比为8.71%;中、低易发区面积与占比分别为2278.18 km 2、1629.48 km 2与53.22%、38.07%。通过与野外调查情况验证,认为评价结果较为合理,可为研究区的地灾防治和国土空间规划提供理论指导和技术支撑。
