A continuous sedimentation at the Xinmin Section, Anshun, Guihzou Province, with the Upper Permian Talung Formation dominated by bedded siliceous rocks, and the Lower Triassic Luolou Formation consisting mudstones and...A continuous sedimentation at the Xinmin Section, Anshun, Guihzou Province, with the Upper Permian Talung Formation dominated by bedded siliceous rocks, and the Lower Triassic Luolou Formation consisting mudstones and marls as well as siliceous mudstones at its basal part indicates that it represents a deeper-water basinal facies across the Permian-Triassic boundary. Based on a systematic conodont biostratigraphic work, nine conodont species belong to two genera have been identified in this study. It enable us to establish five conodont zones at this section, in ascending order, they are： Clarkina changxingensis Zone（beds 1-3-4-2）, Clarkina yini Zone（beds 4-3-5-1-1）, Clarkina meishanensis Zone（beds 5-1-2-5-2）, Hindeodus changxingensis Zone（beds 5-3-1-5-3-2） and Hindeodus parvus Zone（beds 5-3-3-5-3-4）, respectively. According to the first occurrence of Hindeodus parvus in bed 5-3-3, the Permian-Triassic boundary is placed at the base of bed 5-3-3. This conodont zonation of the Xinmin Section provides precise biostratigraphic framework for further investigations on the geological events across the Permian-Triassic boundary at this section. In addition, the new conodont data also reveals that several siliceous beds occurred at the basal Triassic. It provides an exception of Early Triassic Chert Gap.展开更多
By means of the analysis methods of linear regression,climate tendency rate,integral humidity index and dry-wet index,precipitation,agricultural water demand and drought degree were analyzed systematically.The results...By means of the analysis methods of linear regression,climate tendency rate,integral humidity index and dry-wet index,precipitation,agricultural water demand and drought degree were analyzed systematically.The results showed that precipitation tendency rate in crop growing season was-19.983 mm/10 a in recent 50 years,and precipitation reduced by around 100 mm.60%-70% years had basically satisfactory precipitation and the satisfaction degree of natural precipitation towards agricultural water demand decreased by 23%.Due to precipitation decrease,climatic type changed from semi-humid and relative drought to moderate drought.The average water deficit was 56 mm in growth season and 36% years were affected by drought.Spring drought was the most serious with the probability of 64%,followed by autumn drought with the probability of 58%,and summer drought was the lightest with the probability of 24%.The drought probability from planting to seedling emergence in May was 70%,which had the greatest effect on agriculture production.展开更多
Situated at the foot of Yuelu Mountain in Changsha,is the cradle ofnonferrous metal scientific workers—Central.South University of Tech-nology,Professor Chen Xinmin has been working here for nearly
Recently,the China National Intellectual Property Administration released the"List of Enterprises Approved to Use the Geographical Indication Logo."The"Wujiang Silk"geographical indication logo has...Recently,the China National Intellectual Property Administration released the"List of Enterprises Approved to Use the Geographical Indication Logo."The"Wujiang Silk"geographical indication logo has been renewed and launched.This official approval serves to distinguish and celebrate the quality and cultural heritage of Shengze silk,and the use of this symbol is a testament to that distinction.Three enterprises from Shengze have been approved to use the logo:Saint Joy,Huajia Silk,and Xinmin Silk.展开更多
大兴安岭南段西沙拉地区出露大量的中生代新民组(J_(2)x)和满克头鄂博组(J_(3)m)地层,由于其岩石组合中流纹岩的存在,易混淆地层的划分,导致该流纹岩的地层归属存在争议。因此,以流纹岩为研究对象,进行锆石U-Pb测年,地球化学特征分析,...大兴安岭南段西沙拉地区出露大量的中生代新民组(J_(2)x)和满克头鄂博组(J_(3)m)地层,由于其岩石组合中流纹岩的存在,易混淆地层的划分,导致该流纹岩的地层归属存在争议。因此,以流纹岩为研究对象,进行锆石U-Pb测年,地球化学特征分析,并开展了新民组和满克头鄂博组地层剖面对比研究,进而探讨流纹岩的形成时代、构造背景及地层归属问题。研究指出西沙拉流纹岩的地球化学特征为高硅(SiO_(2)平均含量为75.74%)、富碱(Na_(2)O+K_(2)O平均含量为7.69%),并且镁、钙含量较低,属过铝质、高钾钙碱性系列;球粒陨石标准化的稀土元素配分模式呈右倾型,轻稀土元素相对富集,重稀土元素相对亏损,(La/Yb)N介于10.61~14.21,显示出较强的负铕异常(δEu介于0.44~0.53);大离子亲石元素(large ion lithophilic elements,LILE)Rb、Ba和K相对富集,同时高场强元素(high field strength elements,HFSE)Nb、Ta和Ti相对亏损,这说明岩浆起源于地壳物质;LA-ICP-MS锆石U-Pb测年结果显示流纹岩年龄为(167.7±2.6)Ma,形成于中侏罗世,是蒙古-鄂霍茨克洋闭合后伸展构造作用所形成的产物;结合区域地质、剖面岩石组合类型对比研究认为该流纹岩应归属为满克头鄂博组。展开更多
基金supported by the Natural Science Foundation of China (Nos. 41372039, 41272044, 41172024)the ‘Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan)’
文摘A continuous sedimentation at the Xinmin Section, Anshun, Guihzou Province, with the Upper Permian Talung Formation dominated by bedded siliceous rocks, and the Lower Triassic Luolou Formation consisting mudstones and marls as well as siliceous mudstones at its basal part indicates that it represents a deeper-water basinal facies across the Permian-Triassic boundary. Based on a systematic conodont biostratigraphic work, nine conodont species belong to two genera have been identified in this study. It enable us to establish five conodont zones at this section, in ascending order, they are： Clarkina changxingensis Zone（beds 1-3-4-2）, Clarkina yini Zone（beds 4-3-5-1-1）, Clarkina meishanensis Zone（beds 5-1-2-5-2）, Hindeodus changxingensis Zone（beds 5-3-1-5-3-2） and Hindeodus parvus Zone（beds 5-3-3-5-3-4）, respectively. According to the first occurrence of Hindeodus parvus in bed 5-3-3, the Permian-Triassic boundary is placed at the base of bed 5-3-3. This conodont zonation of the Xinmin Section provides precise biostratigraphic framework for further investigations on the geological events across the Permian-Triassic boundary at this section. In addition, the new conodont data also reveals that several siliceous beds occurred at the basal Triassic. It provides an exception of Early Triassic Chert Gap.
文摘By means of the analysis methods of linear regression,climate tendency rate,integral humidity index and dry-wet index,precipitation,agricultural water demand and drought degree were analyzed systematically.The results showed that precipitation tendency rate in crop growing season was-19.983 mm/10 a in recent 50 years,and precipitation reduced by around 100 mm.60%-70% years had basically satisfactory precipitation and the satisfaction degree of natural precipitation towards agricultural water demand decreased by 23%.Due to precipitation decrease,climatic type changed from semi-humid and relative drought to moderate drought.The average water deficit was 56 mm in growth season and 36% years were affected by drought.Spring drought was the most serious with the probability of 64%,followed by autumn drought with the probability of 58%,and summer drought was the lightest with the probability of 24%.The drought probability from planting to seedling emergence in May was 70%,which had the greatest effect on agriculture production.
文摘Situated at the foot of Yuelu Mountain in Changsha,is the cradle ofnonferrous metal scientific workers—Central.South University of Tech-nology,Professor Chen Xinmin has been working here for nearly
文摘Recently,the China National Intellectual Property Administration released the"List of Enterprises Approved to Use the Geographical Indication Logo."The"Wujiang Silk"geographical indication logo has been renewed and launched.This official approval serves to distinguish and celebrate the quality and cultural heritage of Shengze silk,and the use of this symbol is a testament to that distinction.Three enterprises from Shengze have been approved to use the logo:Saint Joy,Huajia Silk,and Xinmin Silk.
文摘大兴安岭南段西沙拉地区出露大量的中生代新民组(J_(2)x)和满克头鄂博组(J_(3)m)地层,由于其岩石组合中流纹岩的存在,易混淆地层的划分,导致该流纹岩的地层归属存在争议。因此,以流纹岩为研究对象,进行锆石U-Pb测年,地球化学特征分析,并开展了新民组和满克头鄂博组地层剖面对比研究,进而探讨流纹岩的形成时代、构造背景及地层归属问题。研究指出西沙拉流纹岩的地球化学特征为高硅(SiO_(2)平均含量为75.74%)、富碱(Na_(2)O+K_(2)O平均含量为7.69%),并且镁、钙含量较低,属过铝质、高钾钙碱性系列;球粒陨石标准化的稀土元素配分模式呈右倾型,轻稀土元素相对富集,重稀土元素相对亏损,(La/Yb)N介于10.61~14.21,显示出较强的负铕异常(δEu介于0.44~0.53);大离子亲石元素(large ion lithophilic elements,LILE)Rb、Ba和K相对富集,同时高场强元素(high field strength elements,HFSE)Nb、Ta和Ti相对亏损,这说明岩浆起源于地壳物质;LA-ICP-MS锆石U-Pb测年结果显示流纹岩年龄为(167.7±2.6)Ma,形成于中侏罗世,是蒙古-鄂霍茨克洋闭合后伸展构造作用所形成的产物;结合区域地质、剖面岩石组合类型对比研究认为该流纹岩应归属为满克头鄂博组。
