[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three differe...[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best.展开更多
Based on the latest high-precision aeromagnetic data,an aeromagnetic anomaly zone is identified at Zhangsanying--Tongshanzi in northern Hebei Province.By the potential field conversion processing,including the reducti...Based on the latest high-precision aeromagnetic data,an aeromagnetic anomaly zone is identified at Zhangsanying--Tongshanzi in northern Hebei Province.By the potential field conversion processing,including the reduction to the pole,vertical derivative,upward continuation and residual anomaly,the authors analyzed the characteristics of three typical aeromagnetic anomalies in Zhangsanying--Tongshanzi aeromagnetic anomaly zone and their geological origin.The methods include the forward and inversion methods,such as 2.5D optimization fitting and Euler deconvolution.Moreover,combined with the geological outcrop,known iron deposits,ground magnetic survey and verification,the authors studied the relationship between the aeromagnetic anomalies and iron deposits.The result shows that the Zhangsanying--Tongshanzi aeromagnetic anomaly zone is composed of 10 large magnetic anomalies with high amplitude and clear boundary.The aeromagnetic anomalies are comparable and intrinsically related to the ground magnetic anomalies and IP anomalies,indicating that the anomalies are caused by magnetite deposits.It has good magnetite prospecting potential in the Zhangsanying--Tongshanzi aeromagnetic anomaly zone.展开更多
Accurately determining the age of the Tuchengzi Formation has direct influence on confirming the boundary between the Jurassic and the Cretaceous systems in northern Hebei-western Liaoning, and on related geological p...Accurately determining the age of the Tuchengzi Formation has direct influence on confirming the boundary between the Jurassic and the Cretaceous systems in northern Hebei-western Liaoning, and on related geological problems in China. However, the Tuchengzi Formation mainly consists of sedi-mentary rocks, with a poor fossil record and especially lack of index fossils. The Tuchengzi Formation is also lack of the type of volcanic rocks that can provide an isotopic age. Therefore, the age of the Tuchengzi Formation has been uncertain. Based on our systematic dating of the tuff interbedded in the Tuchengzi Formation of Chengde and Jinlingsi-Yangshan basins in northern Hebei-western Liaoning, combined with the dating results of previous researchers, here we suggest that the age range of the Tuchengzi Formation in northern Hebei-western Liaoning is from 147 Ma to 136 Ma. It implied that the Tuchengzi Formation was mainly formed in the Early Cretaceous.展开更多
基金Supported by Science and Technology Research Project of Colleges and Universities in Hebei Province(QN2015320)Natural Science Foundation of Hebei Province(C2015101020,E2019101012)Project of Chengde Finance Bureau(CZ2013011).
文摘[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best.
基金Supported by Project of China Geological Survey(No.DD20190028)。
文摘Based on the latest high-precision aeromagnetic data,an aeromagnetic anomaly zone is identified at Zhangsanying--Tongshanzi in northern Hebei Province.By the potential field conversion processing,including the reduction to the pole,vertical derivative,upward continuation and residual anomaly,the authors analyzed the characteristics of three typical aeromagnetic anomalies in Zhangsanying--Tongshanzi aeromagnetic anomaly zone and their geological origin.The methods include the forward and inversion methods,such as 2.5D optimization fitting and Euler deconvolution.Moreover,combined with the geological outcrop,known iron deposits,ground magnetic survey and verification,the authors studied the relationship between the aeromagnetic anomalies and iron deposits.The result shows that the Zhangsanying--Tongshanzi aeromagnetic anomaly zone is composed of 10 large magnetic anomalies with high amplitude and clear boundary.The aeromagnetic anomalies are comparable and intrinsically related to the ground magnetic anomalies and IP anomalies,indicating that the anomalies are caused by magnetite deposits.It has good magnetite prospecting potential in the Zhangsanying--Tongshanzi aeromagnetic anomaly zone.
基金Supported by National Natural Science Foundation of China (Grant No. 90714010)
文摘Accurately determining the age of the Tuchengzi Formation has direct influence on confirming the boundary between the Jurassic and the Cretaceous systems in northern Hebei-western Liaoning, and on related geological problems in China. However, the Tuchengzi Formation mainly consists of sedi-mentary rocks, with a poor fossil record and especially lack of index fossils. The Tuchengzi Formation is also lack of the type of volcanic rocks that can provide an isotopic age. Therefore, the age of the Tuchengzi Formation has been uncertain. Based on our systematic dating of the tuff interbedded in the Tuchengzi Formation of Chengde and Jinlingsi-Yangshan basins in northern Hebei-western Liaoning, combined with the dating results of previous researchers, here we suggest that the age range of the Tuchengzi Formation in northern Hebei-western Liaoning is from 147 Ma to 136 Ma. It implied that the Tuchengzi Formation was mainly formed in the Early Cretaceous.
