Time filter

Source Type

Wang S.,China University of Geosciences | Ye H.,China Academy of Geological science | Yang Y.,China University of Geosciences | Zhang X.,Hebei Institute of Geological Survey | And 2 more authors.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2016

The Huoshenmiao pluton located in the west of the Luanchuan ore district, southern margin of the North China Craton (NCC) is mainly composed of quartz diorite, monzo-granite and granite porphyry. The Huoshenmiao pluton is closely related to the Huoshenmiao Mo deposit. While the degree of research on the Huoshenmiao pluton is very low, which seriously restrict the understanding of the genesis of the Huoshenmiao Mo deposit. Three types of rock including quartz diorite, monzo-granite and granite porphyry has been researched by zircon U-Pb chronology, geochemistry and Hf isotope. The forming ages of quartz diorite, monzo-granite and granite porphyry are 150.3±0.6 Ma, 146.0±0.6 Ma and 145.1±0.5 Ma respectively, and are products of the second magmatism of the Luanchuan ore district, Late Jurassic. Geochemistry and zircon Hf isotope show that the Huoshenmiao pluton belongs to I-type granite, and it results from ascending magma formed by partial melting of different source regions. The quartz diorite stems from remelting of the enriched mantle, while the monzo-granite and granite porphyry are the products of mafic magma derived from remelting of the enriched mantle mixed with felsic magma derived from remelting of the Taihua TTG. © 2016, Editorial Department of Earth Science. All right reserved.

Xi X.,China Geological Survey | Li M.,China Geological Survey | Zhang X.,Hebei Institute of Geological Survey | Zhang Y.,Henan Institute of Geological Survey | And 4 more authors.
Earth Science Frontiers | Year: 2013

Soil organic carbon in middle-east China can be studied by comparison based on the data obtained by multi-purpose regional geochemical survey. The middle-east plain covers the terrain of Hebei, Henan, Hubei, Hunan, Guangdong and Hainan provinces, ranging from relatively higher latitude to low latitude and crossing temperate zone, subtropical zone and tropical zone. More than 334000 km2 were covered in the multi-purpose regional geochemical survey. Top soil (0-0.2 m) carbon storage is 906.84 Mt and average carbon density is 2716.93 t/km2. Including the higher soil carbon density in the northeastern plain, the carbon density in middle-east regions of China exhibited the changing pattern of high low high low from the northeastern plain downward to Hainan Province, that is 3327.8 t/km2 (northeastern plain)→2207.39, 2421.02 t/km2 (Hebei and Henan)→3442.15, 3942.92 t/km2 (Hubei and Hunan)→2255.90, 2936.72 t/km2(Guangdong and Hainan). The soil carbon density in agricultural ecosystem and urban ecosystem presented different changing rule from higher latitude to lower latitude, i.e., in agricultural farmland it changes from low to high, and in urban soil from high to low. The soil organic carbon increased by 14.5% (totally increasing 115.18 Mt and annually averaging 5.76 Mt/a) during past 20 years compared to the value achieved by the second soil reconnaissance. However organic carbon did not increase evenly. The rising rate decreased from low latitude to high latitude, and organic carbon increased in agricultural and urban ecosystem but decreased in tideland, rivers, lakes, grassland, forest and swamp.

Wen S.,Jilin University | Li B.-L.,Jilin University | Li L.-B.,Hebei Institute of Geological Survey | Wang B.,No. 5 Exploration Team of Hebei Geological and Prospecting Bureau
Chinese Journal of Ecology | Year: 2013

Nanquanyan diorite, hardly well-studied, is the metallogenic intrusion of the Lanjia skarn type gold deposit. Based on the studies of geochemistry, zircon LA-ICP-MS U-Pb data, this paper mainly discusses petrogenesis, magma source, tectonics setting of the diorite. Studies show that Nanquanyan diorite belongs to calc-alkaline and metaluminous series. The trace elements of diorite show enrichment in LILE (such as K, Rb, Sr), more mobile incompatible elements (such as Th, U) and LREE, relative depletment of HFSE (such as Nb, Ta, Ti, P) and HREE, and show obvious negative Eu anomalies (δEu= 0.19∼0.25). The ratios of Nb/Ta, La/Nb and Th/La indicate that the diorite mainly comes from the crust. In the Al2O3 + MgO+FeOt diagram, the characteristics of the diorite are similar to those of arc-type active continental margin magmatic rocks. LA-ICP-MS U-Pb zircon data of the diorite give weighted average ages of 170.21±0.73 Ma(MSWD=0.14) and concordant age of 170.21±0.39 Ma (MSWD = 0.018), which are in the middle Jurassic period. It is suggested that during the early Yanshan, subduction of Pacific plate led to extension of continental arc and lithospheric thinning, and asthenosphere mantle magma underplated subsequently and provided thermopower, finally partial melting of the immature lower crurst formed Nanquanyan diorite.

Chen J.,Beijing University of Technology | Fu M.C.,Beijing University of Technology | Wei J.,Hebei Institute of Geological Survey
Advanced Materials Research | Year: 2014

Based on the remote sensing image data of 1970, 1980, 1990, 2000 and 2008, the transfer matrix of land use/cover change were extracted using ArcGIS software, and the paper analyzed the spatial and temporal change of land use/cover change using barycenter transfer model. Results showed that: (1) From 1970 to 2008, cultivated land had been dominated land use type, followed by water area, construction land and unexploited land, and there was small proportion of forest land and grass land; forest land, water area, construction land and unexploited land were increased, and cultivated land and grass land were decreased; the conversions among cultivated land, water area and unexploited land were more closely. (2) The study on barycenter transfer model indicated that from 1970 to 2008, the barycenter transfer direction of cultivated land and construction land was north by west, and the barycenter transfer direction of forest land and unexploited land was south by west, and the barycenter transfer direction of grass land was south by east, with the maximum distance; and that of water area was north by east. © (2014) Trans Tech Publications, Switzerland.

Wang H.,Wuhan University | Wu Y.-B.,Wuhan University | Wu Y.-B.,Northwest University, China | Gao S.,Wuhan University | And 8 more authors.
Lithos | Year: 2014

Accretionary orogenic belts are considered the most important sites for the generation of continental crust. However, it is still not very clear whether in such settings the continental crust has been significantly transported back to the mantle accompanied with its lateral growth. Continental UHP rocks, the best indicators of the recycling of the continental crust, have rarely been discovered in accretionary orogenic belts, which hinder the exploration of this essential process. The possible occurrence of early Paleozoic UHP metamorphism in the Qinling orogen provides an excellent opportunity to address this question. This article reports an integrated study of U-Pb age, trace element and mineral inclusion of zircon from an amphibolite sample in the Qinling orogen. The zircon crystals show typical metamorphic growth zoning, low Th/U ratios, flat HREE patterns, and insignificant Eu anomalies. They give a weighted mean U-Pb age of 490.4. ±. 5.8. Ma. Most importantly, an in situ diamond inclusion was identified from one of the zircon crystals. Therefore, the obtained 490.4. ±. 5.8. Ma age was taken as registering the peak UHP metamorphism. The discovery of in situ diamond inclusion provides important evidence for the UHP metamorphism of the Qinling orogen and indicates that the North Qinling microcontinent was subducted to mantle depths of >. 120. km when it collided with the Erlangping arc attached to the southern margin of the North China Block. Combining with previous results, we suggested that the North Qinling UHP terrane underwent fast exhumation from >. 120. km to ca. 30. km within 10. Myr intervals. As a few examples of UHP metamorphism have been discovered in some accretionary orogens, more attention needs to be paid to the occurrence of continental UHP metamorphism during accretionary orogenic process. Furthermore, evident crustal growth has been documented in the North Qinling orogen during the early Paleozoic. It is inferred that the accretionary orogenic belts may play important roles in recycling of continental crust into the mantle besides generation of continental crust. © 2014 Elsevier B.V.

Discover hidden collaborations