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Ding C.,China University of Geosciences | Zhao Z.,China University of Geosciences | Yang J.,China University of Geosciences | Zhou H.,North China Geologgcal Surey Bureau 514 Group | And 3 more authors.
Acta Petrologica Sinica

The Cretaceous magmatism have been widely taken place in South China, and have created large scale distribution of granitoids and intruded mafic, intermediate and acid dikes, in which the mafic dikes are representative or response to the Cretaceous crustal extension tectonic activity in South China. This paper carried out the research of zircon U-Pb geochronology and Hf isotopes, and elemental geochemistry on the samples collected from the localities of Shishi and Dongfu from Shishi area, coastal Fujian Province. The granite and granodiorite are mediate- To high-K potassic calc-alkaline , and peraluminous , with U-Pb ages of 105. 3 ± 1. 0Ma and 105. 1 ±0.5 Ma. Their zircon εHf(t) range from -0. 9 to +2. 0. The dikes are diabase and diorites , showing metaluminous , mediate- To high-K potassic calc-alkaline features. Two diorites yield zircon U-Pb ages of 89. 5 ± 1. 5Ma and 96. 1 ± 1. 2Ma. The εHf(t) of diorite are in the rage of + 1. 3 to + 5. 0. Both granitoids and dikes in the Shishi area show medium scale fractionation of light rare earth elements (REE) relative to heavy REE, and less Eu anomaly. The total REE of granitoids are less than that of the dikes. The rocks show significant enrichment of large ion lithosphile element ( LILE) and depletion of high field stretch element ( HFSE) , which is the distinct characteristic of rocks from arc-related magmatism. The discrimination geochemical diagrams ( Ta/Hf-Th/Hf, Zr-Zr/Y) suggest that the dikes from this study generated from the tectonic settings of continental margin rift or within plate environments. The dikes maybe intruded within the tectonic transition from continental subduction-related tectonic to continental extension settings, which is the index for the extension. The extension should have occurred during 87 ~96Ma in the coastal Fujian Province, including Xiamen, Shishi , and Jinjiang areas , which is consistent to the regional ~ 90Ma extension , in the multi-stage extension in the Cretaceous evolution in the whole South China. Source

Cui Y.,China University of Geosciences | Zhao Z.,China University of Geosciences | Jiang T.,China University of Geosciences | Yang J.,China University of Geosciences | And 4 more authors.
Acta Petrologica Sinica

This paper presents the petrologic, whole-rock geochemical, zircon U-Pb dating and Hf isotopic data of host granites and dioritic enclaves from the Huitong pluton, southern Jiangxi province. Zircon U-Pb dating results indicate that the dioritic enclave (425. 0 ±4. 1Ma) , is coeval with the host granitoid (425. 8 ± 6. 2Ma) , which is during late stage of Early Paleozoic. The Huitong granitoids are belong to peraluminous (A/CNK = 1.05 ∼1.28) and high-K calc-alkaline series. They are enriched in Rb , Th , U , K , and Pb , and depleted in Ba , Sr , P , and Ti , with significant Eu negative anomaly. The rocks show S-type granite affinities. The zircon £Hf(t) of host granites ( -13.7 ∼ -3. 3) and dioritic enclaves ( -8. 4 ∼ -3. 2) are all negative values , with Hf crustal model ages ranging from 1. 6Ga to 2. 3 Ga. Combined with previous data , a wide range of mature crust anatexis events took place in the southern of Jiangxi Province during Early Paleozoic. The partial melting of middle-lower crust finaUy formed the Huitong pluton , in a post-orogenic extension tectonic environment. Source

Xiao W.,China University of Mining and Technology | Zhangand H.-Y.,Hunan Planning Institute of Land and Resources | Zhang J.-Y.,China University of Mining and Technology
Journal of Engineering Science and Technology Review

Coal deposits in the adjacent regions of Shanxi, Shaanxi, and Inner Mongolia province (SSI) account for approximately two-thirds of coal in China; therefore, the SSI region has become the frontier of coal mining and its westward movement. Numerous adverse impacts to land and environment have arisen in these sandy, arid, and ecologically fragile areas. Underground coal mining activities cause land to subside and subsequent soil erosion, with slope length and slope steepness (LS) as the key influential factor. In this investigation, an SSI mining site was chosen as a case study area, and 1) the pre-mining LS factor was obtained using a digital elevation model (DEM) dataset; 2) a mining subsidence prediction was implemented with revised subsidence prediction factors; and 3) the post-mining LS factor was calculated by integrating the pre-mining DEM dataset and coal mining subsidence prediction data. The results revealed that the LS factor leads to some changes in the bottom of subsidence basin and considerable alterations at the basin's edges of basin. Moreover, the LS factor became larger in the steeper terrain under subsidence impacts. This integrated method could quantitatively analyse LS changes and spatial distribution under mining impacts, which will benefit and provide references for soil erosion evaluations in this region. © 2014 Kavala Institute of Technology. Source

Li Q.,CAS Institute of Remote Sensing | Zhang H.,CAS Institute of Remote Sensing | Du X.,CAS Institute of Remote Sensing | Wen N.,Hunan Research Academy of Geological science | And 3 more authors.
Journal of Applied Remote Sensing

Rice acreage estimation is a key aspect of assessing rice production. A method of estimating rice acreage at the county level is explored, using data from the HJ-1A/B Chinese Environmental Satellite for Hunan Province, which has complex rice cropping patterns. The method combines supervised and unsupervised classification using a mixed-pixel decomposition model. The rice acreage estimation results were validated by interpretation of RapidEye images for early-season rice and ground survey data for medium-season and late-season rice. The results showed a good correlation between the estimates derived from RapidEye and from HJ CCD data for pure rice pixels (R= 0.99, 0.99, and 0.97 for early-, medium-, and late-season rice). The discrepancy was <10% at the plot level (6.5 × 6.5 km) for early-season rice, while it was 12.20 and 12.36% at the plot level (1 × 1 km) for medium-season and late-season rice. These results suggested that the method proposed in this study is capable of rice acreage estimation at the county level. The method can also be used in mountainous regions and areas of fragmented planting. © Society of Photo-Optical Instrumentation Engineers. Source

Zhang H.Y.,Hunan Planning Institute of Land and Resources | Lei F.,Hunan Planning Institute of Land and Resources | Huang F.,Hunan Planning Institute of Land and Resources
Advanced Materials Research

Coal seam floor contours are one of the most important 8 mine maps, and was usually used for coal mine decision-making. However, the graph, which was expressed as lines, has many disadvantages, including inadequate intuitive, poor visibility, and weak in expression of three-dimensional morphology formation. Thus, the readers have to spend more time to reveal the spatial distribution of coal deposits. According to the coal seam floors contours, and considering the constraints of faults in coal seams, the following steps were implemented to acquire coal seam floor DEM, which are: 1) contours discrete; and 2) interpolation using Inverse Distance Weighted method (IDW). The process was easy-manipulated, and the results could reflect the spatial distribution of coal seams in an objective, intuitively, and strong visibility manner. The method could facilitate and guide the analysis of mine design and coal production. © (2014) Trans Tech Publications, Switzerland. Source

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