Shen L.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Gao T.-M.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Gao T.-M.,University of Chinese Academy of Sciences |
Cheng X.,Development and Research Center
Energy Policy | Year: 2012
Since reform and opening-up in 1978, the coal industry in China has been developing rapidly. This article identified major factors affecting the growth of China's coal industry, immediate targets, economic policies, as well as structural reforms of the sector. Authors have divided its developing process into three stages: rapid growth of coal industry (1979-1992); close-down of small-scale coal mines (SCMs) (1993-2001); resource consolidation (2002-present). At the first stage, led by the 'twoleg walking' strategy, SCMs grew significantly, which eased the pressure of energy shortage. From the transition of planned economy to market economy, major state-owned coal mines (MSCs), which were not consistently profitable, would have to learn how to withstand severe competitions and survive. As a result, the central government took several measures to try to keep them alive. This situation was not changed until 2001. Large-scaled coal mine groups were then established by the government when China entered the WTO. MSCs were encouraged to merge with others to form a certain scale, as a way to compete with giant overseas. So a trial was firstly implemented in Shanxi province. © 2011.
Cheng Y.,China University of Geosciences |
Cheng Y.,James Cook University |
Mao J.,China University of Geosciences |
Mao J.,Chinese Academy of Geological Sciences |
And 2 more authors.
Ore Geology Reviews | Year: 2012
Kafang is one of the main ore deposits in the world-class Gejiu polymetallic tin district, SW China. There are three main mineralization types in the Kafang deposit, i.e., skarn Cu-Sn ores, stratiform Cu ores hosted by basalt and stratiform Cu-Sn ores hosted by carbonate. The skarn mainly consists of garnet and pyroxene, and retrograde altered rocks. These retrograde altered rocks are superimposed on the skarn and are composed of actinolite, chlorite, epidote and phlogopite. Major ore minerals are chalcopyrite, pyrrhotite, cassiterite, pyrite and scheelite. Sulfur and Pb isotopic components hint that the sources of different types of mineralization are distinctive, and indicate that the skarn ore mainly originated from granitic magma, whereas the basalt-hosted Cu ores mainly derived from basalt. Microthermometry results of fluid inclusions display a gradual change during the ore-forming process. The homogenization temperature of different types of inclusions continuously decreases from early to late mineralization stages. The salinities and freezing temperatures exhibit similar evolutionary tendencies with the T homogenization, while the densities of the different types keep constant, the majority being less than 1. Oxygen and hydrogen isotopic values (δ 18O and δD) of the hydrothermal fluids fall within ranges of 3.1 to 7.7 with an average of 6.15, calculated at the corresponding homogenization temperature, and -73 and -98 with an average of -86.5, respectively. Microthermometry data and H-O isotopes indicate that the ore-forming fluid of the Kafang deposit is mainly derived from magma in the early stage and a mixture of meteoric and magmatic water in late stage. Molybdenite Re-Os age of the skarn type mineralization is 83.4±2.1Ma, and the stratiform ores hosted by basalt is 84.2±7.3Ma, which are consistent with the LA-ICP-MS zircon age of the Xinshan granite intrusion (83.1±0.4Ma). The evidence listed above reflects the fact that different ore styles in the Kafang deposit belong to the same mineralization system. © 2012 Elsevier B.V.
Feng Z.,Guilin University of Technology |
Wang C.,University of Maine at Presque Isle |
Zhang M.,Development and Research Center |
Liang J.,Guilin University of Technology
Journal of Asian Earth Sciences | Year: 2012
The Guposhan-Huashan twin plutons crop out as an unusually dumbbell-shaped batholith within the Middle Mesozoic Central Nanling Range granitic belt in south China. The batholith was controlled by the east-west-striking Yishan-Quannan deep crustal fault zone, and spatially associated with two regional anticlinoria. Both plutons show concentric zonation patterns and are composed of two emplacement sequences separated by an approximately 9. m.y. magmatic lull, the 160-163-Ma Niumiao-Lisong-Wanggao sequence and the 148-151-Ma Xinlu-Huamei sequence, based on field mapping and observations, geochronology, and geochemistry. In a proposed incremental emplacement and growth model, the early magmas exploited physical discontinuities such as the contacts between rocks with contrasting competence and densities, as well as saddles of regional-scale anticlinoria. Assisted by dominant vertical heat flow and uplifting of the roofs, the Niumiao-Lisong-Wanggao-sequence magmas were subsequently emplaced in an over-accretion style as distinguishable increments during an approximately 3. m.y. span. Gravimetric data, observations of field relationships, as well as analysis of finite strain and country rock rheology confirm that the plutons became thickened considerably due to largely vertical assembling and growth, and most of their space was created by vertical displacement of their country rocks. Interestingly the coeval twin plutons show contrasting development and growth modes during their assembling and thickening process. The Guposhan pluton was built on an outward building mode with a " reverse-zoning" pattern while the Huashan pluton on an inward building mode with a " normal-zoning" pattern. We propose that the contrasting modes largely resulted from their divergent thermal evolution path. For example, the incremental inward building mode helps retain thermal energy and maintain a high temperature in older units, which facilitates injection of subsequent, younger increment units of the same sequence within the older host units. The independent, newer sequence of Xinlu-Huamei magmas, however, were controlled by shallow brittle faults developed in the older sequence units and emplaced as stocks and dykes by a dyke-propagation mechanism. © 2012 Elsevier Ltd.
Pan X.,Texas A&M University-Kingsville |
Shen D.,Development and Research Center |
Dong X.,North Dakota State University |
Patton B.,North Dakota State University
Disaster Advances | Year: 2011
In the context of climate change, there is potential for a higher frequency of natural disasters. Here a linear regression analysis is employed to link the relationship between the natural disaster occurrence and average global temperature from 1980 to 2010. The results indicate that epidemic, extreme temperature, flood and storm events are strongly affected by climate. If the average global temperature increases by 1 °C, the occurrence of epidemic, extreme temperature, flood and storm would increase by 101, 42, 268 and 95 occurrences per year respectively.
Wang X.,Chinese Academy of Geological Sciences |
Wang T.,Chinese Academy of Geological Sciences |
Castro A.,University of Huelva |
Pedreira R.,University of Huelva |
And 2 more authors.
Lithos | Year: 2011
Granitoids varying in composition from biotite-amphibole granodiorite to monzogranite with rapakivi textures have recently been recognized in the Qinling orogen (central China). The granitoids are magnesian, calc-alkalic and metaluminous (A/CNK=0.71-0.95). They contain many mafic to intermediate microgranular enclaves. The enclaves are quenched mafic melts in granitic host magma as evidenced by fine-grained sinuous margins against or transitional contacts with the host granitoids as well as disequilibrium textures and mineral assemblages. U-Pb zircon dating of the granitoids yields: 209±2Ma and 212±2Ma and the enclaves 210±2Ma and 211±2Ma, respectively. The host granitoids and enclaves show obvious silica gap but similar REE and trace element patterns. The whole-rock 87Sr/86Sr(t),εNd(t) and zircon εHf(t) values for the granitoids vary from 0.70516 to 0.70634, -2.3 to -4.4 and 0.7 to -7.6, and for the enclaves from 0.70467 to 0.70600, -1.1 to -4.0, and 1.2 to -8.8, respectively, showing overlapped εNd(t) and zircon εHf(t) values. All these suggest that the two magmatic systems represented by the host rock and enclave are probably derived from distinct sources with sufficient interaction, or common origin but underwent different degrees of crustal contamination. Mineralogical and geochemical data point to enclave dissolution in silicic magma as a major process accounting for the origin of the rapakivi texture. The possible bimodal magmatism suggested by the coeval granitoids and lamprophyre dykes, combined with the structural pattern, geochemical features and regional tectonics, suggest a post-collision setting for the Qinling rapakivi-textured granitoid plutons. © 2011 Elsevier B.V.