Zhu X.-Y.,Beijing Institute of Geology and Mineral Resources |
Zhu X.-Y.,Sinotech Mineral Exploration Co. |
Wang J.-B.,Beijing Institute of Geology and Mineral Resources |
Wang J.-B.,Sinotech Mineral Exploration Co. |
And 5 more authors.
Geology in China | Year: 2012
The early Yanshanian granites related to tungsten and tin deposits in Nanling region have been considered to be biotite granite, monzogranite, albite granite etc. However, microscope and electron microprobe analyzes of the granite related to tungsten mineralization in Yaogangxian, Shizhuyuan, Xitian, Dengfuxian, Limu and Meiziwo show that all the feldspars of the granite consist of K-feldspar and albite (An<5), which suggests that the name should be alkali feldspar granite. The albite of greisen inclusions in the alkali feldspar shows the character An<3. There is no obvious vertical regular variation or zoning of the compositions of the albite and granite within the depth range of 1000m. On the contrary, the plagioclases of the granite inclusions (xenoliths), some granite porphyry dykes, giant batholiths, and Triassic and Paleozoic monzogranite or granodiorite have a wide range of An value of 0∼93, belonging to oligoclase, andesine or even basic plagioclase. The alkali-feldspar granite that contains two kinds of alkali feldspar was usually formed from the rich -volatile (Li -F) magma, with the extensive development of liquid immiscibility at the top of the granite, which caused the enrichment and mineralization of W, Sn, Bi, Mo in the hydrothermal-magma. The An value of the albite in alkali-feldspar granite could be used as an indicator for evaluating granite in search for W-Sn mineralization, because the value is obvious lower than that of barren granite. Source
Gao H.,Chinese Academy of Geological Sciences |
Pei R.-F.,Chinese Academy of Geological Sciences |
Wang A.-J.,Chinese Academy of Geological Sciences |
Cao D.-H.,Chinese Academy of Geological Sciences |
And 2 more authors.
Geological Bulletin of China | Year: 2012
According to the temporal and spatial distribution and the economic characteristics of the marine sand shale-hosted copper deposits and the geological background and sedimentary environment analysis of their mineralization, the authors made typical deposit analysis and geological characteristics correlation of the Dongchuan-Yimen copper mineralization belt in Yunnan Province of China and the Aynak copper orefield (belt)in Afghanistan. The origin of the marine sand shale-hosted copper deposit was analyzed and discussed in the aspects of metallogenic matter source and the ore-forming mechanisms such as the property, role and kinetics of the fluids and the migration, accumulation, sedimentation and emplacement mechanism of metal elements as well as other elements. Then all kinds of "Deposition-Diagenesis-Reformation" mineralization patterns and ore-forming processes related to marine sand shale-hosted copper deposits were analyzed systematically so as to discuss, summarize and review the genetic pattern of the Aynak copper deposit in Afghanistan and that of the Dongchuan snowfall-like sediment-hosted copper deposit. Based on those results, the authors further elaborated in depth the consistency of marine sand shale-hosted copper mineralization and the super ancient continental events as well as the derivative mineralization. Through systematical correlation, the prospecting potential of the Dongchuan-Yimen copper mineralization belt and the marine sand shale-hosted copper deposits in West Kunlun mineralization province of Xinjiang adjacent to the Aynak copper orefield in Afghanistan was evaluated and estimated. Source
Jinhui L.,University of Science and Technology Beijing |
Jinlong D.,China Non ferrous Metals Resource Geological Survey
Proceedings - 2010 1st ACIS International Symposium on Cryptography, and Network Security, Data Mining and Knowledge Discovery, E-Commerce and Its Applications, and Embedded Systems, CDEE 2010 | Year: 2011
Like nuclear power station, once the irradiation room was damaged, nuclear radiation accident will occur, causing the serious nuclear panic. Therefore, a typical structure of irradiation room was presented for an example in this paper to establish a method on evaluating the resistance capability of irradiation room by explosive load. Worrying about explosives under the radical source, the greatest explosives weight was determined at the different explosion location by tensile strength of concrete, and the resistant explosive capacity of the reinforced concrete beam was accounted. © 2010 IEEE. Source
Zhu X.,Beijing Institute of Geology and Mineral Resources |
Zhu X.,Sinotech Mineral Exploration Co. |
Wang J.,Beijing Institute of Geology and Mineral Resources |
Wang J.,Sinotech Mineral Exploration Co. |
And 2 more authors.
Yanshi Xuebao/Acta Petrologica Sinica | Year: 2015
Shizhuyuan large-scale skarn type tungsten and tin polymetallic ore deposit is located at Chenzhou County, Hunan Province, which occurred in the southern margin of the Qianlishan alkali feldspar granite body. The stockwork in skarn includes different types of veins, mostly alkali metamorphic vein (AMV), a few granite vein and greisen veins. The early stage AMV consists of granite vein in the central part, and K-feldspar-fluorite-wolframite in the margins, with garnet-diopside skarn alteration around the vein. The late stage AMV consists of K-feldspar, fluorite, minor actinolite, epidote, magnetite, scheelite, molybdenite, and bismuthinite. The AMV occurs only in the skarn and the skarnization marble, but is lack in the granite. The contents of CaO, TiO2, W, Bi, Mo, Cu, Pb, Zn, Sr and Ba show an increase trend from the granite, granite vein, AMV, to skarn, which may indicate an enrichment of ore materials from the magma to hydrothermal fluids. Evidence from the structure of granite vein in the center and the K-feldspar-fluorite in the margins, together with occurrence of melt or melt-fluid inclusions in the AMV indicate that the veins may have formed from a unique fluid transition from magma to hydrothermal. The evolution of this fluid is continuous from magmatic to hydrothermal process, and the mineralization started before the magma fully consolidation. We suggest the following mineralization model: Firstly, the pegmatite, massive greisen and banded wollastone-garnet skarn formed in the top and outboard of the granite in the latest magmatic stage; then in the prograde stage after widespread hydrothermal-brecciation, magma or the magma-hydrothermal transition fluid flow along the fractures of the carbonate rocks, which formed the stockwork mineralization and cause alteration of K-feldspar and garnet-diopside skarn. In the retrograde stage after magma consolidation, the mineral assemblage includes actinolite, magnetite, scheelite, molybdenum, and bismuth sulfides. In the latest sulfide stage, the temperature and fluid salinity decreased further on, and the Pb-Zn sulfides precipitate in the carbonate rocks outside the skarn. © 2015, Science Press. All rights reserved. Source
You J.,CAS Institute of Geology and Geophysics |
You J.,University of Chinese Academy of Sciences |
Hong T.,CAS Institute of Geology and Geophysics |
Hong T.,University of Chinese Academy of Sciences |
And 3 more authors.
Yanshi Xuebao/Acta Petrologica Sinica | Year: 2016
The time and metal logenesis of collision between different terrains is one of the hottest topics for tectonic evolution and mineralization of the Central-Asia Orogenic Belt. It's unclear that whether there is late-collisional magmatic activity in northeni Xinjiang arra The tectonic transformation time from collision to post-collision, characteristics of magmatic activity and metallogenenic response during this tectonic evolution are also undefined. The present paper reports new geochemical and chronological daia if intrusive rocks in the Xileknduke district, northern area of East Junggar. The intrusive rocks are divided ilito four types, including the 340Ma diorite . 328Ma molizonitie granIte, 325 1a granite porpliyty and 315 Ma quartz prplly. All the four kind intrusive rocks are high-K caic-alkalic. The diorites possibly formed at late-collisional setting. The diontes are rns'talununous , and have typical geochemical signatures of are, including depletion of Nb, Ta and Ti. and without depletion of P and abnormality of ôEu. The nionzonitie granites and granite porphyries possibly fornisl at the early stage of post collisional setting. The nsonzonitie granites are weakly peraliirniisoiis , and have transformational geochemical signatures of arc and post-collisional granite, such as weakly possive abnormality of ôEu , depletion of Nb, Ta and Ti, and medium depletion of 1'. The granite porphvries are weakly iwraltiminous , and have untypical geochemical signatures of post collisional grami ite , itiel imd ing negative Eu ammomnaly , the obvious depletion of NI. Ta , Ti I'. The weakly ps'raluminous quartz porphynes have typical geochemical signatures of Post collisional granite, including negative Eu anomaly, strong depletion of P. were possibly formed at post-collisional extension setting. Evidence that the intrusive rocks in the XilekLmduke district have low (hSr/wSr), ratio (0.702976 toO. 704306) and positive e(D vaiLmes ( +5.8 to +6.8) with t ages ranging from 524Ma to 588Ma suggests that they were possibly derived from partial melting of the Early Paleozoic oceanic crust. It is suggested that the Sawuer island arc had experienced live evolutional perioils in the Late I'alaeozoic as following: subditetion period (froni 400 to 370Ma) , major collision period (froni 360 to 340Ma) late-collision period (1mm 340 to 330Ma), early post-collisioni period (1mm 330 to 320Ma) and post- collisioni extension period ( from 320 to 280Ma). Source