China University of Geosdences

Beijing, China

China University of Geosdences

Beijing, China

Time filter

Source Type

Yao L.,China University of Geosdences | Xie G.Q.,Chinese Academy of Geological Sciences | Zhang C.S.,China University of Geosdences | Liu J.L.,China University of Geosdences | And 3 more authors.
Acta Petrologica Sinica | Year: 2012

Chengchao Fe deposit is a typical skarn deposit in southeastern Hubei Province. Electron microprobe analyses show that the end member of garnets in the skarn stage is dominated by andradite, with minor grossular. The clinopyroxene comprises mainly diopside, with minor hedenbergite. The amphibole in the Chengchao Fe deposit mostly belongs to calcic amphiboles, such as pargasite, tremolite, actinolite and ferropargasite. The end member of garnets in the vein skarn is between andradite and grossular. Vein clinopyroxene is dominated by diopside. Characteristics of skarn in Chengchao Fe deposit shows that granite may play a key role in the formation of skarns and ore bodies.


Wang P.,China University of Geosdences | Wang P.,Beijing Huaxia Jianlong Mining Science and Technology Co.
Geology in China | Year: 2012

The Sishanling iron deposit is located in the northern margin of North China platform and geographically lies in Benfen area, Liaoning Province. The ores are composed of magnetite and hematite and controlled by Anben Formation of Achean Cigou Group, the sedimentary facies is of the oxide - silicate phase. Through the study of element geochemistry of the main minerals, ores and wall rocks, the authors have obtained some useful information: Metamorphic faciès has reached low amphibolite facies, and the BIF can be classified as mafic volcanic - muddy sandstone - ferrosilicic sedimentary formation. The metamorphic volcanic rocks are characterized by oceanic tholeiite. The shale-normalized REE patterns of the ores display depletion of light REE relative to heavy REE, high ratios of Y/Ho and distinct positive anomalies of La, Y. Eu shows stronger positive anomalies in comparison with the other main BIFs in North China platform. The geochemical information of the BIF shows that the ore-forming elements came from the mixed solution of volcanic-hydrothermal solution and sea water, and that the hydrothermal solution was related to the mantle material.


He J.Y.,China University of Geosdences | He J.Y.,Petrochina | Jia C.Z.,Petrochina | Wu G.H.,Petrochina | Xu B.,Peking University
Acta Petrologica Sinica | Year: 2010

Study on several Sinian outcrop sections in Aksu area indicates that unconformity, large cave collapse breccias, solutio: caves, solution pores, solution fissures and grooves should be the identifying features of Sinian paleo-karstification. Horizone-phreati zone and deep-slow-flowing zone are the main parts of the karst vertical zonation. Large cave congeries and honeycomb formation cave are significant evidences of horizone-phreatic zone. The characteristic of deep-slow-flowing zone is isolated caves which are alway associated with the fractures. The paleo-karst model of Sinian is higher-phreatic gentle-slope paleo-karst.


Zhang Y.-F.,China University of Geosdences | Jiang J.-W.,Petrochina
Geology in China | Year: 2010

Plant fossils of 38 species in 22 genera in Middle Jurassic were collected from Lower Yaopo Formation, Upper Yaopo Formation and Longmen Formation on the southern slope of the Jiulong Hill in Mentougou district, Beijing. Statistical data show that the Middle Jurassic flora of the Western Hills in Beijing is dominated by Filicopsida (27.6%), Cycadopsida (25%)and Ginkgopsida (25%), among which Coniopteris with 5 species and Cladophlebis with 17 species were found. The Nearest Living Relatives Method and morphologic features analysis were used to analyze palaeoclimate. The result indicates that the nearest living relative plants of dominant fossils are Osmundaceae, Dicksoniaceae and Cycadopsida, which mainly live in a humid-warm tropical or subtropical climate, and warm-humid climate is also identified from the diversity of Cladophlebis, large feathery compound leaves of Cycadopsida and coarse stems of Equisetales, etc. Consequendy, the Middle Jurassic flora in the Western Hills of Beijing reflects a humid-warm subtropical climate. In addition, the climate had changed into drier and warmer according to the species and the quantity reduction of plant fossils from the Lower Yaopo Formation through Upper Yaopo Formation to Longmen Formation.


Zhao H.-J.,Chang'an University | Zhao H.-J.,Chinese Academy of Geological Sciences | Zheng W.,China University of Geosdences | Yu Z.-F.,China University of Geosdences | And 2 more authors.
Geology in China | Year: 2012

Located in Yangchun basin of western Guangdong Province, the Shilu deposit has developed oxidized Cu and skarn Cu-Mo ore bodies. The skarn ore body genetically is associated with the Shilu granodiorite. Direct Re-Os dating of molybdenite collected from the skarn ore bodies in the Shilu deposit was carried out to better understand the age of mineralization. The results show that the five molybdenite samples from quartz-vein-type ore have 187Re- 187Os model ages ranging from (10411.5) Ma to (104.6±1.5)Ma, with an average of (104.34±0.66) Ma and an isochron age of (104.1±1.3)Ma, consistent with the age of the related granodiorite (107+0.72Ma), which implies that the mineralization took place in the early Cretaceous. Based on previous studies, it is suggested that the Shilu skarn Cu-Mo deposit was formed later than 50Ma when the Jurassic Cu-Fe deposits in Yanchun basin were generated, thus belonging to the large-scale Cretaceous mineralization in South China. It was formed in a lithosphere extension tectonic setting, which was different from the setting of the Jurassic Cu-Fe deposits in this area.


Meng F.,China University of Geosdences | Mao J.-W.,Chinese Academy of Geological Sciences | Ye H.-S.,Chinese Academy of Geological Sciences | Zhou K.,Geological Society of China | And 2 more authors.
Geology in China | Year: 2012

The Laojunshan Intrusion is situated in northern Qinling orogenic belt, which is located in southern Heigou-Luanchuan faulted zone in the Qinling orogenic belt. Based on the contact relationship, the evolution of the intrusion can be divided from early to late into three stages, i.e., small-porphyry fine-medium-grained biotite monzonitic granite, mid-porphyry medium-coarse grained biotite monzonitic granite and big-porphyry medium-coarse grained biotite monzonitic granite. They are characterized by concentric zoning. All the three stages of granites have similar niineralogical and geochemical characteristics. They are composed of potash feldspar, plagioclase, biotite and quartz, but there are obvious differences in the rock texture. They are characterized by high Si (>70%) and alkali (8.28-9.53%) and low Ca (0.68%-2.42%) . They also have relatively high Ba, Sr, Nb, Zr, Th and Rb concentrations and comparatively low Co, Ni, Cr, V and Sc concentrations, belonging to I-type granite. The SHRIMP U-Pb zircon dating of the second and third stage rocks yielded ages of 111 ±1Ma (MSWD =0.41) and 108±1Ma (MSWD =0.39) respectively, suggesting Late Mesozoic. It is inferred that the Laojunshan Intrusion resulted from large-scale late Mesozoic magmatism in eastern China.


Zhou S.-Y.,China University of Geosdences | Zhou S.-Y.,Sinopec | Ma Y.,China University of Geosdences
Geology in China | Year: 2010

The northern part of the Pre-Caspian Basin of Kazakhstan is rich in oil and gas, in which 39 oil and gas fields have been found. Lower Carboniferous and lower Permian strata constitute important oil and gas producing horizons. Recent exploration indicates that there exist lots of beach facies limestones of Middle Carboniferous Bashkirian stage, suggesting that the Middle Carboniferous strata may become a new exploration target. Based on the exploration data, this paper has made a detailed description of macroscopic and microscopic features of Bashkirian beach facies limestones, which will provide an important clue to future oil and gas exploration.


Sun J.,China University of Geosdences | Mao J.W.,Chinese Academy of Geological Sciences | Xie G.Q.,Chinese Academy of Geological Sciences | Zen Z.L.,Gannan Geological Survey Party of Jiangxi Province | And 2 more authors.
Acta Petrologica Sinica | Year: 2012

Tongkengzhang molybdenum deposit is a newly discovered deposit, which is mainly hosted by the Cretaceous granitic porphyry. Based on mineral assemblage and vein crosscutting relationships, the ore-forming process could be divided into three mineralization-alteration stages: Potassic stage, fluorite-biotite ( muscovite ) -K-feldspar-molybdenite stage, sericite-quartz-carbonate stage. The study of fluid inclusions shows that early ore-forming fluids are high salinity magmatic fluids, containing alkalic components and volatile phase, which formed in condition of high pressure ( ∼ lOOObar) and high temperature (550 ∼ > 600°C ) , and were separated to multiphase high salinity fluid inclusions and lower salinity vapor-rich fluid inclusions by boiling.With cooling of ore- forming fluids (420 ∼ 4401) and release of pressure (320 ∼ 360bar) led to re-boiling of ore-forming fluids, which caused precipitation of molybdenite.Give the evidence of widespread occurrence of high salinity (29.58% ∼ 44.12% NaCleqv) fluid inclusions in the sericite-quartz alteration related veins, indicating that the fluids caused the later alteration was dominated by the magmatic fluids, only a few quartz veins are primarily occupied by aqueous inclusions suggesting the mixture of magmatic fluids and meteoric fluids. Meanwhile, the Laser Raman and SEM measurements detected Fe 2 O 3, SO 2 in the early fluids, indicating the early fluids were highly oxidized, the abundance of K-feldspar suggests alkalic environment. The existence of CH 4 and intergrowth of molybdenite and muscovite reveals fluids were in a relative reduced environment, suggesting redox potential fluctuations and the change of pH value could lead to deposition of molybdenite.


Luo Z.H.,China University of Geosdences | Lu X.X.,Scientific Academy of Land and Resources of Henan | Xu J.Y.,National Research Center for Geoanalysis | Liu C.,China University of Geosdences | Li D.D.,China University of Geosdences
Acta Petrologica Sinica | Year: 2010

One of the key questions attracted attention in the resource exploring field is the potential from an intrusion to produce metals. Hence determining the macroscopic indicators of ore-bearing intrusion and providing its theoretical interpretations are of the important responsibilities of scientific studies. However, due to the traditional petrology is mainly concerned with formation and evolution of the dry or H2O-unsaturated systems, but generation of the endogenic mineral deposits is mainly relative to the fluids, the obtained progresses in petrology often can not satisfy exploration geologists. This paper, based on the theory of metallogenesis by transmagmatic fluids, aims at analyzing the features of melt-fluid interaction and their potential effects on ore-forming processes. It is suggested that the rock-forming processes involving huge fluid are obviously different to the generally recognized magmatic processes, and they should leave distinct petrographic signals. Adding or reducing fluid induces density and viscosity of the magma to be changed obviously and modify the solidus temperature and liquidus phase relation and the eutectic composition. Therefore, the textures and structures of intrusive rocks reflect the degree of fluids involved in the rock-forming processes, and can be used as indicators for ore- forming potentials of an intrusion. Separation of the fluids from a melt increases the melt viscosity up to orders of magnitude and solidus temperature and induces to rapid consolidation. Subsequently, portions of the metal-bearing fluids must be trapped into and between the crystal grains, and eutectic and /or poikilitic texture and disseminated structure should be formed. These texture and structure, therefore, indicate which intrusion is the conduit for the ore-bearing fluids. The rheology of poly-crystal magma and the poly-phenocryst porphyritic texture, which broadly occur in many orthomagmatic ore deposits, are of irreconcilable contradicting features in terms of linear system. However, it can be attributed to the unexpected fluxing of the ore-bearing fluid flow into the barren magma. Accordingly, the poly-phenocryst porphyritic texture is a reliable indicator showing preservation of the most of ore-forming metals in the magma body without significant escape. In addition, several other supplementary indicators, which can be used to integratively evaluate the ore-producing potential of an intrusion, are suggested in this contribution. Finally, the authors have concluded that the ore-forming processes involving huge fluids are non-linear and produce series of specific fabrics with important signification for evaluation of mineralization.


Li S.H.,China University of Geosdences | Zhang J.,China University of Geosdences | Deng J.,China University of Geosdences | Wang H.,China University of Geosdences | And 2 more authors.
Acta Petrologica Sinica | Year: 2011

The Chang' an is one of the largest gold deposits in the southern Ailaoshan metallogenic belt in Sanjiang region, and the occurrence of ore bodies is controlled by the brittle fractured zone of Ganhe fault. The ore-forming fluid system is characterized by low to moderate temperature and salinity. The fluid compositions are dominated by H2O, CO2, Cl- , K+ and Na+ , and the CO2 content in main metallogenic stage varies between 21. 162mol% ∼ 32. 832mol% . The δ13 CCO2 values of the fluid system are-3. 427% ∼ 8. 749%, indicating the participation of marine carbonate and magmatism. The δ value varies from-111% to-78.383%, the δ18 values are 10. 527% ∼ 13. 565% and the δ34 S value is concentrated between + 1%o and + 3%, which suggesting the ore-forming fluid probably sourced from the magmatic-hydrothermal system, and the metamorphic water sourced from marine carbonate strata also played an important role in the main mineralization stage. In Cenozoic, the large scale upward alkali-rich magma caused the magmatic hydrothermal fluid to circulate and mix with the metamorphic water in the Jinping area of the southern Ailaoshan belt. The mixed fluid extracted gold and other metallogenetic elements from the wall rock and other geological unites, then migrated them to the proper structural spaces, and rapidly precipitated under some favorable physical-chemical condition, finally formed the micro disseminated gold deposit. According to the comprehensive and contrastive study, the Chang' an gold deposit possesses the typical geological-geochemical characteristics of orogenic-type gold deposit and Carlin-type gold deposit, so it should belong to the Carlin-like gold deposit as a transitional type between orogenic-type and Carlin-type gold deposit.

Loading China University of Geosdences collaborators
Loading China University of Geosdences collaborators