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Yang L.-Q.,China University of Geosciences | Deng J.,China University of Geosciences | Dilek Y.,China University of Geosciences | Dilek Y.,Miami University Ohio | And 7 more authors.
Lithos | Year: 2016

We report new whole-rock geochemical and Sr-Nd-Pb isotope and zircon U-Pb age and Hf isotope data of the Hongshan intrusive suite in the Triassic Yidun Terrane, eastern Tibet. These data allow us to explore the possible causative links between the magmatism and the coeval Cu-Mo mineralization in the region. The Hongshan intrusive rocks have SiO2 of 65.06-73.60 wt.%, K2O of 3.17-6.41 wt.%, and P2O5 of 0.11-0.39 wt.%, enriched in Rb, Th, and U, and depleted in Ba, Sr, P, Ti, Nb, and Eu. These rocks are of high-calc-alkaline to shoshonite series, showing geochemical signatures of metaluminous to slightly peraluminous I-type granite. Magmatic zircons separated from four samples yielded weighted mean 206Pb/238U ages of 79 ± 0.7 Ma, 78 ± 0.5 Ma, 77 ± 0.8 Ma, and 76 ± 0.8 Ma. Low MgO (0.42-1.47 wt%), low HREE and Y, varying εHf(t) (-9.5 to -2.2), and negative εNd(t) (-7.7 to -5.8) suggest that magmas of the late Cretaceous Hongshan plutons were most likely generated by partial melting and mixing of ~20% juvenile lower crust-derived melts, represented by the ca. 215 Ma basaltic andesite from the southern Yidun Terrane, with ancient basement-derived melts represented by the Baoshan S-type granitic melts from the Zhongza Block. We consider that partial melting processes are capable of removing chalcophile elements (such as Cu) and leaving siderophile metals (such as Mo) as residue in the lower crust of the Yidun Terrane, consequently inducing porphyry Cu-Mo mineralization. This consideration enables us to propose that the Triassic subduction-modified, copper-rich lithosphere was crucial for the giant copper mineralization that occurred in the Yidun Terrane during the late Cretaceous. Lithospheric-scale, transtensional faulting, developed as a result of collision-induced escape tectonics in SE Tibet, triggered asthenospheric upwelling, which in turn caused intra-plate extension and magmatism during the late Cretaceous, forming the Hongshan and coeval I-type granitoids within the Yidun Arc. © 2015 Elsevier B.V.

Zhu C.,Minmetals Exploration and Development Co. | Li T.,Jilin University | Yang H.,Copenhagen University | Liu Y.,Jilin University | And 2 more authors.
Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting | Year: 2016

Seismic exploration is sometimes unsuccessful in some areas with difficult geological and topographical conditions such as complex mountainous area. Experiments show that the joint application with seismic and non-seismic methods especially electromagnetic (EM) is an effective way to ensure high quality prospecting. This paper discusses the theory and algorithm of three dimensional forward modeling and inversion of controlled-source electromagnetic method (CSEM) with topography, which is tested to be accurate in theoretical data inversion. The paper consists of two parts: 3D forward modeling and non-linear conjugate gradient (NLCG) inversion. For 3D forward modeling, the finite difference based on scattered fields is implemented, and the obtained apparent resistivity in far field is similar with that of magnetolluric (MT) method on a typical model. Therefore the forward modeling algorithm is suitable and accurate. On the other hand, NLCG is used in the 3D inversion and initial solution optimization is adopted, which can efficiently reduce computation time consumption. Numerical experiments illustrate that the distribution of anomalous bodies can be well recovered by the proposed inversion and the initial solution optimization can dramatically reduce computation time consumption. © 2016, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.

Wang J.,China University of Geosciences | Wang J.,Minmetals Exploration and Development Co. | Yu Y.,Minmetals Exploration and Development Co.
Earth Science Frontiers | Year: 2015

DSO (Direct Shipping Ore) deposits, the high-grade iron ores (w(Fe)>50%, w(SiO2)<18%) in the Labrador Trough of Canada, attracted much attention for the high-grade and significant economic benefits.By studying the geology setting of DSO deposits and the characteristics of typical DSO deposits in the region of Scheffervill,we found that: (1)all DSO deposits are hosted by Precambrian Sokoman iron formation; (2)the structure is considered to be the most important factor that influence the location of the DSO deposits, and preparing the access to deep-hydrothermal fluid and developing enough space to concentrate new recrystallized minerals; (3)the genesis of soft DSO is related to supergene-modified hydrothermal model, while hard DSO only related to hydrothermal model. According to the characteristics of ore-forming processes, we divide the DSO targets of Labrador Trough into 3 zones: the Scheffervill soft DSO zone, Lac Le Fer-Attikamagen soft DSO zone and Astray Lake-Sawyer Lake hard DSO zone. Exploration activities should focus on the areas where the secondary extensional-faults, folds and the contact surfaces between basalt and iron formation intersect the NW striking regional faults, especially when the areas also have the geophysical characteristics of low magnetic-high gravity. Synthesize information of geology and geophysics to figure out the best points to mark as reconnaissance trenching and drilling stage,which can greatly improve the efficiency of prospecting. ©, 2015, Chinese Academy of Forestry. All right reserved.

Li N.,China University of Geosciences | Li N.,Chinese Academy of Geological Sciences | Xiao K.-Y.,Chinese Academy of Geological Sciences | Chen X.-Q.,Minmetals Exploration and Development Co. | Lou D.-B.,Chinese Academy of Geological Sciences
Geological Bulletin of China | Year: 2010

Taking known deposit called Tanyaokou as an experimental region and based on the theory of wall rock alteration, study and experiment have been carried out on mineralization alteration extraction with hyper-spectral remote sensing image. Specifically, research is started with finding some indicative symbols based on alteration theory and studying spectrum features. Furthermore, pretreatment of EO-1 Hyperion imagery includes remove band lines, de-stripping, atmospheric correction and spectral reconstruction. Five end members have been extracted from inversion reflectance, which are used to mapping the study area using SAM method. Therefore, five alteration anomalies have been extracted. Besides, overlay analysis of hydroxyl anomaly information extracted from multi-spectral remote sensing imagery with alteration minerals distilled from hyper-spectral data in order to verify the correctness and feasibility of extraction, at last, repeatable technology processes of extraction for mineralization alteration using multi-source remotely sensed imagery have been established. Finally, according to geological setting and previous research about ore deposit especially on ore bearing stratum, the authors forecast other favorable target areas using alteration distribution map. The result reveals that extraction of anomalies agree with the ore-bearing strata, which shows practical meanings.

Wang C.,China University of Geosciences | Wang C.,University of Western Australia | Chen L.,Minmetals Exploration and Development Co. | Bagas L.,China University of Geosciences | And 4 more authors.
International Journal of Earth Sciences | Year: 2015

Late Mesozoic magmatic rocks from the Taishanmiao Batholith were collected for LA–ICP–MS dating, Sr–Nd–Hf isotope systematics, and whole-rock major and trace element geochemistry to help understand the nature of collisional and extensional events along the southern margin of the North China Craton. The batholith consists of three texturally distinguishable phases of a 125 ± 1 Ma medium- to coarse-grained syenogranite, a 121 ± 1 Ma fine- to medium-grained syenogranite, and a 113 ± 1 Ma porphyritic monzogranite. Most of the units in the batholith are syenogranitic in composition with high levels of silica (70–78 wt% SiO2), alkalis (8.0–8.6 wt% Na2O + K2O), Fe* (FeOT/(FeOT + MgO) = 0.76–0.90), and depletion in CaO (0.34–1.37 wt%), MgO (0.12–0.52 wt%), TiO2 (0.09–0.40 wt%), and A/CNK (Al2O3/(Na2O + K2O + CaO)) molar ratios of 1.00–1.11. All samples have high proportions of Ga, Nb, Zr, Ga/Al, and REE, and depletions in Ba, Sr, Eu, and compatible elements, indicating that the batholith consists of A-type granites. The zircon saturation temperature for these units yields a mean value of 890 °C, and zircons with Early Cretaceous magmatic ages have εNd(t) values of −14.0 to −12.0, εHf(t) values ranging from −18.7 to −2.1, and corresponding Hf model ages of 2339–1282 Ma. These geochemical and isotopic characteristics allowed us to conclude that the primary magma for the Taishanmiao Batholith originated from partial melting of Precambrian crustal rocks in the medium-lower crust. However, the high Nb and Ta contents and low normalized Nb/Ta values for the Taishanmiao granites are due to fractionation in Nb- and Ta-rich amphibole (or biotite). It is further proposed that these aluminous A-type granites were generated in an extensional tectonic setting during the Early Cretaceous, which was induced by lithospheric thinning and asthenospheric upwelling beneath eastern China toward the Paleo-Pacific Plate. © 2015 Springer-Verlag Berlin Heidelberg

He X.,China University of Geosciences | Wang J.,China University of Geosciences | Wang J.,Minmetals Exploration and Development Co. | Wang C.,China University of Geosciences | And 4 more authors.
Journal of Earth System Science | Year: 2016

The Mogou syenite intruded into the Mesoproterozoic Xiong’er Group is the main lithostratigraphic unit, along the southern margin of the North China Craton (NCC). This paper reports zircon LAICP- MS data, whole-rock major and trace element compositions of late Triassic magmatic rocks in the Mogou syenite, in order to constrain the formation age of the Mogou syenite, research the origin and evolution of the magma and analyse the geodynamic setting of the Qinling Orogen (QO) in Late Triassic. These rocks consist of medium- to coarse-grained syenite and fine-grained quartz syenite. Zircon U–Pb dating yields a crystallization age of 226.5±2.7 Ma. The syenites are characterized by high SiO2 (63.49–72.17%), alkali (K2O+Na2O of 11.18–15.38%) and potassium (K2O/Na2O of 2.88–28.11), are peralkaline or metaluminous (molar A/CNK of 0.87–1.02) and belong to shoshonite series. The syenites have ΣREE of 33.01–191.30 ppm, LREE/HREE of 14–20, (La/Yb) N of 11–24, with LREE-rich distribution pattern and obvious differentiation between HREE and LREE. Eu anomalies are positive for the medium- to coarse-grained syenite and weakly negative for the fine-grained quartz syenite. In addition, the syenites are enriched in large-ion lithophile elements (Ba, K, Sr, and Pb) but depleted in high strength field elements (Ti, Ta, Nb, Zr, and Hf), and have high differentiation indices of 91.69– 97.06. These geochemical features indicate that the primary magma of the Mogou syenite most likely originated from a mantle source with minor crustal component, and underwent a fractional crystallization process during its emplacement. The late Triassic A-type Moguo syenite along the southern margin of the NCC was generated in the late stage of the syn-collision event of QO, recording a transition period from compression to extension at around 227 Ma. © Indian Academy of Sciences.

Wang C.,China University of Geosciences | Wang C.,University of Western Australia | Lu Y.,University of Western Australia | Lu Y.,Geological Survey of Western Australia | And 3 more authors.
Precambrian Research | Year: 2016

The Xiong'er rift zone along the southern margin of the North China Craton (NCC) is characterized by exposure of a suite of volcanic rocks and associated mafic - intermediate dykes and sedimentary rocks. In this study, we report for the first time the newly identified late Paleoproterozoic diorite dykes from the Waifangshan Mountain in the Xiong'er rift zone and present results from the LA-ICP-MS zircon U-Pb dating, Sr-Nd-Hf isotope systematics, and whole-rock major and trace element geochemistry. The Wafang diorite dykes intruding into the upper part of the Xiong'er Group yielded emplacement mean ages of 207Pb/206Pb from 1746 ± 22 Ma to 1762 ± 11 Ma. These diorite dykes have extreme low MgO, Cr and Ni contents, and enriched in LREEs and LILEs but depleted in HFSEs (Nb, Ta, and Ti). They are characterized by having negative zircon eHf(t) values of -11.4 to -3.1, a whole-rock initial 87Sr/86Sr value of 0.70196 and eNd(t) value of -8.7, and Pb isotopes (206Pb/204Pb = 16.072-16.295, 207Pb/204Pb = 15.275-15.293, 208Pb/204Pb = 36.538-37.255). These geochemical features, together with trace element modeling, suggest that the late Paleoproterozoic Wafang diorite dykes could be sourced from crustal melting with minor contribution of the mixing of mantle materials. These new data combined with previous studies on the late Paleoproterozoic the Xiong'er volcanism should have lasted for nearly 43 Ma ranging from 1789 Ma to 1746 Ma. Correspondingly, the initiation timing of the Xiong'er rift should be younger than 1831 Ma, but earlier than 1625. The Wafang diorite dykes formed in a rift environment, possibly related to breakup of the supercontinent Columbia. © 2016 Elsevier B.V..

Jiang J.-H.,Chinese Academy of Geological Sciences | Jiang J.-H.,Minmetals Exploration and Development Ltd Company | Wang R.-J.,Chinese Academy of Geological Sciences | Qu X.-M.,Chinese Academy of Geological Sciences | And 2 more authors.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2011

A series of NS-and EW-striking dykes occur in Bangong lake region, western segment of the Bangong lake-Nujiang suture in Tibetan plateau, including both granite porphyry and diorite porphyrite. Based on petrochemical analyses and zircon U-Pb LA-ICP-MS dating combined with field investigation, the present authors propose that these dykes represent a crustal extension event of the Bangong lake arc zone after the closure of Bangeng lake middle-Tethys oceanic basin. The granite porphyries occuring only in NS-strike and the diorite porphyrites occuring both in NS-and EW-strike respectively yield a weighted mean age of 79.59±0.32 Ma (MSWD=1.08) with 13 zircons and (76.9±1.2) Ma (MSWD=2.8) with 6. These results indicate that the crustal extensional process of the Bangong lake arc zone occurring in Late Cretaceous epoch was initialed only in EW-trending and slightly later also in NS-trending. Petrochemically, the two types of the dykes appear arc magmatic features characterized by enrichment of large iron incompatible elements (Rb, U, Th, K, Pb) and depletion of high field strength elements (Nb and Ti) which were attributed to metasomatism of Indian-MORB mantle by subducted sediment melt. Furthermore, by analyzing geochemical characteristics of the dyke, we come to the conclusion that the granite porphyries were generated at a shallower depth under amphibolite facies conditions, and the diorite porphyrites were probably under eclogite facies or garnet amphibolite conditions. And the amount of sediment melt involved in the mantle metasomatism related to diorite porphyrites varies largely from 1% to 10% with a source partial melting degree ranging from 8% to 15%. Whereas in the granite porphyries, the amount varies from 10% to 15% and their source partial melting degree is up to 15%.

Li Y.,University of Science and Technology Beijing | Hu N.,University of Science and Technology Beijing | Chen D.,Minmetals Exploration and Development Co.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

The price with large random fluctuation in mineral market has made it very difficult to do an accurate forecast. To overcome this problem, a multidimensional grey metabolism Markov forecasting method is proposed based on the theories of Grey forecast and Stochastic process. The forecasting effect of the model is tested through a case study and analysis with MATLAB software. The research results indicate that the forecasting precision of the proposed method is high and not limited to forecasting step length. So the method can be used to do a long term forecasting for mineral commodity prices without considering economic crisis. © 2012 Springer-Verlag.

Yao X.,University of Science and Technology Beijing | Hu N.,University of Science and Technology Beijing | Li G.,University of Science and Technology Beijing | Chen D.,Minmetals Exploration and Development Co.
ICSESS 2012 - Proceedings of 2012 IEEE 3rd International Conference on Software Engineering and Service Science | Year: 2012

The multifunctional smart meter combined with ZigBee transmission module as network terminal, to achieve real-time collection of electricity, water, warm, wind and other energy consumed in the production process of mine, and then the data is transmitted to the PC Energy Management System to achieve dynamic data display, metering and billing statements, print and other functions; makes mining enterprises to timely understand the energy and material consumption of production operations, then maximize the utilization of energy and materials, to improve economic efficiency of enterprises. © 2012 IEEE.

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