ISSN 1009-6248CN 61-1149/P Bimonthly

Supervisor:China Geological Survey

Sponsored by:XI'an Center of China Geological Survey
Geological Society of China

    Advance Search

    2013  Vol. 46  No. 1

    Abstract:
    The formation of ore deposits is, nevertheless, related to much the same sort of processes that gave rise to the formation of normal igneous, sedimentary, and metamorphic rocks in the Earth′s crust.The fact that close relationship exists between rock-forming and ore-forming processes means that metallogeny must be relevant to understanding the nature of crustal evolution through geological time. There are essentially two ways to do this. One is to empirically describe ore deposits in the tectonic environment and host rocks in which they occur. The other is to chart continental evolution and place ore deposits into a secular and tectonic framework. The former has been covered in considerable detail,and the latter is a more difficult undertaking and requires a thorough knowledge of the evolution of continents with time. It is difficult,particularly,that understanding ore-forming processes in amalgamation and dispersal of active continent by limitation in conventional undertaking. In this paper,it is applied that the point of view of active global tectonics, from rates of continental growth,evolution of the hydrosphere and atmosphere, secular evolution in global heat production into historic records of sea-level changes,to groping summary ore-forming processes in a setting of active global evolution in order to energizing more thorough research in this specialty.
    Abstract:
    Since the widespread acceptance of the plate tectonics theory by geology community,much attention has been paid to sedimentology during investigating the orogenic belts. On the basis of summarizing the three main development stages of the plate tectonic sedimentology and several excellent individual researches,in this paper,we firstly focus on illustrating the definitions of trench basin,wedge-top basin and forearc basin in arc orogenic belt,and then explicitly introduce sedimentary environment,assemblage and provenance of three kinds of basins with specific examples. In summary,these discussions can serve as general introductions to the readers about the orogenic sedimentology.
    Abstract:
    In the period of 1∶50000 field mapping, precambrian strata was distinguished from theLower Paleozoic strata,intruding the Neoproterozoic tonalite pluton. In situ zircon U-Pb LA-ICP-MS dating on the tonalite pluton zircons yielded an age of the 855±14 Ma and 836±12Ma,representing the tonalite pluton intruding age and being the only Neoproterozoic age in Karakorumbelt,which is important in studying of Karakorum Precambrian geological evolution.
    Abstract:
    Five metamorphic intermediate-acid intrusive rock bodies in Proterozoic have beenidentified in the central Qimantage by the 1∶50000 mineral prospect survey. The intermediate-acid intrusive rock bodies located in amphibolite facies the volcanic-sedimentary rocks are gray-pale flesh red two-feldspar gneiss with eye-shaped. The two-feldspar granites are their original rocks. Zircon U-Pb age is of 832±12 Ma on average,which are known the oldest intermediate-acid intrusive magma products. Geochemistry of rocks is as follows:high K2O(4.92—5.76 ×102), poor FeO, MgO, and CaO. Rocks with high-K are calc-alkaline S-type high-evolution granites that were formed about 34.7 km in crustal thickness. Tectonic setting is shown sys-collision by R1-R2 discriminant diagrams. Rodinia continent closed at about 830 Ma in the East Kunlun. Intermediate-acid magma action reproduced in early Paleozoic. In this process Rodiniabreakup and plates in low latitudes moved to high-latitude.The discovery is important to know the structure evolution of early Paleozoic in East Kunlun.
    Abstract:
    Basic-ultrabasic rocks of Hongshishan is plate tectonics researchers focus on one of therock.The genetic type and tectonic setting of Hongshishan basic-ultrabasic rocks are discussed by the rock chemistry, trace elements,rareelements.Studies have shown that rock types based on combination of rock,compared with the output relations,segregation dunite body′s development, the internal flow structure rock, late dykes and chromite mineralization of various types of rock should be akinds of intrusions of magma types; from petrochemistry, trace, rareearth element geochemistry of the rock is reflected in the late Paleozoic (Carboniferous-Permian) period and the Paleo-Asian Ocean closed in the south and eliminate the meantime, the birdchildren Mountain-British andesitic island arc developed on the southern marginofarift basin,the type of arc magma mantle product,its mechanism or dynamic environment as a backarc spreading and mantle upwelling of continental rift magmatismmechanism.
    Abstract:
    Aikengdelesite is the first found porphyry molybdenum (copper) deposit in EasternKunlun for the past years and the degree of geological work and research for the deposit is quite low.The deposit lies to the Eastern Kunlun southern composite accretion belt. The hosted rocks are diorite, monzonitic granite, granite porphyry, medium-fine grain granite and volcanic rocks and sedimentary rocks of Hongshuichuan Group.In this paper,we present zircon U-Pb age data of monzonitic granite using laser ablation ICP-MS technique. The zircons of granite are mainly euhedral and hypidiomorphic texture, have clear ring and high Th/U ratio (0.83~1.47, average 1.15) which belong to the typical magmatic zircons. The results show that the intrusion mainly comes from late Hercynian but not late Indosinian period with the206Pb/238U average weighted age of (268.7±1.6) Ma (MSWD=0.24) and concordant age of (268.5±0.83)Ma (MSWD=0.051). Comprehensive analysis reveals that the research area has entered into oceanic crust subduction stage in 268Ma±.
    Abstract:
    The homology of the rock mass is analyzed according to the geology, petro-graphic andgeochemical along the rock group of adamellite in the western Qinling(commonly called as“Five golden flowers”).It shows that the invasion sequence is clear. The rock mass includes diorite in earlyphase,biotite adamellite in the metaphase,two-mica monzonitic granites in the late stage.The intrusion has an evolution trend from acidic to alkali with rock forming episode. In the space,the longitudinal lithology is consistent overall, and the structure become thinner from east to west;the transverse structure is similar and the composition is more partial acid to the south.The rock group from the old to the new,they are from the potassium and sodium transition area to potassium,belonging to shoshonitic series and high-K calc-alkaline series. They have similar geochemical features. The REE diagram of the Chondrite-normalized show that they are rich in LREE,and evidently depleted in Eu. The adamellite is formed at 181-232.9Ma (by Rb-Sr) and 178-248.8Ma (by K-Ar). Meanwhile, the value of the ANKC is lower than 1.1, with peraluminous granite. They are Himalayan-type granite. Research shows that the rock group of adamellite has homology.
    Abstract:
    Through 1∶50000 geological mapping of Malan,the authors discovered rapakivi granitein Dongquangobi area for the first time. Dongquangobi rapakivi granite is distributed in the middle section of South Tianshan collision belt,the rock is characterized by rich dark fine-grained dioritic inclusions and special rapakivi texture. This granite appears stock-like,its petrochemistry is characterized by higher Al2O3(14.47%~15.44%)、K2O(3.93%~4.7%)和Na2O(3.4%~3.7%), rich in LREE and LILE and with weak δEu (an average of 0.79) negative anomaly,showing that it has obviously different geochemical characteristics compared with typical wiborgite in the plate. Its formation age is the Late Carboniferous(305±1Ma),which exactly is the end stage ofSouth Tianshan ocean basin subducted northward collisional orogenesis,so it can be concluded that the Dongquangobi rapakivi granite may be a type of orogenic belt rapakivi granite,which is I-type granite formed in the uplifting environment after plate collision.
    Abstract:
    Ore-forming geological conditions,characteristics of geophysics, geochemistry and distribution of mineral resources in the Maiergaixi Region,Southwest Tianshan Orogeny, were analyzed on the basis of previous research results and regional geology together with prospecting practice.It indicated that the most promising minerals are copper,lead,gold and stibium in the region. The deposit types for prospecting in the region are copper deposits related with volcanics,transformed sedimentary copper and lead-zinc deposits,hydrothermal type lead-zinc deposits,stibium-gold deposits related with hydrothermal fluid and gold deposits of tectonic altered rock.The discovered deposits occurred in clastic rocks of paleozoic Upper Siliurian-Lower Devonian Wupataergan terrain and the Yuoshihan ophiolitic rock. The deposits distributed in the outer contact zone of Ludeniewa rock terrain were controlled by compressor-shear faults trending for EW and NEE-SWW.The ore-forming had close relationship with Ludeniewa rock terrain, and abnormal geophysical and geochemical exploration. Six favorable ore-prospecting areas and eight prospecting targets had been delineated. The most promising minerals,deposit types,clues for prospecting and prospecting potential were discussed and summarized. The analysis and ranking for the eight targets are expected to be referenced by field geologists.
    Abstract:
    Nariniya Pb-Zn deposits is located mainly in the Neogene volcanic rock,with obviousmetallogenic layer controltype. Zhabaoma group volcanic rock is one of the main ore-bearing horizons.The geochemical characteristics of the Nariniya group volcanic rocks were researched in this work.The result shows that the volcanic rock is a set of calcium alkaline-alkaline series of acidic rock assemblages with a rich alkali high potassium content. Rare earth distribution pattern is different, the light and heavy rare earth element distilled obviously. δEu is between 0.73 and 0.97,and there is no obvious negative europium anomaly. Trace element distribution mode is approximately consistent,for the original mantle,big ion lithophile elements (K,Ba,Rb,Sr) and Th,U etc lively incompatible elements are enriched and Zr,Ti,Ta,P high field strength elements are relatively less. Rb/Sr is 0.07-0.27,Rb/Sr ratio is 0.07-0.27, which shows the crust-mantle mixing characteristics. The rock may be from EM Ⅱ type enrichment mantlegold bearing mica mantle peridotite of partial melting, crystallization after the separation of the magma chamber rich potassium magma along the tectonic weak part in invasion,and crustal material produce mixed form mixed magma in the earth′s crust shallow in place. Trace elements have high lead and zinc background value,for providing main ore-forming material sources. In the R1,R2 structure discrimination diagrams,sample mainly fall into the impact after the stretchand after collision environment. In the R1,R2 structure discrimination diagrams,sample mainly fall into the impact after the stretch and after collision environment grams,sample mainly fall into the impact after the stretch and after collision environment.
    Abstract:
    There have been finished about 76 701km2 with scale 1∶200,000 and 73 837km2with scale 1∶ 500,000 regionally geochemical exploration in West Kunlun-Altun mineralization belt during the land and resources survey. It covered totally the whole mineralization belt,and provided systematical geochemical data for the mineral resources appraisal and basic geological research. The prospecting information such as lead-zinc ore in Weibao and antimony ore in Huangyangling has been found by anomaly investigation and verification. Evaluation proved that Weibao lead-zinc deposit had a medium size,in a prospective large scale; The large element enrichment regions determined with geochemical methods,such as antimony in east Kunlun and lead in Chalukou of west Kunlun in Xinjiang are significant for the prospects.In subsequent work,14 antimony deposits (spots) had been found successfully in Huangyangling area, which was thefirst antimony mineralization concentration region in Xinjiang;The lead-zinc ore deposits such as Duobaoshan, Tianshuihai and Baotashan, and Kazile copper-silver ore deposit, with a batch of mineral information in addition, were found in Chalukou area, which became an important mineral exploration area in Xinjiang.The geochemical exploration with remarkable effect forcefully promoted the work of mineral resources evaluation in west Kunlun-Altun region in Xinjiang.
    Abstract:
    Mohailaheng lead-zinc deposit is located in Jieduo back-arc foreland basin of the northrim ofthe north of Sanjiang metallogenic belt,its main ore-bearing horizon is the lowercarboniferous supported heteropoly group of carbonate group,Containing ore formation andNWW fracture are important ore-controlling factors. Ore minerals are mainly galena,sphalerite,limonite and so on. The research results of lead isotope in the study area show that lead quarries μ is 9.27-9.77, the average of μis less than 9.58,the average of ωis 39.99,lead isotopic composition has the characteristics of normal lead evolution. Lead quarries 206Pb /204Pb is 18.51-18.92, the average of 208Pb /204Pb is 38.64, with the characteristics of stable isotopic composition. Lead mineralizing materials have the characteristics of crust-mantle evolution in Zartman lead isotope structure. Based on the above analysis, Mohailaheng lead-zinc mine mainly occurs in thick-super thick layers of carbonate rocks,and the mineralization had no direct relation to magmatic activity, which reflected that the lead came from lead mine construction of the upper earth′s crust. lead containing formation or subprime fracture intersection part are favorable met allogenic or prospecting positions.
    Abstract:
    A lot of polymetallic deposits, including the Chabu Pb-Zn-Ag deposit, Saerxite Pb-Zn-Ag deposit and Lamacaolutu Cu-Mo deposit, have been found in the Madate area of eastern Mongolia, which belongs to central Mongolia-Erguna polymetallic ore belt. Throughcomprehensive study on the mineralization age,the ore-forming geological backgroud and thesurrounding rock characteristics of each deposit,we classify the mineralization period of the area into two stages:Late Variscan and Yanshanian. Copper-molybdenum deposit is superimposed mineralization of the Late Variscan and Early Yanshanian,Lead-zinc-silver deposit was formed in the Late Yanshanian. The mineralization of the two types of deposits is closely related to the tectonic and magmatic activity. At the same time,by analyzing and comparing the mineralization characteristics and orebody characteristics of each deposit,we classify these deposits into two genetic types:porphyry-type Cu-Mo deposit and epithermal low-temperature hydrothermal veintype lead-zinc-silver deposit. Based on the trace element analytic results of the ore-forming source rock of Saerxite Pb-Zn-Ag deposi and Lamacaolutu Cu-Mo deposit,we think two genetic types as a unified metallogenic series and establish the porphyry-epithermal low-temperature hydrothermal vein-type mineralization model.
    Abstract:
    The Jiadanggen porphyry Cu(Mo) deposit lies in the east of Qimantage-Dulan suborogen, East Kunlun orogen,Qinghai Province.It is a newly discovered mineral deposit in recent years,and with low degree in studying. The geochemistry analysis on igneous rock samples inthe Jiadanggen mining area shows that the ore bearing porphyry are characterized by high SiO2,alkali,low TiO2,CaO,and MgO,which is high-potassium calc-alkaline series.The REE are characterized by LREE enrichment,with obvious negative Eu anomalies. The trace elements are characterized by K,Rb,Ba,etc enrichment obviously; Ta,Nb,Zr,Hf,etc enrichment relatively; P,Ti,Y,Yb,etc depletion obviously. The characteristics of the REE and trace elements indicated the continental margin arc tectonic setting. Combining regional geology background and geochemistry of the igneous rocks in Jiadanggen deposit,the Jiadanggen igneous rocks may be formed in the early stage of the collision orogeny,continental margin arc and collision orogeny coexistence environment. And it was formed from dehydration of residual oceanic crust which caused mantle wedge partial melting.
    Abstract:
    This paper studies the ore-control factors of the Lantian uranium field,which is the firstunderground leaching exploitation in China. The main ore-control factors locating in the margin of fault basin include multiple magmatic activity,compound faults of NNE & NE and mass mafic dikes of the field. The mineralization process includes 5 stages. ① The formation of theγ52-2;②The preenrichment of U caused by the multiple magmatic activity;③ Alkali-alternation caused by mantle fluid activate the uranium of the accessory minerals,and the mantle fluid provide abundant ∑CO2;④Uranium which is moved as UO2(CO3)O34-deposit in right physic-chemical circumstance and ⑤The phase of overprinting and reworked mineralization of oxidation and leaching.
    Abstract:
    Kyrgyzstan Locates in the central part of Central Asian and in the ancient silk road.Kyrgyzstan is called a"mountainous country".The area of the country is 19.85×104km2,with a 5340 thousand population. The mountainous area occupies about 95% of the total area.Kyrgyzstan has single economic structure.The main industry of Kyrgyzstan is agriculture and animal husbandry. Its industrial basis lags behind. The main industry is mineral resource. So far in Kyrgyzstan more than 20 thousands mineral deposits have been discovered. Metal elements exceeds 1 hundred and fifty,especially gold, antimony, mercury, tin,tungsten and other resources are very rich. As China′s neighbor country,the mineral resources of Kyrgyzstan have aroused wide concern of relevant persons. The author discussed the metallic metal in Kyrgyzstan in order to provide information for comparison of the domestic and foreign mineral resources,"going out"of domestic enterprises,and overseas geological survey. In the same time,we give investment advice to China mining enterprises.
    Abstract:
    Apatite Fission Track (AFT) is a useful tool to rebuild the low temperature thermochronological evolution of rocks. Recent research progress on application and methodlogy of AFT is reviewed in this contribution. We summarized the main factors related to AFT annealing behavior, including: ① enrichment of certain main elements and 238U in apatites. ② alphadecay loss.③ pressure and stress,several problems during experimental observation and the multiple annealing model.Review the previous studies,summarize pros and cons of the current annealing model and its application in analysis of the basin thermal-tectonic evolution history,and orogenic belt uplift (i.e.Tibet Plateau uplift).
    Abstract:
    This paper presents the achievement of landslide researches in China, Japan, Sri Lanka and parts of Southeast Asian countries in three aspects of Hazard Assessment and InventorySystem,Monitoring Method,and Hazard Data Implementation, by reviewing the keynotes,session presentations,and poster communication in proceeding of the conference on" Workshopon Landslide in Southeast Asia: Management of a Prominent Geohazard "held in Indonesia from28th November to 1st December, 2011.The contents in those three aspects basically reflect the focus and prospective of recent landslide researches in Southeast Asian countries. Meanwhile,arevelation for landslide investigation and researches in China is concluded.