内蒙古中部道郎和都格铜多金属矿的地质特征矿床类型及找矿模式研究

Daolangheduge copper polymetallic deposit is located on east edge of Ondor Sum-Bainaimiao metallogenic belt, which is a prospective area of porphyry copper deposit, in Xianghuangqi of central Inner Mongolia. Geotectonically, it occurred in the continental margin accretion belt along the north margin of North China Plate, south of the suture zone between North China Plate and Siberian Plate. The intrusive rocks in this area mainly consist of intermediate-acid magmatic rocks, and the quartz veins, tourmaline veins and the transitional phase are comparatively developed. According to our research, the ore-bearing rock body is mainly quartz diorite while the surrounding rock is mainly biotite granite. Besides, the wall rock alteration are mainly propylitization, pyritization and silicification, which consist of epidotization, actinolitization, chloritzation and so on. The metallic minerals are mainly chalcopyrite and pyrite. In addition, the primary ore is mainly of quartz-chalcopyrite-pyrite type. Above all, Daolangheduge copper polymetallic deposit is suggested to be categorized in the porphyry copper type. With isotopic dating and geochemical research on quartz diorite of ore-bearing rock body, the zircon LA-ICP-MS U-Pb dating of two samples yields an age of 266±2 Ma, falling into the range of late Permian Epoch. It is the first accurate age data in Xianghuangqi area, so it should play a key role in the research of deposit and magmatic rocks in this area. With the major elements and trace elements analysis of 14 samples, the quartz diorite should be among the calc-alkaline series, the geochemical characteristics show higher large-ion lithophile elements of Rb, Sr and LREE, low high-field strength elements of Nb, Ta and high transition elements of Cu, Cr . Also, the REE patterns have negative Eu anomalies. With the same analysis of 4 sample for the biotite granite, the geochemical characteristics show higher Rb, Th,, Zr, Hf and LREE, low Nb, Sm and HREE and Eu has no anomaly. It should be among the calc-alkaline series, over aluminum quality and has characteristics of Adakites. According to isotopic dating and geochemical characteristics of ore-bearing rock body, it is suggested that its materials mainly derived from upper mantle that had fractional crystallization and its magma source region may be affected by fluid metasomatism of paleo-asian ocean. It should be an extensional process of post-orogeny according to regional tectonic evolution. Consequently, because of the decrease of temperature and pressure, the ore forming fluid was raised to surface and mineralized accompanied by magmatic activity which might occur in south of the suture zone. By geological survey, further geophysical and geochemical work is needed. In this area, we have accomplished high precision magnetic prospecting, high density electrical survey, gravity prospecting, soil geochemical prospecting, X-ray fluorescence analyzer prospecting and so on. According to geophysical and geochemical abnormal and surface occurrence, 11 drills are arranged to verification. The type of ores are mainly quartz-chalcopyrite-pyrite ores within 3 drills by drill core logging. Although the grade as well as the scale of already-found Cu deposits are insufficient for industrial exploitation, the mineralization prospect in this region is supposed to be great and the potential in mineral exploration at depth is excellent.

东天山镁铁-超镁铁岩铜镍硫化物矿床通道式成矿机制与岩体含矿性评价研究

A mafic-ultramafic complex belt well developed in Eastern Tianshan, Xinjiang, NW China, which contains a series of Cu-Ni sulfide deposits. This area is the important production basis for Cu-Ni deposits, including Tulargen deposit, Hulu deposit, Huangshan-Huangshandong deposit, Hulu deposit, Xiangshan deposit, Tianyu deposit, Chuanzhu deposit. In China, especially Eastern Tianshan, it is prevalent that large Cu-Ni deposits occurred in small intrusions, typically including Jinchuan, Kalatongke, et al., so the ore-forming mechanism and evaluation rule for those small intrusions are very meaningful and of universal significance. On the basis of the research to typical Cu-Ni deposits, ore-forming conditions and processes are summarized through which to evaluate the ore-bearing potential for barren intrusions and unexplored mafic-ultramafic intrusions. By the contrast, metallogenic rule and mechanism of ore genesis are concluded, and evaluation system is preliminarily set up on the basis of these conclusions. Quantitatively simulation for the composition of olivine is introduced for the first time in China to discuss the interaction between magma and sulfide, and a new method to calculate the Mg-Fe composition of primitive magma is developed. Interaction between magma and sulfide liquid is used to get the Ni content in sulfide liquid. Sulfur isotopic characteristics in sulfide minerals in country rocks and ores are used to judge crustal sulfur introduction, which is applied for the first time in China. Re-Os isotopic characteristics are related to the ore-forming process, to interpret the process of enrichment of chalcophile elements. On the basis of the evaluation system, Mati, Chuanzhu, Luodong, Xiadong, those intrusions are evaluated to their ore-bearing potential. According to the studies to typical Cu-Ni deposits, conduit-type ore-forming model is set up, and the characteristics of the model are concluded systematically. The evaluation system and conduit-type ore-forming model can be helpful to the evaluation of mafic-ultramafic intrusions in this and similar mafic-ultramafic intrusion belts. The studied typical deposits and mafic-ultramafic intrusion include Tulargen deposit, Hulu deposit, Huangshandong deposit, Chuanzhu deposit, Mati intrusion，Luodong intrusion, Xiadong intrusion, and others. Through studies, there are similar characteristics for Tulargen and Hulu deposits in magma origin, composition of primitive magma（MgO=12.5%, FeO=12% and MgO=11%, FeO=10.5% respectively）, magma evolution, mechanism of sulfide segregation and conduit-type ore-forming process. By Re-Os isotopic system, the ore forming date of Tulargen deposit is 265.6±9.2Ma, which is consistent to regional metallogenic event, but little younger. The Mg-Fe composition of primitive magma of Baishiquan, Huangshandong area, Kalatongke is lower than that of Tulargen and Hulu deposit, showing common basalt composition. The Mg# value（Mg#=(Mg/Mg+Fe）increases gradually from Kalatongke to Baishiquan to Huangshan-Huangshandong East. Baishiquan intrusions show relatively higher crustal contamination by evidence of trace element, which indicates the lower magma original source, from depleted mantle to crust. One break is the discovery of komatiitic intrusion, Xiadong intrusion, which shows characteristics of highly magnesium (Max Fo=96). The primitive magma is calculated of MgO=28%，FeO=9%, belonging to komatiitic magma. Tectonic evolution of Eastern Tianshan is discussed. By the statistics of ore-forming data of porphyry copper deposits, magmatic sulfide Cu-Ni deposits, orogenic hydrothermal gold deposits, we believe that those deposits are the successive products of oceanic subduction, are and back-arc basin collision and post-orogenic extention. And Cu-Ni sulfide deposits and orogenic gold deposits occurred in the stage of post-orogenic extention. According to the conclusions, the conduit-type ore-forming mechanism of magmatic sulfide deposit is set up, and its characteristics and conditions are concluded as well. The conduit-type ore-forming system includes magma generation, sulfide segregation, enrichment of chalcophile elements, interaction of sulfide and magma, sulfide collection in limited space in magma conduit and bottom of the chamber, which make a whole ore-forming system.The ore-forming process of Cu-Ni sulfide deposits is concluded as three steps: 1. mantle derived magma rises upward to the middle-upper crust; 2. magma suffers crustal contamination of different degrees and assimilates crustal sulfur, which leads to sulfur saturation and sulfide segregation. Sulfide liquid interacts with magma and concentrates chalcophile elements; 3. enriched sulfide located in the conduit(Tulargen) or bottom of the chamber (Hulu). Depleted magma rises upward continuously to form barren complexes. For the practical cases, Tulargen deposit represents the feeding conduit, and Hulu deposit represents the bottom of the staging magma chamber. So the deeper of west of Tulargen and southwest of Hulu are the favorite locate for ore location. The evaluation for ore potential can be summarized as follows: (1) Olivine can be served as indicator for magma evolution and events of sulfide segregation; (2) Sulfur isotopic characteristics is an efficient method to judge sulfur origin for magmatic sulfide deposit; (3) Re-Os content of the ores can indicate interaction between sulfide and silicate magma and crustal contamination; (4) PGE mineralization is effected by degree of partial melting of mantle; (5) Cu/Zr is efficient parameter to judge sulfide segregation; (6) The effects of multiple magma fractionation and emplacement are important, for inverse order shows the destruction to previous solid lithofacies and orebodies. Mati, Chuanzhu, Xiadong, Luodong, mafic-ultramafic intrusions are evaluated using evaluation system above. Remarkable Ni depletion is found in olivine of Mati, and southwest of the intrusion can be hopeful location for ore location. Chuanzhu intrusion has remarkable evidence of sulfide segregation, but the intrusion represents the narrow feeder conduit, so the wide part of the conduit maybe the favorite location for sulfide to deposit. The ore potential of Luodong and Xiadong is not good. Both the intrusions show no Ni depletion in olivine, and there is no sulfide in country rocks, so no crustal sulfur is added into the magmatic system. For Sidingheishan, a very large intrusion, the phenomenon of sulfide segregation is found, but there are no favorite places for sulfide to deposit. So the Cu-Ni ore potential maybe not good, but PGE mineralization should be evaluated further.

阿尔泰南缘侧向增生过程中的VMS矿床：地质、地球化学特征与成矿机制

The Chinese Altai is one of the most important volcanogenic massive sulfide (VMS) deposit districts in China. All orebodies were lenticular or bedded and stratabounded by a suite of early Devonian volcanic-sedimentary rocks. Hydrothermal feeder zones developed under some of the orebodies. All the ores are massive or laminated, and show typical characteristics of VMS deposit. Based on the mineralizing time and the metal assembles, we divide 3 metallogenic stages: 1, Fe orefroming stage associated with basaltic and sedimentary rocks during very early Devonian; 2, Cu-Pb-Zn oreforming stage associated with rhyolitic and sedimentary rocks during early Devonian; 3， Cu-Zn oreforming stage in the dacitic and basaltic rocks during mid. Devonian. The hosting rocks for all orebodies are different, but they show very similar geochemical and isotopic characteristics. All the felsic rocks show enriched lighted rare earth elements (REE) patterns (La/Yb>5), and with an obvious Eu negative anomalies (Eu/Eu*<0.6). In the meanwhile, all the mafic rocks show flat REE pattern and no Eu anomalies. The Ashele basalt show an apparent Ce negative anomalies (Ce/Ce* <0.76), All the volcanic roks in Chinese Altai show the decoupled property between the high field strength elements (HFSE) and large ion lithophile elements (LILE). The negative Nb, Ta characteristics with respect to adjacent elements indicate that subduction-modified source. The Nd(t) of the hosting rocks for all orebodies changed in a small range (-1.5~5), and the (87Sr/86Sr)i change in a big range. The initial Sr value of the hosting rocks in Mengku and Tiemuerte are obviously affected by the seawater (0.705~0.710), and initial Sr values of hosting rocks Ashele change in a small range (0.704~0.706). All Sr-Nd isotopes of ores have the same range with the hosting rocks, indicating that both the ores and volcanic rocks have the same island arc source. The mean sulfur isotopes of sulfides from Ashele and Mengku are 6.2‰ and 3.4‰, respectively, indicating a deep magmatic source. However, the sulfur isotopes of sulfides from Keketale, Tiemuerte and Keyinbulake changed in -15.8‰~9.9‰, -23.5‰~1.87‰, -8.3‰~1.6‰, respectively. And the big sulfur isotope range indicated that the sulfur of the ores was a combination biogenic and magmatic source. All volcanic rocks from the VMS deposits in the southern Chinese Altai show a typical subduction related environments. Based on the regional and locally geological evidence, here we propose that the southern Chinese Altai is an island arc system, and all VMS deposits formed during the lateral accretion process. No VMS deposit formed during the formation of the island arc during Silurian; Fe VMS deposit formed during the beginning of the opening of the backarc basin in very early Devonian; Cu-Pb-Zn VMS deposits formed during the mature stage of the backarc basin in early Devonian; at last the Cu-Zn VMS deposit formed during the rifted stage of the island arc itself.

浑善达克沙地全新世气候变化与风沙活动—夏日淖湖泊沉积记录

Atmospheric dust as an important factor for climate feedbacks is mainly derived from and drove by the aeolian activities of the semi-arid regions in Asia. Therefore, reconstructing the history of aeolian activities in this region has a great significance in understanding the dynamics of past and future climate changes. This paper made a systematical sedimentology, geochemisty and high-resolution chronology analysis on the sediments from the Xiarinao Lake, which located in Hunshandake Desert, Inner Mongolia, and compared with the meteorological records for identifying the indicator of aeolian activities and climate changes. Based on above work, the evolution history of the aeolian activities and climate changes since 11,000 a BP was reconstructed and the dynamics of the aeolian activities and climate changes in the Hunshandake Desert was discussed. The indicator of aeolian activities was established through the comparison of the clastic and chemical records with the meteorological registers in recent 50 years: 1. The sediments of Xiarinao Lake are mainly derived from eaolian clastic materials and composed of two major components: one is the sand fraction (<4 ) similar to the composition of sand dunes, the other is the silt fraction (>4 ) similar to the atmospheric dust. The sand content and the median grain size, particularly the sand content, show a close association with the intensity of wind, indicating that the particle-size composition of the sediments reflect the variations of the aeolian activities. 2. The proportion of soluble salts relative to the total carbonates in the sediments was correlated to the arid degree registered in meteorological records, suggesting that arid degree might be associated with changes of wind speed and the relative proportion of soluble salts to the total carbonate could be used as the indicator of aridity. 3. The δ18O of authigenic calcite in the Xiarinao Lake show a well correlation with both the atmosphere precipitation and variation of the moisture indicated by the concentrations of soluble salts, suggesting that δ18O of anthigenic calcite is a reliable indicator of humidity. Based on above studies, the evolution history of the aeolian activities and climate changes since 11,000 a BP was reconstructed. At the same time, their association and underlying dynamics was discussed: 1. The evolution history of the eaolian activity was reconstructed by the sand content and median grain size. The result showed that aeolian activities had experienced several different climate periods in the Holocene: the aeolian activities fluctuated with a 500-year cycles during the interval from 10,900 to 8200 a BP; no significant aeolian activities had been developed from 8200 to 6300 a BP; during the interval of 6300 to 2600 a BP, sand content and media grain size had increased gradually, the sand content increased from about 5% to 25%, indicating the intensity of aeolian activity increased in the Hunshandake Desert; since 2600 a BP, intensity of aeolian activity has become stronger and activated the sand dunes. 2. The relative arid degree indicated by the proportion of soluble salts relative to the total carbonate show that both the wind speed and dry degree had being increased since 11,000 a BP. During the interval of 10900 to 6300 a BP, no detectable soluble salt was found in the sediments, indicating the humidity condition; the proportion increased to 20% from 6300 to 4200 a BP, showing the climate became drier; the little change of proportion (20%) suggest that the climate was relative stable during the interval of 4200 to 2600 a BP; after 2600 a BP, the proportion increased, showing the climate became further dry. 3. The δ18O evolution of the lake water was established through analysis of authigenetic calcite δ18O for revealing the variations of relative effective humidity in the Hunshandake Desert. δ18O maintained around -6 ‰ during the interval of 10900 to 8200 a BP, showing the climate was a little dry relative to that of the whole Holocnene; in the period of 8200 to 6300 a BP, δ18O had the most negative values, indicating that it was the most humid interval in Holocene; from 6300 to 4200 a BP, δ18O increased from about -7.5 ‰ to about -3 ‰ gradually, suggesting increased aridity; since 4200 a BP, the climate has become stable and dry. On the whole, the records in this study show that the variation of the relative humidity and aridity is consistent with that of summer monsoon in the Hunshandake Desert. The relationships among the grain size, soluble salts relative content, and the authigenic calcite δ18O indicate aeolian activities is controlled by the aridity in the studied area, and the increased aeolian activities is closely associated with the temperature changes under the relative dry condition. The high wind speed under the low temperature leads to the increased aeolian activity, and the temperature change associated with the aeolian activities might be related with the perturbations of the Siberian High Pressure.

急倾斜金属矿体开采岩体移动规律与变形趋势预测研究

Rockmass movement due to mining steep metallic ore body is a considerable question in the surface movement and deformation issue caused by underground mining. Research on coal mining induced rockmass movement and its prediction problem have been performed for a long-term, and have achieved great progress at home and abroad. However, the rockmass movement caused by mining steep metal mine is distinctivly different from coal seam mining.. Existing surface movement laws and deformation prediction methods are not applicable to the rockmass movement caused by mining steep metal mine. So far the home and abroad research to this theory is presently at an early stage, and there isn’t mature theory or practical prediction method, which made a great impact on production. In this paper, the research object—Jinchuan nickel mine, which is typical steep metal mine, characterized by complex geological conditions, developed faults, cracked rockmass, high geostress, and prominent engineering stability problems. In addition, backfill mining method is used in the mine, the features of rockmass movement caused by this mining method are also different from other mining methods. In this paper, the laws of rock mass movement, deformation and destroy mechanism, and its prediction were analyzed based on the collection of data, detailed in-sit engineering geology survey, ground movement monitoring by GPS, theoretical analysis and numerical simulation. According to the GPS monitoring of ground surface movement, ground subsidence basin with apparent asymmetry is developing, the influence scope is larger in the upper faulted block than in the lower faulted block, and the center of ground movement is moving along the upper faulted block direction with increasing depth of mining. During the past half and seven years, the largest settlement has amounted to 1287.5mm, and corresponding horizontal displacement has amounted to 664.6mm. On the ground surface, two fissure belts show a fast-growing trend of closure. To sum up, mining steep metal mine with backfill method also exist the same serious problem of rockmass movement hazards. Fault, as a low intensity zone in rockmass, when it located within the region of mining influence, the change of potential energy mainly consumed in fault deformation associated with rockmass structure surface friction, which is the essence of displacement and stress barrier effects characterized by fault rupture zone. when steep fault located in the tensile deformation region incurred by underground excavation, no matter excavation in hangingwall or in footwall of the fault, there will be additional tensile stress on the vertical fault plane and decrease in the shear strength, and always showing characteristics of normal fault slip, which is the main reason of fault escarpment appeared on the ground surface. The No.14 shaft deformation and failure is triggered by fault activation, which showed with sidewall move, rupture, and break down features as the main form of a concentrated expression of fault effects. The size and orientation of principal stress in surrounding rock changed regularly with mining; therefore, roadway deformation and damage at different stages have different characteristics and distribution models. During the process of mining, low-intensity weak structures surface always showed the most obvious reaction, accompany with surface normal stress decrease and shear strength bring down, to some extent, occurred with relative slide and deformation. Meanwhile, the impact of mining is a relatively long process, making the structure surface effect of roadway deformation and damage more prominent than others under the influence of mining. Roadway surrounding rockmass deformation caused by the change of strain energy density field after excavation mainly belongs to elastic deformation, and the correspondented damage mainly belongs to brittle rupture, in this circumstance, surrounding rockmass will not appear large deformation. The large deformation of surrounding rockmass can only be the deformation associated with structure surface friction or the plastic deformation of itself, which mainly caused by the permanent self-weigh volume force，and long-term effect of mining led to the durability of this deformation Good pitting fill effect and supporting effect of backfill, as well as the friction of rockmass structure surface lead to obvious macro-rockmass movement with long-lag characteristics. In addition, the loss of original intensity and new structure surface arisen increased flexibility in rockmass and fill deformation in structure surface, which made the time required for rockmass potential energy translate into deformation work associated with plastic deformation and structure surface friction consumed much, and to a large extent, eliminated the time needed to do those plastic work during repeated mining, all of which are the fundamental reason of rockmass movement aftereffect more significant than before. Mining steep deposits in high tectonic stress area and in gravity stress area have different movement laws and deformation mechanism. The steep deposit, when the vertical size of the mining areas is smaller than the horizontal size of the orebody, no matter mining in gravity stress area or in high tectonic stress area, they have similar features of ground movement with mining horizontal orebody; contrarily, there will appear double settlement centers on the ground surface under the condition of mining in high tectonic stress area, while there will always be a single center under the other condition. Meanwhile the ground movement lever, scale of mining influence area and macro features of ground movement, deformation and fracture are also different from mining in gravity stress area, and the fundamental reason lies in the impact of orientation of the maximum principal stress on rock movement features in in-site rock stress field. When mining thick and steep deposit, the ground surface movement and deformation characteristic curves are significantly different from excavating the horizontal ore bed and thin steep deposit. According to the features of rockmass movement rate, the development process of mining-induced rockmass movement is divided into three stages: raising stage, steadily stage and gradually decay stage. Considering the actual exploitation situation, GPS monitoring results and macro-characteristics of surface movement, the current subsidence pattern of Jinchuan No.2 mine is in the early stage of development. Based on analysis of surface movement rate, surface subsidence rate increase rapidly when mining in double lever at the same time, and reach its peak until the exploitation model ended. When double lever mining translate into single, production decreased, surface subsidence rate suddenly start to reduce and maintain a relatively low value, and the largest subsidence center will slowly move along with the hangingwall ore body direction with increasing depth of mining, at the same time, the scope and extent of subsidence in footwall ore body will begin magnify, and a sub-settlement center will appear on ground surface, accompanied with the development and closure trend of ground fissure, the surrounding rockmass of shaft and roadway will be confronted to more frequent and severe deformation and failure, and which will have a negative impact on the overall stability of No.2 mine mining. On the premise of continuity of rockmass movement, gray system model can be used in ground rockmass movement prediction for good results. Under the condition of backfill mining step by step, the loose effect of compact status of the hard, broken rockmass led to lower energy release rate, although surrounding rockmass has high elastic energy, loose and damage occurred in the horizontal ore body, which made the mining process safety without any large geological hazards. During the period of mining the horizontal ore body to end, in view of its special “residual support role”, there will be no large scale rockmass movement hazards. Since ground surface movement mainly related to the intensity of mining speed and backfill effect, on the premise of constant mining speed, during the period of mining the horizontal ore body to end, the rate of ground surface rockmass movement and deformation won’t have sudden change.

成矿流体构造动力学研究—以冀西北后沟金矿和山东七宝山金矿为例

Tectonic dynamics of metallogenetic fluids is a new crossed subjects among fluid geology, mineral deposit geology and structural geology, and is one of the major current projects of geosciences. It is mainly focused on structures and tectonic dynamic induced by fluid motion, variation of physical condition of fluids (such as temperature and pressure), and interaction between chemical component of fluids and wall rocks in the crust. It takes features of deformation and metamorphysim, which formed during interaction between fluids and rocks and have been perserved in rocks, as basic research objects. After studying types, orders, distributions and fabrics of these features, and analyzing and testing physical and chemical information from these features by some techniques, it is intended to reconstruct moving process of fluids, dynamics of interaction between fluids and rocks, and dynamics of mineralizations. Three problems of tectonic dynamics of metallogenetic fluids, which have not been paid much attentions before, have been studied and discussed in this report. Three relative topics are including: 1)Double-fracturing induced by thermal stress and pressure of fluids and mineralization of Gold-copper in Breccia Pipe at the Qibaoshan in Shandong Province; 2)Parting structures induced by K-metasomatism in the Hougou area, northwestern Heibei province; 3)Migration mechanism of dissolved mass in Fe&S-rich fluids in Hougou gold deposit in Heibei province. After a synthetical study of two years, the author has made some new processes and progresses. The main new advances can be summaried as the following: 1)Thermal stress of fluids formed by temperature difference between fluids and country rock, during upword migration process of fluids with high temperature and pressure, can make rock to break, and some new fractures, which surfaces were uasally dry, formed. The breccia pipe at the Qibaoshan area in Shandong province has some distinct texture of fluidogenous tectonics, the breccia pipe is caused by double-fracturing induced by thermal stress and pressure, distribution of gold-corpper ore bodies are controlled powerfully by fluidogenous tectonics in the breccia pipe. 2)The author discovered a new kind of parting structures in K-alterated rocks in the northwestern part of Hebei province. The parting structures have some distinct geometry and fabrics, it is originated from the acting and reacting fores caused by K-metasomatism. Namely, the crystallizations of metasomatic K-feldspars are a volume expansion process, it would compress the relict fluid bodies, and the pressures in the relict fluid bodies gathered and increased, when the increased pressure of the fluid relict bodies is bigger than the strength of K-feldspars, the K-feldspars were broken with the strong compression, and the parting structures formed. 3)Space position replacing is a important transport pattern of dissolved mass in Fe&S-rich fluid. In addition, basing on views of tectonic dynamics of metallogenic fluids, and time-space texture of fluid-tectonic-lithogenetic-mineralization of the known gold-corpper mineral deposit and the subvolcanic complex at Qibaoshan area in Shandong province, this report does a detail prodict of position-shape-size of two concealed ore-bearing breccia pipe.

南海沉积物中的放射虫及其古环境意义

In this paper a systematic study of radiolarian from surface sediments of all the South China Sea (SCS) has initially been done for its deposit ecology, biogeography and paleoenvironment significance. The paleoenvironment information obtained by radiolarian analysis and other sedimentary method for core samples is also made use as the synthesis proxy for revealing the paleoenvironment changes in the SCS and the relations of it with the past globe change during last 200ka. Some results come out of this study as: 1) Radiolarian skeleton chemistry composition and skeleton morphological features were analyzed, chiefly dividing them as 15 types of basic morphological features: 2) Analysis of biogeographical feature demonstrates that the fauna in SCS obviously belonging to a transitional type of west Pacific - Indian Ocean and has a particularity of itself: 3) Tendency of radiolarian population distribution is lower in shallow continental shelf area, increasing gradually toward the abyssal region; 4) Nine character boundaries of radiolarian depth distribution in the sediments from whole the South China Sea may be recognized; 5)Two radiolarian transfer functions for paleotemperature and paleo-primary productivity in the South China Sea have also been established respectively. The equation of transfer function for winter paleotemperature has only an average estimated error of 0.18678 ℃ and the equation for paleo-primary productivity has the calculation accuracy of 85.31%; 6) Changes of radiolarian individuals, numbers of species and H(S) values in core NS93-5 show the completely different oceanic geographical circumstance and ecology structure in the Last Maximum Glacial with present; 7) The abundance variation of some raiolarian warm species and cold species indicate the changes of water masse features along with the paleoenvironment evolution, showing that this sea area clearly is controlled in 6 issues of oxygen isotopes by the cold water masses; 8) By comparative analysis of δ ~(18)O curves with GISP2;s ice core can core 17940 of the northern SCS, the occurring characters of D/O's events 1-21 and Heinrich's events H1-H6 have been revealed in this sea area by core NS93-5, which prove the existence of paleoclimatic tele-connections between the southern SCS and Arctic region since about 200ka BP.

胶东地区金矿床成矿时代及其成矿地球动力学背景-兼论壳幔相互作用与成岩成矿

Jiaodong Peninsula is the largest repository of gold in China. Varieties of studies have been involved in the mechanism of metallogenesis. This thesis is a part of the project "Study of basic geology related to the prespecting of the supra-large deposits" which supported by National Climbing Program of China to Prof. Zhou. One of the key scientific problems is to study the age and metallogenic dynamics of ore deposit and to understand how interaction between mantle and crust constrains on metallogenesis and lithogenesis. As Jiaodong Peninsula to be study area, the Rb-Sr, Sm-Nd and Pb isotopic systematics of pyrite and altered rocks are measured to define the age and origin of gold. The elemental and Sr-Nd-Pb isotopic compositions of dikes and granites was studied to implicate the source and lithogenesis of the dike and granite and removal of lithosphere and the interaction between mantle and crust in the Jiaodong Peninsula. Considering the tectonic of Jiaodong Peninsula, basic on the time and space, this thesis gives a metallogenic dynamics of gold mineralization and discusses the constraints of the interaction between mantle and crust on the metallogenesis and lithogenesis. This thesis reports the first direct Rb-Sr dating of pyrites and ores using sub-sampling from lode gold deposit in Linglong, Jiaodong Peninsula and the results demonstrate this as a useful geochronological technique for gold mineralization with poor age constraint. The Rb-Sr data of pyrites yields an isochron age of (121.6-122.7) Ma, whereas, those of ore and ore-pyrite spread in two ranges from 120.0 to 121.8 Ma and 110.0-111.7 Ma. Studies of characteristic of gold deposit, microscopy of pyrite and quartz indicate that the apparent ages of ore and ore-pyrite are not isochron ages, it was only mixed by two end members, i.e., the primitive hydrothermal fluids and wall rocks. However, the isochron age of pyrite samples constrains the age of gold mineralization, i.e., early Cretaceous, which is in good consistence with the published U-Pb ages of zircon by using the SHRIMP technique. The whole rock Rb-Sr isochron age of altered rocks indicates that the age of gold mineralizing in the Xincheng gold deposit is 116.6 ± 5.3 Ma. The Sr, Nd and Pb isotopic compositions of pyrite and altered rocks indicate that the gold and relevant elements were derived from multi-sources, i.e. dikes derived from enriched lithospheric mantle and granites, granodiorites and metamorphic rocks outcropped on the crust. It also shows that the hydrothermal fluids derived from mantle magma degassing had play an important role in the gold mineralizing. The major and trace elements, Sr-Nd-Pb isotopic data of granites and granodiorites suggest that the Linglong Granite and Kunyushan Granite were derived from partial melting of basement rocks in the Jiaodong Peninsula at post-collision of North China Craton with South China Craton. Guojialing Granodiorite was considered to be derived from a mixture source, that is, mixed by magmas derived from an enriched lithospheric mantle and crust during the delamination of lithosphere induced by the subduction of Izanagi Plate and the movement of Tancheng-Lujiang Fault. There are kinds of dikes occurred in the Jiaodong Peninsula, which are accompanying with gold mineralization in time and space. The dikes include gabrro, diabase, pyroxene diorite, gabrrophyre, granite-porphyry, and aplite. The whole rock K-Ar ages give two age intervals: 120-124 Ma for the dikes that erupted at the gold mineralizing stage, and <120 Ma of the dikes that intruded after gold mineralizing. According to the age and the relationship between the dikes and gold mineralizing, the dikes could be divided into two groups: Group I (t = 120-124 Ma) and Group II (t < 120Ma). Group I dikes show the high Mg and K, low Ti contents, negative Nb anomalies and positive Eu anomalies, high ~(87)Sr/~(86)Sr and negative εNd(t) values and an enrichment in light rare earth elements, large ion lithosphile elements and a depletion in high field strength elements. Thus the elemental and isotopic characteristics of the Group I dikes indicate that they were derived from an enriched lithospheric mantle perhaps formed by metasomatism of the melt derived from the recycled crustal materials during the deep subduction of continent. In contrast, the Group II dikes have high Ti, Mg and K contents, no negative Nb anomalies, high ~(87)Sr/~(86)Sr and positive or little negative εNd(t) values, which indicate the derivation from a source like OIB-source. The geochemical features also give the tectonic constraints of dikes, which show that Group I dikes were formed at continental arc setting, whereas Group II dikes were formed within plate background. Considering the tectonic setting of Jiaodong Peninsula during the period of gold mineralizing, the metallogenic dynamics was related to the subduction of Izanagi Plate, movement of Tancheng-Lujiang Fault and removal of lithopheric mantle during Late Mesozoic Era.

胶东蓬家夼式金矿床矿床成因模型与找矿模型研究

The dynamic environments of mineralization in Mesozoic Jiaodong gold mine concentrated area can be devided into two types, compressive environment which related to intracontinental collision and extensional environment which related to intracontinental volcanic rift. The altered rock type (Jiaojia type) and quartz vein type (Linglong type) which related to the former one, were discovered for several years, and became the main types of gold deposits in recent years. A new type gold deposit, syn-detachment altered tectonic breccia type gold deposit, such as Pengjiakuang gold deposit and Songjiagou gold deposit has been discovered on the northeastern margin of Jiaolai Basin. In this paper, the new type of gold deposit has been studied in detail. The study area is located at the northeastern boundaries of Jiaolai Basin, and between the Taocun-Jimo Fault and Wji-Haiyang Fault, in the eastern part of the Jiaodong Block. Pengjiakuang gold deposit and Songjiagou gold deposit occur in a arc-shape detachment fault zone between conglomerate of Lower Cretaceous Laiyang Formation and metamorphic complex of Lower Proterozoic Jingshan Group. Regional geological studies show that Kunyuanshan and Queshan granite intrusions and Qingshanian volcanism were formed in different period of lithospheric thinning of East China in Mesozoic. Granite intrusions were formed in compressive environment, while Qingshanian volcanism were formed in extensional environment. They are all related to the detachment of Sulu Orogenic Belt and the sinistral motion of Tanlu Fault. The Pengjiakuang detachment systems which were formed in the the sinistral motion of Tanlu Fault are the important ore-controlling and ore-containing structure. The Pengjiakuang type gold deposit, controlled by detachment structure, was formed before Yanshanian volcanic period concerning with mixture of meteoric water and magmatic water found in fluid inclusions of gold ores. The minerogenetic epoch has been proposed in 90～120Ma. the host rocks have been extensively subjected to pyritization, silicification, sericitization and carbonatization. Individual ore-body has maximum length of 800m, oblique extension of 500～700m and gold grade of 1～43 * 10~(-6). Native gold is disseminated in silicified, phyllic or carbonatized tectonic breccia. Sulfur, carbon and lead isotope studies on gold ores and wall rocks show that the sulfur come from the metamorphic complex of Lower Proterozoic Jingshan Group, carbon comes from the marble in Jingshan Group, while a part of lead comes from the mantle. The mineralizing fluid is rich in Na~+ and Cl~-, but relatively impoverished in K~+ and F~-. According to the date from hydrogen and oxygen isotopic compositions (δ~(18)OH_2O = 0.59%～4.03%, δDH_2O = -89.5%～97.9%), the conclusion can be reached that the mineralizing fluid of Pengjiakuang gold deposit was a kind of mixed hydrothermal solution which was mainly composed of meteoric water and magmatic water. A genetical model has been formulated. Some apparent anomaly features which show low in the central part and high in the both sides corresponding to the gold-bearing structure, were sum up after analying a vast amount of date by prospecting the orebodies using gamma-ray spectrometer, electrogeochemical parameter technique, controlled source audio magnetic telluric (CSAMT) and shallow surface thermometry in Pengjiakuang gold deposit. The location forecasting problem of buried orebodies has been solved according to these features, and the successful rate is very high in well-drilling. The structural geological-geophysical-geochemical prospecting model has been formulated on the base of the study of geological, geophysical and geochemical characteristics of Pengjiakuang type gold deposit, and the optimum combinational process of geophysical and geochemical prospecting techniques has been summed up. A comparative study shows that the Pengjiakuang type gold deposit, the syn-detachment altered tectonic breccia type gold deposit, is different from Jiaojia type gold deposits and Linglong type gold deposits, in Jiaodong Block. In general, if formed under an extensional tectonic condition and located at detachment fault zone along the margin of Mesozoic Jiaolai basin, and the gold mineralization has also close genetic relationship with alkaline magamtism. Being a new type of gold deposit in Jiaodong gold mine concentrated area, it could be potential to explore in the same regions which processed the same ore-forming geological conditions and mineralization informations.

宣龙式赤铁矿含矿岩系的成矿过程研究

Xuanlong-type Hematite Deposits, distributed in Xuanhua and Longguang area in Hebei province and hosted in the Changchengian Chuanlinggou Formation of Mesoproterozoic, is an oldest depositional iron deposit characterized by oolitic and stromatolitic hematite and siderite. This thesis made an systematic study of its sedimentary, sedimentology, geochemistry, mineralogy and sequence stratigraphy. Based on above, the mechanism and background of biomineralization are discussed. There are four types of hematite ores including stromatolite, algal oolite, algal pisolite and oncolite. Based on detailed study on ore texture, the authors think both algal oolite and algal pisolite ores are organic texture ores, and related to the role of microorganisms. The process of blue-green algae and bacteria in the Xuanlong basin absorbing, adsorbing and sticking iron to build up stromatolite is the formation process of Xuanlong-type hematite deposit. Researches on ore-bearing series and ore geochemistry show that the enrichment of elements is closely related to the microorganism activities. Fe_2O_3 is enriched in dark laminations of stromatolite with much organic matter and SiO_2 in light laminations with detrital matters. The trace elements, especially biogenic elements, including V, P, Mo are enriched in ores but relatively low in country rocks. The paper also demonstrates on the sequence stratigraphy of hematite deposits and five sequences and twelve systems are divided. The characteristics of sequence stratigraphy show that the deposit-forming location has obviously selectivity and always exists under a transgressive setting. The oxygen isotope in hematite is about -2.2～5.7‰, which is similar to that of Hamlys iron formation of Australia but more negative than that of volcanic or hydrothermal iron deposits characterized by high positive values. The calculation by the result of oxygen isotope analysis shows that the temperature of ancient sea water was 48.53℃. The negative value of carbon isotope from siderite indicates its biogenic carbon source. Meanwhile, the occurrence of seismite in the ore-beds, which indicates the formation of hematite deposits is associated with frequent shock caused by structural movement such as distal volcano or ocean-bottom earthquake etc, show the occurrence of hematite deposits is eventual, not gradual. In shorts, Xuanlong-type hematite deposits were the result of interaction among geological setting of semi-isolated Xuanglong basin, favorable hot and humid climate condition, abundant iron source, microorganism such as algae and bateria as well as the fluctuation of the sea level.

青海德尔尼铜钴锌矿床地质构造背景与成因

The Derni large Cu-Co-Zn sulfide deposit is occurred in the Derni melange belt, which is located in the eastern section of the A'nyemaqen ophiolite melange belt. The Derni deposit is hosted in the mantle peridotites and is very special in the world. Because the studying area is of very bad natural environment and very low geological research, the geotectonic setting and genesis of the deposit have long been debated. This paper studied these two questions and answered them. The research is of great significance to reveal impotant information of deep geology, crust-mantle interaction and geotectonic evolution, to enrich theories in the study of mineral deposit and provide scientific basic data for exploration and exploit of this kind of deposit. Based on the series of new achievements and new cognitions, to start with the geologic setting of the Derni deposit, through detailed field, tectonics, petrology, geochemistry, isotopic geochronology, microfossil, and study of mineral deposit, belongs to a melange belt, including mantle peridotites slice with ore, Late Precambrian sandstone and slate slice, metamorphic rock slice. 2. Petrological and geochemical characteristics indicate that the Derni mantle peridotite is not ophiolite mantle peridotite, but is occurred under the continental crust. 3. The U-Pb isotopic age of single-grain zircon form the accumulative rock suggests that the Derni mantle peridotite were formed in 747±10Ma, and underwent a great period of metamorphic process in 441.5±2.5Ma. 4. Microfossil assemblage from the carbonaceous slate belongs to Late Precambrian. Through petrography and petrochemistry, sandstone and slate were formed in the continental margin. 5. Sideronitic texture, which is first discovered in this study, reveals the characteristics of magmatic liquation. 6. Fluid inclusion explosion temperature of pyrite is in the range of -6.15～+6.64‰, and Pb isotope is consistent with mantle peridotite, which suggest ore-forming materials are from the mantle. To sum up, the upper mantle was melting partially, when it was metasomated by the mantle fluids with abundant Cu, Co, Zn, S, Au and LREE etc. The pockets of magma became enlarged by mantle tenacity shearing, and the pockets of magma occurred magmatic differentiation in the stable field, then the magma and ore pulp together with mantle refractory remnant dirpired and crystallized in the shallow part of the crust.

北祁连与块状硫化物矿床有关的早古生代火山岩的地球化学研究

Different conclusions from previous work are made from the geochemical study for the early Paleozoic volcanic rocks hosting massive sulfide deposits in the north Qilian Orogen. The main points are: (1)The geochemical characteristics of the basalts and rhyolites from the Baiyin deposit are not consistent with that of the volcanic rocks in the continental rift setting, but show the relationship with subduction. The basalts and rhyolites from the Baiyin deposit are probably individual tectonic slice piled by subduction, and there is no bimodal volcanic rock suite occurred in the Baiyin deposit. Zircon U-Pb dating constrains the magmatic emplacement of basalts and rhyolites at 475±10Ma and 453±12Ma, respectively. The basalts are characterized by enriched Th and Sr, and depleted Nb, Ta and Ti. They have relatively high Th/Nb ratios between 0.9 and 1.3. Their εNd(T) values vary from -1.2 to +3.4. The chemical and isotopic compositions display a typical subduction-related signature, and they suggest that an enriched component with the isotopic composition of EMII might have contributed to the generation of the Baiyin basalts. The basalts were likely formed in a mature island-arc or a volcanic arc built on comparatively young or thin continental crust in an active continental margin. The rhyoIites have low concentrations of LILE compared to the basalts. They do not seen to have a relationship with the basalts, because of their significantly higher εNd(T) values (+4.3～+7.7). The high and positive εNd(T) values also rule out their derivation from anatexis of the continental crust. A modeling study suggests that the source.of the Zhe-Huo and Xiaotieshan rhyolites is similar to boninite and IAT (island-arc tholeiite), and hence indicating an intra-oceanic arc environment. (2) The formation of the Shangliugou volcanic rocks from .Qilian area is also related to subduction. The basaltic andesite have low TiO_2(0.45～0.63%) and P_2O_5(0.04～0.09) content, and high Th/Nb ratios (0.3～0.6). They show flat REE patterns. Their εNd(T) values vary in a narrow range from +4.8 to +6.4. The chemical and isotopic compositions indicate that they are derived from a slightly depleted mantle source and are fromed in intra-island arc setting. The rhyolites show calc-alkaline trend. They show enriched LREE and fiat HREE patterns with obvious negative Eu anomaly. They have high Th/Ta ratios (5.0 ～ 11.7) and large negative εNd(T) values (-2.6 ～ -8.4). The rhyolites are formed in active continental margin and result from a mixed process of two endmembers, or crust assimilation. (3) The metal elements of the volcanic-hosted massive sulfide deposit have two sources, the copper and zinc are derived from rhyolitic magmas whereas the lead are probably related to old sediments overlying the rhyolites. (4) It is suggested here that the volcanic rocks hosting massive sulfide deposit in the north Qilian orogen, which are previously considered as a bimodal suite of Neo-proterozoic to middle Cambrian age in a continental rift, are virtually related to subduction magmatism in Ordovician age, and there might have no continental rift magmatism of Neo-proterozoic to middle Cambrian in the north Qilian.

山东平度大庄子金矿床地质地球化学特征及成因——兼论层间滑动角砾岩型金矿成矿模式

The author selected the geological and geochemical characteristics and the genesis of the Dazhuangzi gold deposit in the Pingdu City as the central content of the study. The author summarized geological features of the other gold deposits formed within the same geological setting along the margin of the Jiaolai pull-apart basin and compared these gold deposits with the Dazhuangzi gold deposit. On the basis of the first-hand data obtained from field investigation and from mining production reports, ore-controlling structures, geological characteristics and mineralization regularities of the Dazhuangzi gold deposit are studied in detail. According to the analyzing results of petrochemistry, trace element, rare earth element and fluid inclusion etc., the geochemical characteristics, the genesis and the ore-forming material source of the Dazhuangzi gold deposit and that of the other similar gold deposits along the margin of the Jiaolai Basin are proposed. The study results suggest that the Dazhuangzi gold deposit belongs to the typical interstratified glide breccia type gold deposit, which is controlled by the interstratified glide fault structure located along the margin of the Mesozoic pull-apart Jiaolai basin. The interstratified glide fault structure is in the outer part of unconformity belt between the overlying strata and the basement of the pull-apart basin, being along the marble strata of the Jingshan group. The formation of the ore-controlling structure is related closely with the evolution of the Jiaolai Basin in the Mesozoic. The ore-controlling structure underwent the structural stress changes from compressive to tensional and then to compressive stress with strike slipping features sequentially, which were coincided with the regional tectonic stress evolution. The interstratified glide breccia type gold mineralization mainly occurs in the siliceous-marble breccias and cataclastic rocks within the interstratified glide fault structure. The gold minerogenetic epoch is later than 120Ma when the ore-controlling structure was tensioning and strike-slipping. The occurrences of the ore controlling structure and the gold ore bodies are the same as that of the unconformity belt. The geological and geochemical studies show that the source of the ore-forming material is alike with that of the volcanic rocks of the Qingshan formation, which is widespread in the Jiaolai Basin. Both of them came from the deep crust or even the upper mantle. Based on the geological characteristics and the minerogenetic regularities of the Dazhuangzi gold deposit, a genetic model of the deposit is constructed. In addition, the author used the remote sensing image and exploration results of geochemical and geophysical methods to point out several prospecting areas for further exploration. Through comprehensive study on the interstratified glide fault structure and on the interstratified glide breccia type gold deposits along the Jiaolai pull-apart basin, three types of interstratified glide structures and related gold mineralization are set up according to evolution and distribution of main fault as well as related secondary faults in time and space. They are named as Penjiakuang type, Dazhuangzi type and Fayunkuang type. The author summarized up the minerogenetic characteristics and regularities controlled by these three different types of interstratified glide structures respectively, and set up a general minerogenetic model of the interstratified glide breccia type gold deposit.

陇西盆地晚第三纪风尘沉积的地层学研究

In Asia, the significant environment changes in Cenozoic include: uplift of Himalayas and Tibetan Plateau, formation Asian monsoon system, Aridification in Central Asia. One of major advances in recent studies of eolian deposit on the Loess Plateau is the verification of the eolian origin for the Late Tertiary Hipparion Red-Earth (also called red-Clay) underlying the Quaternary loess. Thus, the Late Tertiary eolian deposit, which has been proven a nearly continuous terrestrial record and sensitive to climate change, provides us an important archive to understand these above Cenozoic environment events. The deposit in eastern Loess Plateau has been extensively studied, while the property and age of deposit underlying the Quaternary loess in western plateau remains unclear. In this paper, detail investigations were made on the Sedimentology, geochemistry of Longxi section, a typical section in western Loess Plateau, to address its origin, and on micromammalian fossils and magnetostratigraphy to address its age. The main conclusions are presented as following: 1. The sedimentological and geochemical properties in Longxi section are highly similar to typical Quaternary eolian deposit in Loess Plateau. Nearly 100 paleosols are recognized in the field, and the grain size are very fine with the median grain size centered at 4～7μm. There is a good agreement of both major and trace element compositions between Longxi deposit and the Quaternary Loess. The REE distribution patterns of Longxi deposit and the Quaternary loess are remarkably similar in shape, with enrichment LREE and fairly flat HREE profiles and clear negative Eu anomaly. The mangnetic minerals in Longxi deposit are mainly magnetite, hematite and maghematite, which are similar to those of the Hipparion Red-Earth and Quaternary Loess. The major difference among them is that the samples from Longxi section contain more hematite. The characteristics of anisotropy of magnetic susceptibility (AMS) in Longxi deposit is highly consistent with that of Quaternary loess, while values of the major AMS parameters, e.g. anisotropy degree, magnetic foliation and lineation, are significantly lower than those of fluvial and lake deposits. These evidences indicate an eolian origin for the sediment. 2. An investigation of micromammalian fossils was firstly carried out for determining the approximate age of the sequence because of lack of materials for accurate isotope dating. Three fossil assemblages were obtained which indicate a chronological range from the Middle Miocene to Late Miocene. The magnetostratigraphical study suggests that it is a near continuous terrestrial record for the period from 13.23 to 6.23 MaB.P. The obtained chronology is highly consistent with fossils assemblages. This section is the oldest eolian deposit presently known in Loess Plateau. 3. The magnetic susceptibly value is high in paleosols than in surrounded weak-weathered layers, which suggests that it may be a climate index on orbital time scale. While it cannot be used as a proxy to address the long-term, change of climate on tectonic time scale, as content of the magnetic minerals is highly variable in different parts of the section. 4. The appearance of Middle Miocene eolian deposit in the Loess Plateau marks the strengthening of aridification of Central Asia. The high degree of similarity between the geochemical properties of Longxi eolian deposit, Hipparion Red-Earth and Quaternary loess a suggests that a rather similar source provenance. The dust accumulation rate (DAR) of Longxi section, which is widely used as a proxy to document the aridity in source areas in marine and terrestrial record studies, recorded the aridity condition in northwestern China over a period from Middle Miocene to Late Miocene. The DAR of the section shows that the continent aridity remains moderate and relative stable over that period.

山东东营凹陷浊积岩油藏形成机制及预测技术

More and more exploration practises and research results prove that deep-water turbidites and slump turbidites in abrupt slope belt as well as slump turbidites in deposit center are favorable places to find subtle reservoirs. Based on sedimentology, sequence stratigraphy, tectonics and petroleum geology and with the tool of computer, this paper focused a set of questions such as the forming mechanism and m&a of turbidite reservoir in Dongying Sag, and obtained a systematic research result from available information of geology, seismic survey, well logging and testing, etc. Since the structural pattern and tectonic stress are controlling factors on distribution of turbidite reservoirs, deep-water sequence and shallow-water sequence have close relation with various turbidites. The author primarily disclose the regular pattern of the turbidites in the abrupt slope trouth, and predict that the abrupt slope is mainly connected to near-bank slump turbidite fans and deep-water turbidite fans; whereas the depocenter area usually developed with front delta slump fans. According to this, seismic-geology models corresponding to various deposit systems can be set up as a principle for predicting the turbiditea in faulted lacustrine basins. Based on comprehensive study of the turbidite reservoir forming condition and main controlling factors, a differential accumulation model and a multiple migration&accumulation model were also set up for abrupt slope turbidities. Referenced the m