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.

东天山地区金矿床成矿流体地球化学及其成矿机制

The mechanism of gold ore formation in the eastern Tianshan Mountains, Xinjiang Uygur Autonomous Region, that has been dealt with from various aspects, remains unclear. On the basis of investigations of regional geology, ore deposit geology, and microscopic observations of ores and related rocks of the Jinwozi, the 210, and the Mazhuangshan gold ore deposits, this thesis made a systematic research on the microthermometry of gangue quartz-hosted fluid inclusions, gas, liquid ion and rare earth element compositions and hydrogen, oxygen isotope compositions of sulfide- and quartz-hosted fluid inclusions, and sulfur and lead isotope compositions of sulfide ore minerals from the major ores in the three deposits. On the basis of the above synthetic studies, sources of ore-forming fluids and metals, and mechanism of gold ore formation in the region were discussed. Gas compositions of pyrite- and sphalerite-hosted fluid inclusions were first analyzed in this thesis. Compared with gangue quartz-hosted fluid inclusions, the sulfide-hosted ones are richer in gaseous species CO2, CO, and CH4 etc. Both gas and liquid CO2 are commonly observed in fluid inclusions, whereas halite daughter minerals rarely occur. Ore-forming fluids for the three gold ore deposits are characteristically of medium to low temperatures, medium to low salinities, are rich in CO2 and Na+, K+, Cl" ions. Gas covariation diagrams exhibit linear trends that are interpreted as reflecting mixing between the magamtic fluid and meteoric-derived groundwater. Regarding rare earth element compositions, the Jinwozi and the 210 deposits show moderate to strong LREE/HREE fractionations with negative Eu anomalies. However, the Mazhuangshan deposit shows little LREE/HREE fractionation with positive Eu anomalies. Hydrogen and oxygen isotope compositions of pyrite-hosted fluid inclusions that were first analyzed in this thesis indicate the presence of magmatic water. Hydrogen and oxygen isotope compositions of pyrite- and quartz-hosted fluid inclusions suggest mixing between magmatic water and meteoric-derived groundwater. Sulfur and lead isotope compositions of sulfide ore minerals indicate multi-sources for the metallogenetic materials that range from the crust to the mantle. On the basis of the above synthetic studies, genesis of the gold ore deposits in the eastern Tianshan Mountains was approached. From the Middle-Late Hercynian to Early Indosinian, geodynamic regime of the region was changing from the collisional compression to the post-collisional extension. During the period, magmas were derived from the crust and the mantle and carried metallogenetic materials. Magma intrusion in the upper crust released the magmatic fluids, and drove circulation of groundwater. Mixing of magmatic fluid with groundwater, and extraction of metallogenetic materials from the country rocks are the mechanism for the gold ore formation in the eastern Tianshan Mountains.

华南震旦纪-寒武纪两期成磷事件及其地球动力学意义

Phosphorus is an important biological and ecological element that to a certain degree constrains ecological environment and nutrient (including carbon) cycling. Marine sedimentary phosphorites are the principal phosphorus supply of the mankind. In the eastern to southern margins of the Yangtze Craton, South China, there are two phosphogenetic events at the Doushantuo stage of the Late Sinian and the Meishucun stage of the Early Cambrian respectively, corresponding two explosion events of life across the Precambrian\Cambrian boundary. Phosphorus ores from the Sinian and Cambrian phosphate in South China can be classified roughly into two categories, namely, grained and non-grained phosphorites. Grained phosphorites, hosted in dolostone type of phosphogenetic sequences and with larger industrial values, occur mainly in margins of the Upper Yangtze Platform, formed in shallow-water environments with high hydraulic energy and influenced by frequent sea-level change. Non-grained phosphorites, hosted principally in black-shale type of phosphogenetic sequences and with smaller industrial values, are distributed mainly in the Jiangnan region where deeper-water sub-basins with low hydraulic energy were prevailing at the time of phosphogenesis. Secular change ofδ~(13)C, δ~(18) O, ~(86)Sr/~(87)Sr values of carbonates from Sinian and Cambrian sequences were determined. A negative abnormal ofδ~(13)C, δ~(18)O values and positive abnormal of 86Sr/87Sr values from the fossiliferous section of the Lowest Cambrian Meishucun Formation implies life depopulation and following explosion of life across the PrecambriamCambrian boundary. Based on a lot of observations, this paper put forward a six-stage genetic model describing the whole formational process of industrial phosphorites: 1) Phosphorus was transported from continental weathering products and stored in the ocean; 2) dissolved phosphates in the seawater were enriched in specific deep seawater layer; 3) coastal upwelling currents took this phosphorus-rich seawater to a specific coastal area where phosphorus was captured by oceanic microbes; 4) clastic sediments in this upwelling area were enriched in phosphorus because of abundant phosphorus-rich organic matters and because of phosphorus absorption on grain surfaces; 5) during early diagenesis, the phosphorus enriched in the clastic sediments was released into interstitial water by decomposition and desorption, and then transported to the oxidation-reduction interface where authigenic phosphates were deposited and enriched; 6) such authigenic phosphate-rich layers were scoured, broken up, and winnowed in shallow-water environments resulting in phosphate enrichment. The Sinian-Cambrian phosphorites in South China are in many aspects comparable with coastal-upwelling phosphorites of younger geological ages, especially with phosphorites from modern coastal upwelling areas. That implies the similarities between the Sinian-Cambrian ocean and the modern ocean. Although Sinian-Cambrian oceanic life was much simpler than modern one, but similar oceanic planktons prevail, because oceanic planktons (particularly phytoplanktons) are crucial for phosphate enrichment related to coastal upwelling. It implies also a similar seawater-layering pattern between the Sinian-Cambrian ocean and the modern ocean. The two global phosphate-forming events and corresponding life-explosion events at the Sinian and Cambrian time probably resulted from dissolved-phosphate accumulation in seawater over a critical concentration during the Earth's evolution. Such an oceanic system with seawater phosphorus supersaturation is evidently unstable, and trends to return to normal state through phosphate deposition. Accordingly, this paper put forward a new conception of "normal state <=> phosphorus-supersaturation state" cycling of oceanic system. Such "normal state <=> phosphorus-supersaturation state" cycling was not only important for the three well-known global phosphate-forming events, also related to the critical moments of life evolution on the Earth. It might be of special significance. The favorable paleo-oceanic orientation in regard to coastal-upwelling phosphorite formation suggests a different orientation of the Yangtze Craton between the Sinian time and the present time (with a 135° clockwise difference), and a 25° anti-clockwise rotation of the Yangtze Craton from late Sinian to early Cambrian. During the Sinian-Cambrian time, the Yangtze Craton might be separated from the Cathaysia Block, but might be still associated with the North China Craton.

河北寿王坟铜矿成矿定年及同位素地球化学特征

Samples from carbonate wall-rocks, skarn, ore of skarn type, later calcite vein, and ore of porphyry type in Shouwangfen copper deposit district were collected. Systematic study was carried out on carbon, oxygen, rubidium, strontium and sulfur isotope compositions of carbonates and sulfides in these samples. The first Isochron dating by the Rb-Sr isotopes in chalcopyrite of ore sub-sample was done as well. The following conclusions were obtained. The age (113.6±4.3Ma), obtained by Rb-Sr isotope isochron dating of chalcopyrite and pyrite from sub-sample of skarn ores, probably represents the true mineralization age of skarn ores. That demonstrates the genetic relationship between granodiorite in Shouwangfen complex and skarn copper ores. On the other hand, the Rb-Sr isochron age (73±15Ma) of chalcopyrite from porphyry ores is a little incredible because of bad synthesizing evaluation. But combined with other age data of igneous rocks, it implies the possibility of hydrothermal mineralization in connection with magma activity during the fourth period of Yanshanian in Hebei Province, even in the whole northern edge of Huabei continental block. Together from structure analysis of sulfide sub-samples, from pretreating preccedure of Rb-Sr isotope isochron and its' valuating, we found out that Rb-Sr isotope isochron of sulfide sub-samples is influenced by the crystal structure of sulfides. That is, sulfide ores with very big crystals are not suitable for sub-sample isochron. Carbon, oxygen, sulfur and strontium compositions, of different minerals in these two kinds of ores, imply that the ore-forming hydrothermal fluids were probably derived from magma deep under the crust. The calcite ~(87)Sr/~(86)Sr ratios from the porphyry are consistent to the initial 87Sr/86Sr ratio of the Rb-Sr isochron of chalcopyrite and pyrite in the skarn ore, indicating that these two kinds of ores have the same source characteristic, although the porphyry deposit was formed probably 40 million years later than the skarn one according to our dating results. Skarn and skarn ores are usually considered as interaction product between carbonate wall-rocks and magmatic fluids, but the carbon of the sedimentary carbonate seems not involved in the skarn ores. Considering the connection of magmatic processes and hydrothermal ore formation in the Shouwangfen district, particularly, the spatial distribution of skarn-type and porphyry-type ores, it is possible that the Shouwangfen ore district corresponds to a hydrothermal ore-forming system, which was promoted by high-intruding magmatic rocks. Systematic stable isotopic research can help to reveal the upper part of this hydrothermal ore-forming system, which mainly related to heated and circulating meteoric water, and the lower part principally related to ascending magmatic fluids. Both skarn and porphyry ore-bodies are formed by up-intruding magmatic fluids (even more deep mantle-derived fluids).

大兴安岭南段中生代火山-侵入杂岩带的双层叠置构造体制兼论滇中武定、易门碳酸质火山岩年代、来源及矿库与找矿研究

These are two parts included in this report. In the first part, the zonation of the complexes in its series, lithofacies, the depth of magma source and chambers is discussed in detailed for the first time based on the new data of petrol-chemistry, isotopes, tectono-magma activity of Mesozoic volcano-plutonic complexes in the southern Great Hinggan Mts. Then, the genetic model of the zonality, double overlapped layer system, is proposed. The main conclusions are presented as follows: The Mesozoic volcanic-plutonic complexes in the southern Great Hinggan were formed by four stages of magma activity on the base of the subduction system formed in late Paleozoic. The Mesozoic magmatic activity began in Meso-Jurassic Epoch, flourished in late Jurassic Epoch, and declined in early Cretaceous Epoch. The complexes consist dominantly of acidic rocks with substantial intermediate rocks and a few mefic ones include the series of calc alkaline, high potassium calc alkaline, shoshonite, and a few alkaline. Most of those rocks are characterized by high potassium. The volcano-plutonic complexes is characterized by zonality, and can be divided mainly into there zones. The west zone, located in northwestern side of gneiss zone in Great Xinggan mountains, are dominated of high potassium basalts and basaltic andesite. The middle zone lies on the southeast side of the Proterozoic gneiss zone, and its southeast margin is along Huangganliang, Wushijiazi, and Baitazi. It composed of dominatly calc-alkaline, high potassium calc-alkaline rocks, deep granite and extrusive rhyolite. The east zone, occurring along Kesheketong Qi-Balinyou Qi-Balinzuo Qi, is dominated of shoshonite. In generally, southeastward from the Proterozoic gneiss zone, the Mesozoic plutons show the zones-mica granitites zone, hornblende-mica granitite zone, mica-hornblende granitite zone; the volcanic rocks also display the zones of calc alkaline-high potassium calc alkaline and shoshonites. In the same space, the late Paleozoic plutons also display the same zonality, which zones are combined of binary granite, granodiorite, quartz diorite and diorite southeast wards from the gneiss. Meso-Jurassic Epoch granite plutons almost distribute in the middle zone on the whole. Whereas late Jurassic Epoch volcanic rocks distribute in the west and east zone. This distribution of the volcano-plutonic complexes reveals that the middle zone was uplifted more intensively then the other zones in Meso-Jurassic and late Jurassic Epoches. Whole rock Rb-Sr isochron ages of the high potassium calc-alkaline volcanic rocks in the west zone, the calc-alkaline and high potassium calc-alkaline granite the middle zone, shoshonite in the east zone are 136Ma, 175Ma and 154Ma, respectively. The alkaline rocks close to the shoshonite zone is 143Ma and 126Ma. The isochron ages are comparable well with the K-Ar ages of the rocks obtained previously by other researchers. The compositions of Sr ans Nd isotopes suggest that the source of Mesozoic volcanic-plutonic complexes in Great Hinggan Mts. is mostly Paleo-Asia oceanic volcanic-sedimentary rocks, which probably was mixed by antiquated gneiss. The tectonic setting for Mesozoic magmatism was subductive continental margin. But this it was not directly formed by present west Pacific subduction. It actully was the re-working of the Paleozoic subduction system( which was formed during the Paleo-Asia ocean shortening) controlled by west Pacific subduction. For this reason, Although Great Hinggan Mts. is far away from west Pacific subduction zone, its volcanic arc still occurred echoing to the volcanic activities of east China, it, but the variation trend of potassium content in volcano-plutonic complexes of Great Hinggan is just reverse to ones of west Pacific. The primitive magmas occurred in the southern Great Hinggan Mts. Include high-potassium calc-alkaline basalt, high potassium calc-alkaline rhyolite, high potassium rhyolite, non-Eu negative anomaly trachy-rhyolite et al. Therefore, all of primitive magmas are either mafic or acid, and most of intermediate rocks occurring in the area are the products of Mesozoic acid magma contaminated by the Paleozoic volcanic- sedimentary rocks. The depth of those primitive magma sources and chambers gradually increase from northwest to southeast. This suggests that Paleozoic subduction still controlled the Mesozoic magmatism. In summary, the lithosphere tectonic system of the southern Great Hinggan Mts. controlling Mesozoic magmatism is a double overlapped layer system developing from Paleozoic subduction system. For this reason, the depth of crust of the southern Great Hinggan Mts. is thicker than that of its two sides, and consequently it causes regional negative gravity abnormity. The second part of this report shows the prolongation of the research work carried on in my doctor's period. Author presents new data about Rb-Sr and Sm-Nd isotopic compositions and ages, geochamical features, genesis mineralogy and ore deposit geology of the volcanic rocks in Kunyang rift. On the base of the substantial work, author presents a prospect of copper bearing magnetite ore deposit. The most important conclusions are as follows: 1. It is proved that all of these carbonatites controlled by a ringing structure system in Wuding-Lufeng basin in the central Yunnan were formed in the Mesoproterozoic period. Two stages could be identified as follows: in the first stage, carbonatitic volcanic rocks, such as lavas(Sm-Nd, 1685Ma), basaltic porphyrite dykes(Sm-Nd, 1645Ma), pyroclastic rocks and volcaniclastic sedimentary rocks, formed in the outer ring; in the second stage, carbonatitic breccias and dykes(Rb-Sr, 1048 Ma) did in the middle ring. The metamorphic age of the carbonatitic lavas (Rb-Sr, 893 Ma) in the outer ring was determined. The magma of carbonatitic volcanic rocks derived mainly form enriched mantle whose basement is depleted mantle that had been metasomated by mantle fluid and contaminated by Archaean lower crust. Carbonatitic spheres were discovered in ore bearing layers in Lishi copper mining in Yimen recently, which formed in calcite carbonatitic magma extrusion. This discovery indicates that the formation of copper ore deposit genesis relates to carbonatitic volcanic activity. The iron and copper ore deposits occurring in carbonatitic volcanic- sedimentary rocks in Kunyang rift results from carbonatitic magmatism. Author calls this kind of ore deposits as subaqueous carbonatitic iron-copper deposit. The magnetic anomaly area in the north of Lishi copper mining in Yimen was a depression more lower than its circumference. Iron and copper ores occurrig on the margin of the magnetic anomaly are volcanic hydrothermal deposit. The magnetic body causing the magnetic anomaly must be magnetite ore. Because the anomaly area is wide, it can be sure that there is a large insidious ore deposit embedding there.

地球化学新方法在隐状矿床找矿预测中的应用研究

With the progress of prospecting, the need for the discovery of blind ore deposits become more and more urgent. To study and find out the method and technology for the discovery of blind and buried ores is now a priority task. New geochemical methods are key technology to discover blind ores. Information of mobile components related to blind ores were extracted using this new methods. These methods were tested and applied based on element' s mobile components migrating and enriched in geophysical-geochemical process. Several kinds of partial extraction techniques have tested based on element' s occurrence in hypergenic zone. Middle-large scale geochemical methods for exploration in forest and swamp have been tested. A serious of methods were tested and applied effetely about evaluation of regional geochemical anomaly, 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system instead of the normal net. 1. Element related with ores can be mobiled to migrate upwards and be absorpted by surface soil. These abnomal components can be concentrated by natural or artificial methods. These trace metalic ions partially exist in dissovlvable ion forms of active state, and partially have been absorbed by Fe-Mn oxide, soil and organic matter in the soil so that a series of reaction such as complex reaction have take place. Employing various partial extraction techniques, metallic ions related with the phase of the blind ores can be extracted, such as the technique of organic complex extraction, Fe-Mn oxide extraction and the extraction technique of metallic ions of various absorption phases. 2.1:200000 regional geochemical evaluation anomaly methods: Advantageous ore-forming areas were selected firstly. Center, concentration, morphological feature, belt of anomaly were choosed then. Geological and geochemical anomalies were combined. And geological and geochemical background information were restrained. Xilekuduke area in Fuyun sheet , Zhaheba area in Qiakuerte sheet, the west-north part in Ertai sheet and Hongshanzui anomaly in Daqiao sheet were selected as target areas, in Alertai, in the north of Xinjiang. in Xilekuduke area, 1:25000 soil geochemical methods sampling based on the net in dendritic water system was carried out. Cu anomaly and copper mineralization were determined in the center area. Au , Cu anomalies and high polarization anomaly were determined in the south part. Prospecting by primary halo and organic complex extraction were used to prognosis blind ore in widely rang outcrop of bedrock. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system were used in transported overburden outside of mining area. Shallow seismic method and primary halo found a new blind orebody in mining area. A mineralization site was fou and outside of Puziwan gold mine, in the north of Shanxi province. Developing middle-large scale geochemical exploration method is a key technique based 1:200000 regional geochemical exploration. Some conditions were tested as Sampling density , distribution sites of sample, grain size of sample and occurrence of element for exploration. 1:50000 exploration method was advanced to sample clast sediment supplement clast sediment in valley. 1:25000 bedrock or soil geochemical methods sampling based on the net in dendritic water system was applied to sample residual material in A or C horizon. 1:2000 primary or soil halo methods used to check anomalies and determine mineralization. Daliang gold mineralization in the northern Moerdaoga was found appling these methods. Thermomagnetic method was tested in miniqi copper-polymetallic ore. Process methods such as grain size of sample, heated temperature, magnetic separating technique were tested. A suite of Thermomagnetic geochemical method was formed. This method was applied in Xiangshan Cu~Ni deposit which is cover by clast or Gobi in the eastern Xinjiang. Element's content and contrast of anomaly with Thermomagnetic geochemical method were higher than soil anomaly. Susceptibility after samples were heated could be as a assessment conference for anomaly. In some sectors thermo-magnetic Cu, Ni, Ti anomalious were found outside deposits area. There were strong anomal ies response up ore tested by several kind of partial extraction methods include Thermomagnetic, enzyme leach and other partial extractions in Kalatongke Cu-Ni deposit in hungriness area in the northern of Xinjiang. Element's anomalies of meobile were mainly in Fe-Mn oxide and salt. A Copper mineralization site in Xilekuduke anomaly area had been determined. A blind ore was foung by shallow seismic and geochemical method and a mineralization site was found outside this mining area in Puziwan gold deposit in shanxi province. A Gold mineralization site was found by 1:50000 geochemical exploration in Daliang, Inner Mongolia.

REE characteristics of the Fanshan alunite deposit in Zhejiang Province, China

REE geochemistry data from the Fanshan alunite deposit indicated that its ore-forming materials came chiefly from the country rocks, with δCe〉0 for alunite ores. According to the differences in δEu, the alunite ores were divided into three types： weak negative Eu anomaly, weak positive Eu anomaly and remarkable positive Eu anomaly. The phenomena of Ce-enrichment in the ores indicated that the Fanshan alunite deposit was formed in an oxidizing environment. Variations in fO2 are corresponding to those in δEu： Eu anomaly varies from negative to positive with increasing fO2. And two other important factors may impact the occurrence of Eu anomalies： the contents of alkaline feldspar and the protolith structure in the mineralization period.

A preliminary discussion on the bio-metallogenesis of Tl deposits in the low-temperature minerogenetic province of southwestern China

Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.

吐哈盆地砂岩型铀矿含矿主岩沉积体系及地球化学特征

吐哈盆地位于哈萨克斯坦板块的东端，与邻国盛产可地浸砂岩型铀矿的中新生代盆地处于统一类型的板块，同属中亚构造－成矿域。吐哈盆地也是我国可地浸砂岩型铀矿的第二个勘查基地。对吐哈盆地砂岩型铀矿的主要含矿建造－中下侏罗统水西沟群沉积体系类型的研究，将有助于区内对砂岩型铀矿成矿和容矿的主要沉积建造的地质认识。而对含矿主岩的地质地球化学研究，则能为区内砂岩型铀矿的成矿作用研究提供依据。在对吐哈盆地形成演化历史分析的基础上，通过对早中侏罗世盆地沉积建造的资料综合、野外调查和室内研究，针对可地浸砂岩型铀矿的地质特征、形成条件等，围绕建造-构造、构造-改造、改造-成矿作用的关系等问题，从区域地质构造背景、沉积体系类型分析和构造变形特征等宏观研究入手，到对钻孔岩芯的微观分析研究，特别是在对十红滩铀矿区的重点解剖的基础上，结合光谱信息提取与增强技术的应用，甄别含矿建造的地质特征及其时空分布格局，对吐哈盆地砂岩型铀矿主含矿岩系的沉积体系类型及其地球化学特征的研究得到以下认识： 1. 吐哈盆地中下侏罗统水西沟群的沉积体系类型包括：冲积扇沉积、辫状河沉积、辫状三角洲沉积系和湖泊沉积。而吐哈盆地十红滩铀矿区砂岩型铀矿的含矿主岩的沉积体系类型则为源自南部觉罗塔格山的辫状三角洲沉积体系。 吐哈盆地十红滩铀矿区砂岩型铀矿的含矿主岩是在盆地短轴方向上的局部性水动力条件和沉积环境下形成的一套以近源短距离搬运形成的粗碎屑沉积建造。这套建造及其沉积体系类型与整个湖盆地的泛湖沉积作用在时间和空间上发生叠置。正是因为不同沉积体系类型在时间和空间上发生叠置，从而导致中下侏罗统的地层总体走向与砂砾岩等粗碎屑沉积体的整体走向有显著的差异。沉积建造的这种空间展布格局对砂岩型铀矿的形成具有重要的控制作用。总体上，这一特点决定了与砂岩型铀矿成矿作用有关的含铀流体的运移方向、规模和铀成矿作用的区域分布和空间展布。 2. 鉴于吐哈盆地中下侏罗统不同沉积体系类型的区域分布和空间展布特征，以及内陆沉积盆地的沉积作用具有相似的沉积格局，建议在查明有利于砂岩型铀矿成矿的砂体所属沉积体系类型的基础上，按沉积体系类型划分沉积单元进行地层的划分与对比，将这一方法运用于内陆沉积盆地的地层划分对比，便于对砂岩型铀矿成矿的最基本控制因素“砂体”的宏观控制，从而为砂岩铀矿成矿作用分析、区域成矿预测和资源勘查提供直接依据。因此，正确区分泛湖水动力体系的区域性沉积系统及其沉积体系和局部性水动力体系的局域性沉积系统及其沉积体系，不仅具有地层学上的意义，更具有实际应用价值。 3. 吐哈盆地艾丁湖斜坡带中下侏罗统的构造变形特征存在明显的空间差异。主要表现为：在横向上，沿艾丁湖斜坡带由东往西不同地段构造形迹不同；在纵向上，不同层位的变形特点各异。总体表现为：以十红滩铀矿区为中心，往东以水西沟群上部第三岩性段（J2x3）的构造反转、逆冲而出现断裂构造为主。中部十红滩一带以水西沟群下部第一层位（J2x1）的宽缓褶皱为主。往西以西山窑组中部第二岩性段（J2x2）较为强烈的地层褶皱为特征。说明中下侏罗统形成之后，遭受过区域性的构造改造。 4. 对钻孔砂岩样品的岩石学研究和显微构造观察表明，十红滩铀矿区含矿砂体最为常见的碎屑有石英、长石（钾长石为主，少量斜长石）、云母以及花岗质岩屑、变质岩岩屑、少量火山岩岩屑，偶见沉积岩岩屑；砂岩中的填隙物主要有高岭石、水云母、绿泥石以及碳酸盐类矿物和少量铁质矿物。胶结物通常为碳酸盐、硅质及一些铁质物质。胶结类型主要有基底式胶结、孔隙式胶结和压嵌式三种类型。且砂岩中存在多期次构造－流体改造的迹象。在整体上，含矿砂体与无矿砂体构造－流体改造的类型相近，但其改造程度各不相同。含矿砂体主要表现为微构造裂隙发育，并有多期次硅质、碳酸盐充填和交代、溶蚀现象。含有石英、高岭石、绿泥石等新生矿物；不含矿砂体则以绿泥石化普遍，碳酸盐化作用强为主要特征。 样品中的蚀变矿物出现微晶黑云母、绿泥石－绿帘石－石英共生矿物组合，出现脆韧性显微构造变形等，预示这套含矿建造曾经遭受过一定程度的构造热变质作用。 5. 钻孔岩芯砂岩样品的稀土、微量元素地球化学特征表明，十红滩铀矿区的砂岩具有统一的物质来源。其稀土配分型式与蚀源区花岗质岩石的稀土配分型式相似。区域氧化作用造成砂体矿物蚀变的同时，也造成砂岩中稀土元素的分馏，且氧化蚀变越强，稀土元素的分馏作用也越明显。与晚元古代黑色页岩平均值相比，十红滩铀矿床钻孔中砂岩Zr和Hf的含量普遍偏高，特别是Hf，大部分样品中的Hf含量均高于晚元古代黑色页岩平均值。 zk32-11-2、zk96-4、zk96-7、zk80-6四个钻孔岩芯的砂岩样品稀土元素特征值δEu，在不同深度的各砂岩中变化较大。无论是单孔还是在钻孔之间，δEu值都表现为跳跃式的变化，且整体上分流河道砂岩中δEu值偏低。相对于δEu值，δCe和TE（1，3）值似乎表现出一定的变化规律。总体上表现为在与泥岩、泥质粉砂岩呈互层产出的三角洲前缘砂岩中，具有较为相近的δCe和TE（1，3）值。而分流河道砂体的δCe和TE（1，3）值相对变化较大，且整体上数值偏小。这些样品稀土元素特征值δEu、δCe和TE（1，3）所表现出的特点与砂体的沉积体系类型分析以及相应的岩石学特点基本吻合。说明不同沉积系统的各类沉积体系，不仅在时空展布上存在差异，砂体的结构及物质组成也存在一定的差异。 6. 根据中下侏罗统不同沉积体系类型在吐哈盆地全域范围的时空配置以及遥感地学的区域氧化还原条件分析，并与十红滩铀矿区相比较，吐哈盆地西部阿拉沟口、柯尔碱一带和了敦隆起西缘的鄯善－小草湖一带，具有和十红滩铀矿区类似的沉积历史、建造特征和区域氧化－还原条件，可以作为进一步开展砂岩型铀矿成矿预测和资源勘查的地段。 7．吐哈盆地的砂岩型铀矿与中亚各国重要的可地浸砂岩型铀矿在盆地类型、含矿主岩的沉积体系、含矿主岩的时代等方面有一定的差异，而其盆地类型及含矿主岩的沉积体系与美国怀俄明地区的可地浸砂岩型铀矿，特别是温得河盆地的砂岩型铀矿的特点较为相似。 8. 遥感信息提取和地学分析，可以提供区域性氧化－还原环境的区域分布信息，甚至可以为寻找潜在有利含矿砂体的空间展布提供依据；借助GIS平台，充分利用3S技术的集成与应用，可望为北方干旱地区可地浸砂岩型铀矿成矿条件分析、远景预测和找矿靶区的快速圈定乃至进行资源勘查的实际工作部署提供新的可操作技术平台。 在取得这些认识的同时，也深感还有不少问题需要进一步补充工作和深入探讨。特别是有关砂岩型铀矿的矿物学和地球化学方面尚有许多现象目前还不能给予很好的解释；对于存在的多次构造－流体的改造作用机理、多期次构造－流体活动之间的相互联系及其与铀矿化的关系；对流体的性质、来源和流体与砂体之间的相互作用关系等还有大量工作需要补充和深入。虽然已获得大量有关砂岩的稀土、微量元素的数据，但对这些数据的处理方法有限，对于其反映的与区内砂岩型铀矿成矿作用有关的信息有待进一步挖掘。另外，由于未能采集到砂岩铀矿的矿石样品，针对铀矿床方面的工作未能开展。

岩石圈伸展对粤北下庄矿田铀成矿的制约机制研究

地球动力学与成矿关系的研究是地球科学研究的前沿领域，而陆内岩石圈伸展与成矿的关系的研究则是该领域相对比较薄弱的环节。 华南地区于白垩—古近纪发生了岩石圈强烈的伸展减薄事件，且岩石圈伸展减薄与该区同时期形成的众多金属和非金属矿床有密切的成因联系，尤其是华南地区的花岗岩型热液铀矿床，显示了与该区岩石圈伸展作用可能有多方面的成因联系。粤北下庄铀矿田位于位于南岭铀-多金属成矿带的南部，是华南地区典型的花岗岩型热液铀矿区，本次研究在深入细致的野外地质工作的基础上，运用流体包裹体地球化学、元素地球化学、同位素地球化学等方法手段，开展了对下庄铀矿田成矿流体性质、成矿过程中元素的活动规律、成矿流体来源及演化等方面的系统研究，初步探讨了岩石圈伸展对该区铀成矿的制约机制，并建立了可能的矿床成因模式。通过研究，本次工作获得了以下几点主要认识： （1）通过对下庄铀矿田部分铀矿床流体包裹体显微测温、激光拉曼光谱及液相成分分析研究，查明了下庄矿田铀矿床矿前期热液属中高温（200℃~350℃）、低盐度（0.72%~5.95%NaCl）、密度中等（0.703~0.830g/cm3）、活动深度较深（2.29km~5.74km）、富∑CO2、相对还原性质的流体；成矿期热液属中低温（主要为154℃ ~250℃）、低盐度（0~1.83%NaCl）、密度中等（0.628~0.867g/cm3）、活动深度较浅（0.19km~1.62km）、富F-、相对氧化性质的流体。 （2）矿石矿矿物电子探针测试分析及岩、矿石的微量元素地球化学分析研研究表明，本区铀矿床主要的原生铀矿物为沥青铀矿、铀石、钛铀矿，铀矿物的形成与Si、Ca、W等元素有密切的关系，而其它金属元素未显示明显地富集。矿石、脉石矿物部分继承了原岩的稀土元素组成，且在原岩基础上又有高度的演化。 （3）进行了矿区内碳酸盐的C、O同位素和黄铁矿的He、Ar稀有气体同位素的分析研究。研究表明，矿化剂∑CO2主要为幔源，大量的He、Ar等稀有气体也来自于地幔。矿区发育的深大断裂构造可能控制了幔源挥发份的加入。 （4）脉石矿物碳酸盐和萤石的Sr、Nd同位素地球化学研究显示，成矿流体中的这些元素主要源于地壳，南区矿床（338、339）的Sr、Nd组成则为富含壳源Sr、Nd的流体与幔源基性脉岩不同程度的水—岩反应所致。另外，碳酸盐铅同位素研究显示，下庄矿区成矿物质铀可能来自帽峰式后期流体交代的花岗岩体。 （5）岩石圈伸展与下庄矿田铀成矿有关系密切：下庄矿田铀矿床明显受伸展构造控制，伸展构造既为导矿构造，又为储矿构造；岩石圈伸展导致的地温梯度升高，大地热流平均值加大，驱动热液流体的流动，为铀成矿提供了主要的热驱动力；岩石圈伸展产生的深大断裂导通了壳幔间的联系，使幔源脱气成因挥发份（主要为∑CO2）沿断裂上升，加入壳源热水循环系统，从而参与了铀成矿。 （6）初步建立了下庄矿田“岩石圈伸展体系下大陆热水系统铀矿床成因模式”。模式认为，华南地区白垩—古近纪岩石圈伸展作用引发区内热水流体的大规模循环，且伸展引起的幔源脱气作用产生的挥发份（主要为ΣCO2）加入了贫铀、贫矿化剂的循环的地下热水中，形成了富矿化剂热水。富矿化剂热水从富铀花岗岩中浸出铀（氧化作用），变为富矿化剂、富铀热液流体，这种热液流体在伸展引起的热驱动下沿构造上升，热液流体上升到浅部时，由于地球化学障、流体压力释放等因素的影响，U被还原沉淀，并在有利部位富集成矿。

地幔去气与铀成矿的关系——以江西相山火山岩型铀矿为例

江西相山铀矿床，位于中生代赣一杭火山岩带相山火山塌陷盆地内，是中国目前发现的最大的火山岩型铀矿床，其独特的成矿环境及成矿机理为国内外地质界所瞩目。本论文主要运用岩石学、构造学寸流体包裹体地球化学、同位素地球化学、热力学方法，从相山铀矿床的成矿构造演化、成矿流体、岩石蚀变特征、成矿物质同位素组成特征以及热力学计算等方面对地慢去气特征、过程以及其与铀矿化的关系进行了详细的研究。本研究取得了以下主要认识：1、构造活动对成矿过程起到重要作用。区域深大断裂构造、慢源岩浆活动和碱交代蚀变作用，是相山铀矿田地（量去气作用产生的地慢流体参与成矿作用的有利条件和证据。2、热力学计算表明成矿期前成矿热液pH值为9．50，呈碱性；成矿期前，UO2（CO3）22-、UO2（Coa）44-两种形式迁移的U占总U的99.96％，即矿床中成矿期前的铀主要是以这两种形式迁移的。3、氦一氢同位素研究表明，相山铀矿床的成矿流体由富CO2和3He的慢源流体与贫CO2的大气成因流体混合而成。相山铀矿床成矿热液中的CO2总体属于慢源碳，主要是由地慢或分布在铀矿床中的漫源基性脉岩提供的，而且大部分是在地壳拉张作用期间由地慢去气作用产生而上升形成了成矿热液。4、相山铀矿田成矿期前的流体包裹体中气泡较大，气体含量较高，表明包裹体捕获时压力较大；成矿期和成矿后的包裹体中气泡较小，并存在大量的纯气相包体，通过激光拉曼分析测得的物相峰值极低，表明包体中所包含组分的含量极低。而且大量成矿期纯气相包体的发现也说明其是在去气过程中捕获的从成矿热液中释放出的气体。从成矿期前到成矿期后，CO2含量减小的变化。也说明了成矿作用中发生了减压去气过程。5、在铀成矿过程中，共发生了两次去气作用。第一次地慢去气作用产生并把C仇带入到成矿热液中，第二次成矿流体去气作用正好相反把CO2从成矿热液中带出。地慢去气作用产生富CO2+H2O的地慢流体运移到地壳浅部与大气降水混和，富含矿化剂的成矿溶液由此可以有效地从赋矿围岩（中酸性火山岩和盆地基底地层）中萃取出成矿所需的U。第一次地慢去气作用产生的富CO2+H2O的地慢流体为成矿提供了最充足的矿化剂（CO2），是成矿作用得以发生的最基本最重要的条件。

Radon and King Solomons Miners: Faynan Orefeild, Jordanian desert

Grattan, J. Gilmore, G. Gilbertson, D. Pyatt, F.B. HUnt, C. McLaren, S. Phillips, P. Denman, A. Radon and King Solomons Miners: Paynan Orefield, Jordanian Desert. The Science of the Total Environment. 2004 319 pp 99-113

The local and global dimensions of metalliferous pollution derived from a reconstruction of an eight thousand year record of copper smelting and mining at a desert-mountain frontier in southern Jordan

Grattan, J.P., Gilbertson, D.D., Hunt, C.O. (2007). The local and global dimensions of metaliferrous air pollution derived from a reconstruction of an 8 thousand year record of copper smelting and mining at a desert-mountain frontier in southern Jordan. Journal of Archaeological Science 34, 83-110