The Isotopic Composition of Noble Gases in Gold Deposits and the Source of Ore-Forming Materials in the Region of North Hebei, China

The source of ore\|forming materials has long been a controversial focus both in metallogenic theory and in ore\|searching practice. This study deals with the helium and argon isotopic characteristics of pyrites from 11 gold deposits and some country rocks in the gold mineralization\|concentrated areas within the three mantle\|branch structures in the region of North Hebei Province. It is indicated that \{\}\+3He/\+4He ratios in the gold deposits are within the range of \{0.93×10\+\{-6\}\}-\{7.3×10\+\{-6\}\}, with an average of \{3.55\} ×10\+\{-6\}; R/Ra=\{0.66\}-\{4.93\}, averaging \{2.53\}; \{\{\}\+\{40\}Ar/\+\{39\}Ar\} ratios vary between 426 and 2073, with the average value of \{\}\+\{40\}Ar being \{8.32\}; and the average of \{\}\+4He/\{\}\+\{40\}Ar ratios is 2.17. \{\}\+3He/ \{\}\+4He ratios in gneiss and granite in the periphery of the mining district are within the range of \{0.001×10\+\{-6\}\}-\{0.55×10\+\{-6\}\}, reflecting significant differences in their sources. \{\}\+3He and \{\}\+4He fall near the mantle, as is shown in the He concentration diagram. Studies have shown that the ore\|forming materials in this region should come from the deep interior of the Earth. With the multi\|stage evolution of mantle plume, ore\|forming fluids in the deep interior were moving upwards to shallow levels (crust). Under such circumstances, there would be inevitably occur crust/mantle fluid mixing, so their noble gas isotopic characteristics are intermediate between the mantle and the crust.

A New Family of Sauropod Dinosaur from the Upper Cretaceous of Tianzhen, Shanxi Province, China

A new gigantic sauropod, Huabeisaurus allocotus gen. et sp. nov., about 20 m in length and 5 m in height, was discovered in the Upper Cretaceous Huiquanpu Formation, Tianzhen County, Shanxi Province. It is notably different from Diplodocidae, Titanosauridae and Nemegtosauridae in the following aspects: the teeth are strong, peglike with a length ratio of the tooth crown to tooth root at about 3 to 1; the cervical vertebrae are long with forked spines; the spines in dorsal vertebrae are relatively high, unbifurcated; the caudal vertebrae are amphicoelous, with anterior neural spines and unbifurcated spines and chevrons; the femur is straight and long, narrow and flat and the tibia and fibula are long and flat. These characters show that the described genus should represent a new family, Huabeisauridae fam. nov. The discovery enriches the sauropod dinosaur record in China, and is quite significant to the study of the taxonomy, evolution, migration, extinction and palaeobiogeographic provincialism of the Late Cretaceous sauropod dinosaurs.

Analysis of the ore-controlling structure of the Shihu gold deposit, Hebei Province and deep-seated ore-prospecting prediction

Under the guidance of the theory of mantle-branch structure-associated metallogenesis and on the basis of the geological characteristics, analysis of the ore-forming and ore-controlling structures, the geochemical characteristics of metallogenesis, the source of ore-forming materials, changes in the physical and chemical conditions of metallogenesis, changes in the vertical width of ore veins, and changes in gold grade of the Shihu gold deposit, the mechanism of its metallogenesis was discussed and the rules of vertical variation of ore veins were summarized in this study. It is pointed out that the orebodies under exploitation at present time should be in the middle and upper portions of gold veins in the Shihu gold mining district. Particularly on the basis of the characteristics of mantle-branch structure-associated metallogenesis, it is indicated that metallogenesis is controlled mainly by such ore-forming conditions as temperature and pressure. Deep-seated ore-forming fluids are characterized mainly by injection and precipitation. So the vein bodies in the adjacent metallogenic structures are of obvious comparability, and there would be great prospects for ore search both at depth and in the periphery of the Shihu gold deposit. Therefore, ore prospecting should be strengthened both at depth and in the peripheries.

Temporal-spatial distribution and ore-forming material source of gold,copper and silver polymetallic ore deposits in the Fuping mantle structure zone

This study was conducted following research on metallogenesis in the Zhangjiajie-Xuanhua and East Hebei mantle branch structure zones. The Fuping mantle branch structure zone is one where Au, Cu and Ag poly-metallic ore resources are concentrated in North Hebei. However, there has existed a long-standing controversy on the temporal-spatial distribution of ore resources and their ore-forming material sources. In terms of age dating and the comprehensive analysis of S, Pb, O, C and Si isotopes, it is considered that the temporal-spatial distribution of ore resources in this mantle branch structure zone is obviously controlled by the Fuping mantle branch structure. In space there is developed such a metallogenic pattern as to be Ag, Pb and Zn polymetallic ore deposits with gold appearing inside and copper appearing outside. Metallogenesis is dated mainly at Yanshanian, the ore-forming materials were derived predominantly from the deep interior of the Earth, and ore-forming fluids were derived largely from Yanshanian magmatism.

Temporal and spatial distribution of Au-Ag polymetallic ore deposits and source of ore-forming materials in the Zhangjiakou-Xuanhua mantle-branch metallogenetic zone

The Zhangjiakou-Xuanhua area is a mineral resource-concentrated area for gold-silver polymetallic ore deposits. The temporal and spatial distribution and origin of mineral resources have been argued for a long time. Based on the comprehensive studies of geochronology and sulfur, lead, oxygen, carbon and noble gas isotopes, it is considered that the temporal and spatial distribution of mineral resources in this area is obviously controlled by the Zhangjiakou-Xuanhua mantle branch structure, as is reflected by the occurrence of gold deposits in the inner parts and of Ag-Pb-Zn polymetallic ore deposits in the outer parts. The mineralization took place mainly during the Yanshanian period. Ore-forming materials came largely from the deep interior of the Earth, and hydrothermal fluids were derived predominantly from Yanshanian magmatism.

Principles and technology for stepwise utilization of resources for mitigating deep mine heat hazards

As is well known, deep mines are hot. As mining depth increases, the temperature of the surrounding rock also increases. This seriously affects mine safety and production and has restricted the exploitation of deep coal resources. Therefore, reducing the working face temperature to improve working conditions by controlling these heat hazards is an urgent problem. Considering problems in cooling deep mines both domestically and abroad along with the actual conditions of the Zhangshuanglou coal mine, we propose a HEMS technology that uses heat resources from deep mines in a stepwise manner. HEMS means a high temperature ex-change machinery system. Mine inrush-water is used as a source of cooling. Twice the energy is extracted from the mine inrush water. Heat is used for building heating in the winter and cold water is used for cooling buildings in the summer. This opens a new technology for stepwise utilization of heat energy in deep mines. Energy conservation and reduced pollution, an improved environment and sustainable economic development are realized by this technique. The economic and social effects are obvious and illustrate a good prospect for the application and extension of the method.

Study on the Metallogenetism of Sub-mantle Plume and Mantle Branches in the Gold Mineralization Concentration Area of Northwest Jiaodong Peninsula

The northwest of Jiaodong peninsula is characterized by its greatest gold concentration area, enormous gold reserves and limited time interval （115±5Ma） of gold mineralization in China. Studies show that the east area of north China began its mantle plume evolution since the Yanshanian movement, and the Laiyang sub-mantle plume and its surrounding mantle branches such as those in Guojiadian, Aishan and Panshidian were formed in the mineralization concentration area of northwestern Jiaodong peninsula. With the development of mantle plume →sub-mantle plume → mantle branch→ favorable expending structures, the deep-derived hydrothermal fluid moved up to the favorable places, such as brittle-ductile or ductile-brittle shearing zones, the internal and external contact zones of intrusions, dense fracturing zones and the contact zones between dikes and countryrocks, and concentrated into deposits. Then the gold mineralization concentration zones that are centralized on mantle branches were formed. This study takes Guojiadian mantle branch as an example to discuss their metallogenetism and conclude the metallogenetic mode.

Comparison between the Xishimen gold deposit and the Shihu gold deposit in western Hebei and analysis of the potential for ore exploration

The Xishimen gold deposit is located in the tectonic zone southeast to the Shihu gold deposit, both of which belong to the same orefield. Then, how is the prospecting potential for the Xishimen gold deposit? A com-parison was made between the Xishimen gold deposit and the Shihu gold deposit on the basis of their geological background of metallogenesis, geological characteristics of the ore deposits, the sources of ore-forming materials, etc. The results showed that both the deposits possess many similarities in the respects mentioned above. And their met-allogeneses can be compared. Therefore, there is great potential for ore prospection in the periphery or at the deep levels of the Xishimen gold deposit. Ore exploration should be well programmed on the basis of a better dissection of the tectonic setting of the orefield. A breakthrough in ore prospection of the Xishimen gold deposit will be of great instructive significance in regionally geological prospecting.

Source of ore-forming material for the Huangtuliang gold deposit,Hebei Province and ore prospecting in the deep periphery

The Huangtuliang gold deposit is characterized by its wide and large ore belt,stable extension and closely spaced orebodies.Unfortunately,no orebody was found by deep drilling.As a result,ore prospecting in this region was once put into dilemma.Detailed analysis of ore-forming and ore-controlling structures in the mining district by the authors has revealed that the ore-forming and ore-controlling structure in this mining district is a steeply dipping(85°-110°/∠70°-85° N-NNE),spade-shaped ductile shear zone,and the ore-controlling structures are a series of nearly erected second-ordered faults which are developed in the upper part of the ductile shear zone,intersecting with the ductile shear zone.Deep cutting of the ductile shear zone made it possible the ascending of ore fluids from the mantle plume at depth and these ore fluids would migrate upwards along the ductile shear zone under certain temperature and pressure conditions.Along their ascending path,the ore fluids would extract ore-forming elements from the country rocks and the extracted ore-forming elements would be deposited as ores in the hanging-wall second-ordered faults.The reason why no orebody was found in early prospecting at depth is that northward-dipping drilling in the southern part of the shear zone extended so deeply as to be beneath the shear zone.Only shallow-level orebodies could be found by southward-dipping drilling practice in the northern part of the shear zone.The location where deep-seated orebodies occurred shifted northwards and the orebodies occurred at greater depth.Therefore,it is natural that no orebody could be found when drill core passed through the shear zone.After the ore-forming and ore-controlling structures were well understood,the focus of ore prospecting was placed on the deep-level,northward-penetrating veins.In this way a number of new blind orebodies of great thickness have been found.On the basis of research development in the mining district,a prospecting plan has been made for ore prospecting in the periphery of eastern mining district.Prospecting practice has shown that there occur generally continuous engineering orebodies at large intervals.So,the Huangtuliang gold deposit has turned at one stroke from a medium sized to a large-sized,even a super-large gold deposit between prospecting lines 30-98.

Characteristics of mantle branch structure in western Shandong and its roles in minerogenesis and ore-controlling

This work deals with the characteristics of mantle branch structure in western Shandong Province, China, with respect to the distribution characteristics and ages of the regional strata, the development of ring-like and radial faults, the development of gently inclined detachment-slip structures in the axial part, mantle-source magmatic activities, regional petrology, petrochemistry and isotope geology. The study indicated that the N-W sharply plunged ductile shear zone in the region of western Shandong cuts through the mantle rocks detached from the deep-seated North China mantle sub-plume, hence leading to unloading in response to depressurization and thereafter the formation of anatexis magma. The intense and complete magmatic evolution series not only manifests a variation trend of alkalinity of magma from high to low and its intrusive depth from deep to shallow, but also reflects that the wall-rock alteration shows a general evolution trend from strong to weak. The evolution of mantle structure played an important role in controlling endo-mineralogenesis, accompanied with the rise of the country rocks. As a result, typical mantle branch structures were formed as observed in western Shandong. At the top of the mantle branch structure was developed an obvious detachment-tilt fault block, and some endogenic ores, at the same time, were uplifted onto the shallow levels.

Deep-Source Ore-Forming Materials and Prospecting of Gold Deposits in Eastern Hebei, China

Eastern Hebei Province is one of the important gold mineralization areas in North China, and detailed investigations have been made in this area. Different mineralization models and different ore-forming sources have been proposed for the gold deposits in this area. As more detailed work was made and more information has been accumulated, it is necessary to make a new investigation on gold metallogenesis and its source. This paper presents the data about 13 gold deposits (occurrences). It is concluded that the element gold came from the deep mantle. Different models of metallogenesis substantially describe such processes that ore-forming fluids were involved in metallogenesis in different favorable loci. Gold ore prospecting should be focused on fluid channel ways and favorable structures.

Preparation of Bentonite Supported Nano Titanium Dioxide Photocatalysts by Electrostatic Self-assembly Method

Electrostatic self-assembly method （ESAM） was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.

Analysis of the ore-controlling role of Guojiadian mantle branch structure,Northwest Shandong Peninsula,China

Metallogenesis in the gold ore-concentrated zone of Northwest Shandong Peninsula is closely related to deep processes.The region in the eastern part of North China entered into the stage of mantle plume evolution during the Yanshanian movement,following the long-time stage of stable platform evolution during Paleozoic time.At that time,the ore-concentrated zone of Northwest Shandong Peninsula just entered into the development-evolution stage of the Laiyang sub-mantle plume and the Guojiadian mantle branch structure in its periphery.The core-mantle-source gold was present in the gas-liquid form,and it migrated through mantle plume→sub-mantle plume→mantle branch structure→favorable tectonic expansion zone to the favorable loci of the mantle branch structure,where gold was deposited as ores,thereafter constituting a series of large-to medium-sized gold deposits distributed around the Guojiadian mantle branch structure.This study also dealt with the Jiaojia fault as the main detachment(fault altered rock) belt on the northwestern margin of the mantle branch structure and also presented a basic cognition about the fact that the Sanshandao fault as the listric fault on the hanging wall of the detachment belt.Furthermore,on this basis,this study also pointed out the orientation for further ore prospecting in this region.

Environmental properties of metallic minerals and their applications in environmental protection in China

In terms of environmental mineralogy, the environmental properties of metallic minerals, including chemical activation, adsorption, pore effect and nanometer effect, have been analyzed. On the basis of the analysis of environmental properties of metallic minerals, the applications of iron-bearing sulfides, iron and manganese oxides in the purification of wastewaters containing heavy metal ions (Cr{6+}, Hg{2+}, Pb{2+}, etc.) have been summarized. Moreover, research on the application of metallic minerals in environmental protection has been anticipated. It should be a piece of dominating work for environmental mineralogic researchers in the future to lucubrate systematically the physical and chemical characteristics of the metallic mineral surfaces, further reveal the reciprocity process between metallic minerals and water surface, perfect the theory and model of the metallic minerals to remove contaminants, intensify study on the facilities and techniques of metallic minerals to remove contaminants, and entail well the extension and propagation of achievements.

Helium-argon isotopic tracing for the Pb-Zn-Ag polymetallic ore deposits in the central-south segment of the Da Hinggan Ling Range

In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range,though some debates still exist on the metallogenesis and sources of ore-forming materials.Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids,and the first He and Ar isotope data have been obtained from the study region.3He/4He ratios in 14 samples collected from 7 mining districts are 2.17×10-6-12.52×10-6,averaging 6.86×10-6 and their R/Ra ratios are 1.56-9.01 Ra,averaging 4.37 Ra.By projecting the data points onto the 3He-4He concentrations diagram,all the points fall near the mantle helium area.The calculated mantle-source helium ratios are within the range of 19.58%-76.96%,with an average of 49.52%.Argon isotopic characteristics are close to those of mantle source,indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.

Study on the ore-forming and ore-controlling structure of the Mujicun Cu (Mo) ore deposit, Hebei Province, China

The Mujicun Cu (Mo) ore deposit at Laiyuan, Hebei Province, is a currently proven large-sized Cu (Mo) polymetallic ore deposit and it is located in the second-ordered fault depression basin of the ditachment belt on the hanging-wall on the western side at the juncture of the Laiyuan dumbell-shaped complex in the northern part of the Fuping mantle-branch structure. Metallogenesis is controlled by diorite porphyrite in intrusive relation with the fault depression basin and other relevant fault structure systems and intenstive wall-rock alteration zones. This study, in conjunction with the most recent exploration data, analyzed the geological background of metallogenesis of this deposit, summaried the geological characteristics of typical ore deposits, determined the alteration zonation of the deposit, investigated regional metallogenesis and the genesis of typical ore deposits, discussed the regional ore-forming and ore-controlling structures, and generalized the regional ore-controlling model and metallogenic model of the deposit. It is considered that the Mujicun porphry Cu (Mo) deposit, the Tieling, Futuyu, Xiaoligou and other skarn-type Fe-Cu deposits and the He'ergou hydrothermal-type Pb-Zn-Ag deposit jointly constitute a three-in-one polymetallic orefield, with the characteristics of typical metallogenic series.

Morphology,Chemistry and U-Pb Geochronology of Zircon Grains in Quartz Monzodiorite from the Sunzhuang Area,Fanshi County,Shanxi Province

The morphology, REE geochemistry and U-Pb geochronology of zircons from quartz monzodiorite in the Sunzhuang area, Fanshi County, Shanxi Province are presented in this study. The zircon crystals can be classified into four main types as： AB, L, S and P, and 24 subtypes such as AB4, ABs, Ls, and S3. The maximum crystallization temperature of zircon was estimated as 850℃, with the minimum of 550℃. The peak temperatures of the zircon crystallization range from 650℃ to 700℃. The abundances of Th and U in the zircon grains show large variation with the Th/U values 〉 0.4. The Th and U values also show a positive correlation in most zircons. The REE abundance of zircon in the quartz monzodiorite ranges from 280.4 ppm to 2143 ppm with an average of 856.4 ppm. The chondrite normalized zircon REE patterns show two types, one is characterized by HREE enrichment and LREE depletion with positive Ce-anomaly and negative Eu-anomaly whereas the other is HREE enriched and LREE depleted with negative Eu-anomaly but without positive Ce-anomaly, and relatively flat patterns. The LA-ICP-MS U-Pb geochronology on the zircons yields a mean age of 133-0.87 Ma. Our data on zircon morphology, composition and U-Pb geochronology reveal that the parent magma of the quartz monzodiorite which was emplaced during late Yanshanian had a mixed crust-mantle source, with crustal components dominating. The magma is inferred to have been water rich and alkaline with initial high oxygen fugacity. Post-magmatic hydrothermal activity occurred under relatively reducing conditions which was conductive for gold precipitation in the Yixingzhai gold deposit.

Analysis of influence of the power plant ash storage yard on groundwater environment

The fluoride contained in the filter liquor produced by fly ash in the thermal power plant which takes the coal as fuel can lead to groundwater pollution. Therefore, it is of great significance to study the migration characteristics of the pollutants in groundwater, in order to control and prevent the groundwater fluoride pollution. By adopting the numerical modeling method, this paper takes the ash-storage yard of Shahe Power Plant in Xingtai City as an example, to study the characteristics of fluoride migration in phreatic water, and establish a two-dimensional groundwater flow and water quality model on the basis of the hydrogeological condition analysis in this study area. Meanwhile, based on the Vmodflow software, the migration regulation of the fluoride in groundwater has been simulated. Because the phreatic aquifer of this area belonging to the Shahe alluvial-diluvial sediments and with a coarse lithology as well as high permeability, the migration and diffusion ability of the fluoride in this area is relatively strong. It turns out that the longest migration distance in 5 years is 892 m and that within 8 years is 1 515 m.

Zircon U-Pb age and Hf isotopic characteristics of the Huangtuliang monzonitic granite, North Hebei Province, China

The Huangtuliang monzonitic granite outcrops on the northern side of the Huangtuliang gold mining district, Chicheng, North Hebei Province. Our predecessors only made isotopic age determination using the K-Ar method. Through LA-MC-ICP-MS zircon U-Pb dating and zircon Hf isotopic composition determination, this study acquired the age of 244.8±2.0 Ma(MSWD=0.57) on the basis of the weighed mean 206Pb/238U ratio, indicating that the Huangtuliang monzonitic granite was formed during the Middle Triassic period, which is the product of Early Indosinian magmatic activities in the region of North Hebei. εHf(t) values vary relatively evenly, within the range of-10.65--14.03, with an average of-12.14. The two-stage evolution model ages, tDM2, vary between 1943 and 2144 Ma, implying that the rock-forming materials of the Huangtiliang monzonitic granite mainly came from the Paleoproterozoic recirculated crustal materials, though a small quantity of enriched-mantle materials would have been involved.

Endogenic Au-Ag polymetallic ore deposits and ore-bearing potentiality of strata

The problem of ore-bearing potentiality of the strata involves metallogenic theory and ore-search orientation.Studies of the spatial distribution of endogenic Au-Ag polymetallic ore deposits in North Hebei indicated that the strata in which ore deposits occurred range in age from Paleozoic,Proterozoic to Mesozoic.In addition the ore deposits are characterized as being strata-bound in nature.The arise and establishment of "extracting" viewpoint may be attributed to the following three reasons:1) influence by the idea of "ore-source bed";2) limitation of analytical techniques in the 1980s'(especially gold element);and 3) a small number of samples(sampling locations were mostly disturbed by mineralization).Studies have shown that ore-forming materials would most probably come from the deep interior of the Earth.Deep-seated ore-bearing materials including Au-Ag polymetals were brought to the shallow levels by way of mantle plume-mantle sub-plume-mantle branch structure multi-stage evolution,finally leading to the formation of ore deposits.