Abstract:In the Yuqia area within the western segment of northern Qaidam Mountains, eclogite lenses and interlayers are enclosed within metapelites, granitic gneisses and small amounts of marbles. Eclogite is composed of garnet and omphacite with varying amounts of amphibole, phengite, zoisite (clinozoisite or epidote), rutile and quartz. Petrography, mineral chemistry indicate that theeclogites record a three-stage evolution connected to Early Paleozoic burial and subsequent exhumation: (1) The prograde stage is composed of garnet cores and large amounts of mineral inclusions including amphibole, epidote and plagioclase. pT estimates give metamorphic conditions of 1.06～1.11 GPa and 560～577℃.(2) The eclogite facies stage is characterized by the assemblages of oriented omphacite, phengite, barroisite and zoisite around garnet porphyroblasts. The assemblages record peak conditions of 2.35～2.51 GPa and 610～680℃.(3) Retrograde assemblages are recognized in amphibolitized eclogite along the eclogite boudin margin. The assemblages of garnet, amphibole and plagioclase record retrograde conditions of 1.09±0.12 GPa and 630±44℃.It is inferred that there existed ahairpin-shaped p-Tpath, and all this suggests that the Yuqia eclogites underwent an evolutionary history of rapid burial and uplift.

Abstract:Qitianling composite granitic pluton is in the middle south of the southeastern Hunan ore concentration area. The Middle Jurassic Qitianling granite, the main intrusive body of Qitianling pluton, is studied in this paper. The Qitianling granite is composed of hornblende biotite granodiorite, hornblende biotite monzonitic granite and biotite monzonitic granite. SiO2 content increases from early to late granitic units, varying in the range of 65.92%～75.68%. The rocks are potassium-high (K2O=4.10%～5.27%, 4.86% on average) and alkali-rich (Na2O+K2O=7.12%～8.24%, 7.85% on average) ones, and have an average K2O/Na2O value of 1.63, ACNK values of 0.90～1.05 (0.96 on average) and KN/A values of 0.71～0.89 (0.78 on average), thus belonging to metaluminous to weakly peraluminous granitoids of shoshonite series and K_high calc_alkaline series. The rocks have an average ΣREE of 375.6 μg/g and show evident negative Ba,Nb, Sr, P, Ti and Eu anomalies as well as positive U, Th, Nd, Zr, Sm and Y anomalies, suggesting evident fractional crystallization. They have ISrvalues of 0.708?54～0.712?81, εNd (t) values of -5.05～-7.57 and tDM ages of 1.35～1.56 Ga, which is lower than the background age of granitoids in Hunan and Guangxi (1.8～2.4 Ga) and the region_al basement's age (1.7～2.7 Ga), implying participation of mantle materials. Various oxide and trace element diagrams for discrimination of structural environment reveal that the Qitianling granite was formed in a post_orogenic extensionalstructural environment. The authors consider that the early Yanshanian tectonicsetting in southeast Hunan and South China is a post_orogenic one instead of an intracontinental rift.

Abstract:The zircons from Qianrentun amphibolite in eastern Liaoning show an uniform absorbing band in cathodoluminescence (CL) images, being of characteristics of zircons in the mafic-ultramafic intusives. SHRIMP U-Pb dating results of the zircons are mainly distributed between the concordia ages of 117～143 Ma with a weighted mean 206Pb/238U age of 128.6±5.1 Ma (204Pb corrected), indicating that the amphibolite was formed in Early Cretaceous. The coexistence of Early Cretaceous mafic-ultramafic igneous rocks and granitoids in eastern Liaoning, i.e. the presence of the bimodal magmatism, suggests that a strong extensional environment existed in the eastern part of the North China Craton in Early Cretaceous and that the thinning of lithospheric mantle reached its culmination in that period.

Abstract:Zircon SHRIMP U-Pb age dating indicates that the Xiaolingzi granite in the Anshan area was emplaced during Early Cretaceous(130.2±2.7 Ma).It is enriched in SiO2, Na2O+K2O, TFeO/MgO, LREE, Zr, Nb and Y, and depleted in CaO, Ba and Sr, thus similar to the widely distributed Qianshan granite with the geochemical characteristics of A type granite in this area. It is suggested that the magmatic activity was related to an extension following the subduction of the paleo-Pacific Plate beneath eastern China.

Abstract:A series of mafic-ultramafic plutons are distributed in the southern margin of Altay folded belt and many of them are associated in space and time with Cu-Ni sulfide deposits. As geologists are divided in opinion on the genesis of the mafic-altra-mafic rocks, the genesis of mineralization is still a problem of much controversy. Some chalcopyrite, pyrrhotite and pentlandite samples were collected from the No.1 and No.2 intrusions of the Cu-Ni sulfide ores inthe Karatungk deposit to carry out Re_Os dating and tracing of ore_forming materials. The two groups of measured points defined isochronal ages of 282.5±4.8 Ma and 290.2±6.9 Ma with the initial 187Os/188 Os rates being0.256 3±0.003 7 and 0.272 1±0.005 3, respectively. The data show that theore-forming age is later than that of the Early Carboniferous rocks which host the mafic-altramafic intrusions, and is corresponding to the extension stage. They share the same mineralization time with the extensively developed shear zone type gold deposits. The ages are also similar to the alkali-rich granitoids developed in the southern margin of Altay folded zone and the northern margin of the Junggar folded belt. Their initial 187Os/188 Os values and γOs values of 202.23～1 061.59 and 195.07～473.24 indicate that large quantities of crustal substances were mixed with the Cu-Ni sulfide metallogenic system in the ore-forming process. 

Abstract:This paper deals with the formation conditions of black shales on the basis of analyzing such items as the component of chloroform bitumen "A" and the gas_facies chromatogram of saturated hydrocarbon. Studies show that the Lower Cambrian black shales in Jindingshan of Guizhou Province are sapropelic type and mixed type oil_forming rocks. The black shales are characterized by high content of organic matters, and the organic sources are algae and fungi. Organic geochemical features indicate that black shales were formed in an anoxic sea environment.

Abstract:Based on such means as systematic petrographical study, microthermometry, and Raman probe analysis, the authors revealed that homogenization temperatures of fluid inclusions in vein quartz from the Xiongcun copper_gold deposit vary from 121℃ to 382℃, mainly in the range of 150℃～250℃. Homogenization pressures of fluid inclusions vary from 1.94×105 Pa to 45.92×105 Pa.Fluid inclusion salinities at the stage of copper mineralization vary in a widerange from 1.23 wt％NaCleq. to 36.61wt％NaCleq., and are distributed in three discontinuous domains. High-salininity fluids existed at the stage of copper mineralization, but gold mineralization was related to low temperature and low salinity fluids. Fluid temperature and pressure characteristics of the Xiongcun deposit coincide with those of epithermal type deposits, but the salinity of the former deposit is higher than that of typical epithermal deposits. Ore-forming fluids of the Xiongcun deposit are rich in Ca2＋, CO2, N2 and CH4，thus belonging to the Na+ -Ca2+ -K+ -Cl- -SO2 -4 system. During the ore-forming process, there existed at least three fluid end_members in the Xiongcun deposit, namely the CO2-N2-CH4-rich member, the low-salinity aqueous member, and the high-salinity aqueous member. Ore-forming fluids of the Xiongcun deposit formed a complex immiscible system, and fluid immiscibility seems to have been one of the important mechanisms for metallic deposition in the Xiongcun deposit. The Xiongcun copper-gold deposit is a peculiar epithermal deposit, which show some typical characteristics of both high-sulfidation epithermal deposits and low- sulfidation epither-mal deposits.

Abstract:The Heijintaizi gold deposit is located on the western margin of the Yangtze craton and also on the eastern margin of Tibet. The gold deposit is hosted in Proterozoic plagiaplite and controlled by a NS-trending ductile-brittle shear zone. Gold mineralization occurs mainly as auriferous quartz veins.This paper presents REE analyses of fluid inclusions and quartz which hosts the fluid inclusions as well as auriferous quartz veins. The results show that the REE content of fluid inclusions ranges from 1?846.4×10-12 to 16 003.4×10-12, that of quartz ranges from 2.15×10-6 to 4.35×10-6, and that of auriferous quartz veins varies from 2.59×10-6 to 7.70×10-6. Combined with REE characteristics of host rocks and Kangding complex in the area, the authors hold that REE characteristics of fluid inclusions give some clues to the origin of the ore_forming fluids, which must have been derived fromdeep fluids. The REE of fluid inclusions in quartz were also derived from deep fluids. It is concluded that a careful study of REE in fluid inclusions may playan important role in probing into ore genesis and fluid evolution.

Abstract:The color of Xinjiang green tourmalines is very peculiar. Inorder to learn their color genesis, the authors used various testing means suchas chemical analysis, absorption spectrometry and Mssbauer spectrometry to study the color of green tourmalines. The content of transitional ions in each sample was determined by chemical analysis. Such ions as Fe2+, Ti4+ and Cr3+ affect green tourmalines. Their occupation, ionic category, valence state and action in the absorption spectra were confirmed by absorption spectra.The chemical formulae of tourmalines were calculated on the basis of oxide contents, and the ion occupation was defined by Mssbauer spectra. An integrated utilization of the above three means has led the authors to understand that the color of the green tourmalines is caused by transitional ions in the crystal.

Abstract:A series of layered double hydroxide (LDH) were synthesized by the coprecipitation method under different physical and chemical conditions. The composition and structure of LDH were determined and characterized by chemical analysis, XRD and IR, and the effects of such factors as equilibrated pH, initial ratio of mixed Mg/Al solution, reaction temperature and drying temperature upon crystallinity, Mg/Al ratio, structure and Mg and Al hydrolysis percentage of synthesized LDH were also investigated. The results indicate that the best conditions for synthesising LDH in this experiment seem to be initial Mg/Al 2:1,pH 10 and synthesis temperature 50℃. Under these conditions, solid products are characterized by single LDH phase, Mg/Al ratio of LDH 2∶1, high crystallinity, Mg hydrolysis percentage 99.21% and Al hydrolysis percentage 98.97%.

Abstract:To find appropriate humidity-controlling material, the authors studied sepiolite and its compound samples for the capacity of moisture absorption and desorption. The relative humidity of a 10 liter glass vessel could be reduced from 70% to 4% by 10g sepiolite, whose moisture adsorption capacity isstronger than that of palygorskite under the same condition. The moisture adsorption capacity of sepiolite (10g) will somewhat weaken after three circulations of absorbing and desorbing experiments. In the last experiment, the sepiolite (10g) absorbed about 0.4g moisture and released some 0.15g moisture. It has been found that 30g sample of sepiolite compounded with white cement can keep the humidity in the range of 40%～50% in a 10 liter glass vessel. Sepiolite can be used as building materials for indoor air humidity control.

Abstract:The dissolving rate of K2O from potassium feldspar and thesolid phase transformation were experimentally studied at 200～250℃ on hydrothe rmal-dissolving potassium feldspar, with CaO as the reactant and under the conditions of different Ca/(Al+Si) molar ratios, liquid/solid weight ratios, reaction temperatures and reaction periods. The experimental results indicate that the dissolving rate of K2O from potassium feldspar is 40%～80% and the solid product is well_crystallized fibrous tobermorite. Wet chemical analysis, XRD, SEM, DSC-TG and BET methods were used to characterize the synthesized tobermorite powers. The synthesized samples are hollow spherical agglomerates formed by fibroust obermorite crystals, which are 49～50 nm in thickness, 100～200 nm in width and 5～10 μm in length, suitable for making calcium silicate insulation materials.The heat insulating temperature of the synthesized tobermorite powder materials is as high as 650℃.

Abstract:The environmental pollution caused by cadmium, a heavy metal toxic element, has aroused geologists' attention. With the progress of the research work, it has been found that cadmium is not dispersive and, in certain geochemical conditions, it is likely to be enriched and can even form orebodies or deposits. Therefore, it is necessary to restudy and re_understand geochemical behaviors of cadmium. This paper describes some advances made in the study of the distribution and modes of occurrence of cadmium, and sums up the distribution and geochemical investigation of cadmium resources in China. It is suggested that we should strengthen the study of abnormal enrichment mechanism of cadmium and the release and circulation of cadmium in supergene geochemical process, which adversely affect the environment.

Abstract:Minerals in atmospheric dusts are mainly derived from soils, building dusts and rising dusts in some areas. The particles are characterized by small sizes, irregular shapes and surface unevenness. Mineral particles show strong biological activity, and exert a special physiological action to human health and biological effect. Surface activity groups of dusts affect their biological effects. Surface properties, free radicals released by mineral dusts or stimulated phagocyte play important roles in causing cell injury and pneumoconiosis. Atmosphere dust components, surface properties and the inhibition and toxic effects of mineral dusts on normal flora in human bodies are all important research aspects in the environmental health effects of mineral dusts.