Abstract:The Miocene volcanic lava in Canmeishan area, belonging to Qiangbaqian rock province of Hoh Xil rock belt, occurs in north Tibet and is composed from early to late of basalt latite, latite and trachytic dacite, with the K-Ar whole-rock ages in the range of 12.81～14.51 Ma. The SiO2 contents of basalt latite, latite and trachytic dacite are 53.85%～56.02%, 59.22%～61.84% and 64.81%～67.70%, respectively. The rocks belong to the shoshonite series and are sub-aluminous: K2O+Na2O 6.21%～8.20%, K2O 3.17%～4.94%, K2O/Na2O=1.01～1.52, TiO2 0.77%～1.88%, ACNK=0.54～0.90 and KNA= 0.57～0.72. ΣREE 297×10-6 ～939×10-6and (La/Yb)N 45.1～127.4 point to intensely-concentratedLREE, with δEu being 0.73～0.95. TheLILE (K, Rb, Cs, Sr, Ba, U, Th) are highly concentrated, while the HFSE (Nb, Ta, Zr, Hf) are comparatively less concentrated. Geochemical characteristics and regional contrast indicate that the source ofMiocene volcanic rocks in Canmeishan area was EMⅡ-mantle. Harker diagrams of selected major oxides, Mg# versus trace element variation diagrams, La/Sm-La diagram and variation of Mg# values and ΣREE all show that basalt latites and latites belong to the comagmatic evolutionary series, and have obviously experienced a high degree of crystallization differentiation. The trachytic dacites belong to another magmatic series produced by partial melting of the rocks formed from the earlier evolved magma. It is thus concluded that the spatial-temporal scale of deep magmatism should be larger than that of the upper volcanic rocks in north Tibet in Cenozoic. Under the compressive tectonic regime, some mantle-derived magma was confined in the depth and turned into rock through cooling. Consequently, the space-time distribution of Cenozoic volcanic rocks in north Tibet must have been related to the evolution of the regional tectonic regime.

Abstract:Geochemical data indicate that Yajiangqiao trondhjemite, Huatan trondhjemite and Mopanshan granite, considered as component parts of Kangding complex formed in Late Archean or Palaeoproterozoic, are similar to TTG in such aspects as low Mg#, Na2O＞K2O, strong fractionationed REE, no or slightly negative Eu anomaly, low YbN, Cr, Ni, V, Nb, Ta, Ti, high Ba, and changeable Sr. SHRIMP zircon dating suggests that Yajiangqiao trondhjemite was emplaced in 778±11 Ma. The results of the study show that Kangding complex is composed of Neoproterozoic granites bearing characteristics of TTG. The formation environments of TTG together with the results of previous studies imply that Neoproterozoic granites were formed by melted basaltic ocean crust under the condition of plate subduction along the western margin of Yangtze block.

Abstract:The 3.0 Ga Tiejiashan granite in the Anshan area is the oldest and largest potassium granite intrusion in the North China Craton. Meta-sedimentary rocks with high maturity in the Tiejiashan granite were once considered to occur as enclaves and to be a main resource from which the Tiejiashan granite came. However, SHRIMP U-Pb dating of detrital zircons from three meta-sedimentary samples commonly gives the ages of -3.0 Ga, being the same as the formation time of the Tiejiashan granite. Therefore, the supracrustal rocks should have been formed after 3.0 Ga, with a tectonic relationship with the granite. It is considered that the supracrustal rocks dated in this study are a part of the 2.5 Ga Anshan Group.

Abstract:The study of metamorphic volcanic rocks of Yaolinghe Group widely distributed in South Qinling tectonic belt is very important in determining the attribute of South Qinling tectonic belt and even the evolution process of the whole Qinling orogenic belt. Results of this study show that Yaolinghe Group possesses different rock assemblages. This conclusion is based on petrochemical and geochemical characteristics in different areas obtained from exploration of metamorphite assemblages and initial rocks as well as analyses of petrochemical components, rare earth and trace elements in Yunxian-Yunxi (Hubei), Shangnan (Shaanxi),Zhen'an, Fenghuangshan, Ankang and other areas. Studies of metavolcanite obviously show that Yaolinghe Group in the center of Ankang-Wudang area is an intraplate tholeiite-partial alkali basalt group formed in a pull-apart intraplate (riftbasin) tectonic setting, whereas Yaolinghe Group in Shangnan, Zhen'an and Fenghuangshan areas are of calcalkali basalt-island arc tholeiite series formed on the edge of the convergent plate-island arc. There must have existed two tectonicregimes in South Qinling region in the period of 650～800 Ma. 

Abstract:Based on Sr and C isotopic sequence stratigraphy, this paper has made a comparison between the Pre Cambrian Sr and C isotopic data from the Jiao-Liao-Xu-Huai area and the variation curves of Sr and C isotopes available abroad. It is shown that the Precambrian strata in the Jiao-Liao-Xu-Huai area were accumulated in the same period. The Sr and C isotopic ratios show good correlation in this area. The accumulation of the strata occurred from 750 to 860 Ma, and continued to the Sinian. These strata are sediments accumulated after Qingbaikou period. It is also shown from the comparison that dating with Sr and C isotopes is an effective way to solve the problem of Precambrian stratigraphic correlation in the case of lack of fossils.

Abstract:Located in a back-arc sedimentary basin in Gandise island-arc, the Jiama copper and polymetallic deposit occurs as stratiform and stratoid bodies in the transitional zone between the reef limestone (J-3d) and sandy slate (K-1l). Stratabound skarn is the ore-bearing rock in the Jiama deposit. With its unique geological characteristics, it has aroused great interest among investigators. Based on REE and silicon isotope characteristics of the Jiama stratabound skarn and a comparison with typical magmatic-hydrothermal contact metasomatism skarn, Sedex deposit and modern seafloor hydrothermal fluid, the authors hold that the stratabound skarn in Jiama deposit is different greatly from the typical magmatic-hydrothermal contact metasomatic skarn, but is comparable with modern seafloor hydrothermal fluid, Sedex deposit and associated hydrothermal sedimentary rock. It is thus concluded that the stratabound skarn of the Jiama deposit has nothing to do with the magmatic-hydrothermal solution, but is associated with the old seafloor hydrothermal circulatory system. It should genetically belong to hydrothermal exhalation. The study has provided valuable evidence for the origin of the Jiama copper and polymetallic deposit.

Abstract:Based on an ore-spots investigation report by No. 311 Geological Party, the authors found some natural moissanites in both artificial heavy sands and thin-sections from the Dongjiashan serpentinite in south Dabie Mountains. The single crystals from the artificial heavy sands are mostly hexagonal,partly irregular and occasionally rhombohedral. The crystals are commonly 250 μm×150 μm in size, with the largest one being 450 μm×100 μm. Some relatively small moissanites were found in thin sections. The Raman shifts of moissanites both[CM(46] as single crystals and as crystals in thin sections are typical and stable. Natural single crystal moissanites are mostly biaxial (+),and subordinately uniaxial (+). However, almost all the moissanites in thin sections are characterized by biaxial crystals (+) with the 2Eup to>20. Although the natural moissanites are considered to be existent in any rocks, the autochthonous natural moissanites can only be found in some kimberlites and meteorites.The moissanite reported here is probably the first occurrence in serpentinites. As both moissanite and diamond have similar tetrahedrally oriented sp3 hybrid bonds and identical glide planes, the behavior of moissanite under stress should be comparablewith that of diamond. It is thus considered that the primary moissanite might have been formed at the depth of ≥300 km, and that it is very important to understand the tectonic evolution of its host rock.

Abstract:In situ high-pressure energy dispersive X-ray diffraction (EDXD) experiments on framework silicate sodalite were carried out by using the diamond anvil cell (DAC) device with a synchrotron radiation source at Beijing Synchrotron Radiation Facility (BSRF). The maximal pressure recorded at room temperature in these experiments reached as high as 17.4 GPa. It was observed in this pressure range that sodalite underwent a phase transition at about 3 GPa and that the d- 222 value showed an abnormal increase when the pressure was higher than 6.3 GPa. The experimental results are explained on the basis of the pressure effects upon the cage and tunnel structures in sodalite.

Abstract:More and more attention has been paid to the mesoporous molecular sieve materials in recent years. Due to the merits of average pore diameter and ordered pore arrangement, the potential value of these materials in various application fields such as catalysis, electromagnetism sensor, nano optical apparatus and chromatogram carrier is considerable. The development in such aspects as synthesis mechanism, texture and application has been reviewed in this paper, and the effects of the preparation method, templates and assistant reagents on the synthesis are also discussed.

Abstract:In order to enhance the surface area, hole density and adsorption quantity of kaolinite, the authors carried out dispersion treatment of the sheet-like kaolinite after delamination and shattering based on the preparation of urea-kaolinite complex by microwave chemical reaction under further radiation. As a result, nano-kaolinite was obtained. The structures of the samples under processing were studied by Fourier transformation infrared spectrometry (FT-IR) and X-ray diffraction (XRD). The morphologies and sizes of the samples were examined by scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM). The results show that, under the same condition, the time spent on delamination under microwave assistance is only 1/20 of the time spent on the single mechanical method, and that the average size of the nano kaolinite is 150 nm.

Abstract:以高铝粉煤灰为主要原料，制备了堇青石微晶玻璃。通过差热分析（DTA）和X射线粉末衍射分析（XRD）确定了合适的热处理条件：核化温度807℃，核化时间2h，晶化温度960℃，晶化时间3h。XRD分析显示，制得微晶玻璃的主晶相为堇青石。SEM分析表明，基础玻璃晶化完全，微晶玻璃中微晶体呈不规则柱状、棒状，微晶体长度为5～15μm，长径比为5～10。

Abstract:A fast gelling process to synthesize kalsilite powder was performed by dropping aqua ammonia into the TEOS-KNO3-Al(NO3)3-EtOH-H2O system, which resulted in the formation of a gel in 5～12 minutes. Compared with the traditional sol-gel method, the gelation time is greatly shortened. The optimum gelling conditions are as follows: molar ratio of H2O to TEOS25, molar ratio of EtOH to TEOS4 and pH value about 9. Kalsilite powder is produced by treating the dried gel under 862℃ for 3 hours. The synthesized kalsilite particle is nearly 50 nm, and most of the secondary particles 5～20 μm. The specific surface area of synthesized kalsilite is 26.3 m2/g with an average intergranular pore size around 11.2 nm. The synthesized kalsilite powder is mesoporous with a bimodal pore distribution. Pure and homogeneous, stable in high temperature and with high potassium content and a bimodal pore distribution, the synthesized kalsilite powder can serve well as an efficient catalyst aid with relatively high application value.

Abstract:Recent advances in nacre used as bone implant are reviewed in this paper. The experiments show that nacre, a type of natural nano-bioceramic material, when used as bone implant for reconstruction of bone defects, is not only biocompatible and biodegradable, but also osteoconductive and osteoinductive. It is likely that nacre will become a good candidate for bone graft substitution in future.

Abstract:At present, the infrared transmission spectroscopy is the best technique for determining whether jadeite is polymer-impregnated or not, and the infrared reflectance spectroscopy is a nondestructive and rapid determination method that provides mainly the fundamental frequency vibration spectra data of minerals and shows new application potentials in gemological research, especially in the identification of gem species. The gemological application of IR reflectance spectroscopy and the identification system of IR spectra of gems, including a database of 318 spectra and a searching and identifying program, are described in this paper.