Abstract:Nankunshan aluminousA_type granite occurs in Longkou County of Guangdong Province, with a outcrop area of about 200 km2. With medium-grained texture, the granite is composed of protolithionite, albite plagioclase, perthite and quartz. The rock usually is weakly peralumious and subalkaline with high alkali ratio rangeand NK/A values. The granite contains markedly low MgO and CaO and extremely high (FeO+Fe2O3) with ahigh FeO*/(FeO*+MgO) ratio. Nankunshan granite is evidently rich in F and poor in Cl, having a high F/Clratio range. Based on its high Zr contents, the calculated zircon saturation temperatures of the rock are relativelyhigh (810~847℃), consistent with those of A_type granites in Australia (839℃,on average). In terms oftrace element data, the granite has high 104Ga/Al and (Zr+Nb+Ce+Y) values. These values are higher than the low_limited values of 2.6 and 350(×10-6) for aluminous A_type granites in Lachlan Fold Belt of Australiarespectively. The rock has higher total REE contents and strongly Eu negative anomalies, showing a sea_gullshaped REE partition patterns on its chondrite_normalized diagrams, and Rb, U, Th, Nb, Ta, Zr, Hf, Sm el-ements show evidently positive anomalies on the primitive mantle_normalized trace element spider diagrams. Thegranite possesses relatively highεNd(t) values (-1.54~-2.87) and lowδ18O Values (7.9‰~9.8‰), indi-cating that its source rocks are located in the interaction belts between the mantle and the crust. Mantle compo-nent accounts for about 63%~69% in its total source materials, as calculated by the mixing model of the mantl and the crust end members on the basis of the isotopic data. These features are obviously similar to those of alu-minous A_type granites elsewhere in the world. The discovery is important for study on the extensional structureof late Yanshanian crust in eastern part of Nanling Mountain.

Abstract:The Cenozoic kamafugites in Lixian County of West Qinling are poor in SiO2and Al2O3but rich in MgO, CaO, TiO2and K2O+Na2O. The modal mineral assemblage is composed mainly of olivine, clinopyrox-ene, nepheline/ kalsilite, melilite/leucite and Ti-phlogopite. The trace isotopic compositions of Sr, Nd and traceelement characteristics of kamafugitic series show distinct geochemical features similar to those of N-OIB and MORB as well as an EMⅠend member caused by metasomatism of asthenospheric fluids. Based on the estima-tion results ofpandTfrom lherzolites, regional geophysical information, regional tectonic settings and the for-mation ages of volcanic rocks, it is held that the formation of kamafugitic series was closely related to the Ceno-zoic lithospheric extension in this area, and that the primitive kamafugitic magma was derived from the low-de-gree partial melting of the thermal boundary layer at the basement of lithosphere beneath the depth of 92 km

Abstract:The basalts of Woniusi Formation at Baoshan area, located in western Yunnan Province, are composed of low-TiO2 tholeiites generally similar to the low-Ti tholeiites from Emeishan large igneous province. They are highly-differentiated magmatites rich in large ion lithosphere elements and high field strength elements, have significant Zr and Hf positive anomalies as well as high87Sr/86Sr and low143Nd/144Nd ratios, and show characteristics similar to those of continental-rift basalts. Geochemically it consists of three eruption cycles which can be divided into three rock units. The early-stage unit 1 basalts are characterized by massive plagioclase-phe-nocryst basalts, amygdaloid basalts and basaltic tuff. The middle-stage unit 2 and the late-stage unit 3 consist of minor olivine basalts and trachybasalt as well as diabase dykes. From the similar geochemical and Sr-Nd isotopic features with Emeishan basalt, they are interpreted as the products that evolved from the same parent magmas and experienced crystal differentiation of plagioclase and clinopyoxene. Their parent magmas were generated from an enriched lithosphere mantle associated with mantle plume. This suggests that the Emeishan large igneous province may have remarkable westward extension.

Abstract:Numerous lamprophyre dykes occur and cut through the Late Mesozoic granitic complexes in Taihang Mountains, North China Craton. These dykes are highly enriched in LIL elements such as Rb, Sr, Ba and K as well as light REE. The highly frac- tioned REE patterns and the regular variation in chemical and Nd-Sr isotope composition show that these lamprophyres were produced from the fractionation of the parent magma, and the ascending magma was contaminated by the lower crust. Most primitive lampro-phyres show low SiO2, high MgO and highly enriched isotope [εNd(120 Ma)=-8.3,ISr=0.705 2], indicating that the parent magma was derived from partial melting of the enriched continental lithosphere mantle. The mantle was enriched in the Middle Pro-terozoic, during when volatile-rich and low-density melts were released by asthenosphere interacting with the above lithosphere.

Abstract:The Sulu high-pressure (HP) metamorphic belt lies on the southeastern margin of the Sulu ultrahigh-pressure (UHP) metamorphic belt in northern Jiangsu. Its outcrops consist mainly of greenschist-facies rocks of the Meso- to Neoproterozoic Yuntai Group-complex. Nevertheless, typical blueschist was only found in the drilling cores from Yangji Town of Guanyun County in northern Jiangsu. The glaucophane greenschist facies rocks discovered in such places of Lianyungang area as Hongshizui, Dongxiliandao and Xieqigou consist of winchite, barroisite, actinolite, albite, phengite, sphene, aragonite, etc. These garnets as a kind of low-diffuse rigid mineral have undergone multi-stage deformation and metamorphism. The evidence of the metamorphism is preserved in the compositional zoning of garnet. These minerals indicate that the outcrops in the study area are part of a HP terrane which was overprinted by greenschist facies metamorphism at the late stage. This discovery provides important evidence for dividing geotectonic units in the Sulu high-pressure terrane.

Abstract:This paper has studied characteristic values and upward changing tendency ofεNd(t),t2DMand fANd in granitic rocks of 430 granite body as well as the variation of these values in linear- and planar-greisens of Xi-anghualing. Nd isotopic characteristics of rocks suggest that the granite resulted from the mixing of the crust material with the mantle material, and that the mantle material derived from the deep source got into and was distributed unevenly in the granite body. The mantle material might have mainly taken the form of mantle fluid to join the process of granitic evolution. Under the Mesozoic background of lithosphere thinning in East China,the mantle fluid underplating induced the remelting of Mesoproterozoic strata, forming granitic magma.

Abstract:The fluid inclusions in several types of rocks in the Dabie UHP zone were systematically investigated in the aspects of petrography and temperature of phase change. The results indicate that the fluid components related to UHP and early retrograde metamorphism belonged to salt-H2O system, those released from partial melting to NaCl-CO2-H2O system and those related to brittle deformation to NaCl-H 2O system. As the effect of pressure decreased in the quick exhumation episode of UHPM rocks, and such changes after trapping as necking-down and explosion occurred in varying degrees in fluid inclusions of all events, the present densities of the fluid inclusions mostly do not reflect the state of the trapping, and their isochores are not suitable for the estimation of trapping temperatures and pressures. The fluid inclusion associations related to distinct fluid-related events were often superimposed on the rocks in UHP and retrograde metamorphism, and hence the geological explanation for chemical and isotopic composition of fluid inclusions based on bulk inclusion analysis is subject to some risk.

Abstract:The ICP-AES method was applied to measure the abundances of rare earth elements in wallrock and ore samples from the Fangshankou V-P-U deposit in Dunhuang City, Gansu Province. The results show that REE of the deposit is usually of the LEE-en-riched type, and that the differences of contents, compositions and negative anomalies of Ce and Eu between samples from the deposits reflect changes in sedimentary environments. Correlation analyses of the samples indicate thatΣREE, which is negatively related to abundances of clay, organic carbon and V2O5, is positively correlated to contents of CaO,MgO,P2O5and U, and the negative correlation ofΣREE to organic carbon results from diagenesis, and that its relations to other chemical components are caused by sedimentary conditions combined with depositional process.

Abstract:In this study, pyridine_Raman spectrometry was used to study surface acid site properties of diatomite. In the experiment,the surface hydroxyl groups could not play the role of Brφnsted acid sites without thermal treatment because they were all covered with water molecules,and there appeared no Lewis acid sites either. After being heated, some B acid sites appeared on diatomite surface,which originated from the surface acid hydroxyl groups that had desorbed water molecules, and the B acid sites reached the maximum quantity after being heated at some 650℃. Under the same treatment condition, L acid sites also appeared, and this was attributed to the structural deformation of clay minerals in diatomite.

Abstract:In order to solve the problem of type assignment of the Qingtian stone from Zhejiang Province, the author made some experiments with such means as X-ray powder diffraction analysis, infrared absorption spectral analysis, scanning electron microscopy and differential thermal analysis. The results show that the main species of Qingtian stone is of pyrophyllite type; nevertheless, there also exist some other types, such as dickite_type, illite-type and sericite-type. This paper has discussed mineral composition, gem features and formation mechanism of the Qingtian stone.

Abstract:Montmorillonite adsorption experiments were conducted in the fluoride solution. The results show that an excellent negative correlation exists between the adsorption ability of montmorillonite and pH values of the solution. Montmorillonite adsorbs large quantities of fluorine ions and the defluoridation effect is remarkable at low pH value. With the rising of the pH value, the amount of fluorine adsorbed by montmorillonite decreases rapidly and, what is worse, montmorillonite seems almost not to adsorb fluorine ions at all in basic-neutral solution. The amount of montmorillonite and the concentration of fluoride solution also affect the amount of fluorine adsorbed on montmorillonite. This is believed to be the result of a positive surface charge build-up on the montmorillonite at low pH that causes affinity of the negatively charged fluoride ions. In addition, when the concentration of the fluoride solution increases, the electric double layer becomes thin and theζpotential falls, resulting in flocculation of montmorillonite together with fluoride ions. In addition, the ionic exchange between the fluoride ions and OH-is an important factor responsible for the adsorption of fluorine onto montmorillonite in acid solution.

Abstract:A kind of unnamed Fe-Cr-Ni mineral was found in chromite of Luobusa ophiolite in Tibet. EPMA shows that its molecular formula is Ni0.45Cr0.29Fe0.26, and the powder X-ray diffraction data are shown as follows (inside the parentheses areI/Io,hkl): 2.060(100, 111), 1.775(70, 200), 1.261(60, 220), 1.076(50, 311), 1.027(50, 222). According to the powder diffraction data, the crystal structure of this alloy belongs to theγ-Fe kind of metal element. The authors determined the atom coordinate and calculated the theoretical powder diffraction pattern in term of the arrangement ways of the metal element. The calculations reveal that the theoretical powder diffraction pattern is basically consistent with the observable powder diffraction data. The crystallographic data of Fe-Cr-Ni alloy can be summed up as follows:a=3.562 2 ,space groupFm3m, the number of molecules in unit cellZ=4, Dc=8.212 g/cm3.

Abstract:This paper is mainly devoted to the refinement of the crystal unit cell parameters of the native manganese oxide from the supergene oxidation zone of the Xiangtan manganese deposit, Hunan Province. With the computer programs of Rietveld_DBW 9411 and Pirum, it is revealed that the body_centered monoclinic cryptomelane is the main phase of the mineral. It is for the first time to give the unit cell parameters of native cryptomlane in this area:a0=0.997 4 nm,b0=0.286 3 nm,c0=0.969 3 nm,β=91.467°,V =276.66×10-3nm3. It is also pointed out that the troubles of refining are caused by the extreme difficulty in finding a single crystal particle and by the XRD pattern characterized by broadening, relatively high background and asymmetry.

Abstract:As the Sr, Nd and Pb isotopic samples are likely to be contaminated during the process of powdering, the method adopted by the Isotopic Laboratory at the University of Hawaii is introduced in detail. The process consists of choice and cut of samples, coarse fracturing, cleaning, picking up and powdering. With this method, the contamination by other materials can be reduced to the minimum, and the advert effects of some alterations and oxides can be eliminated.

Abstract:Grinding the mixture of kaolin and hydrazine concentrate can not only raise the speed of intercalation so that the intercalation rate reaches 96% in 10 minutes, but also greatly improve the refining of kaolin. When the complexes are heated to 120℃, the gas they send out can further delaminate kaolin. In this way, we can get the refined kaolin whose grain size is -2μm>90%, and the lamellar crystal is perfect. This technology offers an innovational thinking and a method for preparing double 90" refined kaolin.

Abstract:Wehrlite with formula Bi2+x Te3-x was first found in Hungary. The name was changed to pilsenite in 1982 with the formula being changed to Bi 4Te3, and tsumoite was found within the compositional range of former wehrlite. Nevertheless, some researchers have still taken the composition of wehrlite as that of pilsenite or taken tsumoite as pilsenite. This paper aims at reminding the researchers not to use the incorrect names.

Abstract:Gemstones often show abnormal extinction under polariscope. This paper gives a summary and explanation to these phenomena, with the purpose of helping testers judge the optic characters of gemstones more accurately.