Abstract:Early Paleozoic volcanic rocks in Tianshui and Baoji areas along the eastern segment of North Qilian orogenic belt consists of Hongtubu basaltic lavas and Chenjiahe intermediate-acid volcanic rocks. Geochemical analyses show that Hongtubu basaltic lavas are similar to the intercalated basalts in Chenjiahe intermediate-acid volcanic rocks in characteristics, both fallen in the tholeiite series with high TiO2 (1.50%～2.73%). Their∑REE are 65.97×10-6～133.46×10-6 and 78.04×10-6～175.55×10-6 respectively， both are slightly enriched in LREE ［(La/YbN being 2.00～4.40 and 2.71～4.40 respectively］，and both have no obvious Eu anomaly or weak Eu negative anomaly（δEu being 0.85～1.10 and 0.85～0.99 respectively）. Basalts from two groups are typically characterized by selected enrichment of LILEs, low abundances of HFSEs relative to NMORB, and prominent troughs of Nb and Ta, with low Nb/La ratio（0.28～0.43）, which indicates the affinity of these volcanic rocks to island arc tholeiite（IAT）. In addition, εNd（t）（+2.22～+4.08）values of basalts suggest that their mantle sources are similar to the depleted mantle source. Zr/Nb=17.21～36.33 and Ce/Nb=5.73～8.17, implying geochemical characteristics of N-MORB. Sr, Nd and Pb isotopes from Hongtubu basalts are similar to those in Chenjiahe basalts in composition. In the diagrams of εNd(t)-(87Sr/86Sr)t, (207Pb/204Pb)t-(206Pb/204Pb)t,(87Sr/86Sr)t-(206Pb/204Pb)t and εNd(t)-(206Pb/204Pb)t for basalts, the data are fallen in the DM, EMⅠand EMⅡ areas, probably with a little crustalontamination, indicating that the magma of basalts might have had a mixed gin.Thentermediate-acid volcanic rocks from Chenjiahe belong to the calc-alkaline series,they have relatively high abundances of REE∑REE=127.51×10-6～276.01×10-6）, and are significantly enriched in LREE[（La/YbN= 4.79～13.51]. Most intermediate-acid volcanic rocks show weak Eu negative anomaly (δEu=0.53～1.20). The trace element patterns of Chenjiahe acid volcanic rocks are similar to those of the ocean ridge granite (ORG), with marked troughs of Nb, Ta, Zr and Hf. A synthetic study shows that the Chenjiahe intermediate-acid volcanic rocks in the eastern segment of North Qilian orogenic belt were formed in an island-arc setting, whereas the Hongtubu basalts were formed in an intra-arc rift setting (or an initial back-arc basin setting), probably being products of the early spreading evolution of the island_arc system towards the back-arc basin in the eastern segment of North Qilian during late Early Paleozoic. The results obtained provide evidence for the existence of the trench-arc-basin system at the juncture of Qilian and North Qinling orogenic belts.

Abstract:There are many deep xenoliths in silicified aegirine syenite porphyry ot Xiaoqiaotou area, Yunnan Province. A petrographic analysis combined with electron microprobe analysis and SEM shows that black opaque matters, whose composition is mostly of microcrystalline silicate and magnetite, are widely found running reticulately through mineral particles, crystals and cleavage cracks in association with metasomatic alteration in the mafic-ultramafic xenoliths and their host rocks. It is concluded that microcrystalline silicate and magnetite show characteristics of liquation in the back-scattered electron image. Such a microcrystalline solid, which assumes black opaque state under transmitted-light microscope and might have resulted in metasomatic alteration, is one of the direct microcosmic manifestations of mantle fluid metasomatism with characteristics of melted and supercritical fluids.

Abstract:Garnet clinopyroxenites were found in Mama valley of Cona area, southe astern Tibet. They are enclosed as lenses in the garnet sillimanite gneisses of the Greater Himalayan Crystallines and consist of Fe-rich anhedral garnet, diopside with high Fe2+/(Fe2+ +Mg) ratio, quartz, Ti-poor ferrohornblende and magnetite, together with such accessory minerals as zircon and apatite. The garnet grains somewhat exhibit zoning patterns formed in the prograde metamorphism. Whole-rock compositions of the garnet clinopyroxenites are characterized by high SiO2 (59%～61%), Fe2O3(18%～19%, total iron), CaO (12%～13%) and Al2O3(5.3%～5.4%).Solid-phase thermobarometry reveals recrystallization of the garnet and diopside at temperature of 650～700℃ and pressure of 0.8～1.0 GPa. Texture, mineral paragenesis and compositions, therefore, indicate probable derivation of the garnet clinopyroxenites from dehydration-driven partial melting of Fe-rich amphibolites in the middle crustal levels. Thus an example of amphibolite facies garnet clinopyroxenites is presented inthis study.

Abstract:Weizhou Island in Beihai City of Guangxi is the largest Quaternary volcanic oceanic island in China. The latest eruptive product is basanitoid, which covers the tuffite strata of Late Pleistocene Huguangyan Formation (Q3h).It is worth mentioning that many peridotite xenoliths were found in the strata.They are distributed in the basanitoid pyroclastic flow with the unique form of volcanic breccia, quite different from normal xenoliths. As the xenoliths have experienced blasting, they might be called xenolith fragments. Obviously, such xenoliths constitute one of the most peculiar types of peridotite xenolith occurrence. The original xenoliths might have been dunite and harzburgite. Bothock structure and microprobe data show that these peridotite xenoliths were derived from the oceanic lithosphere mantle. The estimated equilibrium p-T conditions of xenoliths are about 1.3 GPa and 960～1040℃, with the corresponding stable depth being 40 km. Besides, the xenoliths came from a place much shallower than their host rocks, suggesting that they were accidental xenoliths. And they experienced blasting before emplacement.

Abstract:The Baogutu porphyry copper deposit, a gold-rich porphyry copper deposit, is located on the margin of western Junggar Basin in Xinjiang. The average Au, Ag and Cu contents of the deposit are 0.25 g/t, 2.56 g/t and 0.30%, respectively. Two ore-forming stages have been observed. The early stage, during which Cu-Mo-Au assembly was formed, seems to have been the main mineralization stage. The latestage, during which the Cu-Au-Te-Bi assembly was generated, only occurred in local places of the ore deposit and was not large in scale, but it played the role of enriching the ore. According to the microscope observation and electron microprobe analyses of the polished sections and polished thin sections, the authors consider that at the early ore-forming stage, Au content was higher than Ag content, and these two elements existed homogeneously in sulfides as solid solutions, with no independent minerals formed. The late ore-forming stage was characterized mainly by the formation of argentiferous minerals and complex Cu-Au-Ag-Te-Bi minerals, with the major minerals being hessite, Bi-bearing hessite(?), Ag-bearing tetradymite (?), Ag-bearing wittichenite, electrum etc. These min-erals are present as slender veins superimposed upon earlier mineralization. Though limited in scale, the late stage mineralization played an important role in improving the economic value of the deposit.

Abstract:The behavior of structural OH in clinopyroxene (Cpx) and orthopyroxene (Opx) during successive heating, cooling and stepped heating was investigated by in-situ Micro-FTIR measurements under temperatures ranging from 25℃ to 500℃at 100℃ increments. The results suggest that both Cpx and Opx exhibit a decrease in OH stretching vibration frequency with increasing temperature, and the variation is reversible. The shift in absorption band frequency is controlled by thermal expansivity of the OH site or lattice interstice.

Abstract:A REE-bearing mineral, i.e., monazite, was discovered in the Ni-Mo ore from the Tian'eshan_Huangjiawan Ni-Mo sulfide layer of Zunyi, Guizhou Province, on the basis of electron microprobe analysis. The monazite is distributed as fine scattered particles and vermicular aggregates in the Ni-Mo ore, coexistent with Ni- and Mo-bearing minerals. High La and Ce contents (La2O3: 25.70%～30.52%, Ce2O3: 22.96%～27.68%) and low Sm and Th contents（Sm2O3: 0.49%～0.80％,ThO2:0%～0.19%）of the monazite show the characteristics of hydrothermal generated monazite.

Abstract:In recent years, copper isotope can be measured precisely thanks to the improvement of analytical methods and the use of MC-ICPMS, and hence this field has become a new frontier in earth sciences. Copper isotope shows considerable variation in nature (from －3.03‰ to 5.74‰). This paper briefly describesand reviews the analytical methods and fractional mechanism of copper isotope. On the basis of data available, this paper focuses on the relationship between copper isotope composition and temperature, stages of mineralization and sources of ore-forming elements. As an important ore-forming element, copper exists widely in different geological systems and is active in ore_forming and rock-forming processes. Therefore, copper isotope may become a sensitive geochemical tracer and can play an important role in showing the sources of ore-forming elements as well as the ore-forming process and mechanism.

Abstract:Acid activation of palygorskite clay is important in improving its grade and applications, and hence the study of acid activation mechanism of palygorskite clay and its related factors has both theoretical and application values. The variation characteristics of mineral components, mineralogical features and surface of activated palygorstite clay as well as the related factors are summed up in this paper. The existing problems and research direction of palygorskite clay activation are also discussed.

Abstract:This paper studied the adsorption of heavy metal ions on kaolinite in the presence of humic acid (HA). Three adding sequences, composed of one co-adsorption process and two pre-adsorption processes, were compared with each other in this study. When Cu2+equilibrium concentrations were lower than 10 mg/L, no significant difference in the amount of Cu2+ adsorption was observed in the three adding sequences. When Cu2+ equilibrium concentrations were higher than 10 mg/L, the Cu2+ adsorption amount for co-adsorption and kaolinite pre-equilibrated with two Cu2+ adding sequences were slightly higher than that for kaolinite pre-equilibrated with HA. In order to investigate the effect of HA on heavy metal retention, the authors first prepared the HA-kaolinite complexes by adding HA solutions of varied proportions to kaolinite, and then used the HA-kaolinite complexes to study Cu2+ adsorption at pH 5. The results show that complexes have higher Cu2+ adsorption capacity than pure kaolinite. When HA contains carboxylic and phenolic active groups, the adsorption sites on kaolinite increased by HA adsorbed on kaolinite and form the S—HA—Cu ternary structure on the complex surface. The Cu2+ adsorption amount was related positively to the proportion of HA in the complexes. The formation of the S—HA—Cu ternary structure is the main adsorption mechanism on HA-kaolinite complexes at pH ＜5. Several mechanisms coexist in the complex system when the pH increases from 5 to 7. In the solution con-taining Cu2+ and Cd2+ at 1∶1 molar ratio, the HA-kaolinite complex displays higher selectivity to Cu2+ as compared to Cd2+.

Abstract:The study aims at improving the adsorption performance of montmorillonite for relatively large molecules. Making use of the property that phenanthroline can form coordination compounds by reacting with the transitional metal cations, the authors modified montmorillonite by using two different methods. The effect of the formation forms of coordination compounds on the structure and the absorption performance of modified montmorillonite were studied by measuring its decolorization performance for dye and analyzing its X-ray diffraction. In this paper, the thermal stability of modified montmorillonite was investigated too. The results show that the interlayer spacing of montmorillonite can be further enhanced through the reaction of montmorillonite containing transitional metal cations with phenanthroline to reach over 1.76nm. It is shown that the two-stepsynthetic method, by which metal cations are introduced into the interlayer of montmorillonite and then the coordination compounds are in-situ synthesized, hasa better effect. In addition, modified montmorillonite shows a fairly good thermal stability up to 400℃.

Abstract:A series of chlorinated hydroxyapatite(ClHAp) solid solutions composed of hydroxyapatite and chlorapatite were synthesized by the solid reaction method and were investigated using FTIR spectroscopy. In the experiment, vibration frequency of the hydroxyl group appeared at 3572 and 632 cm-1 in pure hydroxyapatite(HAp). When Cl- ions entered the crystal structure of HAp, a new absorption band was observed at 3494 and 673 cm-1respectively. These phenomena indicated that the hydrogen-bond forming in the channel structure made the stretching band shift towards a lower frequency and also resulted in the flexual band shift towards a higher frequency. A comparison with the FTIR spectra of fluoridated hydroxyapatite showed that the location and amount of vibration bands of the hydroxyl group in ClHAp were mainly affected by the hydrogen_bond and its surrounding structural variation.

Abstract:This paper has studied the effect of tourmaline powder on the treatment of CODCr in oilfield waste water under different conditions. The result shows that the rate of CODcr degradation is mainly affected by such factors as processing time，quality，particle diameter and aqueous pH. Under the conditions of processing time 60 min，tourmaline powder quality 200 g/L，particle diameter 100μm andpH 9.0， the CODCr of oilfield waste water was reduced to 68.46 mg/L，and the cleaning rate reached 82.25% For the purpose of finding the best treatment conditions，the effect of tourmaline powder on the CODCr in oilfield waste waterwas studied in combination with the means of ultraviolet ray, infrared ray and ultrasonic wave. The results show that these three methods are effective. The treatment rate exceeded 90% when the study was combined with ultrasonic wave, and the processing time was shortened by more than 83% when the study was combined with ultraviolet ray. This experiment has broadened the application field of this kind of environmental mineral material.

Abstract:Using such means as ICP-MS, IC, XRD and IR, this paper has systematically studied the compositions of Chinese pearls and their shells characterized by different geneses or different localities. Some conclusions can be reached: ① Freshwater cultured pearls contain relatively rich P, Mn and Ba, whereas sea-cultured pearls have comparatively abundant Sr, Zn, Cr and Ni. ② Compared with freshwater cultured pearls, sea-cultured pearls have more varieties and higher content of cations and anions as well as higher content and level of amino acid. ③ There exist consistent compositional variations between sea-cultured pearls and their shells or between freshwater cultured pearls and their shells. Nevertheless, there are obvious compositional differences between the nacres and the pearl cores of sea-cultured pearls. These results can play a certain role in identification and theoretical-pharmacological researches of pearls.