Abstract:The Qunjisayi porphyry granite is located in Awulale area of Western Tianshan Mountains. It intruded into the volcanic rocks of lower Permian Wulang Formation located at the northwestern end of the Qunjisayi anticline. All samples from the pluton are characterized by porphyraceous texture, the phenocrysts are composed of plagioclase, potassium feldspar, hornblende and biotite, and the matrix consisting mainly of plagioclase, potassium feldspar and quartz is of granitic hypidiomorphic microcrystalline-granular texture. The porphyry granite is geochemically characterized by high SiO₂ (71.17%～72.59%)and Na₂O(8.86%～9.39%), and low K₂O(0.07%～0.28%), with A/CNK being 0.87～0.92 and A/NK 0.97～1.01. It is enriched in Th, U, Pb, but depleted in Nb, Ta, Sr, P and Ti. It is also depleted in Rb, Ba and K relative to Th and U. The porphyry granite belongs to peralkaline-mataluminous fractionated I-type granite. The zircon SHRIMP U-Pb age of the porphyry granite 302±4 Ma indicates its generation in the Late Carboniferous to Early Permian period. It is suggested that the porphyry granite is similar to the lower Carboniferous basalts in the same area, as evidenced by the following data: low initial Sr isotope ratio (I_Sr=0.705 12～0.705 36), positive εNd(t)=＋2.1～＋2.7,f_Sm/Nd=-0.43～-0.56 and the Nd model age(t_DM=713～863 Ma). In association with the tectonic background, it is inferred that the primary magma of Qunjisayi porphyry granite was most likely derived from the partial melting of the underplating basaltic rocks under the conditions of amphibolite- or garnet-phase after collision.

Abstract:The Yinachang deposit is located in central Yunnan Province and geotectonically lies along the southern Kangdian axis and on the southwest margin of the Yangtze block. It is a typical Proterozoic Fe-Cu-Au-REE deposit in this area. The ore-forming process can be divided into four stages: magma stage, metasomatism-mineralization stage, hydrothermal ore-forming stage and post-mineralization stage, among which the first 3 stages constituted the dominant period for the precipitation of Fe, represented respectively by breccia magnetite, disseminated magnetite and grained veinlet magnetite. Magnetite of the 3 kinds contains certain amounts of SiO₂, Cr₂O₃, Al₂O₃ and MgO, and the breccia magnetite has the highest radio between major elements and Fe, foll-owed by disseminated magnetite and veinlet magnetite. Magnetites of different types show remarkable differences in trace elements content. The distribution of rare earth elements in disseminated magnetite has lanthanide tetrad effect, while the distribution of the breccia magnetite and the grained veinlet magnetite is right-oblique. The formation of the magnetite at Stage 1 was considerably controlled by magmatic activity, and the upwelling of Fe-hosting magma caused the deformation of wall rock and the precipitation of the breccia magnetite. Fe-bearing fluid was separated from the magma at the metasomatism stage, and went through a composition exchange with the wall rock, which led to the precipitation of large quantities of iron. The addition of outer fluid at the 3rd stage reformed the magnetite, making the magnetite more similar to that of hydrothermal origin. According to the composition of the magnetite, the deposit has a magma-metasomatism mechanism, similar to things of the IOCG deposit.

Abstract:The Xikuangshan type ferro-copper deposit is an important deposit type in the Dongchuan copper mine. Although previous researchers made detailed investigations, the origin of this kind of deposit remains controversial. In order to probe into the genesis and sources of the ore-forming materials of its ferro-copper layer, the authors analyzed the O isotopic compositions of the Xikuangshan type ferro-copper deposit and studied its isotope geochemistry. The results show that the values of δ³⁴S in sulfides (from -10.9‰ to 15.9‰, with an average of 0.455‰) can be divided into three groups: ① values between ±4‰ (15 pieces), with the characteristics of meteoritic sulfur; ② values in the range of ±(5～8)‰ (6 pieces), influenced by the volcanic sedimentation; ③ values in the range of ＞10‰ or ≤-10‰ (2 pieces), suggesting that sulfur came mainly from the rock magma (volcanic eruptions) and subordinately from seawater sulfate and stratigraphic biological sulfur. The carbon of the Xikuangshan type ferro-copper deposit has the characteristics of mantle-derived carbon, implying that mantle material participated in the ore-forming process. The δ¹⁸O_V-SMOW values of magnetite change between 1.3‰ and 9.8‰, with an average of 4.875‰. The composition characteristics of O isotope indicate that the deposit belongs to the volcanic sedimentation-exhalation deposit. The main ore-forming source came from volcanic eruption, and the metallogenesis was connected with magmatic activities, marine facies chemical sedimentation and seafloor hydrothermal solution sedimentation.

Abstract:The formation conditions of phenakite were studied through investigating its gas-liquid inclusions by means of Laser Raman spectrum analysis and microscopic heating/cooling stage. The observation of phenakite samples revealed numerous randomly-distributed yellow acicular transparent solid inclusions, a few red granular opaque solid inclusions, lots of gas-liquid inclusions and healed cracks. The gas-liquid inclusions in phenakite were divided into two types according to their forms and substances. Type Ⅰ included rich liquid two-phase H₂O-NaCl inclusions (Ⅰa) and pure liquid H₂O-NaCl inclusions (Ⅰb), whereas Type Ⅱ could be further divided into three-phase H₂O-NaCl-CO₂ inclusions containing liquid CO₂(Ⅱa) and two-phase H₂O-NaCl-CO₂ inclusions without liquid CO₂(Ⅱb). Then some gas-liquid inclusions of different types with clear demarcated gas part and liquid part were chosen to do further test. Using Laser Raman spectrum analysis, the authors affirmed that phenakite is a kind of silicate which contains Be as the matrix for inclusions, and that the gas part of the gas-liquid inclusions contain such components as CO₂ and water vapor, whereas the liquid part is NaCl aqueous solution with the dissolution of a little CO₂. Two different gas-liquid inclusions were chosen for microscopic heating/cooling stage test, and the results show that the homogenization temperatures of the inclusions are from 378.9℃ to 425.5℃ by homogenization method, and their freezing points are about -12.1～-6.3℃ by freezing method. These data were used to figure out the salinities of these inclusions, which are 9.60%～16.14%. Calculations show that the homogenization pressures range from 234.44 MPa to 428.56 MPa. The formation temperature and the formation pressure of phenakite estimated from homogenization temperature and homogenization pressure are about 378.9～425.5℃ and 234.44～428.56 MPa respectively.

Abstract:The CO₂ fluids and volcanic clastic rocks chosen from Nanbeier Depression were studied experimentally at different temperatures(100, 120, 140, 160 and 180℃). The results show that the corrosion intensity of feldspar and calcite will be enhanced gradually with the increasing temperature, but the dissolution degree of quartz is very low. The tuffaceous material can be dissolved by CO₂ fluids, and it seems to be the main dissolution object of CO₂ fluids. Chlorite and boehmite were found on the surface of the sedimentary tuff sample at the temperature of 160℃ by scanning electronic microscope (SEM). Considering that there are a good many carbonate minerals (especially dawsonite) and secondary solution pores in Tamtsag Basin, the authors hold that the CO₂ fluids have made considerable contribution to the formation of secondary pores in Tamtsag Basin.

Abstract:As one of the significant geological units in the Helan Mountain area, the Suyukou Formation has long been considered to be of the coastal beach facies. In this study, lithology, facies, biota and other new findings show that it was deposited in the alluvial fan facies. An erosion surface is located in the base of the alluvial fan, which is characterized by complex gravel, heterogranular texture, graded bedding, and turbidity current. Zircon dating of diabase yielded ages of 530～540 Ma, suggesting an early cracking basin, which probably resulted in the formation of the alluvial fan in the Suyukou Formation.

Abstract:In this paper, the effect of various inhibitors, such as disodium hydrogen phosphate, citric acid and sodium silicate, on flotation separation performance of powder quartz and andalusite was investigated by using sodium oleate as the flotation collector. The results showed that disodium hydrogen phosphate was an efficient inhibitor for separating andalusite from powder quartz. When the concentration of disodium hydrogen phosphate was set to the optimum one of 0.47×10^-2 mol/L and the pH of flotation liquid to 8.5, the recovery difference between andalusite and powder quartz was as high as 47.86%. The results of infrared spectra and Zeta potential analyses revealed that the interaction between sodium oleate and andalusite powder resulted from the physical and chemical adsorption, while that between sodium oleate and powder quartz was due to the physical adsorption, suggesting that sodium oleate was more efficient in collecting andalusite. Also disodium hydrogen phosphate was found to play the role of desorption of powder quartz from sodium oleate, consequently inhibiting the flotation of powder quartz and resulting in the flotation separation of powder quartz from andalusite.

Abstract:The end-member extraction is the foundation of the hyperspectral remote sensing information extraction and analysis and is also the key to pixel unmixing. In view of hyperspectral remote sensing data characteristics of the study area, the authors carried out the digital image processing of the radiance correction, minimum noise fraction (MNF) and pixel purity index (PPI) and, on such a basis, extracted the end-member spectra by using two-dimensional scatter diagram and three-dimensional scatter diagram, and conducted the research on the discrimination of end-member attributes. The extraction and analysis of rocks and minerals constitute the foundation for the recognition of rocks and minerals and directly affect the accuracy of the results.

Abstract:The formation characteristics of the iron-manganese oxides were studied by leaching the quartz sand columns periodically with different concentrations of mixed iron and manganese ions for forty times. The results were as follows: ① With the increasing leaching times, the concentrations of iron and manganese ions and pH value of leaching liquids generally exhibited decreasing first and increasing afterwards. ② Iron and manganese oxides produced under different treatment conditions showed extremely significant difference in content. The higher the concentrations of iron and manganese ions in the treatments were, the higher the content of iron and manganese oxides coated on the sands was. The condition that the molar concentration ratio of iron and manganese ions of leaching liquid was 2∶1 seemed to be the most favorable condition for the formation of iron and manganese oxides. With the increase of leaching times, the increase of iron-manganese oxides content slowed down. The content of iron and manganese oxides in different layers of sand columns showed significant difference. The content of oxides in the sub-layer (20～30 cm) was obviously higher than that in the other layers. ③ The correlations between different forms (amorphous form and crystal form) of iron oxides and manganese oxides in various stages (ten leaching times comprising one stage) showed difference, and the ratio of iron and manganese oxides, especially in amorphous form, rose with the increase of leaching times.

Abstract:Calcined kaolin used in specific paper filler requires a higher oil absorption value. In view of the resource shortages of the calcined kaolin with high oil absorption value in the market, this study aims at investigating factors influencing the oil adsorption of the calcined coal-series kaolin and seeking for ways to improve the oil absorption value of calcined kaolin. Coal-series kaolin used as raw materials in this study was obtained from Tangshan area, which was calcined in the temperature range of 600～1 000 ℃, with the interval of 50℃. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to conduct morphologic observation and phase identification of calcined kaolin respectively. Calculation of loss on ignition and detection of such parameters as pH value, specific surface area and Zeta potential were used to analyze their influences on oil adsorption value. The results show that the highest oil adsorption value of calcined kaolin is up to 76.3 g/100 g at the temperature of 750℃; and Zeta potential, pH value, specific surface area constitute the notable factors influencing oil adsorption value, with the influence of specific surface area on the oil absorption value of the calcined kaolin being the greatest.

Abstract:This paper briefly reviews the research history of the welding process of volcanic pyroclastic materials both in China and abroad, sums up and explains the terms related to the welding process and, furthermore, discusses the textures and structures that occur in the process. In addition, the authors also try to summarize the welding mechanism of the pyroclastic rocks from both field investigations and indoor experiments and deal emphatically with the research significance, so as to arouse more attention to the pyroclastic materials in volcanic activities and related welding process among researchers in China, thus helping understand the volcanic eruption effect and rebuild the eruption history.

Abstract:The recent research on HP-UHP metamorphic tourmaline is summarized in this paper. Tourmaline is a common mineral existent in sedimentary, igneous and metamorphic rocks. A variety of experiments demonstrate that this mineral can be stable in an exceptionally large p-t range, i.e. at p-t conditions ＞850℃ and ＞4 GPa. Owing to the low volume diffusion, the preservation of growth zones in tourmaline has become an effective key to investigating the boron evolution in rocks, the fluid-chemical history and the metamorphism of rocks. The research on the structure and chemistry of tourmaline reveals that components, such as Al and F are correlated with the formation temperature. According to different boron sources, the formation modes of HP-UHP tourmaline can be categorized into three types, i.e., Type A, Type B and Type C. Based on the analyses of typical HP-UHP tourmaline in the world, the authors sum up the general characteristics of this mineral: ① most HP-UHP tourmaline is dravite; ② the crystallographic X-site is highly occupied (＞0.8 pfu); ③ excess B (3.2～3.3 pfu) is common; ④ Ti, Mn, Li and Cl have low abundances; and ⑤ the δ¹¹B values range from -16‰ to +1‰. As for future work on HP-UHP tourmaline, we should highlight the relationships between crystal chemistry and p-t conditions during its formation, the trace-element partitioning between tourmaline and fluids, and the phase equilibrium modeling for B-bearing mineral assemblages.

Abstract:The essence of A-type granitoids is the enrichment of iron and the depletion of magnesium, and the A-type granitoids mean the collage of the felsic igneous rocks formed under the reduced environment. The term "A-type granitoids" is purely descriptive, and has no petrogenetic implications. The origin of the common metaluminous and peraluminous A-type granitoids needs high geothermal gradient, whereas the low pressure is not the essential condition for generating these melts.

Abstract:A-type granites are silicon-, alkali-rich, water-poor granitoids, characterized geochemically by poor Al, Sr, Eu, Ba, Ti and P. A-type granites are formed under low pressure and high temperature conditions, and have no choice for source rocks. The essence of the A-type (or the Nanling type) granites lies in the melting of granitic magma under low pressure and their generation mainly in the tectonic setting of crustal extension and thinning. The several "A-type granites" abroad cited by Wang Yang et al. are actually mostly outside the category of A-type granites and were not formed under low pressure conditions.