Abstract:Major element, trace element and Sr_Nd isotope data of two types of Late Mesozoic metaluminous and high_K calc-alkaline intermediate_felsic volcanic rocks from the Lishui Basin in Lower Yangtze valley are reported in thispaper. The first type is represented by the trachyandesites occurring in the Longwangshan Formation. These rocks span a SiO2 range of 58.0%～58.9%, characterized by significant LILE (e.g.,Rb=104×10-6~117×10-6, Ba=651×10-6～695×10-6)and LREE (e.g.,Ce=47.44×10-6～4896×10-6)and Nd-Ta depletion with insignificant Eu anomalies (Eu/Eu*=0.87～1.01,with an average of 0.95), and similar Sr and Nd isotopic compositions[87Sr/86Sr(i)=0.705?51～0.705?57, εNd(t)=-3.6～-2.9］to thecontemporaneous mafic lavas. These rocks are spatially coeval with the mafic volcanic rocks and are interpreted as the differentiates of the basaltic magmas after removal of a fractional assemblage of amphibole + plagioclase + apatite. The second type is composed of trachytes occurring in the Dawangshan Formation. These rocks span a SiO2 range of 61.9%～66.4% and MgO range of 1.07%～2.56%,showing similar trace element features to trachy-andesites of the Longwangshan Formation. Compared with basalts and trachyandesites from the Longwangshan Formation, they have higher k2O, Rb, Th, REE, HFSE, lower FeOT, TiO2, P2O5, CaO, Sr and compatible element contents, and more radiogenic Sr and less radiogenic Nd isotopic compositions [87Sr/86Sr(i)=0.706 63～0.708 13; ε Nd(t)=-7.7～-4.8］. The unique characteristics (e.g., K-rich, metaluminous and dacitic compositions) in these rocks argue against an origin of crust_derived melts. It is thus considered that these melts as differentiates of the primary basaltic magmas were subjected to as similation and fractional crystallization. 

Abstract:In rock series, Yanshanian intrusive rocks in the Zhejiang-Jiangxi-Anhui border area are similar to those in the Tongling and Dexing areas, being all high-K calc-alkaline series. In rock types, the rocks in the Zhejiang-Jiangxi-Anhui border area are more acid than those in the Tongling and Dexing mineralization-concentrated areas, i.e., the rocks in the former consist mainly of monzonitic granite and granodiorite, whereas those in the latter are granodiorite and quartz diorite. Rittman index gradually increases, A/CNK gradually decreases and K/K+Na gradually decreases from the Zhejiang-Jiangxi-Anhui border area to the Dexing area, and then to the Tongling area. In petrologic chemistry, the intrusions in the Zhejiang-Jiangxi-Anhui border area are richer in Si and K than those in the Dexing and Tongling areas, with the evolution towards the depletion of Si and K from the Zhejiang-Jiangxi-Anhui border area to the Dexing area, and then to the Tongling area. The intrusions in the Zhejiang-Jiangxi-Anhui border area are depleted in Mg, Fe and Ca dark minerals and incompatible elements such as Ti and P. The intrusions evolved towards the depletion of Si, K and enrichment of Mg and Fe from the Zhejiang-Jiangxi-Anhui border area to the Dexing area, and then to the Tongling area. In original petrologic types, the rocks in the Zhejiang-Jiangxi-Anhui border area are mainly I-type monzonitic granite and dioritic granite, with very few samples belonging to S-type granite. There is no S-type granite in the Dexing and Tongling mineralization-concentrated areas. The trace elements, isotope features and petrologic features of the Zhejiang-Jiangxi-Anhui border area indicate that the source was mainly derived from the crust, whereas the source of the intrusions in the Dexing and Tongling areas from crust-mantle mixing, or from the entry of large amounts of mantle materials into magma. The Zhejiang-Jiangxi-Anhui border area is situated on the Jiangnan anticlise; the Dexing mineralization-concentrated area lies on the southeast side of the eastern anticlise, and is close to the Qiantang sag; the Tongling area lies in the lower Yangtze sag area. These backgrounds are likely to be some of the factors which result in the difference in original petrologic types of these areas. In the light of petrologic assemblages, original types, petrochemical features and sources, the authors hold that it is difficult to find the Tongling-type Cu deposits and the Dexing-type Cu, Mo deposits in other areas except for Xiaoyao area.

Abstract:The Xiangshan volcanic-intrusive complex consists of Late Mesozoic acid pyroclastic rocks interbedded with sedimentary rocks, acidic lava, intermediate-acidic shallow-ultrashallow intrusive rocks, composed mainly of clastoporphritic lava, granitic porphyry and rhyodacite. The magmatic activity started with the eruption, experienced mainly volcanic effusion and ended at shallow_ultrashallow magmatic intrusion. The rhyodacite, once as the overfall facies, belongs to 2ndmember of Upper Jurassic Daguding Formation. The single-zircon U_Pb dating of the rhyodacite shows that the age of the rhydacite is 129.54±7.93 Ma, younger than the age of clastoporphritic lava which is the principal part of Xiangshan volcanic-intrusive complex. Combined with the modes of occurrence and shape characteristics of the rhyodacite, this paper holds that rhyodacite is apost-volcanic shallow or ultrashallow intrusive body, i.e., rhyodacitic porphyry. According to the age data available and the borderline age of 145.5 Ma between Jurassic and Cretaceous, the authors consider that the formation age of the complex is Early Cretaceous.

Abstract:A series of leucogranites occur in lenticular and banded forms in the Altay high-grade metamorphic zone, Xinjiang. According to their mineral assemblages, these leucogranites can be divided into three groups: Al2SiO5_bearing leucogranites, muscovite-plagioclase leucogranites and muscovite monzo-leucogranites. An analysis of major elements shows that these leucogranites belong to S-type with A/CNK being 1.1～2.14. From the muscovite monzo-leucogranites through muscovite-plagioclase leucogranites to Al2SiO5_bearing leucogranites,SiO2 contents increase and Al203, Na2O and K2O contents decrease. The phase relations in pTpseudosection for the NKFMASH system and the calculation of melt composition at different pressures and temperatures show that the melts of Al2SiO5-bearing and muscovite-plagioclase leucogranites might have originated from an uplifting process of the kyanite-type metamorphic zone, with no relation to the muscovite dehydration-melting reaction. Moreover, the Al2SiO5-bearing ucogranites were probably not directly crystallized from the melt, but had to do with some losses of alkaline components through fluids. The uscoviteo-leucogranitesprobably originated from a heating process through the muscovite dehydration-melting reaction. The modeling of phase relations alsoindicates that the staurolite dehydration-melting reaction must have played a very important role in the melt formation.

Abstract:Petrological and mineralogical characteristics of the granulites from the Qiongzhong complex were studied in this paper, and the temperatureand pressure conditions for the formation of the granulites were estimated by avariety of geothermometers and geobarometers. The results show that the granulites belong to typical low-pressure granulites formed in an environment of high_temperature and low_pressure (low p/T), with peak temperature being 824±15℃ and corresponding pressure lower than 0.5 GPa. The granulites were cooled during late retrograde reaction which terminated at the temperature of 705℃, withthe corresponding pressure near the peak. Therefore, the p-T path of the low-pressure granulites from the Qiongzhong complex was clockwise, composed of two phases of heating during early slow decompression and nearly isobaric cooling (IBC) during late retrograde reaction. Combining characteristics of the p-T path of the granulites with the features of relatively weak deformation and regional tectonic setting，it is considered that the low-pressure granulites from the Qiongzhong complex were formed in an environment of crustal extension. The possible mechanism is as follows: because the crust was thinned by extension, the crustal heat flux was raised by the introduction of magmas generated through decompression of the asthenosphere, and then prograde metamorphism took place in theoverlying rocks (including crystallized magma); afterwards the geothermal gradient disturbed by extension was restored to normal gradient and, as a result, theclockwise p-T path composed of two phases of heating during decompres-sion and nearly isobaric cooling (IBC) was produced.

Abstract:During the period of Late Carboniferous and Early Permian, the sandstone with abundant volcanic dust fillings was mainly deposited in a peat marsh environment, which constituted a favorable reservoir of coal-formed gas in Ordos Basin. Studies show that the original fillings of sandstone are mainly superficially hydrolyzed volcanic dust, which is a superfine mixture of aluminosilicate and silicate. It is difficult for volcanic dust to form zeolite during hydrolyzing under the condition of acidic syngenetic water in a peat marsh environment. The tuff fillings of sandstone are susceptible to the property and activity of the formation water, and have mainly experienced synaeresis, dissolution, alteration, carbonate metasomatism and recrystallization in a burial environment. The evolution of tuff fillings of sandstone can improve the quality of reservoir locally, but enhance the heterogeneity of reservoir regionally.

Abstract:Molecular dynamic simulation, a kind of theoretical method that supplements high temperature and high pressure researches, was performed on MgSiO3 perovskite. The size effects on the properties of the systems, especially some parameters affected greatly by the system sizes, have been seldom discussed before.Two different sizes of cubes were simulated and, especially, the differences of thermal expansivity, compressibility and equations of state were compared. One 8×8×8 cells cube and one 4×4×4 cells cube were simulated from 300 K to 3?000 K and 0.1 GPa to 100 GPa in this study. The result shows that the equilibrium of temperature and energy not only coincides well with the experiment data but also agrees well with other thermal parameters and equations of state. Thermal expansivity of the two sizes in comparison with diamond anvil experiments indicates that the bigger cube coincides with Funamori et al.'s result. The diversities of the bigger cube are less than 1% from the results of high pressure and high temperature experiments.Consequently, simulating a system as big as possible canhelp to get a relatively reasonable molecular dynamic simulation result.

Abstract:With the continuous improvement of the isotopic and tracing technologies for dating rocks, geologists have gained increasingly deepened understanding of the mantle and the interaction between the crust and the mantle in the past twenty years. Correspondingly, the knowledge of the A-type granite has been continually renewed. At present, just like adakite, A-type granites have covered granitoids (including their extrusive rocks such as rhyolite and rhyoandesite). The identification of A-type granites depends increasingly upon their major and trace elements as well as their isotope characteristics. Although A-type granites have diverse sources and genetic models, their tectonic setting remains mainly dominated by the extensional system.

Abstract:With the development of modern analysis, great breakthrough in PGE measurement has been achieved. Platinum group elements(PGEs) can now be regarded as one of the important fields in petrology, ore deposits and geochemistry. At present, the PGEs are becoming an increasingly important element group to trace the characteristics of geochemical processing. In this paper, the new data of laboratory partitioning of platinum-group elements and gold are summarized from literature abroad. The results of the controlled atmosphere experiments have yielded more S-rich sulfides, which seem to be the most appropriate laboratory data to be applied to magmatic sulfide-PGE deposits. It is also found that the sulfide liquid immiscibility model alone can not account for the apparently high concentration of PGE-Au in PGE-Au sulfide reef deposits based on these laboratory partitioning coefficients, suggesting the existence of extensive transformation and enrichment by either rock-melt process or rock-fluid process during the protracted post-accumulation and late magmatic history of large igneous bodies.

Abstract:Contamination by continental crust or lithosphere can yield subduction-type signatures and lead to the misidentification of contaminated continental basalts as arc related ones. Uncontaminated asthenosphere (or plume) -generated continental basaltic rocks are normally characterized by (Th/Nb)N＜1,Nb/La≥1, low87Sr/86Sr(t) ratios, high εNd(t)values, similar La/Nb and La/Ba ratios to ocean island basalts (OIB) and “hump=shaped”mantle-normalized multi-element patterns without negative Nb, Ta and Ti anomalies. As the uncontaminated asthenosphere (or plume) -generated basaltic rocks have been found in the studied volcanic successions, the possibility can be basically excluded that they belong to island-arc or active continental margin volcanic rocks. For the basic lavas with subduction-type signatures, we can judge whether they are really island-arc or active continental margin basalts by studying Zr contents and Zr/Y ratios or Zr/Y[CD*2]Zr diagram.

Abstract:Synthetic 13X zeolite was used to conduct static adsorption experiments on lysine. The effects of pH, temperature, time and zeolite dosage on adsorption rate were experimentally investigated. In the experiments, the ratio of adsorption reached a plateau value when the adsorption time was 30 min at the ambient temperature, and the saturation adsorption capacity of 13X zeolite on lysine in wastewater was 51.73 mg.g^-1 when pH= pKa1 = 2.2. The adsorption isotherm for the process was approximately linear, and the ion exchange was probably the major adsorption mechanism. 13X zeolite could be regenerated by saturated NaCl solution without the noticeable loss of capacity. The desorption rate was higher than 95 %. Experimental studies indicate that 13X zeolite is suitable for the purification of lysine-bearing wastewater.

Abstract:The Longhekou Reservoir is a very important water source for the Chaohu Lake. Clay minerals from core ALE in the Longhekou Reservoir were analyzed qualitatively and semi-quantitatively. The result shows that the clay minerals are mainly chlorite (Ch/V), with many years' average quantity being 40%, subordinately kaolinite and illite, and minor smectite. 40 years' average quantity of illite in the reservoir is only 21%, lower than that of the surface sediments in the Xiaotian River (54%) and in the Huashi River (63.5%). The percentages of clay minerals in the Longtan River are similar to those in the Longhekou Reservoir,but obviously differ from those in the Xiaotian River ane Huashi River. The physiognomic and geological features have a strong impact on the surface sediments in the Longhekou Reservoir basin, and the sediments of the Longhekou Reservoir have an intimate relationship with the environmental dynamic forces and the features of clay mineral crystallization. The results also show that the clay minerals from the Laolong River have exerted an obvious effect on the reservoir sediments, and this is very important in the control of soil erosion.