Abstract:Southeast Hunan is divided into two tectonic units by the Indosinian primary subduction fault (Chaling_Chinzhou fault), i.e., Yanling-Rucheng upwarping region to the east of this fault, and Hengyang-Guiyang downwarping region to the west. The Indosinian granitoids are high-K calc-alkaline peraluminous on the whole, and can be divided into two groups. The first group occurs in the NW-trending faults of Hengyang-Guiyang downwarping region, and is composed of hornblende biotite granodiorite, hornblende biotite monzogranite, biotite monzogranite and two-mica monzogranite; the rocks have relatively low contents of SiO2 with an average of 69.68%, and are mostly weak peraluminous with an average ASI value of 1.08 (0.96～1.29); they have comparatively low ISr values (0.708?0～0.716?8 ) and t2DM ages (1.48～1.72 Ga), high εNd(t) values of -8.90～-5.83. The second group lies in the Yanling-Rucheng upwarping region and Jiangjunmiao sub-upwarping region of Hengyang-Guiyang downwarping region, and is composed of fairly acidic biotite monzogranite and twomica monzogranite, with an average SiO2 content of 72.23%; the rocks are strong peraluminous with ASI valuesof 1.01～2.60 (averaging 1.30), and have rather high ISr values (0.715?9～0.734?5) and t2DMages (1.81～1.97 Ga) and low εNd(t) values (-12.0～-9.85). According to these characteristics as well as lithospheric structure and A/MF-C/MF diagram, it is thought that the second group granites were derived from schist and gneiss of the middle crust, whereas the first group granites came mainly from rocks of the middle crust, with the probable participation of minor basic granulite from the lower crust and mantle, suggesting the underplatingof mantle magma. Based on multiple oxide and trace element-diagrams for discrimination of structural environments, geological characteristics and tectonic evolutional settings, the authors consider that the Indosinian granites were formedin a post_collisional tectonic setting of the syn_orogenic stage, and the thickening of the crust and the subsequent weakening of the stress caused the melting of the middle crust, with magma formed sequentially. The underplating of mantle magma caused lower crust and mantle materials to enter the granitic plutons in the downwarping region and deep faults. Researches indicate that the Early Yanshanian granitoids were formed in a post-orogenic tectonic setting, and the Indosinian and Early Yanshanian tectonic settings restricted each other.

Abstract:A harzburgite xenolith sample from Paleogene basalts in Shuangliao area of Jilin Province records the information of upper mantle metasomatism. Primary orthopyroxenes are surrounded by secondary clinopyroxenes and olivines, forming reaction texture or existing as residues in secondary clinopyroxenes. These phenomena appear around spinel only. Electronic probe analyses reveal that secondary clinopyroxenes are characterized by high Mg#, Cr# and CaO/Al2O3 , secondary olivines by high Mg#, CaO and Cr2O3 content, and the metasomatizedrim of spinels by high Cr# and CaO. As metasomatism had no influence on Mg# in peridotite, and the melt-rock reaction proceeded in order of Opx+Sp+melt (Ⅰ)→Cpx+Ol+melt (Ⅱ), the authors consider that the lithospheric mantle in Shuangliao area was metasomatized by carbonate melt or silicate melt rich in carbonate. This conclusion is based on experiments and literature. The metasomatismresulted in decreasing content of orthopyroxene, increasing contents of clinopyroxene and olivine in peridotite, and the transformation from harzburgites to wehrlites.This metasomatism may occur in the melt_rock reaction zone located in theasthenosphere-lithosphere boundary, suggesting that the asthenosphere-lithosphere interaction resulting from lithosphere thinning and asthenosphere upwelling remained active in Shuangliao area in Early Tertiary. 

Abstract:Zircon SHRIMP results indicate that the Caixi pluton in southwest Fujian was formed at 150±3 Ma. Caixi monzonitic granite is characterized by rich Si and alkali,weakly peraluminous nature, negative Eu (*Eu≈0.54～0.66) anomalies, enrichment of LREE, and depletion of Ba, Nb, Ta, Sr, P, Eu, Ti. They are characterized by Sr-Nd isotopic composition with (87Sr/86Sr)i being 0.710?462～0.712?265, εNd(t) -8.68～ -9.81 and t2DM1.51～1.61 Ga. The biotite of rocks is characterized by rich Al, Mg, and belongs to the type of crust-mantle mixed sources based on the triangle diagram of Fe2+ -Fe3+ -Mg2+.According to geochemical characteristics and petrological, mineralogical as well as geological data, it can be concluded that Caixi pluton be longs to the crust-source type granite formed by partial melting of the crust-derived rocks correlative to Proterozoic crust in the transformation from convergent to divergent tectonics. There were some materials mixed with the mantle materials in the process of rock formation.

Abstract:The Hercynian-Indosinian granitoids in Hongshishan area of the Beishan orogenic belt belong to the calc-alkaline series and have characteristics of is land-arc granitoids. A study of their petrochemical, geochemical and Nd-isotopic characteristics shows that they have the characteristics of “adakite”These rocks have the following characteristics: SiO2＞56％，Al2O3≥15％,Na2O and Sr are high, MgO<3％, Mg#=30.71～59.13, Sr/Y=19.71～72.86, Y<18×10-6（6.0×10-6～14.7×10-6）; no Eu anomaly or only weak negative Eu anomaly can be observed; REE distribution patterns show strong REE segregation and belong to the type of enriched LREE; and there exist very prominent negative Nbanomaly and obvious positive Sr anomaly in the trace element spidergram εNd(t) values are positive ［εNd（t）＝4.09～5.67］, major samples fallinto the area of adakite on (La/Yb)N-YbN and Sr/Y-Y diagrams Therefore, the discovery of the adakitic rock has great significance in the study of Late Paleozoic tectonic evolution and geodynamics and the search for ore deposits in the Beishan orogenic belt of Gansu Province

Abstract:The reservoir volcanic rocks of Early Cretaceous Yingcheng Formation in the Qingshen gas field of Songliao Basin are composed mainly of rhyolites. SHRIMP zircon U-Pb ages of nine volcanic rock samples from Xingcheng and Shengping range from 111Ma to 115 Ma, falling into the Early Cretaceous Aptian to Albian stage. The volcanic eruption ages of the two regions suggest that all the reservoir volcanics were formed at the same period of volcanism, and this understanding is quite different from the previous opinions on these rocks. In the past, the volcanic rocks were thought to have different ages, and the volcanic reservoir rocks of Shengping were believed to be younger (K1yc3) than those from Xingcheng (K1yc1) . It seems that these opinions should be modified according to the authors' results. The results achieved in this paper is of great significance in exploring and exploiting volcanic gas pools within the Songliao Basin.

Abstract:The thermoluminescence (TL) technique has been widely used in various academic fields, but has not yet been involved in the determination of the volcanic cycle (stage) and the judgment of the type of volcanic rocks. Based on studying the TL features of all the volcanic rock samples from the boreholes Shengshen 7 and Yangcan 1, Xujiaweizi,Daqing City, as well as some samples from other boreholes, the authors have reached the following conclusions: (1) In the borehole Shengshen 7, the TL peak-types and total TL integral intensities of the rocks are similar to each other at the top, probably suggesting that the volcanic rocks are eruptive materials of the corresponding period; the TL parameters of the rocks vary rhythmically in the middle and at the bottom, and this may be the result of thermal alteration of the rocks at the top of each eruption by later eruptive materials which consumed part of the cumulated radiation. (2) In the borehole Yangcan 1, the volcanic cycles (stages) can be divided into two subcycles and four stages based on the TL feature variations. At the bottom of the cycle, the rocks show double TL peaks, and the intensities of the main TL peaks show remarkable differences, proba-bly indicating that the bottom rocks are multisource ejected prod-ucts from different volcanic structures, and the products of the small cycles are superimposed upon each other; the intensity of the dominant TL peak decreases upward,reflecting the declining of the eruptive activity of the volcanics. The rocks at the top cycle show a single peak, and the TL intensities only show insignificant differences, implying that the rocks belong to a suite of cognate products. (3) In the borehole Shengshen 7, the TL features of the andesites without obvious alteration are similar to each other; and in the borehole Yangcan 1, the TL features of the tuffaceous rocks with homogeneous lithofacies and without alteration are very similar too. These phenomena show that the utilization of the TL technique to distinguish rocks of pyroclastic fallout facies and determine lithology of lava is feasible.

Abstract:Using the homogenization temperatures of brine inclusions formed in the same period as hydrocarbon inclusions, in combination with the burial and heat history, the authors got to know that the formation time of the natural gas reservoir of sandstone in 3rd and 4th Member of Denglouku Formation should be 96～81.5 Ma, which can be further divided into three periods, namely 93～91Ma, 88.8～82.8 Ma and 82 .3 Ma～81.5 Ma. The first two periods lasted relatively long, whereas the third period lasted comparatively short. According to the phenomena that the distribution of the secondary pores is controlled by T4 fault macroscopically and that there exists the development-underdevelopment-development cycle microscopically, it is held that fractures served as the migration pathways of the acid fluids. The formation time of early T4(the sedimentary time of Denglouku Formation, 1st Member of Qingshankou Formation and Yaojia Formation) was the time when the secondary pores were formed. The matching of the reservoir and the cover seemed to be most perfect in the sedimentary period of 1st Member of Qingshankou Formation, during which the formation time of the secondary pores and that of the injection of hydrocarbon matched well, resulting in the easy formation of gas reservoirs. The matching of the reservoir and the cover was relatively good in the sedimentary period of Yaojia Formation, however during which the gas source remained insufficient. In this period, the secondary pore belts could form low-yielded gas reservoirs or gas-water formations. The matching of the reservoir and the cover was the worst in the sedimentary period of Denglouku Formation, during which the secondary pore belts could hardly be preserved, leading eventually to the formation of dry formations.

Abstract:With the high_temperature_pressure technique, the crystalline melt inclusions (MI) in beryl from Xihuashan wolframite-quartz veins were homogenized and quenched into glasses. The glasses were analyzed by electron microprobe for the first time. It is shown that they are composed mainly of SiO2(70.72%) and Al2O3 (13.94%), with minor K2O(2.0%) and extremely low other oxides. Melt inclusions contain a lot of dissolved volatile components (mainly H2O, up to11.5%). The liquid-and gas phase of fluids in melt inclusions was analyzed by laser Raman microspectrometry, and the results indicate that CO2 and H2S contents are relatively low in liquid phase (CO2～7.8%,H2S～4.3%), whereas gas phase consists mainly of reduced gas. The analyses of glasses represent the composition of residual melt at the final stage of crystallization differentiation in the granite-H2O_HF system. Melt inclusions coexisting with primary fluid inclusions in beryl from wolframite-quartz veins suggest that the ore-forming fluids were not only hydrothermal solution but also magmatic-hydrothermal transitional fluids composed of coexistent silicate melt and supercritical fluid, and mineralization began at the magmatic-hydrothermal stage.

Abstract:Intergranular rutiles from six UHP eclogites in the Dabie orogen were investigated by Micro-FTIR and EMP analysis. The results show that all grains show two strong absorbance bands at 3280 cm-1 and 3295 cm-1, withan occasional weak and wide absorbance band at ～3360 cm-1, which are all ascribed to structural OH. Comparisons with the results of HT-HP experiments indicate that the 3280 cm-1 band is caused by Ti3+ +H <—>Ti4+substitution, the 3295 cm-1 band is attributed to Fe3+ +H<—>Ti4+ substitution, and the ～3360 cm-1 band is possibly related to Mg2+ +2H<—>Ti4+. The calculated water contents (expressed as H2O wt.) based on two reliable IR absorbance coefficients are 161×10-6～854×10-6 and 202×10-6～1075×10-6respectively, and the results will increase by about 4～5 times if other absorbance coefficients are applied. Hence the relatively high water content in literature should be considered carefully. Similar to coexisting garnet and omphacite, heterogeneous distribution of water on the outcrop scales in rutiles implies a very limited fluid mobility during UHP metamorphism and a quick subduction and exhumation process. 

Abstract:Based on powder simulation experiments, the authors preliminarily simulated the acid and alkaline environments in which the ancient jades are buried. In the soaking experiment, the different massive shapes of jade materials were dipped in acid and alkaline buffer solutions, and the contrast analysis with the result of the powder simulation experiment was carried out, with the purpose of deepening the understanding of the weathering mechanism of the ancient jade.

Abstract:Selecting natural dolomite as raw materials, the authors made a new kind of pearl nuclei through mechanic grinding and surface treatment. Beside having similar properties to mollusc shell nuclei, the new pearl nuclei possess some advantages such as white color, strong luster, round shape and cheap cost. The research and development of the new pearl nuclei can not only protect biological resources and ecological environment, but also help to meet the need of future pearl production.