Abstract:The West Tianshan area is located in the northern part of the Yili plate between the Junggar plate and the Tarim plate, and is an orogenic belt between the Junggar plate and the Yili basin. Porphyry deposits are mainly developed in Lailisigao’er area lying in the central part of the Late Paleozoic Biezhentao kokirqin arc island. The straight distance between the 3571 Cu deposit and the Lailisigao’er Mo deposit is less than 1 km. The ore-bearing porphyries are predominated by monzodioritic porphyry and granodioritic porphyry. Systematic petrological and mineralogical investigation indicates that the rocks are orogenic calc-alkalic granites formed under the conditions of anhydrous high-temperature (740～790℃) and high oxygen fugacity (10-9～10-11 Pa). Porphyries in the 3571 copper deposit were emplaced shallower than those in the Lailisigao’er ore deposit, as evidenced by the estimation of the pressure (the former being 140～230 MPa and the latter 300～430 MPa). In addition, they were derived chiefly from the crust contaminated by mantle materials. Based on geological setting and geochemical characteristics, it is inferred that the dykes outcropped in the 3571 copper deposit may correspond to the upper part of the dykes from the Lailisigao’er ore deposit, and therefore the area beneath the 3571 ore district should be regarded as a potential target for the prospecting of porphyry Mo deposit

Abstract:The Beilekuduke biotite granites in the study area have long been thought to be of S-type. Nevertheless, the preliminary research conducted by the authors shows that biotite granites are actually typical aluminous A-type granites, which have the following characteristics: enriched silica (SiO2=75.25%～76.67%) and alkali (Na2O+K2O=8.08%～8.97%), low magnesium (MgO=0.02%～0.18%) and calcium (CaO =0.39%～0.89%), obvious variation of oxidation index (W=0.02～0.12), high FeOT/MgO ratio (12.71～84.51, 34.55 on average). K2O＞Na2O, NK/A=0.86～0.95 (0.92 on average), A/CNK=0.97～1.02 (higher than 0.95), thus belonging to sub-aluminous—ultra-aluminous calc-alkali—weak-alkali rocks. In trace element and REE characteristics, the rocks are enriched in HFSE (such as Ga, Zr and Hf) and depleted in Ba, Nb and Sr. 10 000 Ga/Al ratios (2.97～4.20) are exclusively higher than the lower limit value of the A-type granites (2.6), obvious higher than average values of I-, S-type granites (2.1 and 2.28, respectively). In Zr, Ce, Nb versus 10 000 Ga/[CM(46]Al and FeOT/MgO versus (Zr+Nb+Ce+Y), SiO2 diagrams, the samples fall into the area of A-type granites, and are obviously different from things of I, S-type granites. The above characteristics show that Beilekuduke biotite granites are very similar to such typical aluminous A-type granites in the world as aluminous A-type granites in the coastal area of Fujian Province, in west and east Jungaar and in the Lachlan fold belt of southeastern Australia. In Nb-Y-Ce, R1-Ga/Al and R1-R2 tectonic diagrams, they belong to post-orogenic granites. The determination of the Beilekuduke typical aluminous A-type granites not only has geological significance in the study of the crust material composition and tectonic evolution in Kalamaili area but also opens up a new orientation in looking for tin resources related to aluminous A-type granites in northern Xinjiang.

Abstract:The Bairendaba silver-polymetallic deposit is located in Keshiketeng County of Inner Mongolia, China. The region is an important part of the metallogenic belt on the western slopes of the southern Da Hingan Mountains. Proterozoic biotite plagiogneiss (Baoyintu Formation) and Variscan quartz diorite outcrop in the district. Based on vein cross-cutting relationships and ore structure, three mineralization stages can be recognized. These comprise: quartz-polymetallic sulfide stage, fluorite-hydromuscovite stage and calcite-sulfide stage. Arsenopyrite, pyrite, chalcopyrite, marcasite, pyrrhotite, sphalerite, galena and boulangerite are the main metal minerals, while the gangue minerals are dominated by quartz, fluorite and calcite. Petrographic, microthermometric and LRM (Laser Raman Microprobe) results of fluid inclusions in quartz from stage 1 and fluorite from stage 2, show that from stages 1 to 2, the ore-forming fluids pass from high-moderate temperature, CH4-rich fluid to low temperature water-rich fluids. The salinity of the ore-forming fluids is low salinity. Pure CH4-fluid inclusions were found in quartz from stage 1, but not in fluorite from stage 2. Integrating data on ore geology, regional mineralization background, distribution of mineral deposits and fluid inclusion results, it is concluded that the Bairendaba silver-polymetallic deposit is a Yanshanian magmatism-related, structure-controlled and moderate-low temperature hydrothermal system. Sulfur isotope composition suggests a deep source for ore-forming material.

Abstract:The carbonatite paleokarst rocks of Upper Carboniferous Huanglong Formation constitute one of the most important natural gas reservoirs in Linshui of eastern Sichuan-northern Chongqing area. Based on structural features of karst rocks, the authors have divided the karst rocks of Huanglong Formation into four types, namely slightly corroded karst rock, medium degree corroded and porous karst rocks, strongly corroded brecciated karst rocks and strongly corroded and altered secondary gray-karst rocks. Moreover, two types of cements of limnic calcite and limnic dolomite and hydrothermal dolomite of reburial period are included in the karst rocks. A synthetic analysis of geochemical characteristics of rare earth elements has led to the conclusion that karst rocks or cements of different rock textures, components and corrosion intensities obviously have different REE geochemical characteristics. It is thus thought that the migration, distribution, enrichment and abnormal effects of the REE can not only be used to distinguish fluid properties and paleo-hydrologic conditions but also serve as one of the important indicators for evaluating and forecasting paleokarst rock reservoirs.

Abstract:The pelletal grained pumpellyite (Fe2+)（?）occurs in basaltic druses of Zhaotong area, Yunnan Province. The associated minerals include epidote, babingtonite, quartz, prehnite, calcite etc. Scanning electron microscopy reveals that pumpellyite (Fe2+)（?） is tabular and somewhat bended in the direction of cylinder and forms grains around the inclusions. The growth modes depend on the position of inclusions in grains, and the nearer it is to the surface of grains, the more parallel its arrangement. The fluid inclusion thermography and Raman spectra of quartz indicate that pumpellyite (Fe2+)（?） is a product of low temperature hydrothermal activity(148～169℃), with the salinity being 11%～12% and the ore-forming fluids enriched in H2O and minor CH4. In addition, the formation of pumpellyite (Fe2+)（?）grains is possibly related to organic material(CH4).

Abstract:A layer of oolitic hematite deposit occurs at the bottom of the Carboniferous Zongchanggou Formation in Longmenshan, Sichuan Province. The ferruginous oolith within it consists of various nuclei and concentric lamellar shells. The oolith nuclei are mainly comprised of hematite intraclast, fragmentized oolith shells or hematite that contains terrigenous quartz sand. The obvious differences of colors and components exist between the oolith lamellar shells composed of hematite and those composed of kaolinite. The lamellar shells can be divided in color into dark black, ferruginous red and white, with the corresponding Fe2O3 content of the lamellar shells being 39.472%～8.200%, 12.988%～24.275% and 3.617%～9.230% respectively. An analysis of components, texture and relative characteristics of oolitic hematite enables us to make an estimation. It is held that the oolitic iron was formed in a semi-closed or closed barrier lagoon environment. The iron and aluminum weathering crust formed in late Yanguan stage provided the material foundation for the generation of oolitic hematite.

Abstract:he authors analyzed chemical characteristics and differences between sedimentary rocks, and the results obtained have established the application basis for X-ray fluorescence (XRF) analysis in logging, which is a new logging technique called XRF-logging. The differences in lithologic characters and thicknesses of strata provide a prerequisite for the stratigraphic analysis with the XRF-Logging technique. It is proposed in this paper that the decimeter should be used as the criterion of the lower sampling limit for the XRF-logging technique. A practical procedure for identifying lithologic character and judging horizons using the XRF-logging technique is illustrated in this paper, and a prediction of the application vista of the XRF-logging technique is also given. It is pointed out that the main element database of sedimentary rocks and stratigraphic profiles should be established for further application of the XRF-logging technique.

Abstract:Volcanic rocks constitute the main deep exploration target in eastern Changling depression. Drastic changes in volcanic lithofacies and lithology as well as strong reservoir heterogeneity make it difficult to predict favorable reservoir belts. Based on volcanic exploration results in the depression, the authors studied the volcanic features, distribution, main controlling factors for the formation of reservoirs and the exploration potential. The volcanic rocks in the depression are mainly distributed along big deep faults and superimposed by many times of volcanic eruption in the vertical direction. There exist four kinds of volcanic lithofacies and nine sorts of subfacies. Explosive tuff and overflow rhyorite reservoirs have many gas pores, solution pores and fractures, and possess the best physical properties. The deep formation in the depression has experienced a low exploration degree but possesses abundant hydrocarbon resources, and volcanic rocks are distributed extensively there and have good reservoir-forming conditions, suggesting a very promising hydrocarbon exploration potential.

Abstract:Velocity sensitivity in the Ed3 reservoir of Gaonan area results from the migration of kaolinite distributed in pores. As the length and diameter of kaolinite are dominantly larger than the throat diameter, the velocity sensitivity becomes increasingly lower in samples with the lowering clay matrix content and gets higher and higher with the increasing clay content. Calcite cement is mainly distributed in rock pores of the reservoir, and minor cement and clay mineral matrix are distributed in the throat, indicating that earth acid rather than hydrochloric acid is more effective in acidification. Due to the extensive existence of secondary enlarged quartz in throat, strong alkali drilling fluid may somewhat help to improve the reservoir permeability. However, as the critical value of pH is about 7.7 which results in the secondary precipitation, and the flowing back of the drilling fluid is difficult, the alkalinity of drilling fluid should be taken into account during the drilling process. Montmorillonite and illite/montmorillonite are different greatly in content in different positions, which determines the difference of salt sensitivity in the reservoir.

Abstract:With the continuous appearance of jades associated with jadeite, the researches on the genesis and synthetic technology of jadeite are facing new challenges and opportunities. The existing National Standard of Jadeite Nomenclature has become too broad, and it is difficult to distinguish jadeite in the traditional concept from its transitional species, which would hinder the healthy development of the market. In addition, more and more studies show that in the subduction zone of high pressure, jadeite is spatially and temporally related to other high-pressure rocks such as ureyitite (jade), omphacitite (jade) and groeclogite. The authors believe that the diversification of rock zonation and lithology of these high pressure rocks can be attributed to the metasomatism that took place between deep melt and ultrabasic rocks in the subduction zone, and thus propose a hypothesis of subduction melt metasomatism to explain jadeite formation. It is held that the subduction zone, deep melt and ultrabasic rocks constitute three necessary conditions for the formation of jadeite and its transitional varieties. It is also thought that the introduction of fluid phase in the synthesizing process can possibly alleviate the harsh conditions of high temperature and high pressure reaction and hence realize the successful synthesis of commercial jadeite.

Abstract:Using Na-bentonite from Xinjiang as materials of geosynthetic clay liner (GCL), the authors performed the dry purification middle test and industrial test to determine the best production condition. The results prove that, under the best condition, the performance of the product is greatly improved, and the expansion index and the methylene blue adsorbed by bentonite can reach the GCL product standard without the addition of any subsidiary materials. The outcome obtained by the authors can be used to directly guide industrial production and hence have a very important practical and economic significance.