花岗岩造岩矿物的分选试验研究

Procedures of mineral separation for rock.forming minerals from granites (biotite,phlogopite, muscovite, serisite, amphibole, quartz, K-feldspars and plagioclase) are presented. By taking advantage of differences in the physical and chemical properties of these minerals, end product containing 98 percent or more of a singular mineral.species can be obtained for mineralogical studies.     

吉林陨石的不透明矿物

Opaque minerals in the Jilin meteorite inelude kamacite, taenite troilite, chromite, ilmenite, schreibersite, pyrite, pyrrhotite, chalcopyrite, sphalerite and graphite.Five of the above-mentioned minerals have been discussed in more detail in terms of optical and physical properties, chemical composition, coexisting relationship, and the order of crystallization. It is indicated from this study that, with the exception of a small amount of Ni-Fe cbondrules, silicate minerals are the first to erystallize followed by chromite, ilmenite at the early stage of nebula condensation, while Ni-Fe phase in the matrix is considered to be of a more later erigin. At the late stage of nebula condensation troilite resulted from the reaction of Ni-Fe metal with residual H2S vapor. As indicated by the occurrence of coarse grained Ni-Fe metal, the recrystallization of troilite and the apparent Neumann lines in kamaeite, it is expected that opaque minerals in the Jilin metevrite have undergone different degrees of thermal and impact metamorphisms.     

Some High—P—Subtype and Low—P—Subtype F—Rich Granites in South China

The F-rich granites in South CHina could be distinguished as the high-P subtype and the low-P subtype according to their P2O5 contents.There are obvious differences in chemical composition of these two subtypes,The high-P subtype is strongly peraluminous and characterized by low silica and very low REE contents,while the low-P subtype is weakly peraluminous and characterized by high silica and very high REE contents.There are also some differences in chmical compositions of feldspars and micas for these two subtypes,The phosphorus of the high-P subtype mainly appears to be in the feldspar structure as PAlSi-2 substitution or subordinately in amblygonite as an accessory mineral,while the phosphorus of the low-P subtype is mainly in apatite and other phosphate minerals.     

Tetrahedrite-Group Minerals in the Jinjitai Gold Deposit,Western Sichuan

There are quite a few tetrahedrite-group minerals in the Jinjitai gold deposit, western Sichuan, which occur in an interstratified fractured zone of Middle Devonian carbonate rock series. The gold ore consists of pyrite, chalcopyrite, tetrahedrite-group minerals, galena, sphalerite and gold-silver series minerals, with an element association of Au-Cu-Ag-Pb-As-Sb-Bi. Electron microprobe analyses of the tetrahedrite-group minerals gave the following results: copper 40.04 to 42.27% (average 40.04%), iron 1.24 to 7.78% (average 4.13%), zinc 0.39 to 7.06% (average 3.58%), arsenic 5.41 to 17.40% (average 8.84%), antimony 2.70 to 20.46% (average 15.87%), and silver 0.02 to 0.73% (average 0.28%). The mineral varieties include zinc-antimony-tetrahedrite, iron-antimony-tetrahedrite, iron-tennatite and zincotennatite. These data show that there is a complete isomorphous series between Sb and As. From above downwards tetrahedrite varies from zinc- and antimony-rich to iron- and arsenic-rich compositions. Their occu     

Phase—Controlled and Gas—Washing Fractionations During the Formation of Petroleum Reservoirs

By PVT fractionation experiments to model phase-controlled and gaw-washing fractionations during the formation of petroleum reservoirs,the authors measured the physical and chemical properties of products formed in different fractionation staes and made a correlative analysis of the influence of depressurization and gas washing on oil/gas molecular composition and the rule of fractionation.The analytical results showed that gas washing is an important factor affecting the physical properties of crude oils.and also can be regarded as a good genetic interpretation of marine wax-high oils in the Tarim region,Xinjiang,China.Phase-controlled and gaw-washing fractionations can lead to the formation of condensates and their differences in chemical composition from crude oils are a direct reflection of evaporating fractionation.Phasecontrolled and gaw-washing fractionations have a great influence on the composition of molecular compounds and relevant parameters.So phase-controlled and gas-washing fractionations during the formation of petroleum reservoirs are not only favorable to identifying different processes of formation of petroleum reservoirs,but also to the scientific application of routine geochemical parameters.     

新矿物等轴铂铜矿的发现及其命名问题

Isoplatinocopper,a new mineral,has been found in a bistagite-pyroxene amplhibolite intrusive in the Yenshan Region,China,This mineral has been identified to be isometric and pale yellowish-white in color with a molecular formula of Pt4Cu5,α0=3.786A,specifie gravity=14.5,and no magnetism.In reflected light it is essentially isotropic,and yellowish-white in eclor with reflective power being 58% for green light,61% for yellow and 61.5% for red respectively,and its microhardness 127-220kg/mm^2.On the ground of the data on their chemical composition and crystal structure,Pt-Fe-Cu and Pt-Cu platinum minerals are divisible into two types,i.e.tulameenite which includes those with a composition of Pt5Fe4Cu-Pt2Fe3Ci2 and Pt2FeCu,and isoplatinocopper which possesses a composition of Pt4Cu4-Pt4Cu5.5     

铋碲铂钯矿和铋碲铂矿的晶体结构

The crystal structures of biteplapalladite and biteplatinite have been determined using three-dimensional and two-diraeusional data respectively. Both of them has CdI2 structure type, with a space group of D3d^3, Z = 1, but the locatioa of (Te, Bi)deviates slightly from ideality. Atomic coordinates of the two minerals are identical:(Pd, Pt, Ni) or (Pt, Ni) is (001/2), (Te, Bi) is (1/3 2/3 0.242, 2/3 1/3 0.758). The R value of biteplapalladite is 0.075, and that of biteplatinite is 0.09. It can be regarded that all minerals in the system biteplatinite-merenskyite belong to the same structure type of CdI2.     

Simulating experiment on the enrichment of precious metals in Lower Cambrian black shale series of Hunan and Guizhou provinces

Adsorption experiments were made at room temperature and neutral pH value on different types of min-erals associated with the Lower Cambrian black shale series polymetallic layers in Hunan and Guizhou provinces on nanometer-sized Pt colloids and PtCl42--bearing ionic solutions with an attempt to constrain the relationship between the different types of minerals in the polymetallic layers and the enrichment of platinum group elements (PGEs). Experimental results showed that the different types of minerals show strong selectivity to the adsorption of nano-meter-sized Pt colloids and PtCl42--bearing ionic solutions. Metallic sulfides, organic matter and clay minerals are the strong adsorbents of PGEs, while quartz, albite, muscovite and other silicate minerals show a week adsorbility to both of them. This phenomenon is well consistent with the geological fact that metallic sulfides, organic matter and clay minerals in the polymetallic layers of the black shale series are the major carrier minerals of PGEs, giving a thorough explanation to the mechanism of enrichment of previous metal elements. Adsorption may be a principal mechanism of enrichment of precious metal elements under lower temperature conditions. The presence of the aforementioned strong adsorbents is the good geochemical barriers for the enrichment of PGEs.     

Environmental properties of metallic minerals and their applications in environmental protection in China

In terms of environmental mineralogy, the environmental properties of metallic minerals, including chemical activation, adsorption, pore effect and nanometer effect, have been analyzed. On the basis of the analysis of environmental properties of metallic minerals, the applications of iron-bearing sultides, iron and manganese oxides in the purification of wastewaters containing heavy metal ions （Cr^6＋ ,Hg^2＋ , Pb^2＋ , etc. ） have been summarized. Moreover, research on the application of metallic minerals in environmental protection has been anticipated. It should be a piece of dominating work for environmental mineralogie researchers in the future to lucubrate systematically the physical and chemical characteristics of the metallic mineral surfaces, further reveal the reciprocity process between metallic minerals and water surface, perfect the theory and model of the metallic minerals to remove contaminants, intensify study on the facilities and techniques of metallic minerals to remove contaminants, and entail well the extension and propagation of achievements.     

Geochemistry and Petrogenesis of Intracontinental Basaltic Volcanism on the Northwest Arabian Plate,Gaziantep Basin,Southeast Anatolia,Turkey

Volcanism along the northwest boundary of the Arabian Plate found in the Gaziantep Basin, southeast Turkey, is of Miocene age and is of alkaline and calc-alkaline basic composition. The rare earth element data for both compositional series indicates spinel–peridotite source areas. The rare earth and trace elements of the alkaline lavas originate from a highly primitive and slightly contaminated asthenospheric mantle; those of the calc-alkaline lavas originate from a highly heterogeneous, asthenospheric, and lithospheric mantle source. Partial melting and magmatic differentiation processes played a role in the formation of the petrological features of these volcanics. These rocks form two groups on the basis of their ~(87) Sr/~(86) Sr and ~(143) Nd/~(144) Nd isotopic compositions in addition to their classifications based on their chemical compositions(alkaline and calc-alkaline). These isotopic differences indicate a dissimilar parental magma. Therefore, high Nd isotope samples imply a previously formed and highly primitive mantle whereas low Nd isotope samples may indicate comparable partial melting of an enriched heterogeneous shallow mantle. Other isotopic changes that do not conform to the chemical features of these lavas are partly related to the various tectonic events of the region, such as the Dead Sea Fault System and the Bitlis Suture Zone.     

Raman Spectroscopy of Garnet—group Minerals

The Raman spectra of the natural end members of the garnet-group minerals,which include pyrope, almandine and spessarite of Fe-Al garnet series and grossularite ,andradite and uvarovite of Ca-Fe garnet series, have been strdied.Measured Raman spectra of these minerals are reasonably and qualitatively assigned to the internal modes, translational and rotatory modes of SiO4 tetrahedra, as well as the translational motion of bivalent cations in the X site.The stretch and rotatory A1g modes for the Fe-Al garnet series show obvious Raman shifts as compared with those for the Ca-Fe garnet series ,owing to the cations residing in the Xsite connected with SiO4 tetrahedra by sharing the two edges.The Raman shifts of all members within either of the series are attributed mainly to the properties of cations in the X site for the Fe-Al garnet series andin the Y site for the Ca-Fe garnet series.     

我国铂族元素矿物的电子探针研究

Summarized in this paper is authors work on electron microprobe studies of platinum group minerals in China since 1964. Of the studied minerals, quite a number are new platinum group minerals discovered for the first time in the world. Those discovered for the first time in China fall into seven broad groups, including 253 varieties as revealed by electron microprobe analysis. L.S. Birks‘s method was adopted in electron probe quantitative analysis and correction.The authors suggest that it is appropriate to use the correction coefficients compiled by L.S.Birks in 1963 to quantitatively correct electron microprobe data on platinum group minerals.     

A Study of Occurrences of Ag in Pb-Zn-Cu Ore Deposits in China

A systematic study of occurrences of silver in 156 Pb-Zn-Cu ore deposits indicates that silver mainly occurs in nonferrous metal ore deposits in forms of association and paragenesis. It occurs mainly as independent minerals in nature and occasionally as ion adsorption, isomorphous or amorphous silver minerals. Nearly 190 silver minerals have been discovered in China. Their shapes, constituents, textures, grain sizes, embedded types, distribution patterns, mineral assemblages and metallogenic series suggest that these characteristics are closely related to geneses of deposits and dependent of ore-forming conditions. Pb, Zn and Cu sulphides are the main carrier minerals of silver. The partition of silver in ore is constrained by the mineralization intensity, grain size and embedded form of silver minerals and mineral assemblages.     

Diagenetic reactions in reservoir strata and geochemical properties of pore fluid and its origin in Songliao Basin

The reservoirs of the SOngliao Basin are composed of typical unstable sandstones,with high percentages of volcanic fragments and feldspar,In the course of sedimentation and burying,a series of physical and chemical reactions took place between minerals and pore water and water-rock reactions and ion exchange caused changes in ion assemblage of pore water,Hydration-hydrolysis,dissolution and the albitization of feldspar made many ions free from their framework and inter into the pore water,and induced the precipitation of a large amount of authigenic minerals such as smectite and chlorite,During the diagenesis of sandstone.diagenetic reactions involved several stages with increasing depth,and so did the precipitation of authigenic minerals and the transformaiton of minerals.The migration of ions is related with the precipitation,transformation and dissolution of authigenic minerals.Thus,to deepen our study on sandstone diagenesis is an important link for the analysis of ion migration in the evolution of pore water ,the origin and evolution of pore water could be tracked in terms of the geochemistry of fluid inclusions in authigenic minerals.And the isotopic composition of the authigenic mineral calcite can provide its genetic information.     

Geochemical Styudy of Gold and Arsenic Mineralization of the Carlin-Type Gold Deposits,Qinling Region,China

Element geochemistry of gold arsenic and mineralogical features of their sulfides in the Carlin-type gold depostis of the Qinling region are discussed in this paper.The initial contents of ore-forming elements such as glod and arsenic are high the ore-bearing rock series in the Qinling region.Furthermore,both the metals are concentrated mainly in the diagenetic pyrite.Study on the mineralogy of arsenic-bearing sulfide minerals in the ores demonstrated that there is a poistive correlation between gold and arsenic in the sulfide minerals.Available evidence suggests that gold in the As-bearing sulfide minerals in likely to be presented as a charge species(Au ),and it is most possible for it to replace the exxcess arsenic at the site of iron and war probably deposited together with arsenic as solid in the sulfide minerals. Pyrite is composed of(Aux^3 ,Fe1-2^2 )([AsS]x^3-[S2]1-x^2-),and arenopyrite of (Aux^3 ,Fe1-x^3 )([AsS]x^3-[AsS2]1-x^3-).The occurrence of glod in the As-sulfied minerals from the Carlin-type gold depostis in the Qinling region has been confirmed by electron probe and transmission electron microscopic studies.The results show that gold was probably depostied together with arsenicas coupled solid solutions in sulfide minerals in the early stage of mineralization.Metallogenic chemical reactions concerning gold deposition in the Carlin-type As-rich gold deposits would involve oxidation of glod and concurrent reduction of arsenic.Later,the deposited gold as solid was remobilized and redistributed as exsolutions,as a result of increasing hydrothermal alteration and crystallization,and decreasing resistance to refractoriness of the host minerals.Gold occurs as sub-microscopic grains(ranging from 0.04tp 0.16μm in diameter)of native gold along micro factures in and crystalline grains of the sulfiedes.     

Sorption properties of 1, 3, 5-trichlorobenznene on kerogen

Kerogen is an important organic matter fraction widely spread in soils and sediments. It plays a major role in the sorption and sequestration of hydrophobic organic contaminants （HOCs） such as trichlorobenzene （TCB）. It is known that kerogen is geochemically heterogeneous due to the differences in source materials and diagenesis history. We hypothesized that kerogen derived from different source materials and diagenetic history exhibits different sorption properties for TCB. We employed two different kerogen materials （coals） as the original materials and two series of kerogen for a given series with an identical source material but different alteration history were yielded through thermal treatment at temperature ranging from 200 to 500℃. The original and treated materials were characterized for their physicochemical properties. Sorption experiments were conducted with batch reactor systems using 1, 3, 5-TCB as the HOCs sorbates and the original and treated materials as the sorbents.     

Study of the Stacking Sequences of an Irregular Mixed-Layer Illite/Smectite (I/S) Clay Mineral—with a Discussion on the Existence of Minerals with Two-Dimentional Lattice and One-Dimentional Quasi-Lattice

There are two aspects in the study of irregular mixed-layer clay minerals: one is the kinds and ratios of their basic structural unit layers and the other is the junction probabilities of the unit layers. Irregular mixed-layer illite/smectite clay minerals (I/S) are widespread in nature. While studying the clay minerals from the Permian-Triassic (P/T) boundary bed, the authors found that I/S clay minerals are developed in all P/T boundary clay layers in areas from the northwest to southeast of China. Systematic mineralogical studies of the I/S clay minerals from Hunan, Hubei, Sichuan and Zhejiang were made by means of X-ray, infrared spectroscopic, electron microscopic and chemical analyses and a deepened study of the stacking sequences of their structural unit layers was conducted by the MacEwan one—dimentional direct Fourier transform. It was found that the stacking of the illite and smectite crystal layers along the c axis can be derived from Fibonacci sequences. Hence, the authors propose that such I/S clay minerals are possessed of two—dimentional crystal lattice and one—dimentional quasicrystal lattice.     

华北某含铂铜镍硫化矿床的两期铂矿化

Two stages of platinum mineralization, i.e., the main stage contemporaneous with Cu-Ni sulfide ores and the hydrothermal stage are recognizable in the platinum-bearing Cu-Ni sulfide deposit under investigation. In addition to antimonian michenerite-testibio palladite which occur in both stages, sperrylite, cooperite and osmian laurite are formed in the first stage and the presence of sudbryite and nicleoan sudbryite characterizes the second. Statistics shows different correlations among Cu, Ni, Pt, and Pd in the two stages.Being rich in Ni, the main stage exhibits a close correlation between Pt-, Pd-mineralization and Cu, with roughly equal tenors of Pt and Pd. During the second stage Cu is enriched, accompanied by increasingly strong mineralization of Pd while the mineralization of Pt is developed to a less extent and closely related with Ni. In the first stage the correlation between Pt and Os, Ru, Ir is notable, while that between Pd and Rh is intimate. According to occurrence, texture and structure of the sulfide ores, the main platinum mineralization is considered to have taken place through sulfide segregationinjection during magmatie stage. The second platinum mineralization is a typical hydrothermal process related with basic-ultrabasic magma.     

Regional Metallogenesis of the Chang’an Gold Ore Deposit in Western Yunnan: Evidences from Fluid Inclusions and Stable Isotopes

<正>The Chang'an gold ore deposit in western Yunnan is located at the southern segment of the Ailaoshan metallogenic belt.The ore bodies are preserved in fractured Ordovician sedimentary clastic rocks.The gold-bearing minerals occur dominantly in sulfide-quartz veins.Fluid inclusion analysis shows that the Chang'an gold ore deposit is characterized by epithermal gold mineralization at temperatures between 200℃and 280℃at a shallow crustal level.The mineralizing fluids have intermediate to low salinity(6%-18%) and low densities(0.72-1.27 g/cm~3).The ore minerals haveδ~(34)S in a range from -13‰to 3.57‰,concentrated from -2.06‰to 3.57‰with an average of 1.55‰.The ~(206)Pb/~(204)Pb,~(207)Pb/~(204)Pb and ~(208)Pb/~(204)Pb values are 18.9977-19.5748,15.7093-15.784,39.3814-40.2004 respectively.These isotope data suggest that the ore-forming elements were mainly derived from mixed crustal and mantle sources.The Chang'an gold ore deposit and Tongchang Cu-Mo deposit are closely related to each other in their spatial distribution and age of formation.They have similar sources of mineralizing elements and identical ore-forming metal elements,and show a close relationship in physical and chemical conditions of mineralization.The two deposits constitute an epithermal-porphyry -skarn type Cu-Mo-Au mineralization system in the Tongchang-Chang'an area,which is related to the Cenozoic high-K alkaline magmatism.     

Selection and Basic Properties of the Buffer Material for High-Level Radioactive Waste Repository in China

Radioactive wastes arising from a wide range of human activities are in many different physical and chemical forms, contaminated with varying radioactivity. Their common features are the potential hazard associated with their radioactivity and the need to manage them in such a way as to protect the human environment. The geological disposal is regarded as the most reasonable and effective way to safely disposing high-level radioactive wastes in the world. The conceptual model of geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineered barrier system. The buffer is one of the main engineered barriers for HLW repository. It is expected to maintain its low water permeability, self-sealing property, radio nuclides adsorption and retardation properties, thermal conductivity, chemical buffering property, canister supporting property, and stress buffering property over a long period of time. Bentonite is selected as the main content of buffer material that can satisfy the above requirements. The Gaomiaozi deposit is selected as the candidate supplier for China＇s buffer material of high level radioactive waste repository. This paper presents the geological features of the GMZ deposit and basic properties of the GMZ Na-bentonite. It is a super-large deposit with a high content of montmorillonite （about 75 %）, and GMZ-1, which is Na-bentonite produced from GMZ deposit is selected as the reference material for China＇s buffer material study.