Abstract:Metamorphism,being a global phenomena,has beet considered as one of the most important geological processes, which is intimately linked with the development of crustal history, and varies accordingly with their tectonic setting. While in considering tectonic setting of metamorphism, a subsidence area of a crustal segment with some specific original rock sequences controlled by a definite tectonic environment in the onset of metamorphism is usually denoted. It gen- erally possesses mobile characters as exemplliled by the great subSiaence togetn- er with anomalous geothermal gradients or strong deformation effects, which may be caused by the change of thermal regimes deeply down to the mantle. Thus, it may be conceived that the tectonic setting acts as some fundamental causes in inducing different types of metamorphism. Rock types and sequences reflect both general and subtle features of tec- tonic settings. They also suggest salient aspects of dynamothermal history through time. Although they have been generally affected by the metamorphism with the elimination of original mineral associations and their fabrics, yet, their original rock types and rock sequences could be justified by careful field observations, laboratory works, and interpretatioal of petrochemical data relevant to metarocks. Original rock associations pertinent to metamorphism may be classified into several important categories, viz. the sedimentary sequences, the mixed type sedimentary sequences, the mafic and ultra.mafic sequences, and the specific types of volcanic rock series. They are largely controlled by the tecto- nic environments during the evolution of earth's crust. In a metamorphic terrane, metamorphic rocks usually form well-defined rock sequence, named as metamorphic formation with some charateristics in its rock assemblages. The metamorphic formation is defined as a set of definite metamorphic rock sequence pevailing over metamorphic terrane, and represent the products of their original rock sequences together with the types of meta- morphism affected. Variations of metamorphic formations depend on either as the change of original rock sequence, or as the change of metamorphic types. In general, it is considered as an important generality of the relationship between the original rock sequence in a given tectonic environment and the metamorphism thus involved. Generally thoy show evolutionary trend within succession of metamorphic terranes. Several important types of metamorphic formation are also tentatively grouped under the heading of various metamor- phic grouzps.
Abstract:In this paper the authoxs took the Fuping Group for example to introduce the method of B. E. Lujinco (B. E. PyAeHxo) which used quantitative mineral- ogy calculation for inferring the chemical composition of rocks and restoring the protolith nature of metamorphic rocks. Conversion coefficients of some minerals were added with hundreds of mineral analyses. Comparing this method with the other protolith restoration methods, the authors concluded: 1 .This method is applicable for protolith restoration. Its advantages are of being economic, quick and simple in performance. 2.This method is conducive in solving some problems of protolith restora- tion which are difficult to be solved with the orther petrochemical methods. For example, in the case of some thin-bedded rocks this method may be used for calculating the mineral contents of each layer separately, restoring the protoliths nature of each layer and discussing their forming environment. 3 .The practice work indicated that this method is not quite successful for restoration of the protolith nature of amphibolitic rocks, but it is satisfac- tory for restoration of other type rocks.
Abstract:On the basis of the field observations and laboratory works in recent years, the author has an attempt to discuss the relationship between the ma- terial source of uraniferous granitic rocks and uranium-mineralization. The mesozoic uraniferous granites in the southeast of China are formed by partial remelting and palingenesis of continental crust type sediments, volcano-sedi- merits and small numbers of original granite under the condition of increasing temperature and pressure in the tectonic acts. In this paper the author explained chiefly the characteristics of material source of uraniferous granitic rocks from the following ten respects; 1)the asso- ciation of granitic rocks; 2) the petrochemical composition of granitic rocks; 3) the composition of biotites; 4) Th/U ratio; 5) the accessory minerals; 6) the trace elements; 7) volatile compositions; 8) the distribution patterns of the rare earth elements; 9) the composition of stable isotops and 10) the temperature for formation of granites.
Abstract:Gananite reported in this paper is a new bismofluoride mineral found in the tungsten-bearing quartz veins with tungsten minerals-from Laikeng, Southern Jiangsi. Associated mineral are; bismuth, bismuthinite, pyrite, wolfra- mite, chalcopyrite and quartz. The mineral is present as aggregates (O.I5mm-0.076mm) of anhedrai grains of unequal size, with semi-metallic luster, color is brown to black and greenish black with a dark grey streak, traBSlucent, no cleavage, fracture one- veu, brittle. Ho =135-153kg/mm2 . Dcalc.=8.928g/cm3. Under reflected light, isotro- pic with grey reflection color in air and grey internal reflections. Reflectance values (in the air and oil):407nm (11.08)(4.21),435nm(12.32) (10.07),546nm (12.75)(11.08),591nm (I2.92) (12.63),621nm(12.96) (11.37),647nm (I3.27) (11.49). Single crystal studies could not be carried out because no single crystal has been found. The X-ray powder diffraction data are essentially identical to the data for synthetic a-BiF3 given on J. C. P. D. S, card 11-10 and are indexed on a cubic cell with a=5.825(1)A,z= 4, The space group of synthetic material is p43m. The strongest lines in the pattern are; 3.37(10) (111),2.91(7)(200), 2.059(9)(220),1.756(8)(ε11),1.682(5)(222),1.334(5)(331),1.188(5)(422)。 The chemical constituents of Gananite are Bi=78.98%and F=20.40%, total 9 9.38%.These yield the chemical formula BiF3. The mineral is'named after its locality. Type material is deposited in Ge- ological Museum of China, Beijing.
Abstract:Selenium rich argyrodite, is a new vanity of argyrodite, found in thb black shale of Bai-Guo-Yan, N. W. Hubei province. Most crystals are irregular graasules: A few grains are perfect octahedron. Twinning on the spinet type. Colour bright black, brittle, strong metallic luster, opaque, conchoidal fracture, streak grayish black. Under the microscope in ref- lected light, it is drak .gray, very weak pleochroism, R=25.5 (λ=546mu). HVHN50-75,D=6.70.Its chemical formula (Ag8.08G0.92Se2.50S3.75) is calculated from the results of chemical quantitative analysis. The data of x-ray diffraction with the Dbye method showed that it is a pseudo-body-ceatered cubic lattice. Psuedo-cell ao=21.44A,.Single crystal x-ray analysis showed that it belongs to the orthorhombic system, ao=15.164 A, bo= 7.511A,co=10.68A入,v=1217A3,z=4. The space group may probably be Pna21 or Pnam. In the 200-500cm-1,the infrared absorption spectrum present obviously four absorbed bands; 426,374,268,and 246 cm-1.On the differential thermal curve, there ate two wide exothernnal peaks folded together in the region of 250-450.
Abstract:Koenenite[4NaC1·4 (Mg, Ca)CI2·5Mg(OH)24AI(OH)3]from syrinite ore deposit, Jiangcheng, Yunnan is light yellow in color, and becomes dark brown due to weathering. It is foliate with cleavage {0001}perfect. The specific gravity is 1.82-2.08, after soaking iii water it reduces to 1.97.The hardness is 2.06-2.1. No=2.529, reddish brown. Ne=1.557, colorless. Ne-No=0.028.It shows weakly, biaxial 2V<10°. The X-ray powder pattern of the mineral has strongest lines; 5.45(90),3.25(50),2.812(100),2.380(70),2.130(60).Koenenite consists of two trigonal substructure layers; [Na4(Ca, Mg02Cl12]4-and[Mg7AL4 (OH)22 ] 4+.The CI-lattice unit cell has parameters; a=4.070A,c=32.646A,v=541.23A,space group Ram. The OH-lattice unit cell has parameters; a=3.051A,c=10.882A, v=101.132A3,space group P3m1. The structure of koenenite, as viewed along c axis is one of regmarly alter- hating NaCI-like chlorine and brucite-like OH double layers. All possible octahedral sites are randomly occupied by the metal ions. The strongest lines of the X-ray powder pattern for the material formed by soaking koenenite in water are; 7.73(90),3.835(100),2.570(70),2.285(80), 1,935(80)、1.526(80),1.495(70),1.316(50),1.269(60),1.200(50),0.975 (50).The unit cell parameters a= 3 .048A,c=23.190A,v=186.578A3,space group R. Chemical analysis of a water absorbed product after soaking koenenite in water gave: SiO2 0.63,Fe203 0.96,A1203 23.98,Ca0 0.18,Mg0 32.49,Ms0 0.17,H20 25.30, Cl 15.52,sum 99.23%,leading to the formula, [Mg7Al4(OH)22[Cl4.H20].
Abstract:The systematically mineralogical study of a swelling chlorite found from Wuding, Yunnan, is reported. The data of form, physical property, chemical analysis, X-ray powder diffraction, thermal analysis, infrared spectrum, electron microscope and changes of the mineral after heating are described in this paper. The untreated chlorite has a 14.68A of d(001)which changs to 16.13A when treating with ethylene glycol and to 14.30A after heating to 550℃(2hrs). Heated above 900t it has been changed into bronzite-hypersthene. The chemi- cal analyses gave, SiO2 34.71,A1203 12.10,Fe203 4.59,Fe0 7.48, Ca0 0.61, Mg0 23.60, H20+10.34 and H20-5.35%·The swelling chlorite is fibrous. In this paper data of X-ray diffraction as well as infrared spectrum patterns while heated to 330 ℃,550℃.620℃ 820℃. 900℃,1000℃ and 1100℃are recorded.
Abstract:Determination of trace amounts of REE with ICP spectroanalyzer JY 38 controlled by PDP 11/03 computer was described. The geochemical samples were fused with Na202 and separated by ion-exchanging on a column (0.6 × llcm) of cation exchange resin. The detection limits of this method are from 0.23ng/1(Lu) to 8. leg/1(Ce) for 15 RE elements. The relative standard deviation for ten determinations of GSD reference samples is about 3%.
Abstract:A new extractive paper-chromatography for the colorimetric determination of micro amounts of uranium with arsenazo III in rocks has been studied. The sample solution in nitric acid meduim was developed on the filter paper with butanone-MIBK-HNO3 H20 (80:80:20:20) for 1-2 hrs. The Rf values were found to be 0.9-1.0 and 0.4-0.5 for U and Th respectively, the other elements such as RE, Fe, Ti, Mn, W, Ni, Co and Mg were zero.. This method could be applied to the determination of 0.0000x-0. OOx% uranium in rocks.
Abstract:The posibility has been shown by using PMBP resin for separation and determination of trace amounts of REE in the presence of a small quantity of benzoyl acetone. The REE can be eluted quantitatively by using O.1N hydro- chloric acid. The relative standard deviation (n=8) for two samples containing 0.171%,0.320%REE are 0.0062, 0.004 respectively.
Abstract:A method of determining trace amounts of gold in rocks by using flame- less atomizer is discribed. The recoveries of gold from the organic phase by back-extraction and effect of background, interfering substance under the op- timum condition were examined. The detection limit is 8.9 × 10-12g of Au. The relative standard deviation for sample containing 0.38g/T is 6.6%(15 deter- minations).
Abstract:A rapid and selective X-Ray fluorescence spectrometric method for deter- urination of trace amounts of REE in ores is described. It is based on the pre- concentration with ion-exchange paper. Beer's law is obeyed for REE of 0-100ppm. The detection limit is 0.x ppm. The results obtained are in good agreement with those obtained by isotopic dilution measurement and neutron activation analysis.
Abstract:In the presence of ethyl alcohol, there exists a sensitive polarographic ca- talytic wave of the complex formed by Pb-Kl- V (IV)-ascorbic acid. The wave is available for the determination of lead within the range of 1-2ug/ml. The detection limit of lead is 0.0005ug/ml, the wave peak appears at -0.30v in 003M hydrochoric acid medium.
Abstract:A polarographic method for continuous determination of copper, lead, nickel and cobalt in geochemical samples is reported. Copper gives a sensitive peak in a solution containing HCl, KCNS, NH2. CH2. COOH and ascorbic acid; in the same solution lead can be determined by adding potassium iodide; nickel and cobalt are determined by adding NH4OH, NH4Cl, sulfosalicylic acid and dime- thyglyoxime. The detection limits are 0.02ug/ml for Cu, Pb; 0.01ug/ml for Ni, Co.
Abstract:A method is suggested for determination of Rh and Ir. It is based on using dithioacetamide as preciptating agent for preconcentration of Rh and Ir. In a solution of dilute sulfuric acid Rh and Ir are reduced by stannous chloride, the microgram quantity of arsenic is used as carrying agent. The recoveries obta- fined are in agreement with those obtained by assay method.
Abstract:A rapid method for determination of boron in acidic medium by using fluoborate ion-selective electrode was studied. This method was based on converting of boron iato tetrafluoborate ion with hydrofluoric acid and then the concentration of tetrafluoborate was measured with fluoborate ion-selective electrode. Macro amounts of iron, aluminum, calcium, magnesium and manganese etc did not cause interference. The recoveries of boron were 95-103%
Abstract:Dimethylheptyl methylphosphonate (P350) was used as a stationary phase for concentrating uranium and thorium. The behaviour of Kel-F, silica gel etc as supporter were tested. A solution containing 15 % HN03, 15 % NH4N03 [or 7 0 % Al (N03) 3] and 2 % tartaric acid of U and Th is used for column sorption. Th and U were separated by elution of 5N HCl and 0.2% NaF respectively. The chromatographic column could be used more than 80 times.
Abstract:This paper presents the separation of REE with P507 extraction resins. Car- bon powder, BaC12 and NaCl were used as the spectroscopic buffer for simul- taneous determination of 15 trace rare earth elements by a 2-meter grating spectrometer. The detection limits of different elements are from 0.001 ug-to 0.3ug.