摘要:wring the symposium in Beijing (1983)，the Group on the 5ystematics of Volcanic Rocks of the Commission on Petrology of the Geological Society of China agreed on recommendations on the classification，and nomenclature of volcanic rocks, which were suggested by Li Zhaonai et al. (Institute of Geology, Chinese Academy of Geological Sciences, 1983) and use for China. The classifi- nation system consists of three parts, namely th,e mineralogical quantitative classification, the chemical quantitative classification and the qualitative clas- sification. They have been compiled on the basis of the enormous, actual data of more than 20 provinces, cities and autonomous regions in China. The data processing and automatic plotting of volcanic rocks are performed by such. programs as GIGS-GPV-8010，GIGS-GPV-8 02 0，8030，8040，8050 (Li Zhaonai, 1980) on M160 computer. The main types of volcanic rocks are essentially cor- responding to each other in the mineralogical quantitative, chemical quantita- five and qualitative classifications, and all of them may be used alternatively in different cases. According to th.e classification schemes, th.e volcanic rocks are divided as follow: rhyolite, alkali(feldspar)rhyolite,dacite,quartz andesite, and- esite,basaltic andesite,quartz latite(trachyandesite),latite(trachyandesite),latite (trachyandesite),foid-Bering latite(trachyandesite)，quartz trachyte, trachyte, fold-bearing trachyte, quartz alkali(feldspar)trachyte, alkali(feldspax)trachyte, fold-bearing alkali(feidspar)trachyte, phonolite, tephritic phonolite, tholeiite, basalt (talcalkali basalt)，alkali olivine basalt, oligoclase basalt (mugearite)，andesine basalt (hawaiite)，traachybasalt, tephrite, basanite, phonolitic tephrite,tephritic foidite,phonolitic foidite, foidite, picrite alkali picrite, meimechite and melilitite. The geological features of the various types of volcanic rocks are systematically described in the Bulletin No. 8 of the Institute of Geology,Chinese Academy of Geological Sciences.
摘要:During the symposium in Beijing (1983),the Group on the systematics of Volcanic Rocks of the Commission on Petrology of the Geological Society of China agreed on recommendations on the classification and nomenclature of volcanic -ocks, which were suggested by Li Zhaonai et al. (Institute of Geolo- gy, Chinese Academy of Geological Sciences, 1983) and use foi China. The classifications and nomenclatures consist of three parts, namely th,e basic scheme (Table I )，applied to laboratory work;the simplified scheme (Table 2)， corresponding to the recommended scheme of the IUGS Subcommission on the Systematics of Igneous Rocks (R. Schmid, 1981)，applied to field work; the principles of nomenclature. The geological features of the various types of vol- canic rocks are systematically described in the Bulletin No. 7 of the Institute of Geology, Chinese Academy of Geological Sciences.
摘要:The greenschists are of wide distribution in metamorphic series of Jianzhen Group, Northern Fujian, which range from several to decades of meters thick, partially up to hundreds meters. As a result of regional metamorphism the rocks were metamorphosed to assemblages of greenschists and lower amphiboIite facies and appeared usually in masive, banded or schistose structures. These rocks are composed mainly of actinolite, epidote, chlorite, albite (plagioclase)，and minor amphibole, diopside, garnetand forsterite. from the characters of mineral association, relict texture andstructure, accessary menerals, petrochemitry and their field occurence the ori-ginal rocks of these greenschists were defined as med-basic volcanic rocks, med-basic intrusions, layered tuffs, argillaceous carbonatite and"Skarn-Like" rocks. The med-basic volvanic rocks including spilite (Na20/Qa.O> 0.4) and basalt (Na2O/Ca0<0 .4) are characterized by relict volcanic texture and contain more than 40% albite (plagioclase).The accessary minerals are presented as euhedral, of those the agatites have length; width ratio of 3:1. Med-basic intrutions are composed mainly of amphiboles and plagioclases, which characterized by blastoprismatic texture with coarse grains. Layerred tuffs appear in a stable occurence and contain both the volcanic and sedimentary elastic meterial. The accessary minerals are various in kind and all have an irregilar form. From analysis the rocks contain 1.5-2 % Na2O, 1-2 % TiO2 and 10-20 % CaO. Argillaceous carbonatites, remaining no original texture, are composed mainly of actinolite, epiolote and chlorite, and usually lack of plagioclese. The rocks have Ca0+Mg0 content of 25-30%, Na2O and TiO2 less than 1%and 0.5 % respectively. The "skarn-like" rocks remaining no orginal texture are composed mainly of coarse epidote, diopsite and garnet. The rocks have Mg0+CaO content more than 25% and 1-2% Ti02.
摘要:Trace elements of 304 purified mineral samples collected from 33 lead-Zinc -pyrite ore deposits in the south of Hunan were studied. The minerals includes galena (115 samples)，sphalerite (109 samples) and pyrite (80 samples)·The contents of trace elements were given by chemical analysis. It was found that the differences of the contents of some trace elements and the ratios of some element pairs are rather significant. Based on these differences these ore depo- sits can be classified into two types, hte post magmatic hydrothermal deposites relatd to Yanshanian acid to intermediate-acid hypabyssal and al- trahypabyssal magmatic rocks(I)and the transformed sedimentary ore deposits related to late Palaeozoic formations of carbonate rocks( II).In the logarithmic coordinate diagrams the points representing the contents of some trace elements and the ratios of some element pairs in the minerals of these two types of deposits distribute independently in separated areas. And so the author consi- ders that it is effective to differentiate metallogenic types of ore deposits ac- cording to these values. Based on a great amount of analytical data the trace element metallogenic criteria for these two types of deposits have been summed up as follows:
摘要:Hongtoushan copper deposit is a typical high metamorphosed one of the massive sulphide type. It occurs in the biotitehornblende-plagioclase-gneiss of anshan group of archaean era. The study shows that the ore has undergone a regional metamorphism of hornblendite facies as well as its wall rock. The main metamorphic fabrics are as follows, 1，Deformations 2 .Annealings 3 .Partial refusion and 4. change in mineral phases. Deformatiom fabrics include metamorphic rounding texture of quartz, frac- Lure in ore and minerals, plastic filling, pressure twins and undulatory extinc- tion. The metamorphic rounding texture of quartz is a characteristic fabric of the massive sulphide ore under a regional metamorphic condition. Annealing brought about a readjust of the surface tension of grains and the tending of equilibrium. When fully annealed, a single-phase ggregation may develop a foam texture with triple junction angle close to 120‘and a Lwo-phase aggregation may form characteristic dihedral angles, the size of which depends upon the interfacial free energy ratio. An important sign of metamorphism is the poikiloblastic texture of one another between minerals. The grain size of sulphide, especially of pyrite can indicate the degree of metamorphism. There are some evidences that a partial refusion took place at the peak of metamorphism. around the coarse sphalerite there are fine myrmekitic inter- growth of sphalerite, chalcopyrite and pyrrhotite. The rising of temperature, the change in oxygen and sulphur fugacities resulted in the change of mineral phases. That is the phase change between pyrite, pyrrhotite, magnetite etc. The thin rim of uralite and chlorite situated between sulphides and quartz (or feldspars) is伍。products of solid reaction, but not of hydrothermal process.
摘要:Mannardite was discovered in China in 1981.but due to the valence state of Ti, the authors could not submit to the commission on new minerals and new mineral name,IMA earlier. Chemical,physical properties, X-ray powder diffraction and space group, unit cell constants are all the more or less iden- tical with those of mannardits. But there are differences in occurence and mi- neral association. For other minor differences one can find in the comparison table (table 2).
摘要:Mixed type diamonds occur in porphyritic Kimberlite tube in China. It a- mounts to 6% of the total diamonds yield. Mixed type crystal of diamond is composed mainly of type I molecules and a less amount (about third to fif- th of the crystal) of type I molecules. The crystals are colorless, transparent and small octahedra (most sized mm).On the ultra-violet transparent pho- tographs, within the crystal, shows small black area of opacities, and outside of this area shows white area transparent under emissive ultra-violet light (wa- velenth 2370A).On the ultra-violet spectrogram, absorption edge of the black area is between 2916A—2970A，but the white area transmits ultra-violet light beginning at 2230A，Its representing forbidden band width is 5. 51 ev. On the infrared spectrogram, the black area shows strong absorption at 1175,1282， 1370 cm-1 and week absorption at 1100 cm-1 that they were lead. by rich, bi- nitrogen and poly-nitrogen; But the white area have no absorption peak lea- ding by impurities of nitrogen. Therefore, in a mixed type diamond, local small black area marks type , I，and vast white area indicates type II.
摘要:A rapid and simple fluorescence spectrophotometric method for determma tion of cerium in ilmenite is studied. Ferric ion and Cr(VI)are ieduced by hydroxylamine hydrochloride; Tl(1)，Au (III)，Pb (1I)，V(V)，Bi ( III)are reduc- ed by aluminum foil. There is no interference from 32 kinds of metal ions co- mmon in ilmenite. Beer's law is obeyed in the range of 5-800 ppb of cerium. Its C. V. for sample containing 2911 ppm and 78 ppm of Ce are 2.6% and 11.60o repectively(n=7).
摘要:A sample solution in 0.2 N hydrochloric acid was passed through a cations exchange column. The cations such as Fe, Cu, Cd,Zn, Co, Ni, Mn, In, Ca and Mg were quantitatively separated from S, As, P, Se and etc. 2 N hydrochloric acid was selected to eluate the above metals. The metals were determined by aas, spectrophotometry, polarography and induced colorimetric method separ- ately.
摘要:A method of simultaneous determination of the major elements in silicate rocks and related materials using inductively coupled plasma atomic emission spectrometry (ICP-AES) was presented. Lithium metaborate fusion technique has been used for preparing the sample solutions. Data on detection limits, calibration method, possible spectral interferences and correction, precision and accuracy of determinations were presented. The analytical results of more than 20 geochemical reference samples wid- ely differing composition have been presented and no significant matrix effects were observe.
摘要:In order to resolve the problem of matrix correction in the determination of the trace elements (including rare earth elements) for rocks, this paper has made a study on the relative absorption including incident and fluorescence absorptions and its relation with the wavelength. A general equation of calcu- lation the cofficient of absorption correction is described, in the case that there is an absorption edge of the major elements between the analytical line and the coinpton peak of the characteristic target line. The problem of matrix correction in the determination of most elements of which the effectivety re- solved by this method.
摘要:The optimum conditions are studied for fluorimetric determination of hafni- um based on separation with, 743 cation and 717 anion exchange resins. The exitation wave length and the emission wave length are found to be 401 nm and 506 nm respectively. The concentration of Hf obeys Beer slaw in the ra- nge of 0-1 ug/10ml. The recoveries obtained by addition of standard Hf-solu- tion were 98-108 %.
摘要:A Simple method for the determination of micro amount of potassium in cele- stine by aas was studied. The interference of Ba, Sr and Na ions were elimin- ated by adding suitable amounts of th.e restrainer (LaCl3) and masking agent -EDTA sohaion. "The sample was decomposed with HF+HC14,, the solution containing LaCL3 and EDTA was adjusted to 1% hydrocbloric acid medium, the potassium was determined by aas directly.
摘要:98.1% of Au in 10% aqua regia medium is adsorbed by polyfoam in kine- tic state. After ignition of the foam, the ash is subjected to spectrographic de- termination. Beer's law is obeyed for 5-1000ηg of gold. The C. V. of samples containing 1.3-27.2ppb of Au are 24.4-25.4 % (n=11).The detection limit of gold is 2ηg.
摘要:The matrix correction is suggested for determining Ga by flameless aas. The background is corrected by adding lmg/ml Ni using D2 lamp in 2 % nitric acid medium. The sensitivity of this method is 8.8 × 10-2g/1% Its C. V. for sample containing 0.02ppm of Ga is 1.81%(n=11).The re- coveries obtained by addition of standard Ga-solution are over 90 % . the mea- surable concentration range is O.OOOx-0.OOx % Ga.
摘要:A high1y sensitive method of neutron activation analysis for determination of gold was studied. The methdd has a good selectivity. The samples need not any processing and many elements can be determined simultaneously. The sen- sitivity of this method is 10-8 -10-9g of gold.
摘要:A simple and highly selective photometric determination of micro amount of tin is based on reverse phase chromatographic separation with TBP extrac- tion resin. More than twenty Kinds of mefials in minerals did not interfere. It molar absorptivity is 1.48 × 105 1 mol-1 cm-1 at 510 nm. The C. V. for sample containing 0. 019 % of Sn is 3.73% (n=15).The measurable concentration ran- ge is n × 10-3一10-1% of tin.