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摘要:The montmorillonite-illite clay rocks Vere extensively deposited in transi- tional period between Permian and Triassic in south China. We have chosen 6 samples from the boundary clay rocks and apical and base plate of them at Guangyuan Sichuan province and Changxing Zhejiang province. We used neu trop activation analysis method to get results as follows: 1.The contents of Cs, Hf, Ta, Th, U, Zr in samples of boundary clay rocks are clearly higher than those in overlying and underlying strata of them. The ratio of Th/LT shows higher anomaly, but the ratio of Zr/Hf is low anomaly (See Table 1). 2.The property about the trace elements in samples of overlying and un- derlying strata is that the contents of Ba, Co, Cr, Ni, Sr are higher than those in boundary clay rocks (See Table 1). 3.REE date of samples from Zhejiang and Sichuan provinces are shown in table 2 and given in fig. 1-2 after average standardization chondrorites.The maximum values of ΣREE for boundary clay rocks at these two regions are 436 and 338 respectively. The ΣREE value of siliceous limestone in underlying stratum is very low as 43.3 and 47.4.And ΣREE value for mud-shale rocks in overlying stratum is 224 and 188 respectively. The similarity of the average REE pattern for boundary clay rocks and the overlying and underlying strata of them illustrates that the origin of REE at part of the origin is alike basi- cally. 4.Comparing the REE pattern with those of Permian subgreywacke and Triassic shale in same age in Australia (B. Nance 1976).It is clear that they are similar or nearly parallel. The value La/Yb is also similar. But Eu negative anomaly is more clear in China ( See Table 3 and Fig. 3 ). 5.Comparing with REE pattern of clay in American platform (L. A. Has- kin et al. 1966)，we can see that not only ΣREE but also the value of every single element as well as La/Yb, Sm/Eu value in China are 2-3 times higher than those in American platform (See Table 2 and Fig.4). As these conclusions above, they illustrate that the geochemical envi- ronment and the enrich conditions of rare earth elements are anomalous in China. May be this relates with geological events in the region, but now we do not know exactly. So that we think the Permian and Triassic is not con- formable contact, may be paraconformable contact.
摘要:The tectonic environmints of Dabieshan have long been discussed a mong geologists. In 1976, We raised the opinion that there perhaps may be a "f ossil subduation" trending E. W. Recently we have system a tically studied the minerals from this metamorphic terrain of Dabie group in Hubei and Anhui. and their P-T Conditions. The lower proterozoic Wuhe group in Anhui is also considered.Phanerozoic formation discordantly overlies on these metamorphosed terrains. The radioactive age of zircon is Machao group are 1328, 1578 my., the age of biotite in Wuhe group are 1650, 1767, 1810 my. High P-Low T minerals, such as omphacite, garnet, crossite, barroisite, phengite, of barroisite-ecologite, amphobole-schist and gra.nulite facies are the main subjects of this study. According to the study of minerals in Dabieshan metamorphic terrain we suggest that the Dabieshan was a plate boundary of paleoceanic plate in finning cycle Low T-High P metamorphic belt was found in the southern side of the mountain, i. e., the oceanic side. Pressure de- creased northward.
摘要:Some data of melting temperatures have been ohtained, including the intial melting temperature of the matrix 1000°0-1050℃，the completed melting temperaturel 0 5 0 ° -110 0℃and the intial melting temperature of the porphyritic crystals 1100°-1120℃，the completed melting temperature 1150°-1200`℃, by the melting experiment at 1 atm for a series of volcanic rocks-karatophyres of Zheyaoshan and Huoyanshan deposits in Beiyinshang. When the homogeneous glasses are formed from the fusion of matrix, a large number of gas bubbles are observed. According to the data mentioned above, it is suggested that the volcanic rocks-karatophyres of this area should belong to the produces of magma which is rich in volatile flux. All of the rocks formed from rapidly cooling magma ·under the condition close to the crater, are regarded as lava with a diagenetic aemperature at 1000°-1150℃.
摘要:There are six equations have been derived from the double standard mathod of accurate determination of isotope ratio in this paper. Several methods of measuring isotope ratio can be designed according to the basis of these equatiops. The determinate result of each method is coincide with the standard deviation. Most of the results measurd by MAT-Ch5 mass spectrometer coincided with that measured by M M 6 0 2 D mass spectrometer.
摘要:To index X-ra.y powder diffraction lines of an unknown crystal is, in. general, based on the known cell constants, or on the high symmetry of crys- tals. The constants and λ in the d-calculating formula can be cancelled by the ratio method. The experimental d(A)-values are expressed by the recip- roca,ls of the squares of the (dA)-values, i. e. d*2hkl.Ry. By dividing the rear d*2hkl´s by those of the first, second, third etc., in the order of the initial descending d(A)-values we acquire the ratio values. In order to reduce the calculation, we take first ten or twenty lines in diffraction patterns and take three dividings with the 1st, 2nd and 3rd d*2hkl as divisors. For isometric crystals, there is a maximum common factor (M. C. F.)in the ratio d*2(hkl)/d*2(hkl)m,i.e. a*2( =d*2100).For tetragonal, trigonal or hexa- gontal crystals, the ratios of d*2hoo, d*2oko and d*2hko are either the same as those in isometric or showing some particular values;c can be found after the determination of a and b. For orthorhombic, d*2(hkl)n/d*2(hkl)m=h2n+k2n/(b/a)2+l2n/(C/a)2/h2m+k2m(b/a)2+l2m/(c/a)2 and for monoclinic, d*2(hk!)n/d*2(hkl)m=1/sin2β[h2n+l2n/(c/a)2-2hnlncosβ/(c/a)]+ k2n/(b/a)2/1/sin2β[h2m+l2m/(C/a)2-2hm lmncosβ/(c/a)]+k2m/(b/a)2 Calculations of the ratios show that the more the approach of b/a's and c/a´ s of two crystals, the more the approach of their respective ratios of the d*2hkl´s. The essential of the method is to find the b/a(=A) and c/a(=C) from the given d(A)-values by calculating and comparing the ratios of the d*2hkl (Qhkl).These ratios are arranged systematically with A, C as coordinates in order to facilitate the locating of &C of an unknown. Sixty orthorhom- bic minerals of known &C were calculated and the ratios of the nearest A and C may be discriminated, as in A=0.904，C=0.7,80 &A=0.904,C=0.784， A=0 .8919，C=0.354&A=0.983，C=0.355 and hence the method is practi- cable. The same and high reliabilities of both a,b,c and d(A)-values are neces- sary. The accuracy of calculations depends on that of a, b, c and d(A)-va- lues,found experimentally. For monoclinic crystals the angle varies from 90° to 120°.
摘要:The barytocelestine is one of the main gangue minerals in the molybdenum deposit of Huanglung Pu area. The veins of molybdenite-galena-pyrite-barytoce- lestine-quartz-calcite occur as large veins or network veins in spilite of the Xionger grup of Sinian Suberathem. The mineral is sallow, cream yellow and milky white in colour, and greasy in lustery usually 4 × 1.2-3 × 2.5cm in size, it has a platy form and sometimes with beaded shell-layer structure on its crystal faces. Specific gravities and hardness determined of two samples are 4.06 and 4.13 and 157kg/mm2(3.6) and 159kg/mm2(3.7) respectively.The mineral is optically biaxial positive with 2v= 61-630; (001)cleavage perfect; firstorder yellow interf erence colour s parallel- axial extinction; positive or negative elongations and Ng=1.637, Nm = 1.629 Np=1 .627，Ng-Np=O.OlO.It has been found that barytocelestine is often replaced by calcite. The unit-cell dimensions of two samples are as follows, a=8.472, 8.509， b=5.381, 5.408;c=6.927, 6.958A;v=315.80, 320.19A3;z=4. The strongest lines in the x-ray powder pattern are 3.465 ( 4.5)，3.325(10)，3.210(6)，2.998(7.5)， 2.755(4.7)，2.691(4)，2.065(6)，2.032(4). The calculated molecular formula of barytocelestine is(Sro.59 Bao.34 Ca0.04)SO4. The weathered product of the barytocelestine shows a white or yellowish white colour and has a mesh structure. It is identical with baryte.
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摘要:A method for the determination of rare earth elements at chondritic abundance levels is described. Dissolution of rock samples is accomplished by sodium peroxide fusion. Rare earth elements are separated from matrix concomitants and pzeconcentrated by canon exchange employing No. 1 resin. The analysis of the samples is performed on a Jarrell-Ash model 1160 Atom- Comp spectrometer with 60 channels. A DEC PDP 11/23 minicomputer controls the ICAP spectrometer and is interfaced to a LA-120 DECwriter for data reporting. A precision of 1-5.5%(RSD) was attained. Analyses of several hun- dreds of rock samples showed that the method is well suited to the routine simultaneous determination of 15 rare earth elements.
摘要:A potentiometric titration procedure has been developed for the determi- nation of V( llI)，V(IY)and V(V)with potassium dichromate solution in carbo- naceous shale. Two potential breaks are observed in the titration curve. The first corres- ponds to the oxidation of V(III)to V(IV)，and the second to the oxidation of V ( IV)to V ( V).The determination of V( V)in a mixture of V (IV)and V (V)is accomplished as follow: 1) Both V(IV)and V ( V)are reduced to V(Ill)by Fe(II)and titrated V (III)with K2Cr2O7. Thus the total amount of V(IV)and V( V)is determined. 2) The amount of V(IV)in the mixture can be determined separately. 3) The difference between the two amounts is the amount of V( V). Under the conditions proposed for the titration of V(III)，V(IV)and V( V). Ca( II)，Mg( II)，AI ( llI)，Fe( III)，Cr ( III)，Cu (1I)，Ni( II)，Cd( 1I)，Mo ( VI)，W (VI)， F-，Cl- and SO4(2-)do not interfere, but Fe( II)，Ti( III)and NO2 - interfere. The relative error of the method is 1± 1%.
摘要:A DC arc technique combined with simple chamber electrode is used for excitation and a mixture of potassium iodide,sulfure, potaassium pyrosulfate and graphite powder was selected as reactant-buffer. The electrodes need to be pretreated by impregnating in a saturated solu- tion of K2S2O7 containing minor amounts of iodine and potassium iodide in order to prevent the escaping of sample vapor from the wall of chamber elec- trode and suppress the intensive evaporation of rock-forming elements. The analytical sensitivity is enhanced and the spectral interference of Sb and As limes by the ghost from Si and Mg lines is reduced. The method can be used to analyze these elements simultaneously with a 1-meter grating spectrometer. The detection limits of these elements are: Ge, In, Tl and Bi~0.1ppm;Sb~0.3ppm; Cd~0.5ppm; A~3 ppm.
摘要:The determination of silver by atomic absorption spectrophotometric me- thod in ainmoniacal medium gives poor reproducibility and negative error. The present investigation describes that coprecipitation phenomenon under various conditions is the main factor of defects. This paper suggests that determination of silver can be carried out in ammoniacal citrate medium.
摘要:The conditions for micro determination of Vanadium with 5-Br-PADAP as a chromogenic agent have been tested. The complex formation occurs in phosphate medium in the presence of H2O2 at pH 2.0-2.25.Detection limit of Vanadium is 10 ppm. It has been Confirmed that Vanadium, 5-Br-PADAP and H20f forms a ternary complex, and the combined ratio of this complex is 1:1:1。
摘要:A new colorimetric method for the determination of trace amount of boron with ethyl Rhodamine B as a chromogenic agent is studied.The elimination of the interference of tantalum and diverse ions are described .Beer's law holds for the range of 0-6 ug B/10 ml. The recoveries obtained by the addition of known amount of boron are nearly 100%
摘要:In sulphuric acid medium tungsten forms a ternary complex with bromo- pyrogallol red and cetyltrimethyl-ammonium bromide. The Beer's law is obe- yed for tungsten oxide of 0-200 ug/50m1. By the addition of EDTA and NH20H.HCl twenty kinds of foreign ions do not interfere and the quantity tolerance for chromium is 30 times that of tungsten.
摘要:A rapid method for determining calcium in alkalic medium by using po- tentiometric titration has been developed. In this method calcium ion-selective electrode and calomel electrode used to detect the end poiirt.
摘要:The optimum conditions are studied for determination of trace amount of 14 elements ( V, Mo, W, P, Li, Bi, Cd, Pb, U, Zn, Cu, Co, Ni, Mn) in geological samples based on group separation with 732 cation exchange resins. The eluants HC104-H2O2, HBr, H2SO4-H2O, HCl and(NH4)2C2O4 are selected for different group. Lower detection limits are obtained by this procedure.
摘要:This review describes mainly the present situation of superhighsensitive chromogenic agents (pay particular attention to water soluble Porphyrin) and their reactions.
摘要:The determination of total suflur in pyrite by combustion method gener- ally gives low result.This article systematically discusses various catalytic fluxes used in this method and all kinds of factors such as fusion, combustion and absorption which influence the combustion determination. It has been convinced that vanadium pentoxide is a desirable catalytic flux.
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