Abstract:In the territory of SW China and SE Asia, between 100-120º east longitude, there is a NS trending syncollision tybe granite belt, At the northern end this granite belt begins with Lincang granite body (LG) and Pinghejie granite body (PG), W Yunnan, It runs southwards to join the medial granite zone of Thailand and the western granite zone of Malaysia, These two granite bodies with total exposure of 11000 km2 have typical features of continental crust-derived origin. The main characteristics are; (1)Peraluminous, with ANKC values greater than 1, 00 (1, 082 for PG and 1.106 for LG)，(2) Rich in potash relative to sodium, with Na/K ratios less than 1.00 (0. 88 for PG and 0. 95 for LG);( 3 ) Relatively lower in Sm/Nd ratios (0.17 for PG and 0. 20 for LG);( 4 ) Relatively higher in Rb/Sr ratios (1. 35 for PG and 2. 03 for LG)，( 5 ) Enriched in Sn (13. 7 ppm for PG and 14. 6 ppm fer LG)，(6) Higher in initial Sr ratios (0. 7205 for PG and 0.7340 for LG);(7) Negative:εtNd values(-12. 6 for LG) etc, The source materials for these two granite bodies are considered to be a mixture of about 70-80% upper continental crust and 20-30% lower continental crust materials by modelling using mixing two different Sr and Nd isotope isotope compositions proposed by Faure (1986).The magma for LG and PG was generated from 30-35% partial melting of this source material based on the partial melting equation of Rb, Sr, Rb/Sr proposed by Shaw.

Abstract:Most of lamprophyres in Laiyuan and Fuping are alkali lamprophyres. They mainly consist of camptonite, alkaliminette, alkali-kersantite, alkali-vogesite and transition types of them .The main mafic minerals in alkali lamprophyres are kaersutite, biotite, Ti-bearing diopside as well as a few altered olivine, and the felsic minerals are mainly plagioclase and alkali-feldspar. The calc-alkali lamprophyres are mainly consisted of non-titanium mafic minerals (such as hornblende, diopside) and two kinds of feldspar. The two series of lamprophyres can be distinguished by the following major marks; the alkali lamprophyres have SiO2<46% or F≥5% or TiO2﹤1.5%，and in contrast, calc- alkali lamprohyres have SiO2≥46% or F﹤5% or TiO2﹤1.5%.The lamprohyre magma in this area may have been less or not contaminated with the crustal rocks. The calcite in alkali lamprophyres may be the primary minerals.

Abstract:This paper presents the systematic analytic result of rare earth elements (REE) from the granitic rocks associated with two-large molybdenum deposits, which may have provided some special information for the origin and evolution of the granitic rocks in the area. 1 .The REE patterns of the Laoneushan granitic batholith and Shijiawan graniteporphyry exhibit a rightward declined curve with a fai址negative Eu anomaly. The REE have content of 207.11-268. 52ppm, HREE/LREE=0.03- 0.06, and δEu=0.45- 0.55.The Laoneushan batholith and the Shijiawan graniteporphyry, showing a similar chondrited normalized REE curve, are produced at the same evolution stage by magma derived mainly from crustal remelting, The Shijiawan graniteporphyry is a branch of the Laoneushan batholith. 2. The Jiaduicheng graniteporphyry bordered with the ribbon rocks is petrochemically characterized by high content of F, K, Mo and HREE and depletion in Ba, Sr, Ca and LREE, The REE values of this rock range from 117.10 to 140.20ppm with HREE/LREE=0.13-0.15 and δEu=0.46-0.47. The REE pattern of ,the graniteporphyry is presented as a rightward declined curve with negative Eu anomaly, This unique REE pattern can only be interpreted by thermogravitation diffusion of magma, which may be used for evaluation of molybdenum-bearing granitoids. 3 .The variation of LREE and HREE in the altered granitoids in a great degree is a result of the multiphase hydrothermal alteration. With increase of F in ore-forming solution, the LREE content in the altered granitoids becomes depletion, while the HREE still maintains unchangeably. These suggestions mentioned above are consistent with the result of the petrographic and isotope studies.

Abstract:The volcanic rocks in the Baitoushan volcano mainly include trachyte, quartz trachyte and comendite. They, together with the underlying Changbaishan basalts, constitute a series from basalt to peralkaline acid rocks and have extreme enrichment in some imcompatible elements (REE, Zr, Nb, Zn, ect.) but are depleted in some of the others (transitional elements, St, Ba ect.). The linear correlation of some pairs of these elements has been observed in the rock series. REE distribution patterns of these rocks display a rightward decline curve with a distinct negative Eu anomaly and gradually rise in their levels and slopes from basalt fo peralkaline acid rocks These features clearly indicate the genetical relationship between the Baitoushan volcanic rocks and underlying basalts. According to the careful study of the features of the trace element models the authors suggest that the fractional crystallization may have played an important role in the origin and evolution of the Baitoushan volcanic rocks. The model of partial melting could not explain the extreme enrichment in some elements but strong depletion in the others in the peralkaline rocks. Mineral phases involving in every stage of the differentiation areestimated by variation of trace elements.

Abstract:Povlen type hydroxyl-chrysotile is a new variety of Povlen type chrysotile, whose absorption, infrared, Mossbauer, EPR and NMR spectra are reported in this paper. Experimentation shows that the absorption spectra are caused by crystal-field transitions of Fe3+ and Fe2+ ions and charge-transfer transition of Fe3+→Fe3+, the infrared spectra by stretching vibrations of OH and Si-O, rotation of OH and bending vibrations of Mg-O and Si-O, the Mossbauer spectra by Fe2+octa.,Fe3+octa., and Fe3+tetra., the EPR spectra by Mno2+octa., Fe3+octa and Fe3+tetra.,and the NMR spectra by pipe water in fibre and OH on Mg-octahedra and Si-0 tetrahedra. It is also demonstrated that, when heated to 825℃,the structure was destroyed and forsterite phase formed. In addition, this paper interprets the color of Povlen type hydroxyl-chryso- tile and describes structural environments of the above transitional metal ions and OH in this mineral.

Abstract:The Dushan jades of Nanyang occur as veins in the tremolitized gabbro body. Various sorts of typical samples (white jade, green jade, white-green jade, brownish black jade) have been selected to perform polished and thin section microscopic observation, EMP, XRD and infrared spectral analysis, microhardness determination and SEM observation.The results of these studies show that Dushan jades are very peculiar in mineral composition, with "pure" anorthite and zoisite as the main minerals associated with a series of Cr bearing minerals, such as chrome-epidote, chromian muscovite margarite, chromian biotite-phlogopite, volchonskoite and chromite. Rock-forming minerals are characterized by high calcium, high aluminium and poor silicon, suggesting that Dushan jades were formed in a rather unusual geologic environment. Due to integrated control of original rocks and late-stage hydrothermal fluids, the main products are Ca-bearing aluminosilicates. With the intensification of hydrothermal metasomatism, the minerals might haev evolved in order of anorthite-zoisite, epidote-muscovite, and margarite-volchonskoite. Many minerals of Dushan jades contain chromium, which must have had much to do with the green and bright green colors of Dushan jades.

Abstract:The megacrysts discussed in this paper occur in Cenozoic alkali basalts of Jiangsu-Shandong-Anhui area. Garnet megacrysts belong to pyrope-almandine series, while monoclinic pyroxene megacrysts are of aluminous augites. Both megacrysts were formed through early crystallization of basaltic magma at high pressure. In contrast, the anorthoclase megacrysts seem to be of a relatively low pressure phase.Seven megacryst samples were analyzed for REE. The garnet megacrysts are characteristically rich in HREE, and the chondrite-normalized patterns show that (La/Yb)N ratio and (Ce/Yb)N are respectively 0.01-0.02 and 0.03-0.08. Fractional crystallization of the garnets caused HREE depletion in the melt. The augite megacrysts contain higher MREE, lower LREE and lowest HREE, with (La/Yb)_N ratio and (Ce/Yb)N being respectively 3-16 and 4-27. The augites led to MREE depletion and LREE enrichment in the basaltic magma. The anorthoclase megacrysts show relatively high positive Eu anomalies, Eu/Eu ratio being 4-7. Their crystallization gave rise to slight, negative Eu anomalies in the melt. The patterns of megacryst/melt REE partition coefficients are consistent with chondrite-normalized REE patterns of megacrysts.It can be concluded from the above discussion that REE distribution patterns of LREE enrichment and HREE depletion in alkali basalts are caused jointly by degree of partial melting, fractional crystallization of megacrysts and differentiation of basaltic magma.

Abstract:Cornwallite and cornubite were found in oxidized zone of the Debao skarn type Cu-Sn ore deposit in Guangxi. The former is jade green and bluish green in color and radial-fibrous, platy and botryoidal in form. The wet chemical analysis shows its composition to be Cu0 60.96, As25 30.53, A1203 0.13, Si02 0. 68, P2O5 0.50, Fe0 0.15, H2O+ 6.98, totally 99.93 (in percentage), with the ideal chemical formula being [Cu5(AsO4)2(OH)4.H2O]·The X-ray powder data agree with JCPDS 12-287, and the strong diffraction lines are 4.77(210)(3), 4.56(001)(7)，3.52(111)(10)，3.21( 4 O1)(8), 3.12( 3 11)(5)，3.02 (311)(5), 2.74 (411)(5), 2.49(511)(4), 2.43(601)(6)，2.30( 6 11)(6),1.888(3)，1.773(4)，1.651 (7)，1,532(3).Calculated cell dimensions a=17.547A，b=5,914A.c= 4.666A， β== 91. 6º，Z.=2;mononlinic; space group P21/a: H=4, D(mean)=4. 43. Refractive indices: Ng = 1 .846, Nm=1. 843, Np=1.833(±0.002).Biaxial negative, 2V=60º一 70º. The cornubite is green or greyish green in color and botryoidal in form. The electron, microprobe analyses of four grains are Cu0 62.29%，As2O31.54%, Feo 0.20% and sio2 0.13%(H2O+ undetermined), suggesting an ideal chemical formula of [Cu5(As04)2(OH)4], The X-ray powder data are basically consistent with JCPDS 12-228. The strong diffraction lines are 5.355(20), 4.711(100), 4.585(30), 3.587(30), 3.492(70), 3.101(30), 2.683(80), 2.557(40), 2.483(40), 2.300(50),1.746(30),1.571(30),1.519(30), 1.374(20).H=4. D(mean)=4.51; Biaxial negative, 2V=30º -40º (eye estimation).Refractive indices n=1.75- 1.85± (n=1.798 as calculated by Graston formula).

Abstract:Based on a study of six garnet samples from Archeozoic metamorphic rocks in Inner Mongolia, this paper discusses the relationship of crystal shape, physical properties, chemical composition of garnets and components of the rocks to spectroscopy as well as the formation condition of garnets.The end member components calculated from mineral composition indicate that the garnets in aluminous gneiss consist mainly of Mg-rich almandine, while those in amphibole websterite are composed chiefly of Ca-rich almandine. Chemically, calcium content of garnets is as a rule rather low, controlled by composition of the host rocks. With very few exceptions, the ceil parameter (a0) grows larger with the increasing Ca(2+ ) content.It is considered from an analysis of Mssbaurer spectra that garnets in metamorphic rocks of Jining Group might have mostly been formed under areduction conditions.

Abstract:Fayalite aggregate is a rootless rock black in color and consists almost exclusively of fayalite一(Mg0.0169 Fe0.9802Mn0.003)2 [SiO4].The crystals are tabular and columnar in form with the largest grain size reaching 10 mm. The aggregate shows over-cooling texture `with dendrite, In this paper, systematically mineralogic data are given about this rare fayalite whose composition approaches the erid and member component of fayalite.