Abstract:Major element and trace element contents have been determined for Fuxi granodiorite body and Jiufeng adamellite body in southern Hunan and nor- there Guangdong, and also for such basement strata in Nanling region as Sibao Group, Banxi Group and Sinian-Ordovician rocks. In addition, Sm-Nd isotopic data have been obtained for Fuxi and Jiufeng rock bodies, with isochron ages being 463 Ma and 159 Ma, εNd(t) - 6.8 and -10.4 and tDn} 1728 Ma and 1896 Ma respectively. It is preliminarily concluded that source rocks of these two rock bodies might have been Proterozoic contine}ltal crustal rocks in nature. Trace element quantitative modelling for petrogenesis of thesee rock bodies was carried out with the aid of the formula for batch partial melting, i. e. CL/C0=1[D0(1-P)] The data obtained, combined with the geological and geochemical characteristics, have led the authors to believe that the Fuxi gra- nodiorite, being a product of the crystallization of a melt, was formed by 50% partia.l melting of Sibao Group or similar Lower-Middle Proterozoic rocks, whe- reas the Jiufcng adamellitc by 55% partial melting of Banxi Group or similar racks in the region.

Abstract:The microspherules reported here are discovered in lamellar plagioclase amphibolite of the Gongchangling No. 2 Mine. The microspherules can be divided into two kinds: one is black, opaque, and with magnetism; the other is canary-citrine, transparent-semitransparent, and with weak or no magnetism.Most of them are glassy, but those with strong magnetism have become magnetite. The microspherules have many kinds of surface and inher textures such as vesicle, tubercle, bubble breakdown and intergrowth, indieating that they were formed under such cotiditions as high temperature, abundance of volatile components, strong plasticity, and rapid movement and cooling. The microspherules are compositionally charadterized by high contents and wide variation in SiO2 (2.7%--55.9%), Al2O3(1.7%--23.9%), TFeO(2.1%-92.6%) and CaO(0.5%--33.5%) .Based on the present study, it is thought that their formation might have been related either to volcanism or to meteorite impact. whi-chever origin the microspherules are of , the following important information can be drawn: (1) the original rocks of the lamellar plagioclase amphibolites are basic tuffs formed by resedimentation; (2) metamorphic temperaturepressure conditions are somewhat inhomogenous in the study area.

Abstract:The migmatitic granite-gneiss dome has the following characteristics: 1 .It looks elliptic in plane and funnel-shaped in profile, being 50一100 km long and 20-40 km wide. 2 .With the gradual intensification of metamorphism, migmatization and granitization from the low-grade area to the center of the migmatitic granite- gneiss dome, there appear in. turn sericite-chlorite zone, biotite zone, garnet zone, staurolite zone, kyanite （andalusite) zone, sillimanite-cordierite zone, migmatite zone and migmatitic granite-gneiss dome, indicating an increase in temperature from 400℃to 700℃ and drop in pressure from 0.85 GPa to 0.35 GPa. 3·From the low-grade area to the center of the dome, a progressive sequ- once of metamorphic structures can be observed, which finds expression in a series of prograde folds and schistosities. The nearer the rocks are to the center of the dome, the higher grade of tectonism and more deformation they have undergone. 4 .The migmatitic granite-gneiss dome consists mainly of biotite migma- titrc granite-gneiss and leuco-migmatitic granite-gneiss intercalated with migma- tined mica schist. In such aspects as attitudes, rock types, modal abundances, fabrics, petrochemistry and rare earth elements, there exist continuous and gradual variations from phyllite mica schist, migmatized mica schist to biotite migmatitic granite-gneiss and from metamorphic rhyolite, leptite, migmatized leptite to leuco-migmatitic granite-gneiss, suggesting that the two sorts of mig- matitic granite-gneiss are genetically related to meta-petite and metamorphic acid volcanic rocks respectively and should attribute their formation to m}ta- morphism, migmatization and granitization. The thermal dome of progressive metamorphism, the structural dome of progressive deformation and the migmatitic granite-gneiss dome constitute a thermal-structural-gneiss (TSG) trinity dome. The unified temporal-spatialevo- lutionary process of progressive metamorphism, deformation, migmatization and granitization implies that the formation of the TSG dome is attributed to heat fiow upward gushing of fluids rich in K, Na and Si, and differential diapric uprise around the center of the regional thermodynamic anomaly.

Abstract:A study of garnet and biotite from Archean stratified metamorphic rocks in northern Liaoning shows that these two minerals exhibit oscillatory zoning in chemical composition, especially in the ratio of Mg to Mg + Fe. An investigation into their growth process reveals that such zoning is a nonequilibrium self-organization or dissipative structure formed as a result of a nonideal state of these minetals during Archean metamorphism. The oscillatory variation in chemical composition of minerals is an intrinsic characteristic of the petrochemical system under noneguilibrium conditions instead of resulting from periodic changes in such external conditions as temperature and pressure. In addition, the significance of oscillatory zoning in minerals in the study of metamorphism is discussed in detail in this paper.

Abstract:Rock assemblages, trace elements and mineralogy of volcahic rocks along the Lancangjiang belt in southwest Yunnan show that these rocks have the main properties of shoshonite series. According to their geological, Petrological and geochemical characteristics, they are believed to be intracontinental arcvolcanic rocks. The K2O-,Al2O3-rich rhyolitic volcanics of Middle Triassic Manghuai Formation belong to collision type arc-volcanic rocks, while the K2O-high salt-shoshonite-latite of the upper Triassic Xiaodingxi Formatiom and the bimodal type volcanics assemblage of potassic trachybasalt-K2O-high rhylite of Manghuaihe Formation are of lag-type arc-volcanic rocks.

Abstract:This paper presents partition coefficients of 69 chemical elements (Li, Rb,Cs, K, Na, Ca, Ba, Sr, Mn, Fe, Mg, Cu, Pb, Zn, Co, Ni, Be, La, Ce, Nd,Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc, Cr, In, Ga, Al, B,Cd, Sb, Bi, U, Th, Zr, Hf, Si, Ti, Ge, Sn, Mo, Nb, Ta, W, V, P, F, Cl,S, N, O, C, As, Pu, Re, Os, He, Ne, Ar, Kr and Xe) and the univalent radical (OH) in 28 minerals (olivine, clinopyroxene, orthopyroxene, amphibole,biotite, Phlogopite, plagiocla-se, K--feldspar, quartz, magnetite, ilmenite, garnet,zircon, apatite, allanite, topaz, sphene, cordierite, hauyne, leucite, nepheline,whit-lockite, brookite, petovskite, melilite, armalcolite, spinel and rutile) from 8 types of rocks, namely metaluminous (ultra) basic rock, peralkaline (ultra) basic rock, metaluminous intermediate rock, peralkaline intermediate rock,metaluminous acid rock, peralkaline acid rock, peraluminous acid rock and ultra-acid rock. It is found through an integrated ahalysis and comparison that the composition and structure of minnerals and melts seem to be the most important factors controlling mineral-melt element partitioning. Importanceshould be attached to minral structure and Al-supersaturation of melt which have, not been discussed by research workers. Finally, the present state and theproblems to be solved in the study of mineral--melt element partition coefficients are analysed, and the future trends of this research field are predibted.

Abstract:Using a transmission electron microscope equipped with an energy disper-sive spectrometer(AEM), the authors have detailedly analysed and studied the mode of occurrence of iron and titanium in the kaolin deposit. The AEM study has revealed two distinct forms of iron and titanium inthe kaol in deposit: (1) Fe(3+) and Ti may substitute for Al in the octahedral layer and evenly distribute theinselves throughout the lattice in the kaolin minerals, which convincingly suggests that Fe and Ti are structural components of the kaolin minerals, called structural iron and structural titanium respectively. (2) There are separate iron and titanium minerals existing as impurities,such as hematite, maghemite, goethite and anatase. It is found that the iron minerals are present either as absorbed iron minerals on the surface of kaolin mineral flakes or as fine separate iron minerals, and that structural iron and structural titanium constitute only a small proportion, with most iron and titanium present as separate iron and titanium minerals. Based on the above studies, the authors have presented in this paper a feasible technological process for reducing Fe and Ti content of kaolin, which Provides a dependable scientific basis for improving the quality of kaolin, raising its ecoromic value and putting the kaolin resources to rational use.