Abstract:The lamproites in Zhenyuan area, Guizhou, are structurally confined to the deep faults in the platform or the platformal fold belts. They are the hypabysal intrusions and occured as a dike or a sheet ranging from several centimetres to several metres thick and tens to thousand metres long in the Shenchong, Baifen and Sinantang complexes. The rocks, as a whole, display distinct lamprophyric textures and massive structures with porphyritic crystals of Ti-phlogopite, diopside and pseudo-olivine. The matrix minerals, except that mentioned above, are consisted of sanidine, leucite, amphibole, apatite, zircon, rutile as well as a few pyrope and chromite, The compositions of phlogo- pite, chromite and pyrope are similar to that of lamproites from West Australia, which in Mycher, J. Geny diagram are plotted to the area of lamproite. These rocks petrochemically belong to the potash-ultramafic and characterized by K2O>Na20, K2O/Na2O=20.85--66,51.They have a higher content of REE and the REE patterns display an enrichment of LREE, which are similar to that of Vest Australia. The experiment of mineral separation indicated that there is a small amount of diamond in the D5 body,

Abstract:Jiucaide and Jilogshan bodies are located at 6km to the north of Wuji- ngfu town, Jieyang County and 15km to the northwest of Shantou City respe- ctively, They are both in form of volcanic cones with area less than 0.2 km2, The volcanic rocks are mainly consisted of basanites and alkali-olivine basalts with abundance of ultramafic inclusions-spineI Iherzolites which chara- cterised by inequigranular and porphyroclastic textures, The basaltic rocks in composition belong to the potash subseries of alka- line series and are characterized by higher CaO, K20+Na2O and TiO2, and lower SiOz and A1203, Except for enrichment of the incompatible elements, such as P, K and Ti, the basalts, have higher AI2O2/Ca0 ratio, with M value=60-70, index of consolidation nearly to 40 and degree of melting=4%.All these features indicate that the basaltic rocks are product driven from the mantle peridotite, The fusible componealts of the ultramafic inclusions are similar to that of fertile mantle, The olivines and the orthopyroxenes in the ultramafic inclusions have lower Fo and En respectively, and the clinopyroxenes are characterized by higher AI2O2, TiO2 and Na2O, The calculated temperature and pressure for the Iherzolites are confined to 10500C and 21.6 × 108 Pa respectively, The basa- ltic rocks have a high RFE abundance with enrichment of LREE, and La/Yb =15.63. The REE abundance of ultramafic inclusions approaches to that of the primary mantle,

Abstract:Structural study on deformed plutons, attempted to determine the strain type, strain patterns and strain history within and around intrusions may be as a guide to explore the emplacement mechanism of granites. The main methods available in structural geology are briefly reviewed and examples of recent study of emplacement mechanism of plutons in different tectonic settings are briefly described. It is emphasized that the tectonical stress, in combination with the natural bouyancy and ascending tendency of magmas, can generate the varied emplacement mechanisms of granites.

Abstract:The metamorphism of marble of Banyukou Formation in Wutaishan region, Shanxi province, is controlled by buffering process according to its total mineral assemblage of tremolite, phlogopite, dolomite, calcite, microclineane, quartz.The Xco2 of fluid in epidote vein in the Kouquan valley is 0.08; while in its surrounding clolostone, larger than 0.4. The difference in Xco2 in the vein and its surrournding rock also provides evidence that the fluid composition is controlled by buffering.The fluid composition in epidote vein remains unchanged, it shows that fluid composition is controlled by infiltration, The mineral assemblage in country rock is phlogopite, tremolite, calcite, and dolomite, which furthermore indicates that fluid composition is controlled by infilatration, To sum up, the metamorphic fluid composition in this region is controlled by combined buffering and iaLfiltration. The infiltrated fluid is usually less than 1/4 rock volume, Where is monomi- neral vein, there is more abundant infiltrated fluid, which in epidote vein is as high as whole rock volume ( 99%).

Abstract:Triphylite-lithiophilite, a perfect isomorphous series, has been found in six mineral occurrences of China, Of these, four are in the rare-metal granite pegma- tite$ of Xinjiang where all of the samples are lithiophilite, The Mn-rich features are also observed in other Fe, Mn minerals of Xinjiang pegmatites. In 1984, a few specimens of triphylite were discovered in Napping rare-metal pegmatite of Fujian. The mineral is one of the few Fe, Mg-richest triphylites in the world, Another triphylite occurs in Shangxian pegmatite of Shanxi province, L1p to pow, a pe- rfect triphylite-lithiophilite series has been foupd ip Chipa, whose mineralogical properties are all listed in the paper. Researches on the chemical compositiop of triphylite-lithiophilite show that, besides the major constituents Fe2+ and Mn2+，the cations at the octahedral M ( 2 ) site in the minerals are Mg2+, Ca2+, Fe2+.The highest Mg0 content is 7.38 wt%. Geperally speaking, Mg2+ replaces Fe2+ easily, while Ca2+ sometimes substitues for Mn2+ at the M ( 2 ) site, Pure triphylite has not been found yet in the nature and LiFe[P04] contents of all native triphylites are lower than 80%.Neverthe- less, there are very pure lithiophilites in nature. The paper illustrates the relations of chemical composition (Fe/Mn) to physical properties, optical properties and unit cell dimensions of the series, With the increase in Fe/Mn ratio, the specific gravity and the index of refraction will grow up, the cell parameters will decrease, and the optic axial angle will vary regularly, The rising of Mg2+, Ca2+ contents of the minerals, on the other hand, will also cause an obvious variation in the above properties. The IR spectral analysis of four triphylite-lithiophilite samples collected in China has been made to find the correlation between chemical composition and IR absorb peaks, The results show that there exists gocd linear correlation bet- weep absorb peaks from 475-455cm-1 and chemical composition; it 'is therefore feasible to use IR spectra for semi-quaptitative determination of chemical compo- sition of this series.

Abstract:This paper is a part of systematic studies on the isomorphous series of wolframite. The experimental results show that the frequencies and the adsorption intensity of several absorption bands of the wolframite exhibiting in the region of medium and far IR spectra are linearly varied with respect to the relative contents of FeWO4 and MnWO4. The correlation regression equations as well as diagrams between frequencies and x(Fe/Fe Mn)are given in the paper, and the reason for the frequency change and the absorption intensity change with respect to x has been discussed.

Abstract:The quartz monzonite-monzonitic granite masses are the main intrusive pro- ducts in Donghai area, northern Jiangsu and can be classified as I-type grani- toids, The major rock-forming minerals are composed of actinolitic hornblende, Mg-rich biotite, oligoclase, perthite and quartz, with sphene, apatite, zircon, mag- petite etc, as chief accessories. The thermodynamic calculation indicates that the physicochemical crystallization conditions of the magma are t=910一690℃, log fo2=-12, f H2o=(1.3-1.8) × 108Pa and log(fH2o/fHF)=3一4 , The 1 st set of transition elements are abundant in hornblende, biotite and sphene, but are obvi- ously reduced in oligoclase, perthite and quartz, As hornblende, biotite and oligo- clase play the most important part in the contribution of REE contents to the whole rocks, they control the REE distribution patterns of the rocks, These three minerals are usually rich in HREE with comparatively large negative Eu ano- maly, while plagioclase is relatively rich in LREE and exhibits positive Eu ano- maly, Thus, with the advance of magmatic fractionation, the mafic minerals and plagioclase will be gradually separated from each other, anal this will lead to the depletion of HREE, transition elements of 1st set and Eu contents.

Abstract:TheJining Group in Inner Mongolia consists of a suite of hypometamorphic rocks of granulite facies, with the lower part being mainly two-pyroxene-plagio- clase gneiss origina,tinD froTn volcanic rocks and the upper part, sillimanite-garnetpotasn ieiaspar gneiss from normal seaimentary rocxs, lne garnet samples collec ted from different parts of Jiazing Group belong chemically to similar species and are composed mainly of almandine ( 50-60 norm%)and pyrope (34-42 no- rm%)，with less andradite and spessartite. The tzace and rare earth elements in garnets from granulites of Jining Group have been determined by means of modern highprecision neutron activation ana- lytical technique. Expeximental results show that the chondrite-normalized pattern of rare earth elements is mainly affected by the properties of original rocks instead of by the composition of garnets, In the process of metamorphism the gannets from metamorphic volcanic rocks mostly retain the distribution characteristics of mag- matic type garnets, showing considerable enrichment of heavy rare earth, elements, while those from metasedirnentary rocks fail to show obvious LREE and HREE separation but have relatively strong negative Eu anomalies. It is considered that the rare earth element characteristics of the gannets in metamorphic rocks might serve as an indicator fox distinguishing ortho-rocks from para-rocks, and for determining properties of original rocks.

Abstract:There exist a variety of heavy minerals in coastal surficial sediments of Guangdong province, and nearly 40 sorts have been discovered in this study. Of them, the most important ones include ilmenite, hematite, magnetite, zircon, tourmaline, biotite and hornblende; next come epidote, diopside, tremolite and limonite. The authigenic minerals consist mainly of anhydrite, native copper, pyrite and siderite. These minerals are distributed along various coastal sections in different proportions and with different morphologic characteristics. An integrated study suggests that these heavy minerals are derived from source rocks with similar components, mainly granitoids and part of epimetamorphic and/or altered rocks, Nevertheless, in accordance with the differences in source materials, the heavy minerals might be grouped into terrigenous, near-soarce-authigenic and near-source mineral associations; in addition to the factor of material sources, it is mainly the sedimentary environments that control the contents ofheavy minerals, the types, morphologic characteristics and horizontal distribution of minerals in various coastal sections. The distribution patterns of heavy minerals controlled by different sedimentary environments might be classified into three types: (1) estuary pattern, predominated by river transportation; (2) harbor pattern, influenced chiefly by tidal sorting; and (3) island type, governed primarily by wave erosion. The three sorts of mineral associations as controlled by material sources are exactly consistent with the three distribution patterns of heavy minerals. Such a relationship has been well established for sediments of various coastal sections.

Abstract:Using transmission electron microscope and heating stage techniques, the authors have studied the phase transition of P21ca enstatite(En56Fs41Wo3).When the sample is heated to 900℃ or so, the diffraction spots of k≠2n in OkL diffraction of P21ca enstatite disappear, forming orthopyroxene with Pbca symmetry, The phase transition from P21ca orthopyroxene to Pbca orthopyroxene is achieved through the change in the rotation type of Si-O tetrahedra chain which is Srotation in the structure of P2lca orthopyroxene, This phase transition experimeat demonstrates that P21ca orthop3rroxene is the low-temperature polymorph of Pbca orthopyroxene.