Abstract:There are 200 basic-ultrabasic bodies of Yuanbao mountain. They are layered and divided into three zones: west, middle and east, which have been folded along with surrounding rocks. They are characterized by the rhythmic units consisting of basic-facies, ultrabasic-facies and mid-basic pyroclastic bed which retaines the pyroclastic textures and the cross bedding. The ultrabasic-facies, which constitutes a principal proportion of basic-ultr- abasic rocks, belongs to the harzburgite-websterite series. There are the cumulative textures and the chilled margin in their border facies. The petrochemical characteristics of the rocks are as follows: Na2O+K2O<0.5%, K2O<0.1%,TiO2<1%, CaO/Al2O3(most)=0.45-1.15. The rocks are roughly similar to the ultramafic komatiites.The middle zone contains a high content (70 ppm) of tin in the central facies of ultrabasic rock and local concentrates occur in the border facies forming the ore bodies. The mid-basic pyroclastic bed has strongly mineralized. The tin ore is as thick as 1-20m belonging to a type of cassiterite-sulfide. The tin deposits had been formed by following geological processes. The tin-bearing magma from the upper mantle is liquation-defferentiated first producing a tinbearing or tin-rich unltrabasic and basic magma. With the magma erupting crystallization-differentiation and hydrothermal activity mobilized the oringiual enrichment, as a result, the tin deposits formed. The ultrabasic rock of the east zone has a high content of platinum (up to 0.04 g/t) concentrated to the border facies to form ore. The platinum ore was formed by the magmatic crystallization and the mobilizing of the hydrothermal solution.

Abstract:In this paper proposed the magmatic complexes in the mountain Tai are two series of origins, namely anatexic granitic series with crustal sources which embraces all the granitoids, and dioritic series of magmatic differentiation which comprises all the diorites.

Abstract:The paper discusses the inherent factors and physicochemical condition of silicate Liquid.immiscibility.It suggests that Gexcess>0 in magma is internal reason of immiscibility, rich P2O5, TiO2, REtE, Zr, Ta, etc.in magma are induce- ments.The calculation of chemical potentials shows that ocelli-matrix from ocellar Bi-Py-syenite and syenitic and pyroxenitic magma unit had been equi- librated in liquid state, Yang Yuan magma immiscibility could occur in upper crust and at 1200℃ under reasonable geological condition. Two immiscible liquids of the parent magma may seperate into two magmatic units.The intermediate rock resulted from seperation of two liquids were incomplete.

Abstract:The crystal structure of mathiasite, a new mineral from Sbandong provin- ce, has been determined, and the crystal chemical formula is written as(K, Ca) (Ti, Cr, Fe, Mg, Zr)21O38. The mineral belongs to trigonal system having space group of R3, with its cell parameters being a=10.3722A，c=20.7161A，aR= 9.1403A and a=69.137°. 1554 independent diffraction data were collected on RASA-5RP auto-four- circle single crystal diffractometer; coordinates, temperature factors and site occupancies for all atoms were obtained and refined; atomic distances and ang- les were calculated. The final deviation factor R is 0.047. Mathiasite occurs in lcimberlite and must have formed under high tempera- ture and pressure. Through the determination of its structure, the coordination about such atoms as Ti, Cr, Mg and K, especially. the coordination about Zr atom in the complex oxide dominated by Ti, has been revealed. This research contributes to the mineralogy and crystal c乡emistry of acces- sory metallic minerals in kimberlite.

Abstract:Tinan ludwigite, a new Sn-rich subspecies of ludwigite, occurs in a magnesian skarn borate deposit at Qiliping, Changning County, Hunan province. The SnO_2 content of the mineral varies from 4.6 to 12.0 wt. %, and the chemical formula is (Mg(1.64)Fe_(0.35)(2+)Mn(0.01)(2.00)(Fe(0.55)(3+)Sn(0.16)Mg(0.28))(0.99)BO5, which has never been previously reported. The authors have studied the mineral in such aspects as its optical and physical properties, chemical composition, X-ray crystallography, and crystallochemistry, with a crystallographic comparison given between this mineral and its analogues.From the above investigation, the authors have come to the conclusion that Fe(3+) position has been occupied by Sn(4+) in the crystal structure and the charge is compensated by having Mg(2+) It is also the authors' opinion that tin not only is a minor component but also serves as a species-forming element ludwigite.

Abstract:On the basis of detailed microscope and microprobe studies of fresh samples from some intermediate subvolcanic rocks and syntectic granitoid rocks in West United States and East China, the reason for the high Mn contents in some ilmenite has been investigated. This results show that,in the granitoids studied; 1. All the Mn-rich ilmenite is the product of oxidation "exsolusion", which indicates that low temperature (755º-450℃)，high fo2 and slow cooling velocity make up prerequisite for the formation of Mn-rich ilmenite. 2. There is no correlation between MnO(II)and Hm(II). 3. MnO(II) does not correlate with sphene contents in the rocks. 4. The correlation co0fficient between MnO(II)) and modal quartz plus alkali -feldspar is+0.82(N=21), with a confidence level of positive correlation at 99.9%. 5. The correlation coefficient between MnO(II) and modal mafic silicates is -0.70 (N=21) with a confidence level of negative correlation at 99.9%, which shows that the MnO(II) decreases with increasing content of fer- romagnesian minerals. 6. The correlation coefficient between MnO(II) and the ratio of modal mafic silicate to magnetite is -0.76, with a confidence level at 99.9%. The mafic silicates with high Mn mineral/melt distribution coefficient are the main host minerals for Mn2+，but quartz and alkali-feldspar with low Mn mineral/melt distribution coefficient do not accommodate Mn2+ in their lattices. Duiing the crystallization of mafic component-rich magma system, the more mafic silicates precipitate, the more. Ma2+ gets into the lattice of silicate mine- rats, which prohibits the high-Mn ilmenite from formation. During the .crystal- lization of leucogranitoid magma system, the more quartz and alkali feldspar precipitate, the more Mnz+ is enriched in residual melt, which.impels the high- Mn-ilmenite to be produced. The magma which has undergone a high degree of fractional crystallization for mafic silicates is not helpful to bring about the formation of Mn-rich ilmenite. Mn-content in ilmenite is also dependent on the ratio of fH2O2 of the magma system, the high fo2 and low fH2O facilitate decomposition of hornblend and biotite, and favour the formation of Mn-rich ilmenite. Mn-content in ilmenite may be applicable to discriminate between acid volcanic and subvolcanic rocks and to estimate the contents of mafic silicates and of quartz plus alkali-feldspar in some intermediate-acid rocks. The Mn-con- tent in ilmenxte may be useful in inference of fH2O and fo2 of leucogranitoid granitoid magma and in distinction of the intrusions related to porphyry copper deposits from barren ones.

Abstract:The present paper describes a program fitting complex Mossbauer spectra of geological samples on the microcomputer system. It is written in FORTRAN一N and has several constrained conditions for choice. With the help of the CROM- EMCO system-1 microcomputer, the authors have used this program to deal with0the data of Mossbauer spectra of such common minerals 'as ilmenite, pyroxene, omphacite, hornblende, vivianite, staurolite, glauconite, biotite,hematite,magnetite and pyrrhotite, resulting in a "good fitting" for all the spectra.

Abstract:Certain samples, which are of pre-cambrian metamorphic rocks in China (Hebei Province and Inner Mongolia etc.), post-cambrian metamorphic rocks in Tibet and other areas, as well as granitic rocks with different ages and genesis, have been observed by means of CL (cathodoluminescence). CL related to certain concentrations of the transition elements, may reveal textures in rocks and show indirectly the characteristics of chemical composition of minerals. This paper deals with the application of CL to the studying of metamorphic and granitic rocks as follows; 1) determing metamorphic grade indirectly, 2) revealing the palimpsest structures of primary rocks, 3) identifying finegrained and luminescent mineral, 4) studying mineral reactions, 5)reconstructing deforma tionstructures.