Abstract:It is demonstrated in this paper that the so called "nondiamondiferous kimberlite" in the northern Chaidam mountains is actually garnet peridotite.This is the first garnet peridotite ever recognized in the Tibetan plateau.Petrographical and mineralogical data indicate that the rocks are representative of materials from the mantle wedge overlying a subducted slab. The temperature and pressure of the final reequilibrium of the mineral assemblage are estimated to be around 25 x lO8 Pa and 850℃ respectively, displaying a geotherm characteristic of an orogenic belt. The discovery of eclogite and garnet peridotite suggests that the northern margin of the Chaidam mountains is a coherent highpressure metamorphic belt formed as a consequence of subduction of oceanic lithosphere and continental collision in Paleozoic era.

Abstract:This paper presents the concept of petrological structure in the study of crust- mantle structure. The crust-mantle petrological structure of three regions(Hebei plain, Taihang-Wutai and Eerdnosi) of the North China continent is suggested based on the petrological and geobarometric data of the Precambrian metamorphic rock series, the Mesozoic and Cenozoic magmatic activity, and the upper mantle xenoliths in the Cenozoic basalts, in combination with the geophysical data. and the experimental meaurements of Vp values for the rock samples at high temperature and pressure. It is emphasized that, with the combinative constraints of Vp、 Vs a and petrological structure,one can effectively recognize the difference in composition of the sialic crust among the different regions, and distinguish the upper mantle low-velocity layer from mineral phase transition (spinel or garnet phase).This paper has reached the conclusion that the crust-mantle petrological structure and its evolution are closely related not only to the Archeozoic-Early Proterozoic tectonic-magmatic events, but also to Phanerozoic tectonic-magmatic events and the extent of the reformation, and that the crust-mantle petrorological structure is the important record and evidence for tracing the nature and evolution of the continent tectonics.

Abstract:Dahuigou wollastonitite of Jilin province occurs in strata of argillaceous banded marble intercalated with siliceous banded marble, with the direct host being marble. Stratoid in form, it consists mainly of wollastonite (over 95%)，together with small amounts of diopside, garnet and calcite. Geological, petrological, mineralogical and geochemical studies of wollastonitite combined with experimental researches conducted by previous workers indicate that wollastonitite of this area is a kind of metasomatite formed by regional metamorphic hydrothermal process, and the wollastonite within it belongs in low-temperature triclinowollastonite (a-CaSiO3).

Abstract:The Archean metamorphic rocks in Miyun area consist mainly of supracrustal rocks and gneisses of tonalite-trondhjemite-granodiorite (TTG) composition.In the supracrustal rocks, there are many characteristic fabrics, such as symplectic coronas of Opx and retrograde metamorphic rim of Di and/or Gt.According to correlations between mineral inclusions and metamorphic reactions,the metamorphic minerals are composed at least of four generations, which represent four stages of the granulite facies metamorphism in this area. According to above-discussed metamorphic mineral assemblages and mineral reaction as well as metamorphic P-T estimates, metamorphism of the supracrustal rocks in Miyun area is characterized by an anticlockwise type PTt path .

Abstract:Nodular limestones are widespread in Permian of Yunnan-Guizhou region and consist of light-colored (light grey, grey or dark grey) pure limestone nodules and dark-colored (greyish black) mud-containing limestone "wrappings" showing laminations which are actually swarms of microstylotites (also called pressuresolution seams).Nodules and wrappings are commonly ccomposed of the same type of limestones which might be biograin limestones, biograiny lime-mud limestones, biograin-bearing lime-mud limestones or lime-mud limestones.The above studies have led the authors to believe that nodular limestones, instead of being products in a certain kind of sedimentary environment, were formed as a result of pressure-solution diagenesis.

Abstract:Minerals of the pyrochlore-microlite group belong to principal Nb, Ta accessory minerals in the Beauvoir granite, France. Most of their grains are euhedral with colors ranging from white,yellowish to greenish. Their sizes vary from microns to millimeters. Microlite is absent in the BIII facies and rare in the BII facies, but very abundant in the BI facies; pyrochlore appears only at the top of the Beauvoir granite. Over 30 electron-microprobe analyses arc consistent with the general crystalchemical formula: A2-mB2X6Y1-n.pH2O, where principally A=Ca, Na, U; B=Nb, Ta,W,Sn,Ti; X=O; Y=F, OH. The hydration often appears at the rim or along micro-fracture in grains of pyrochlore-microlite, acompanied by leaching of Na, Ca, U from the A site and of F from the Y site, and by the introduction of K, Ba into the A site. The Nb/(Nb+Ta)ratio of the pyrochlore-group minerals has an increasing tendency upward in the granite body. These minerals are generally rich in uranium, the highest percentage found of UO2 is 15.05%.On the one hand,certain pyrochlore-microlites may be considered as uranpyrochlore-uranmicrolite, and on the other hand, rnicrolite of the lower part contains on average 6.3% UO2; in contrast, microlite and pyrochlore of the upper part have the mean content of 9.0%. Pyrochlore-group minerals show zoning structure, due chemically to the oscillatory variations in Nb and Ta. At the top of the granite, minerals of this group may replace manganocolumbite, leading to the formation of a special replacement structure related to the late stage subsolidus interaction between magma and meteoric fluid.

Abstract:Based on the train of thought of bionics,the present paper,by utilizing sedimentary oolites, oncolites and concretes, has made a comparative study on structures, composition and formation conditions of four common urolith stones. It is considered that although these materials are produced in quite different environments in nature or in hurnan bodies, there are many aspects which are useful in explaining their formation mechanisms. The structure of oolite layers and the recrystallization and replacement of concretes can be used to make comparative explanation of the formation mechanism and growth genesis of urolith stones. In addition, the theory of local supersaturation and epitaxy in the urolith growth hypothesis can also be introduced into formation theory of sedimentary oolites, concretes and oncolites. In fact,urolith stones at the incipient formation stage is quite similar to sedimentary oolites, while the recrystallization and replacement of concretes resemble the late stage growth of urolith stones.The thermoluminescent effects of sedimentary oolites and urolith stones are also shown for the first time in this paper. It is demonstrated in this paper that calcareous,dolomitic and siliceous oolites and oncolites can be distinguished not only by differential thermal curves but also by thermoluminescent curves. What is more, struvite, whewellite, uric acid and systine urolith stones might be recognized by infrared absorption curves and by thermoluminescent curves as well.Therefore,a new approach to oolites and urolith stones has been developed with the thermoluminescence method.

Abstract:In recent years,several Carlin-type gold deposits have been found in Hunan-Guizhou area. Some of these deposits are stratiform ones on tops of the paleokarst denudation planes, and others are tabular ones extending along faults. Chemical phase analysis was carried out to study the mode of occurrence of gold in the gold deposits,and the results show that,in primary ore,the content of free gold is very low, with above 95% of gold encapsulated in pyrite and sericite.In ore deposits on tops of the paleokarst denudation planes, sericite is the most important carrier of gold, whereas in the ore deposits within the faults, pyrite is the most important carrier of gold. The close spatial association of gold with pyrite and sericite suggests that the deposition of gold was synchronous with the growth of pyrite and tbe recrystallization of sericite. The gold microparticles encapsulated in minerals can not be leached by cyanidation. In the supergene process, pyrite and sericite in primary ore are oxidized and decomposed. The gold microparticles encapsulated in those minerals are released and then accrete into larger particles. In oxidized ore, 80% of gold is free gold, and thus the economic value of the ore improves greatly.

Abstract:Megacrystalline "tourmaline" at the Zhongshan Station, Antarctica, is in fact kornerupine. The tourmaline is fine-grained and minor in amount and can be classified at least into three types according to its optical properties, composition and textural relations, with the types corresponding with the stages of metamorphism. The mineral is stable in the granulite facies in the area because it is buffered by grandidierite and kornerupine on boron. Some compositional featares of the melt and volatiles in metamorphism and incongruent melting can be reflected by the changes in the composition of tourmaline and the compovents of the mineral assemblages.

Abstract:The present paper deals with the physical principle and application range of the first instrument for measuring heat-sensitive parameters of minerals in the world as well as its effectiveness in measuring metallic and nonnetallic minerals.Its tentative application to the prospecting for gold deposits in Zhejiang and southern Jiangxi is also described.