Abstract:The Mashan khondalite series in eastern Heilongjing Province,China, was regionally metamophosed during the late Archeau to early Proterozoic and subsequently underwent migmatization. Two zones of progressive metamorphism are recognized: the granulite facies zone and the amphibolite zone. Studies on their textural relation and metamorphic reaction reveal that the metamorphic rocks in the granulite facies zone have undergone three episodes of metamorphism from lower amphibolite facies to upper amphi- bolite facies, and finally to granulite facies. At the stage of lower amphibolite fades, in high-aluminium and alkali- depleted rocks, pyrophylliite transferred directly into prismatic sillimanite, whereas in normal pelitic rocks, chlorite and muscovite formed during low grade metamorphism transferred into andalusite and biotite. The P-T condi- bona of the stage are inferred to be 530-5600℃，(3-4)×108Pa. At. the stage of upper amphibolite facies, muscovite in high.-potassium metapelites was converted into sillimanite and potash feldspar in the presence of quartz. The P-T conditions of this stage are 600-7000℃，(4-5)×108Pa. The graaulite facies metamorphism is marked by the appearance of hypersthene of metamorphic origin in mafic rocks and some of pelitic rocks. The "peak" metamorphic temperature and. pressure of this stage are 800- 8500℃，and 7.4 × 108Pa respectively. After the granulite facies metamorphism, with the crustal thickening caused by the folding or thrusting during regional metamorphism, isostatic uplift of tlae crust resulted in the formation of cordi'erite from the conti- nuous reaction of sillimanite+garnet+quartz .P-Tconditions of the stage are calculated at 800℃，and (4.5-5)×108Pa. The temperature and pressure of migmatization stage determined by Bi-Ga and Ga-Pl-Sil-Q pairs are 700-750C，and(3.5-4)×lO8Pa respectively. Mineral assemblages and metamorphic reactions of other rock series at different stages are also discussed. On the basis of the above discussion, a possible P-T-t path of the Mashan khondalite series in the regional metamorphism is given in this paper. The similarity of the P-T-t path of metamorpb:ism of the Mashan Group to that of typical orogenic belts and its uniform P-T conditions on a large scale suggest that the metamorphism of the Mashan khondalite series occurred in a regional orogenic background.

Abstract:Hydrogen and oxygen isotopic.compositions were measured on some (L- C) serpentinite samples of ultramafic rocks from Hegenshan,Jingyu,Dong- qiao, Luobusha in China: δD=-101—-146, δ(18)O=1.0—7.55. Estimates of the isotopic compositions of waters, that produced the serpentinization of ultramafic rocks in the present work range:δD=-77—-122, δ(18)O=1.4-4.9 at 330℃. According to difference of isotopic compositions

Abstract:There is an ophiolite zone along Yiyang-Dexing-Wuyuan i.n northeastern Jiangxi at the southeastern margin of the Jiangnan oldland.It is widely Held that the ophiolites is a boundary between two first-order tectonic units, the Yangtze and South China blocks, consisting of fragments of ocea- nic crust squeezed up during its subduction in Proterozoic, but some consi- der that it is a Mesozoic suture between the two great old masses. The mineral Sm-Nd isochron gives an age of 1034±16 Ma (MSWD=1.0)，thus suggesting that the ophioliaic blocks may be a product of the Proterozoic subduction of the oceanic crust rather than a Mesozoic suture.

Abstract:The total REE contents of kimberlites in China exhibit wide variations, ranging from 218.9 ppm to 1473.24 ppm. The kimberlites are characterized by simple linear REE distribution pattern showing extreme enrichment in LREE. The abundances of La and Yb are 180-1190 and 3-15 times those of chondritic respectively. La/Yb ratios range from 73.16 to 517.5. Principal mineral carrier of REE in kimberlites is perovskite (40-20000 times chondritic abundance).Apatite (15-5000 times chondritic abundance) is of subordinate importance.Phlogopite(0.25-27 times chondritic abundan- ce)，pyrope (0.45一7.9 times chondritic abundance)，Cr-spinet (0.2-1 times chondritic abundance) are low in REE. The REE contents of whole rocks of kimberlites and distribution patterns ire mainly controlled by perovskite.

Abstract:The authors collected and studied about 500 samples of major, 120 samples of trace arid 135 samples of rare earth elements of the volcanic rocks from the Northern Qinling Mountains and the southern margin of the North China platform .The volcanic rocks of the Xiong'er Group and the Dahongkou Formation areB-type of volcanics series, being the products of the contamination of mantle-derived mafic magma with crust-derived silice- ous magmas in the magma chambers of crust, with, continental rift tectonic settings. The metatholeiite formations of the Kuanping Group and the Qinling Group belong to A-type volcanics series, with mantle-derived magma genesis and sea trough tectonio settings.The spilite-keratophyre formations of the Erlangping Group and the Danfeng Group are C+A-type and C- type volcanics series, being the. mixing products of the magma from the lower crustal bottom and that from hot mantle diapirs at crust-mantle transitional zones, with sea basin tectonic settings.

Abstract:The Guoshan kaolin deposit, located in the area from Tongan county town to xinxu of Fujian Province, is of weathering residual type formed by weathering of adamellite.Completely-weathering zone, semi-weathering zone and parent rock can be separated in downward succession, along the weathering profile .The completely-weathering zone (i. e. the main ore body) can be further divided into four mineral segments by estimation of the relative content of kaolinite and halloysite using transmission electron micros- copy .Studies. indicate that kaolin minerals are mainly concentrated in the completely-weathering zone. The clay minerals have been studied systematically by such means as analytical el.,ctron microscopy (AEM)，x-ray diffraction (XRD)，infrared absorption spectra (IR)，chemical analysis and optical examination. The results obtained show that they consist mainly of kaolin minerals (kaolinite and halloysite) associated with small amounts of allophane, imogolite., sodic montmorillonite, hydromuscovita and gibbsite .Kaolinite and halloysite, are common members of the kaoli. group in. the 1:1 dioctah}edral phyllosilica- tes. Allophane can also be regarded as a mineral related to this group. Detailed investigations show that kaoliztite has low degree of order and irregular crystal form in the semi-weathering zone, higher degree of order and pseudo-hexagonal sheet form in the completely-weathering surface soil zone .Such a regular variation in the degree of order and crystal form of kaolinite in the weathering profile of monzonitic granite serves as an indi- cator of the developmental stage of the weathering crust. Halloysite is mainly of 2H20 (7A) type, with transitional types of 10A to 7A and 7A to kaolinite also discovered by XRD and. AEM .The crystals of halloysite are basically spherical and tubular in form. Halloysite contains interlayer water which is readily dehydrated, and dehydration might result in partial or complete splitting amd unrolling of tubes and the formation of the polygo- nal cross section. Having been dried, spherical halloysite takes somewhat polyhedral form due to shrinkage .Morphological feature is very important in the study of kaolin minerals and has been used as a diagnostic criterion to distinguish different mineral species in kaolin minerals.

Abstract:Garnet group is one of the major rook-forming minerals in dark mafic rocks, gxanulite and gneiss of the Archean metamorphic complex in Liaoxi- Chifeng area. It is of pyrope-almalndine series containing lots of grossular molecules accordiazg to electron microprobe analyses and is close to alman- dine according to infrared absorption spectra. Mossbauer spectra of garnets show that the increase in Fe3+ coxltent will lead to further deformation of six-coordinated polyhedra in garnets .There exists positive correlation between the cell parameter so and the Ca2+ content of garnets .Chemical composition and structural relationship with other coexisting minerals suggest that garnets are products of granulise facies metamorphism under the condition of temperature 700-840℃` and pressure 0.85-1.10 GPs. The reactions causing the foxmation of garnets are complex, which include the temperature rising dehydration reaction of hornblende and plagioclase and the sliding reaction from the hypersthene + plagioclase assemblage to the garnet + clinopyroxene assemblage.

Abstract:The Huanggang-Ganzhuermiao ore belt of east Inner Mongolia is tin- polymetallic ore belt i.n Southern Da Hinggan Mountains. Data of major and minor elements in magnetite, cassiterite, galena and sphalerite from ore deposits within this ore belt suggest that these ore deposits are of skarn， hydrothermal, porphyry and grei.sen types related to Yanshanian magmatic activity and that iron in ores came from regional Permian marine interme- diate-basic volcanic rocks whereas partial lead and zinc from Permian geo- syncli顶c sediments. Studies also indicate that galena and Sphalerite in tungsten-tin deposits related to Yanshanian subalkaline granite diffei obt}i- ously from these minerals in lead-zinc deposits associated with Ya}zsha}lian intermediate-acid granitoids i.n contents and ratios of minor elements.

Abstract:The space group and unit cell of yingjiangite from the Xiazhuasng ura- nium deposit, Guangdong Province, have been determined for the first time by single-crystal X-ray diffraction analysis.Its unit cell is orthorhombic, space group Bmmb (63)，a=15.707 (3)，b=17.424(3)，c=13.692(2)A. V = 3747A3.Z=4.Dc二4.60g/cm3, Dm=4.54 g/cm3.Chemical formula: (K2,Ca) (UO2)7(P04)4(OH)6·6 H2O.Biaxial negative with 2Vc=36°，2 Vm=36-38°， Ng=1.707(2)，Nm=1.703(2)，Np=1.666(1)·Optical oiientatiori: , Ng//Y, Nm//X and Np//Z.

Abstract:The basic method for the study of grain contact probability is to record the transition sequence from one crystal or mineral species to another along a line in a thin section. The number of each type of contacts is then displayed in the form of contact probability matrix in comparison with random contact probability matrix. The data obtained in this way may indicate whether or to what extent the position of one mineral species is dependent on the position of another mineral .Generally speaking, minerals of the same species or the same generation tend to be in contact with one another .The grain contact probability can therefore be employed to distinguish mineral assemblages. A study of the grain contact probability of charnockite in Taipingzhai ahows that the major mineral facies are composed of minerals of two different generations, and this is consistent with the conclusion .reached by petrographic studies.