Abstract:U-Pb isotopic ages of four Early Praterozoic granitic bodies in southern Zhejiang have been determined:Xiaji admellite 1975士180Ma, Lizhuang adme- llite 1870士136Ma, Tianhuo granodiorite 1832士80Ma, and Sanzhishu migmatite 1863士144Ma, These data show that the rocks of the Zhejiang-Fujian Preca- mbriari metamorphic basement underwent an intense magmatic thermal event in the period of 1875士100Ma.This magmatic thermal event, which resulted in migmatization, granitization and magmatic intrusion in the basement rocks, played an important role in the formation of Zhejiang-Fujian stable crystalline basement. These results also suggest that the formation of the host rocks of the granitic rocks, namely Badu (Mayuan) Group, occured be- fore 2.OGa. The 1863士44Ma U-Pb age of migmatite and 2071士48 Sm-Nd iso- chron age of amphibolite in Sanzhishu demonstrate that at least part of the "Hexi" Group is of Early Proterozoic rather than Late Paleozoic. The meta- morphic rocks in Sanshishu may be a part of Zhejiang-Fujian metamorphic 'basement.

Abstract:A type of calc-alkalic rock-biotite-pyroxene diorite was discovered in the Shuiquangou weakly-aklaline complex of northern Hebei. Its mineral compo- sition shows that it is possibly a new type of igneous rock. It consists of bio- ti te (about 15%)，augite(about 15%)，oligoclase-a ndesi ne(approximately 65%)， K一feldspar (some 5%)and other accessory minerals(less than 1%).Compared with other rocks of Shuiquangou complex, it contains higher LREE and high field strength elements as well as Fe, Mg and Ca and lower Si02，K20+Na2O- and A1203.

Abstract:A new type of inclusions, cumulus-quenched rock inclusions,was discovered in the Jiguanshan pluton of Tong ling,Anhui Province.Being a kind of cumulus rock with fine-grained texture,the inclusions consist approxima- tely of 80% pyroxene,8%apatite,4% magnetite and 8% groundmass. The groundmass,noted for the domination of plagioclase and fine-grained texture,is merely present among some pyroxene grains and grades into a quenched rim towards the edge of an inclusion. This rim was formed by quenching when a pyroxene inclusion was broken and brought to the shallow place after the cumulation of pyroxene but before the crystallization of inte- rgranular melt.The inclusions are consistent with the host rocks in pyroxene composition and initial Nd and Sr isotopic ratios,suggesting that they are cognate inclusions.

Abstract:Eclogite masses and some other rocks in Donghai-Ganyu area of JiangsuProvince show many chairactoristics of ophiolites and seem to be relict fra-gments of the oceanic crust.The protoliths must be basic lava and cumulatemafic rocks of ophiolftes,The basalt exhibits chemical composition of oceanicridge tholeiite and contains abundant large-ion lithophile elements,REE andLREE,thus belonging to E-MoRB,These rocks were formed in an ocearnicbasin environment between the Subei-Jiaonan terrane and the Jiaobei terra-ne,with their magma derived from the partial melting of the enriched ma-ntle and the deep mantle current.As a result of plate subduction and colli-sion,these plutonic eclogites were emplaced in different horizons of the Do-nghai Group.

Abstract:This paper has made a systematic investigation into REE，trace element and stable isotope geochemical characteristics of major Yanshanian Cu (Mo) mineralized intrusives in Zhejiang Province. The Cu (Mo) mineralized intrusi- ves in Zhejiang are mostly enriched in LREE and might be further divided into two types, one with no obvious Eu anomaly serving mostly as parent rocks of skarn type deposits, and the other with strong Eu anomaly being mostly direct ore-bearing porphyries. The Cu( Mo)mineralized intsusives con- tain relatively low Ti，Ni and Cr but comparatively high Rb，Ba，Hf，F，C1 and S.According to correlations of Sr+Ba-Li+Rb+Cs, Nb-Y, Ta-Y and Rb一Y+Nb, the Cu(Mo)mineralized intrusives mostly belong to I type, for- med by volcanic arc and synorogenic collision. Studies on Sr-O isotopic rela- tionships of these rocks indicate that the initial Sr-δ18O whole rock(%0) variation points of the major Yanshanian Cu (Mo) mineralized intrusives in Zhejiang all fall into the low 18O rock area formed by altered basalt or meteoric water-hydrothermal alteration，with the intrusives mostly exhibi- ting genetic characteristics of crustmantle mixed magma. The intrusives, may be divided into two types: one includes epicontinental depression syntectic granitoids(diorites)close to intracontinent of northwestern Zhejiang, serving frequently as parent rocks of porphyry Cu (Mo) deposits, porphyry-skarn Cu (Fe)deposits or polymetallic depositss the other includes epicontinental fault syntectic type granitoids (diorites) of southeastern Zhejiang, closely related to porphyry Mo(Cu)deposits and porphyry-epithermal Cu(Au)deposits.

Abstract:There exist a lot of Cpx-peridotitic xenoliths in basanites of Maguan,Yunnan Province. Detailed researches on mineralogy and geochemistry have been done to understand the genesis of the xenoliths,The ressults show that there is no equilibrium between Cpx-peridotitic noddle and Its host rock,basanite,The formation depth of xenohths is relatively shallow(less than 60 km).The mantle area in which Cpx-peridotites are located has undergone light depletion and late stdge metasonmatism. All these xenoliths are occasional ones brought up tosurface by basanitic magma during its ascending.

Abstract:The phenomena of interstratification(mixed layer)have been consideredas special structural phenomena in silicates since they were recognized. The-refore,interstratified minerals,whose basic structure sheets(BAS)belong tothe subclaee of layer silicate,have been classified into the category of clayminerals. However,there exists another kind of interstratified minerals whoseBAS belong to more than one class(such as sulfides,chlorides,hydroxides,carbonates and silicates).In order to compare with the traditional intersta-tified minerals,we propose a new concept-interstratified mineral with basicstwcture sheets of different classes,and restrict this concept within five res-pects from the structure and composition of BAS to the stocking regularityof BAS. Valleriite,a typical interstratified mineral with basic structure sheets ofdifferent classes,is also studied in this paper. Electron microprobe analysesindicate that the degree of mismatch between sulfide layer and hydroxidelayer is higher,the results of X-ray analyses show clearly the diffractionsfrom d001 to d007,and repetition interval of 11,45A,The studies by means ofhigh resolution transmission electron microscopy also reveal the lattice fringeimage of 11.4A in c-direction,and disorder in a-and b-directions, o there isno supercell in valleriite,and this differs from the view held by H.T. Evans(1968)that valleriite is a mineral with supercell with c= 34.10A and a=64.46A.

Abstract:Kaolinite, dickite and nacrite are polytypes of the kaolinite family, in which kaolinite is quite common while nacrite is very rare in nature. As is well known, different kaolinite polytypes occur in different gelogical environ- ments. Nacrite usually appears in an environment with relatively high tem- perature and pressure. Therefore, it is of great significance in theory and practice to distinguish kaolinite polytypes in detail. Characteristics of the kaolinite family from the Early Carboniferous Fang- jiashan kaolin deposit were studied by means of X-ray diffraction, infrared spectroscopy and potassium acetate intercalation. With the entrainer of K-acetate acted on the kaolin, an intercalated compound with a 14.0A spa- cing appeared. After it was replaced by water, a characteristic 8.35A base spacing of nacrite hydrate intercalate was formed. Under the condition of normal atmosphere, the nacrite hydrate was stable. However, when the nacrite hydrate was placed in an atmosphere with saturated ethylene glycol, the nac- rite hydrate was destroyed rapidly. This demonstrates that Fangjiashan kao- lin is a nacrite-bearing kaolin deposit. Further"n.ore, IR and intercalation technique also show that the aacrite mineral exists in a form of coarser fraction larger than 2 um and the domain of kaolinite decreases with the increase in that of nacrite. This may indicate that nacrite was formed thro- ugh reconstruction of kaolinite under geological structural stress. The nacrite- bearing kaolin deposit is only seen, in the vicinity of the Jiangshan-Shao- xing deep fault, along the transitional zone of two geological units, suggesting that the movement of the Jiangshan-Shaoxing deep fault might have con- tinued to the Hercynian period or even to the Yanshanian period. It is the compression and compresso-shearing of the fault that provided the pressure for the formation of nacrite in this area.

Abstract:The explosive-collapsed breccia gold ore deposit seems to be a major and representative one among the Qiyugou type gold deposists. The ore field is located at the Southern margin of the North China platform,Gold minerali-zation was genetically related to the evolution of the Middle-Late Yanshaniancalc-alkaline magma. The whole ore-forming process underwent vanward,major and late alteration-mineralization periods,with native gold being thepredominant gold ore mineral. This paper deals mainly with typomorphic characteristics of native gold.2800 grains of native gold have been studied by the authors by means ofnaked eye, microscopy and electron microprobe analysis.In the light of thetypolnorphic characteristics so far established,it is presumed that the brecciatype gold deposits under exploration may be considerable in scale,and that,besides the auriferous J_4 and J_2 breccia orebodies,the other breccia bodies inthe Qiyugou ore field ought to have good prospects.The existence of gold crys-tals{111},{111} {110},{100}may indicate rich gold mineralization areas.The denudation depth of the orebod ies(auriferous breccia bodies)may becstimated with the help of the regular zoning pattern of the gold crystalforms in space. This special zoning may also be used to evaluate ore potentialand prospects of all other breccia bodies on the outskirts. Moreover,the rela-tively high content of bismuth in native gold may be taken as an indicatorfor ore prospecting and evaluation.

Abstract:Fersilicite is a rare Si and Fe metallic mineral.Up till now, five sorts of mineral facies have been discovered, namely gubeiite (Fe3Si)，xifengite ( Fe5Si3 )，fersilicite (FeSi)，ferdisilicite (FeSi2) and suessite (a-Fe3Si)，of which the first two minerals were found in the alluvial bed of Yanshan area, belonging to cosmic dust minerals. In 1980，Hong Wenxino first reported the discovery of ferdisilicite in Tibet and Gansu; afterwards, this mineral was successively found in such provinces (regions) as Jiangsu, Anhui，Xinjiang, Liaoning，Hebei and Zhejiang，and its host rocks are magmatic rocks, sedimen- tary rocks and metamorphic rocks, with mafic and ultramafic rocks being dominant. The host rocks were formed from Archean to Cenozoic, and the southern Zhejiang Proterozoic metamorphic area seems most widely distsibu- ted. Ferdisilicite of China contains Fe 41.1%一49.90o and Si 49.1%-55.9%， being deficient in Fe and rich in Si as compared with the theoretical values. In addition, ferdisilicite contains such minor elements as Mn, Al，Ce, Eu, whose contents are different in different areas. Besides fersilicite, the associa- ted minerals of ferdisilicite include sporadic native silicon (Si)，and this has been confirmed by mineralogical and electron microprobe analyses and X-ray diffraction data. The areas producing primary native silicon so far known include Liaoning，Zhejiang and Fujian. Genetically, fersilicites axe derived either from mantle magma or meteo- rite falling.The fersilicites in the southern Zhejiang metamorphic area might have been related to the Archean meteorite falling event.

Abstract:Pseudomorphous turquoise was discovered by the author in Maanshan area. Though similar to nodular and veinlet turquoise in many mineralogical and ore deposit characteristics, pseudomorphous turquoise preserves the crystal form of apatite, with its ore-forming parent rock being apatite-magzietite- actinolite dikes.The formation of pseudomorphous truquoise requires specific geological conditions such as rock, geological structure, wall rock(parent rock) alteration and surface oxidation，and therefore this mineral is rarely seen in the world.

Abstract:Rheologies of crustal rocks and minerals are mainly controlled by tempe- rature and their composition. Since rheology reflects strain velocity of an object, the study is closely related to deformation. Under the high temperature condition of lower crust, rheologies of different rocks and minerals obviously increase in contrast to their viscosities and relative viscosities. So, the lower crust as a whole flows easily, distributes strain homogeneously, and is deformed penetratively. Nevertheless, rheology increases in order of schist