Abstract:The Daposhang section at Muhua, Changshun. Guizhou. is an excellent and attractive DevonianCarboniferous boundary section. The transitional beds between the Devonian and Carboniferous of the sectionare continuous and well exposed. belonging to the deep-water basin facies Abundant fossil groups have beendiscovered from this section: conodonts. ammonoids. trilobites. ostracods. vertebrate microfossils and so on.So far as known. it has the most continuous and complete conodont zonation for the Devonian-Carboniferousboundary beds in the world. It is especially worth pointing out that both typical Siponodella pracsulcata andthe transitional forms between S. praesulcata and S. sulcata have been found from the upper pracsulcata Zoneof the Daposhang section. Evidently. we can not only prove the actual existence of the evolutionary lineagefrom S. praesulcata to S. sulcata, but also exactly define the level of the Devonian-Carboniferous boundary. Inthis paper. the development of the Devonian-Carboniferous boundary beds at the Daposhang section is dealtwith and the section is compared with the Muhua section and the Nanbiancun section which are the candidatesfor the Devonian-Carboniferous boundary stratotype. In the authous opinion the Daposhang section is obvi-ously better than the Muhua and the Nanbiancun sections. hence it can be recommended as one of the candi-dates for the international Devonian-Carboniferous boundary stratotype.

Abstract:Since Jurassic. intense and repeated tectonic movements have taken place in eastern China, of which theYanshanian movement is the most important. Thereby the development of the basins between the Jurassic andEogene in the studied areas may by divided into two different stages, i.e. the Yanshanian subcycle (J-K_1~1) andthe North China subcycle (K_1~2-E). The basement and tectonic stress field of the basins played an obvious role in controlling thesedimentary-tectonic development of the basins. and down-faulted basins might form under different stressstates. Besides. the shearing stress also played an important part while the basins were forming in the notedareas.

Abstract:In the Indosinian period. the climate was scorching hot and the source of seawater was ample in Hubeiand its neighbouring areas. so the basic conditions for the formation of evaporites were favourable. Under thisprerequisite. the reason why salt deposits occurring in some third-order tectonic units between the Jiangnanoldland-upwarped zone and the Dabashan upwarped zone differ in degree of development is mainly due to thetectonic factors during sedimentation. If favourable tectonic factors are present, large amounts or evaporiteswill form: on the contrary. they will not.

Abstract:Experimental studies on the two solid solutions franckeite s.s. and cylindrite s.s. yielded among others thePb-free endmembers of franckeite and cylindrite respectively. In these endmembers the lead content of the twomineral phases are completely substituted by bivalent tin. A third phase, ottemannite s.s. with (Fe. Sb)-bearingcompositions, was further identified in the Pb-free 4-component system Fe-Sn-Sb-S. Pb-free franckeite andcylindrite could only be synthesized as homogeneous phases at high temperatures. The ottemannite s.s. was ob-tained at 600℃ but an extensive existing range was also confirmed at temperatures below 500℃. The phase relations were discussed in the pseudoternary subsystem SnS-SnS_2-FeSb_2S_4. The following se-quence of Pb-free phases and phase assemblages were observed under increasing Sn~(4+) content at 600℃:herzenhergite (SnS)+franckeite, franckeite, franckeite+cylindrite, cylindrite, cylindrite+(Fe, Sb)-ottemannite.(Fe, Sb)-ottemannite. (Fe. Sb)-ottemannite+berndtite (SnS_2). The assemblage cylindrite+berndtite was identi-fied in synthetic systems involving Pb. The phase Fe. Sb-ottemannite s.s. appears to be stable only under Pb-de-ficient and high sulfur fugacity conditions.

Abstract:The Chinese continent is a component part of the present Eurasian plate. The history of its geologicaldevelopment is a process of the convergence of palaeo-plates. the oceanward migration of volcanic belts andvolcanic island-arcs, and the accompanying growth of the intracontinental rifts in the later stage. So theChinese continent abounds in nonmetal resources. Based on the plate-tectonic settings in which those depos-its were formed, the nonmetallic deposits can be generally classified into those related to the sutures andophiolites. those related to the volcanic island-arcs. those related to the back-arc epicontinental sea. those re-lated to the intracontinental rifts and those within the plate interior. They all show certain characteristicregularities of distribution. The evolutionary process of the Chinese continent is so complicated that somenonmetallic deposits have various origins and are characterized by multi-stage mineralization. multiplicityof types and superimposition of mineralization. All these are of great significance in deepening the under-standing of the formation and modes of occurrence of the nonmetallic deposits and in prospecting for min-eral resources.

Abstract:The technique of mineral prediction by pattern recognition has been developed through the applicationof computerized pattern recognition to geological exploration. The principles and computing method of thistechnique as well as some characteristics of its application in geological exploration are expounded in thispaper. Some of the study results gained by the authors in this aspect are also given. which include classifica-tion of oil-field waters. evaluation of gossans of main ore deposits in China, prediction of ore resources inthe Dachang Sn-polymetallic field. and appraisal of Pb and Sn anomalies and prediction of mineral re-sources in southern Hunan. Some of the prediction results have been proved correct.

Abstract:The paper deals with the metallogenic conditions and regularities of the region ol the lower-middle reachesof the Changjiang River in China. The complicated structural network with the Changjiang (Yangtse) deepfracture as its trunk is the leading rock-and ore-controlling structure of the metallogenic belt. Thehigh-potassium granodiorites of the first magmatic sequence of the Mesozoic Yangtse syntexis type and thesodium-rich diorites of the second sequence are genetically related to the copper ore series and the iron ore se-ries respectively. and occur respectively in the block-faulted and-folded uplift area and the down-faulted vol-canic basin as well as the transitional zone between the two. The ore-hosting horizons show specific associa-tions of rocks and often contain ore beds basically of stratabound nature.

Abstract:From the determinations of surface heat flow based on silica geothermometry, residual heat flow,radiogenic heat production of rocks, thermal conductivities of rocks and so on, the temperatures at differentdepths of the lithosphere in Fujian Province are estimated by using a one-dimensional steady-state model. Ac-cording to these and the research on geological structures. the possibility of existence of various geothermalsystems in Fujian is discussed. The authors consider that in Fujian, geothermal systems related to shallow magmatism do not exist andhot dry rock systems can not be exploited for the time being. However, intermediate-and low-temperaturehydrothermal systems are well developed. They are controlled by active faults and distributed widely insoutheastern Fujian. but do not have an anomalous heat source. The groundwater circulates at great depthsand has a temperature usually less than 150℃ with less discharge but good quality. It can be used directly as avaluable geothermal water resource but not suitable to be developed as an energy source.

Abstract:NO.lMass Extinetion一A Fundamental Indieator for Major Natural Divisions of Geoiogieal History···一··-··一x“D“ovi(徐道一), Zhang Qln、en(张勤文)and su。Ylyln(孙亦因)The Marine Cretaeeous in the Western Part of the Tarim Basin of Xinjiang and Its Depositional Environments···············1···························.·一·...·...............…… ·····、···········,·……Hao Yichun(郝治纯), zeng xuelu(曾学鲁)and Gu。xlan…