For the purpose of deepening the interpretation of regional gravity datait is necessary to utilize data on the crust and the deeper part provided bydeep seismic sounding. Several geoscientific global transects completed in Chinain the past few years have furnished such possibility. We hold that only onthe basis of the gravity density model which is designed according to thesetransects and agrees with the reality can effective interpretation result beobtained. The conversion of data obtained at a few deep seismic soundingstations into gravity Moho is extremely unreliable, and the metallogenic pro-gnosis made on such a basis will not be correct. The new gravity model shouldinclude multi-layered structure of the crust, faulted block, varying densitycharacter, density ununiformity and not great undulation of Moho as well asthe possibility that fractures are gentle shear zones at depth. The two-layerstructural model neglects these basic characteristics and therefore its interpre-tation has no practical significance.

This paper describes briefly the basic principles for analysing lithologyand coal quality with the optimized scale transformation method, and discus-ses tentatively important technical parameters in logging objective function,convergence criteria in iterative solution process and initial iterative valueswith a suite of principles for their selection put forward. Based on calculati-ons for changing some technical parameters, we have analysed and comparedmajor technical indices (such as convergence rate) of some important scaletransformation methods, and advanced the best scale transformation methodfor analysing lithology and coal quality. In addition, a discussion is made onsome troubles that might occur in conducting such analysis with the scaletransformation method, with the means for overcoming these troubles sugge-sted.

This paper discusses a F-K field deviation imaging technique-recursion F-K deviation, which is developed by combination of the normal speed F-K deviation with the deviation of phase-shift method characterized by verticalvarying velocity. Under the condition of horizontal layered media, the devia-tion precision of this method is not restricted by the dip angle, and its calcu-lation time is considerably shorter than that of the phase shift method. Byintroducing the concept of series deviation, We have putforward a new develop-ment of recursion F-K deviation-residual recursion F-K deviation. Theo-retical and practical data processing shows that this deviation method canfurther raise deviation precision and calculation efficiency.

On the basis of paleomagnetic study of samples collected from dykes inJunggar massif and large quantities of geological data, it is confirmed thatJunggar massif was located 35° north latitude in Early Permian, lying basically in the same latitude zone as Tarim massif, Kazakhstan massif and Siberia andserving as a component part of Laurasis continent. The authors have also madean analysis of tectonism in this area since Early Permian.

When there exists certain temperature difference, the single crystal ofpyrite will produce thermo-electrotrmotive force and assume four conductiontypes, i.e., p type, n-p type, p-n type and n type. Different conduction typesare closely related to physicochemical environments during the formation ofpyrite. There are three basic physicochemical factors that decide the condu-ction type of pyrite. Determine the thermo-electromotive force of pyrite, anddivide it by temperature difference between the two electrodes, we can getthermoelectric coefficient of pyrite. In different types of ore deposits, spatialdistributions of thermoelectric coefficients of pyrite are different. The thermo-electricity of pyrite might be used to predict concealed ore bodies, studymetallogenic zonality and evaluate denudation extent of ore deposits.

This paper discusses the phenomena and nature of static effects in sonicfrequency telluric electromagnetic method of controllable source, reviews theavailable methods for correction of static effects, describes the principle andoperation of a spatial filtering correction method designed by the authors, andwith examples illustrates its. effectiveness and limitation.

This paper deals with the influence of cable on antenna radiation field inthe borehole electrpmagnetic wave method. Based on theoretical analysis andexperimental verification, it puts forward some effective measures for suppres-sing such influence.

The soil carbonate △C survey now becomes a major method in China's geocbemical petroleum prospecting and has been used in different stages ofsurface geochemical oil-gas prospecting (rough survey, reconnaissance anddetailed investigation, with fairly good results obtained; nevertheless, it hasbeen found that this method fails to yield distinct geochemical anomalies insome areas. In order to raise the effectiveness of △C survey and make it display anomalies satisfactorily in different landscape areas, we performedrather thorough and systematic basic experimental research.This paper describes in detail the result of the study, and points out thecauses of such unsatifactory result in using △C method. It is suggested thatcarbonates with different sorts of thermal phase state be adopted as effectiveindices in different landscape areas to replace the previous method which onlyused a single index (△C) to conduct survey.

This paper deals tentatively with geochemical characteristics of the Jigu-anzui copper-gold deposit as well as geochemical behaviors of major ore-formingelements and associated elements in the process of metallization. The criteriafor geochemical exploration in this ore deposit have been drawn and themodel for geochemical prospecting has been established to make ore prognosisin depth or outskirts.

In order to make full use of the advantages of exploration geochemistryin ore prospecting, we have used the method similar to that in the study ofgeochemical characteristics of veinlike hydrothermal metallic deposits to performtrial geochemical prospecting in the Badu fluorite deposit of Longquan coun-ty, Zhejiang province. The purpose for this study is (1) to get to know geo-chemical characteristics of wall rocks. stream sediments and water madiahosting this type of fluorite deposits in the process of mineralization, and (2)to find out features of primary and secondary anomalies in this type of oredeposits. The data obtained are expected to provide some geochemical groundsfor the prospecting and evaluation of this type of ore deposits in unknownareas. Studies show that primary anomalous elements associated with the formation of fluorite deposits include F, As, Sb, Ca, Ag, Mo, Y in Group I and Na, Mg, Al, K, Ti, Ba, P, Nb, Pb in Group II with elements in Group I being positive anomalous ones and those in Group II being negative anomalous ones. Primary anomalous of all these elements exhibit'tonal arrangement. Axial zoning of the positive anomalous elements are in upward succession F- Ca-As- Sb-Y-Ag-Mo. Stream sediment and heavy sand survey indicates that placer fluorite anomalies and F anomalies might have formed in drainage system near the denuded fluorite deposit, SO that fluorite may serve as an indication mineral and F as an indicator element in ore prospecting. Hydrogeochemical studies suggest that F^- and Ca⁺⁺ hydrochemical anomalies may appear within the fluorite orefield, which are of some significance in indicating enrichment locality of orebody and extension of ore zone.