On the basis of achievements obtained in surface rock survey and borehole primary halo studies performed in the Zijinshan copper-gold ore district, the present paper has discussed in detail horizontal and vertical anomaly distribution characteristics of halo-forming elements in the ore deposit, determined main ore-forming elements and associated elements, calculated zonal sequence of elements, expounded zonation of anomalous elements and, based on super-orehalos, be low-ore halos and element zonation and using multiplictive ratios, formulated Criteria for evaluating denudation level of copper and gold ore zones. These data. combined with geological characteristics of the ore district and ore deposit. have led the authors to establish the geological-geochemical prospecting mo del of the Zijinsban ore district. In geocbemical exploration conducted on the outskirts of the roe district. economically valuable orebodies and new mineralization types (porphyry gold, copper and molybdenum ores) were discovered, thus laying a foundation for the development of the Zilinshan district into a large-sized copper deposit.

A new method has been developed for rapid field determination of 0. 010-50μg-g silver. The method consists of two independent yet correlated parts: one is Ag-TMK-SDS tribasic complex light-guide colorimetric determination methood for directly determining 0. 25-50μ/g silver,and the other is mercapto group isolation and enrichment micrcbead-separating colorimetry for determining 0. 010-0. 25μg/g silver. These two parts can be comploted successively in the same test liquid.The former has a detection limit of 0. 006μg/ml (k= 3), and for determining silver in copper, lead and Zinc standard ore samples GSO-Cu-1 (containing silver 3. 81μg/g), GSO-Ph- 1 (containing silver 14.7μg/g) and GSO-Zn-1 (containing silver 13. 5μg/g), RSD(n =11) values are 1.6%, some 3.7%and 3. 4 % respectively; the latter can detect 5 ng/g silver, and for determining silver in geochemical standard sample GSD-3 (containing silver 0. 5μg/g), RSD (n=11) is 6. 6 %. Tee method is fairly simple, convenient, accurate and sensitive. With a light-guide colorimeter, the determinations are remarkably improved in accuracy and precision, being equivalent to results obtained by atomic absorption method, and this suggests that the method has a bright future ill application.

in order to solve the problem of site selection for a nuclear power station in Guangdong and evaluate the reliability of the pre-selected site of a nuclear power station in nuclear safety, experts from the Aerogeophysical Remote Sensing Center studied in 1994 deep tectonic characteristics and crustal stability of this region on tEe basis of aeromagnetic data and, as a result, acquired important geological achievements, thus providing deep geophysical data for site selection of the nuclear power station and opening up a new field in tEe application of aeromagnetic survey.

Besides standardization, zero correction error constitutes the most common error source of a gravimeter. Based on data accumulated in high-precision gravity elploration carried out by the authors in recent years, this paper has made a comparatively comprehensive and objective analysis and investigtion: (1) analytical conclusions were drawn on normal zero variation and zero mutation character of Lacoste-Romberg gravimeter; (2)by employing dynamic and static separate procesiug technique for measured data, the paper analysed zero correction error resulting probably from zero nonlinear variation when the gravimeter works continuously from several to tens of days; (3)through analysis and calculation of measured data, the referential values concerning the effect of zero mutation upon observation precision of the gravimeter were obtained; (4) in accordance with the practical problems arising from the use of gravimeter, the measures for improving zero drift linearity wete proposed.

The key to the processing of deep reflection seismic data seems to be the cxtraction and enhancement of deep weak effective signal from the disturbing background, thus arising the signal-to-noise ratio and resolution ratio of the profile. The interpretation of the deep reflection seismic profile should be focused on the large geological tectonism and its genesis; geological rsgularity ought to be used to po rform integrated geological interpretation. In interpretation, the analysis and study of the formation and characteristics of some related disturbing wave would contribute to reliable geological inferanch and niterpretation of the deep reflection set seismic profile.

The present paper has dealt with the principle of transient state Rayleigh wave elploration, and analysed various factors affecting transient state Rayleigh wave exploration and the datacollecting technique tEat should be adopted. With practical examples. the paper Las tentatively probed into the effects of several sorts of data-processing upon frequency dispersion curve calculation.and the influence of evaluating phase deviation by mutual spectral method upon the precision of surface wave frequency dispersion curve calculation. Finally, characteristics of three sorts of anomalies that appear in the frequency dispersion curve and the causes for their formation are discussed.

Due to the complexity of the near-region field and the limitation of the frequency domain electromagnetic sounding used at present, the near-region frequency domain electromagnetic sounding remains an unsolved problem in geophysics. Based on the theory of near-region field, the present paper, by introducing the theory of combination wave, has put forward a definition formula of apparent resistivity suitable for near-region frequency domain electromagnetic Bounding. Such an apparent resistivity can effectively suppress background field in the near region, make prominent the function of geoelectric anomaly information, and reflect objectively electric variation regularity of geoelectic section.

Using transient electromagnetic method, the authors searched for caves, structural shatter zones and faulted zones from the surface to a depth of 100m at the site of principal shaft in a certain deposit of Huangshi City and, on the basis of the data obtained, discussed the genesis of the caves. The geological tasks suggested by the mine were satisfactorily fulfilled.

In the aspects of theoretical calculation and field data processing, the present paper Las dealt with the interpretation method for one-dimentsional full-region apparent resistivity of electric dipole source transient electromagnetic sounding as well as the related pie-processing. of measured data. magnetic field calculation and the inverse method of measured data, magnetic field numerical values.