Some advances have been made in recent years in the technique for processing three-dimensional depth migration before stack. Nevertheless, as the amount of calculation work for this technique is very great and the precise depth-interval velocity is required, the technique fails to attain the objective of large-scale applicatio. On the basis of applying large scale computer, this paper deals emphatically with the formulation of the model for precise depth interval velocity and suggests the coherent inversion of three dimensional intervl velocity and the optimization of the model for dimensional depth-interval velocity.

This paper has described regional geochemical background of antimony in Hunan, analyses the distribution regularity of antimony anomalies and its relationship with structure and magnetic rocks, probed into the crustal evolution in relation to antimony mineralization, established a mantle-crustal tectonic metallogenic model for the Xikuangshan antimony orefield, and made ore-prospecting prognosis.

This paper advances a new data processing technique-subregion median contrast filtrering method.It uses subregion to simulate spatial variation of the background, calculates critical values of anomalies with EDA technique, and measures the undulation of field values with the contrast as the datum. This technique fairly satisfactorily solves the problem of recognizing weak anomalies, and the preliminary application proves it to be effective.

Based on the calculation and analysis of the velocity spectra of the theoretical geological model for six horizontal homogeneous bedded media under the condition of typical topographic relief, this paper points out that the utilization of the conventional horizortal base level technique for extracting stacking velocity under the complex topographic condition fails to attain the precision of velocity and will produce false longitudinal and latitudinal velocity variation regularity. It is also demonstrated that the use of the slipping base level method to extract stacking velocity can not only eliminate the effect of topographic relief but also satisfy the velocity precision of seismic exploration. In addition, the method can reflect the real interval velocity.

In view of the low signal to noise ratio seismic data character of Yanqi basin, the author made large quantities of analyses and tests and, on such a basis,designed a low signal to noise ratio seismic data processing framework dominated by such processing methods as interactive iterative static correction technique, the technique for suppressing stochastic interference and linear interference, suface compatibility amplitude proccessing technique, wavelet normalization proccessing and denoise technique of post interactive f-x domain prediction. Practical data proccessing has proved the framework to be evidently effective.

Based on a description of the principle of surface wave survey exemplified by the surface wave exploration in the harnessing and beautification of Fenhe River, this paper recounts the field work method,data-processing and geological effects of surface wave exploration.

The high resolution gravity and magnetic survey was used to solve the problems in coal exploration under nappe.The existent state of diabase was strudied with magnetic anomalies,and the existence of nappe was confirmed.The distribution of coal series strata under napper was studied according to the gravity anomalies and thier data processing results,and it was pointed out that the best potential target area for coal exploration was the Taihang-Xutai gravity low zone.The high resolution gravity and magnetic survey is one of the effective means in early stage exploration to look for coal series strata under nappe.

Based on the basic principle of magnetotelluric static migration and the processing of large quantities of measured data,this paper puts forward for suppressing static migration-the standardized correction method for static migration,which is more effective than the traditional static correction method.The kernel of this technique is the utilization of lithologic electrical parameters and the surface or shallow strata at the positions of measuring points to standardize the first branch of the apparent resistivity curve,and the use of interactive visualized static migration software to correct the apparent resistivity curve.Practice shows that this method is a fairly ideal technique for static migration correction.

The magnetic model of vertical cuboid was used to study the three dimensional analytic signal equation.The result shows that the three-dimensional analytic signal equation is an approximate relational expression,with the degree of approximation being in relation to the geometric parameters of the magnetic source.When the technique for enhancing the analytic signal is used to calculate the buried depth of the boundary of the magnetic source,the error depends on the radio between the horizontal scale of the magnetic source and the buried depth of its top surface.

In using the long measurement range gravimeter,we should use sectional scales to arrange gravity data when the relative variations of the sectional standardized scales are larger than 1/1 400.For the purpose of raising the quality of gravity data arrangement,this paper summarizes some circumstances which may occur in using sectional scales of the gravimeter to calculate gravity values of the observation point when the gravity observation values lie in different measurement range sections.

The decision-making analysis means the study of matching relationship and correlation between various geochemical indices in the studied model area for determining weight values of various indices and forming an integrated geochemical index (association value).On such a basis,one can calculate associative values of various sample points and compare them with the associative critical value so as to achieve the aim of separating background from anomalies.It can also be used to sieve effective indices and serve as reference for variable combination.In an application study within a certain oil gas area,the anomalous area is basically consistent with the limits of the oil and gas accumulation and corresponds to the structural closure.

The establishment of the long-range exploration system is a new trend in the exploration field.The core of the long-range exploration system should consist of data warehouse with abundant content as well as tool library or technical library which includes various data processing and data analysing methods.This paper recounts the analyti cal technique for geophysical data and the long-range operation in the exploration field with a view to provide a model for this sort of systems.

In the exploration process for harnessing and renovating local railways in Shanxi,the interborehole electromagnetic wave fluoroscopy was used to search for mined out area of coal pits,which yielded satisfactory geological effects.

This paper has recounted the technique for correcting the attitude of plunging fold strata in the application of paleomagnetism to the study of geological structure,and derived the conversion formula for experts' reference.