Quite a large amount of teleseismic profiling has been conducted in the past 10 years or so in the Tibetan Plateau to study the lower crust upper mantle structure, yielding informative data for the geomechanic features ranging from the in depth seismic velocity image, upper mantle anisotropy and the identification of the low velocity body and layer. Along with the improvement in seismic equipment, the method has become the major means in the studies on deep seated structures in an inexpensive manner. Marked achievement has been gained in seismic tomography, the study of receiver functions and the analysis in shear wave splitting. However, room for further studies remains.

This paper describes the working principle and main technical indices of the newly developed CD 10 field portable gamma ray full spectrometer.Its gamma ray energy analytical range is 30～3 000 keV,it has 1 024 analytical channels,its ¹³⁷Cs energy resolution ratio is lower than 12%,and the digital spectrum stabilizing technique is adopted instead of radioactive spectrum stabilizing reference source so as to realize noninterference natural gamma ray full spectrometry.With the examples of its application to geological evaluation in nuclear environment,the paper illustrates main characteristics and prospects of the gamma ray full spectrometer.

Based on mineralization enrichment and uranium radium equilibrium variation characteristics of interstratified oxidized zone type sandstone uranium deposits,the authors used surface radioactive radon technique,namely ²¹⁸Po measurement technique,to make ore prospecting test in this type of uranium deposits within Northwest China.The results show that the utilization of curves obtained from ²¹⁸Po measurement to the delineation of uranium mineralization enrichment position within the interstratified oxidized zone is feasible and effective.

According to the analysis of newly compiled 1:2 000 000 gravity and magnetic data,there exist three (eastern,central and western) deep tectonic areas in northern China,which are bounded in the east by Helan Mountain Liupan Mountain Longmen Mountain line and in the west by Xingxingxia Ruoqiang line.It can thus be seen that the eastern area covers North China Northeast China area,the central area comprises Inner Mongolia Gansu Qinghai area,and the western area is Tarim Junggar area.The eastern and western parts consist of two oldest Archean Early Proterozoic stable land masses of China,whereas the central part is the Proterozoic land mass,which is rather active due to the compressive action of Qinghai Tibet plateau.It is also held that the original boundary,namely Da Hinggan Mountains Taihang Mountains Wuling Mountain fault,exists merely in the eastern tectonic area and does not form the boundary separating various areas.

In this paper the authors put forward the non contact prediction method of outbursts in the light of characteristics of the geophysical field of outbursts and the practical conditions of the outburst mine. This method combines outburst points and dangerous zones and consists mainly of electromagnetic technique. For regional prediction the paper suggests utilizing the ratio wave penetration and seam seismograph techniques, and for local(or point) prediction geological radar and seam electric sounding methods can be used. The practical application of ratio wave penetration proves to be especially successful in predicting the outbursts. The alleviation and prevention of the natural disaster caused by outbursts in coal mines are of great significance.

In this paper,the authors developed analytical techniques for more than eleven elements in various phases of active state and discussed the crux in extraction operation,analysis and determination.

Being one of the major modes of occurrence of light hydrocarbon in sedimentary strata,the adsorbed light hydrocarbon is mainly derived from light hydrocarbon source of oil and gas accumulation.Its adsorption physicochemical state,composition and content characteristics embrace exttremely abundant and important geochemical information.With different means, the adsorbed light hydrocarbon can be absorbed from samples of sedimentary rocks and then be analysed for its composition and content.In this way,one might understand the oil and gas information of the horizon represented by the samples and the underlying strata from different angles.

In view of characteristics of seismic data of gobi sand dune areas, this paper, through various data processing means such as quality control, high pass filltering, dip angle filltering, field static correction, surface consistency deconvolution, precise velocity analysis, denoising before stack,multiple iterative operation of residual static correction, denoising after stack and modification after shift, has raised the data quality of seismic profiles in low signal to noise ratio areas and managed to form the seismic data processing technique for such complex areas as gobi, foreland and dune. Practical application of data from Qinghai and Xinjiang proves this data processing technique to be reliable and effective.

Techniques for estimation of the intrinsic Cole Cole parameters of a buried polarizable body are studied.it is shown that the nomograph correction technique can be used only if the resistivity distribution of the earth model is known and the resistivity of the polarizable body is approximate to that of the country rock,and that it is impossible to estimate the intrinsic Cole Cole parameters by using the techniques based on inversion of the spectrum measured at one station,provided the resistivity distribution of the earth model is not known.It is alsoshown that for some simple earth model,the technique based on joint inversion of the spectra measured at two or more stations can be used to estimate the intrinsic Cole Cole parameters.It is suggested that a techinique which determine the resistivity distribution of the earth model first and then estimate the intrinsic Cole-Cole parameters by inversion of the spectrum at one station may be a suitable techinique.

Through studies based on characteristics of “dynamic conductor”,this paper has formed a suite of “mise a la masse”detection theories and techniques for underground dynamic conductor,and described the object of their application,the geoelectric model,the technical basis,some detection methods and their preliminary application.

Using electromagnetic wave interborehole tomographic imaging(CT)technique,one can find out the distribution of fissures,closely spaced fissure zones and strong medium weathering zones in bedrock of nuclear reactor,study the variation characteristics of electromagnetic wave adsorption coefficients of some fissures or closely spaced fissure zones along profiles in different specific directions within the same borehole,and infer the preferred direction of the distribution of bedrock fissure zones.

The transient electromagnetic exploration method is a new promising measurement technique in the present geophysical exploration field.Being simple and practical,this technique can be used to measure the geological structure from the surface to strata.The present paper recounts the utilization of industrial computer to compose the high performance transient electromagnetometer and describes in brief the application of this instrument.