This paper recounts the achievements made in geological mapping work in the East Tianshan Mountain area, which include the classification of lithologic characters and the division of magmatic rocks and structures. These achievements were made through integrated researches and field geological and geophysical-geochemical integrated investigation on the basis of large-scale high-precision aerogeophysical integrated survey.

In subsequent prospecting for blind orebodies with primary halos in Huangchengshan, similarity discriminant analysis was applied and discriminant indices were constructed. Combined with other indices such as element contrast analysis of A1 vein, the work eventually made good progress. The achievement made supplies geochemical basis for evaluating the ore district, reducing the prospecting area and speeding up the exploration.

There exist evident differences in crustal structure and thickness among various terranes in Qinghai-Tibet Plateau. The crustal structure histograms of these terranes are presented. Studies show that it is the tectonic superposition of the crust caused by the collision of terranes that results in the development of the low-velocity layers in the crust of most terranes. The shallower crustal layer with felsic-intermediate composition is considered to be the lower half of the crust, with the original composition preserved. The materials of the low-velocity layers have not been subjected to partial melting because the temperature remains lower than the melting solidus.

Based on 1:50 000 stream sediment survey in Sanchuan-Chitudian, Luanchuan County, Henan Province, the characteristics and regularities of elements' distribution was expounded by the numbers in this paper. The main ore-forming elements and their enrichment stratum was pointed, and the ore-searching direction was pointed in future this area.

With a practical example, this paper points out that the utilization of the logging method and the integrated comparative analysis in combination with regional geological data can reveal the spatial distribution of underground concealed structures and strata of different epochs and delineate favorable sectors for underground water exploration.

Seismic traces abound in singularity, which is essentially attributed to the first arrival of wavelets. Spline functions are of discontinuity and continuity. In some sense, the first arrival is the discontinuity for seismicity. The algorithm for singularity detection has been presented. The procedure includes some steps. Taking spline functions as scale function, constructing one low-pass filter and defining one operator with the theory of wavelet packet, one can isolate the low frequency of signal iteratively and decompose seismic traces singularly. Based on the processing of the model and field data, the algorithm can evidently improve the resolution and desirably eliminate ground-roll; Moreover, the algorithm has no limitation for any hypothesis.

In order to achieve the remote reference measurement in the seabed magnetotelluric data acquisition, every instrument needs to collect the data synchronously. Therefore, the precision and stability of the clock become the key link in keeping normal operation of the equipment. The authors designed a highly precise clock module with the error margin only at the microsecond level, which uses the microcontroller as its main control unit and employs such techniques as serial communication and I2C. This paper mainly describes the hardware and software design of the clock.

A high-order difference scheme is derived from the dilatational wave equations of two-phase media, and the corresponding absorbing boundary conditions and stability conditions are also provided, based on which a high-order finite difference numerical modeling algorithm for dilatational wave equations of two-phase isotropy media is realized. It is shown that this method can greatly improve the precision on condition that the calculation time is a bit extended. This method can be applied to both pre-stack and post-stack numerical modeling.

With the advantages of higher resolution, higher accuracy, in-situ image of borehole wall even in muddy slurry and sufficient post-processing softwares, the borehole acoustic televiewer can supply abundant useful information for foundation analysis in civil engineering investigation. This technique has been widely used abroad but has seldom been utilized in China. This paper gives a brief description of the principle of the borehole acoustic televiewer survey as well as the related technique and deals with the data interpretation.

Based on summarization of near-surface imhomogeneity effects in 2D forward modelling resistivity pseudosections from pole-dipole arrays in the high-density resistivity technology, this paper describes a filtering scheme which uses two-side pole-dipole array to remove the near-surface inhomogeneity effects. This scheme has been successfully applied to field data processing.

Using the expression for the relationship between IP phase and polarizability obtained from the complex resistivity Cole-Cole model, the author calculated and drew the curve of the IP phase with the variation of polarizability and, through the characteristic analysis of this curve, summed up their approximate relationship. An approximate interpretation method for IP phase is put forward, which has been proved to be effective.

Based on "self-adaptivity" and "mathematical microscope nature" of wavelet analysis in data-processing of the transient electromagnetic method, this paper has put forward the processing method and flow chart for two-dimensional wavelet transform of special TEM data, and compiled visualized processing software. The core of this technique lies in calculating the positive and negative variations of Lipschiz indexαfor distinguishing the normal field from the anomalous field so as to effectively extract pure anomalies from the TEM data. The processing of the measured TEM data from a Cu-Ni deposit has yielded satisfactory result.

Complex topography seriously affects the interpretation of CSAMT. Considering the influence of the topography, the authors analyzed in detail the geoelectric section model and made CSAMT two-dimensional inversion for the direct calculation data of the model. The result is basically consistent with the shape of the direct model. The electric section obtained can satisfactorily reflect the underground geological structure and accord with the geological data. All this proves the correctness and effectiveness of this technique.

The tentative application of the frequency domain high density electric method to the detection of the underground palace under Qin Shi Huang's tomb turns out very effective. The work has not only proved the existence of the underground palace but also detected its location, size and buried depth. In addition, its completeness has been demonstrated.

Through regional geochemical survey in Xinyang-Tongbai area, geochemical data of more than 40 elements were obtained. The report of geochemical survey extensively includes characteristics and distribution and concentration regularities of these elements. The relationship of environmental geochemistry to human health and agricultural production is also discussed in this paper.

Based on a comparison between the achievements made by the airborne electromagnetic method in Song-Liao region and the available hydrogeological data, this paper explains the role played by the airborne electromagnetic method in such regional agricultural eco-geological investigations as the determination of soil salification limits and extent, the division of underground water quality, the classification of soil grain sizes and the prediction of salification trend. It is shown that the airborne electromagnetic method is characterized by low cost and high efficiency.

Based on the flying survey over the known Cu-Mo polymetallic deposits conducted by the aerogeophysical (electric/magnetic) integrated stations, the author, in accord with the principle of using the data of known deposits to guide the prospecting work of the unknown areas, has established an aerogeophysical (electric/magnetic) integrated prospecting model in search for porphyry Cu polymetallic deposits in grassland, forest and swamp areas. The aerogeophysical anomalies delineated by this tentative model yielded good results in ground inspection.

Based on a brief description of the basic principle of the Acoustic Doppler Current Profiler (ADCP) and exemplified by some typical environmental monitoring engineering cases, this paper gives a brief account of the achievements made by this technique in such engineering fields of Hong Kong as marine environmental quality monitoring and marine engineering environmental evaluation. The practical engineering application shows that the adoption of ADCP technique could yield satisfactory environmental monitoring result. The importance and effectiveness of applying this technique to environmental quality monitoring is also explained.

This paper describes the techniques of applying 5 m network high-precision gravity survey to engineering exploration, which include geodetic survey, gravity survey and three-dimensional inversion. Through the elimination of gravity influence on the engineering design parameters of the hilltop buildings, the human interference correction was realized. The forward calculation was made by using the precise forward formula for theoretical gravity anomaly of vertical prism, and the inversion was also conducted with the generalized inverse method. As a result, the structural characteristics of the top relief of the fresh granite batholith in the Shixiawei landslide-tackling area in Kowloon of Hong Kong were revealed. A comparison with the drilling result shows the reliability of the depth contour map for the top surface of the granite batholith.

This paper has discussed and analyzed the anomaly spreading phenomena in high density electric survey, and put forward the return-to-the-original-position method by means of correlation analysis. The calculation indicates that the return-to-the-original-position method is of great significance in the interpretation of complex anomalies, as evidenced by the application of the return-to-the-original-position method to sphere and plate on Pole-Pole and Wenner-alpha arrays.

During the seismic exploration in complex surface areas, the differences in excitation seismic sources, detectors and surface rocks would result in rather obvious wavelet differences and deterioration of the reflection data. In this paper, the two-step deconvolution is used for consistency processing of shotpoints and detection points so as to eliminate the differences in shotpoints and detection points. The tentative processing of some practical seismic data has proved its effectiveness.

This paper has analyzed the theoretical basis of applying media interchange to determining air attenuation coefficients, dealt with the scope and condition of its application and formulated a revised formula for the calculation of air gamma attenuation coefficients. The calculation results show that the technique is effective and can play a guiding role in the correct measurement of air gamma attenuation coefficients in airborne gamma survey.

In the artificial source electromagnetic exploration, it is important to keep the transmitting current steady. On the basis of analyzing the normal current-regulation technology, the authors put forward a high-precision digital current-regulation technology. An example is also given to illustrate the software and hardware designing method based on the technology.

With some typical examples of engineering quality inspection, this paper describes in detail the achievements made in such aspects of engineering inspection in the Hong Kong Special Administrative Region as highway surface thickness, surface course hollow of the air landing strip, submarine tunnel lining and urban underground network investigation. All these achievements prove the effectiveness and necessity of applying the ground-penetrating radar technology to the nondestructive engineering quality inspection.

With the advantages of high efficiency and low cost, the single-channel marine reflection seismic survey has broad application prospects in the field of offshore engineering geophysical exploration. Based on a description of its basic principle, this paper deals with the method for suppressing the interference of multiple wave and noise under the condition of offshore shallow water and, exemplified by some typical cases in Hong Kong, recounts some related marine seismic techniques such as data acquisition, data processing and data interpretation.

Based on a brief description of the basic principle of the side scan sonar (SSS) system, this paper recounts in detail the achievements made by the SSS in such engineering fields of Hong Kong as submarine landform studies, fill-in-the-sea engineering monitoring, archaeological investigation and submarine artificial culture area planning. With some typical examples, the paper also deals with some techniques related to this method such as engineering design, data acquisition, data processing and data interpretation.

This paper sums up in brief the basic principle of multibeam sounding technique and, exemplified by some typical marine exploration cases, describes the application of this technique to such fields as marine environmental exploration and fill-in-the-sea engineering in Hong Kong. Some practical experience gained in applying this technique to engineering is also given in this paper.