Lots of important advances have been made since the performance of the general geological survey: 1:1000000 regional gravity survey has on the whole covered the whole continent of China; quite a few geological achievements have been obtained, with the major achievements being encouraging; technological progress in regional gravity survey is prominent, and various high-precision gravimeters and GPS systems have been extensively applied; the regional gravity database information system and several two- and three-dimensional forward and inversion softwares have been popularized; the new regional gravity survey standard has been formulated. To adapt the work to the new situation, we should speed up 1:200000 regional gravity survey and arrange the investigation and research work in a more rational way. The investigation task and design for each sheet should be more clear and definite; the methods for topographic correction and GPS altitude correction ought to be improved so as to raise the topographic correction precision; the interpretation level of the regional gravity survey result should be raised, and the report compilation should be further improved.

In this paper, the author has listed the serious consequences caused by the ignoring of the reliability of the inference and interpretation, dealt with the train of thought and countermeasures for gravity and magnetic anomaly interpretation under complex conditions (i.e., the correct and rational utilization of techniques and technologies), and put forward suggestions concerning the scheme for dividing the reliabilities of inferred results and the new fashion for result expression.

Utilizing the latest regional gravity data and consulting aeromagnetic, remote sensing and regional geological information, the author studied sub-areas of the gravitational field, faulted structural systems, tectonic elements, local anomalies, deep structures and ore-forming prospect areas (belt). Some new viewpoints were proposed concerning the trend and extension of the southwestern end of the Altun strike-slip fault, the origin of two low gravity zones was discussed, the altitude of the Moho discontinuity in the lower part of the Bangong Co-Nujiang junction zone was deduced, and the new understanding of the Bangong Co-Nujiang junction zone was proposed from the gravity angle. It is considered that there were two thickening centers in the earth crust after the collage of the Qinghai-Tibet blocks. A Mesozoic-Cenozoic sedimentary basin was recognized and preliminarily studied. In combination with such data as geology, mineral resources and aeromagnetic survey, four ore-forming prospect areas (belts) were tentatively delineated.

The authors constructed a series of gravity base maps and interpretation maps on the basis of interpretation of the 1:1 000 000 regional gravity data from central-eastern Qinghai-Tibet plateau. Some new tectonic units were delineated, such as Jiali lower crust melt zone, Lhasa lower crust uplift, Wulawula-Zaduo Paleozoic uplift zone, Tanggula Yanshanian magamtic arcs, and South Gangdise Yanshanian-Himalayan magamtic arcs. The authors support the opinion that Bangongcuo-Nujiang juncture zone should serve as the northern boundary of the Gangdise Mountain. Over 100 faults and many zones of intermediate-acidic magamtic rocks were recognized, in which the Tanggula magamtic belt is unfavorable to petroleum accumulation in Qiangtang basin. It is also concluded that there are widespread igneous layers beneath the middle-lower crust in northern Gangdise-Kekexili and there also exist very strong tectonic stress opposite to the adjusting power of the gravity balance in the plateau crust. All of these conclusions provide evidence for further study of geological tectonics in Qinghai-Tibet plateau and contribute to the search for polymetallic deposits related to magmatic rocks.

The completion of 1:1,000,000 high-precision aeromagnetic survey in central and western Qinghai-Tibet plateau has filled in the largest gap in the aeromagnetic survey of Chinese mainland. The methods and technologies adopted and the geological interpretation results obtained have provided the most complete and valuable regional geophysical data for the basic geological survey and the mineral resources exploration arrangement in Qinghai-Tibet plateau. The achievements made have also accelerated the development of the air-borne geophysical technique in China.

Several deep faults in the eastern part of East Kunlun Mountains within Qinghai Province were delimited, such as East Kun Middle, East Kun South, East Kun North, Buqing Mountain South Rim and Hot Spring-Hongwa Mountain. Based on Bouguer gravity anomalies and regional gravity investigation result of ten charts (1:200,000) in eastern East Kunlun Mountains as well as abundant gravity anomaly information like regional field and residual field information extracted form such data-processing methods as window average and horizontal derivative in combination with aeromagnetic anomaly and other information, this paper provides new opinions on the spreading locations of such deep faults as East Kunlun Middle and East Kunlun North. According to twelve faults inferred recently from gravity data, this paper also holds that the Jian Mountain-Halihade Mountain fault is the boundary fault of two first grade tectonic units. Using the quantitative computational method of fitting Bouguer Gravity Anomalies profile, the authors obtained the formation parameters of some deep faults in eastern East Kunlun Mountains.

This paper has described several data-processing methods for the gravity anomaly in Chengbu area, analyzed the gravity anomaly and its characteristics after the location-field transformation, given a preliminary explanation and deduction of the gravity anomaly and a tentative prognosis of the favorable ore prospecting sectors. According to the characteristics of the gravity anomaly and the geological and geochemical information, 10 faults and four semi-concealed rock bodies (Lanrong-Tanjiaao-Zhaomianshan, Huangping, Dongbei and Kangkou) were deduced, which can be regarded as the favorable ore-prospecting sectors. Based on the half-quantified inversion, it is concluded that the Neimiaoer rock body and the Yuechengling rock body in Hunan Province are not connected in the depth, and the Wutuanshan rock body and the Miaoershan rock body are not linked with each other either.

According to the 1:200000 regional gravity data in northwest Hebei, this paper deals with the application of regional gravity survey to the exploration of intrusive bodies in northwest Hebei. Based on a detailed study of the gravity anomalies in this area, the authors delineated several important rock bodies and, on such a basis, generalized the gravity and magnetic field marks for qualitative interpretation of magmatic rocks and their modes of occurrence. In addition, geological-geophysical models for several kinds of intrusive bodies were formulated, and new understanding concerning the distribution characteristics of the magmatic rocks in this area was put forward.

Spatial distribution characteristics of Nappe tectonic in northern Hubei were studied half-quantitatively or qualitatively by using regional gravity and aeromagnetic data. Some complex geological problems in northern Hubei were discussed, thus extending the research field of regional gravity survey.

From the available gravity and magnetic data in combination with other geophysical and geological information, this paper deals with the Guixi rift. It is held that local gravity anomaly is superimposed upon the background of regional negative Bouguer gravity field in that area, which is consistent with the relative magnetic high of the deep-source magnetic field and similar to the gravity and magnetic characteristics of the continental type rift. The possible existence of Guixi rift is also discussed in this paper.

This paper describes the achievements made in 1:200,000 regional gravity survey in central and eastern Guangdong area since the implementation of the Tenth Five-Year-Plan.

on a synthetic study of density as well as magnetic and electric properties of rocks, the authors hold that the general Cenozic basement can be determined by gravity anomaly inversion, and that Archean and lower Proterozoic crystalline basements can be located with the help of aeromagnetic anomalies. A detailed study was carried out on the vertical distribution of Cenozic, Mesozoic and Paleozoic strata by using MT information. A study of Shijiazhuang depression revealed a low uplift, which is favorable for geothermal prospecting in Cambrian and Ordovician limestone. Two deep depressions in NS and EW directions were also detected in Shijiazhuang City. One is from the Railway Station to Yongbi and the other is from Yongbi to Ershilipu.

Tianjin, as one of the pilot cities in urban geological survey, possesses specific geological conditions and deep overlying strata. During the urban three-dimensional geological structure survey, especially in the deep coverage areas, the method in which combined gravity-magnetic-electrical explanation and different inversions by mutual verification and combined explanation are adopted has proved to be very effective in detecting such phenomena as the depth, distribution and thickness of the main stratigraphic boundaries, the plane spread of the surface fractures and the deep-seated faults and the distribution of the concealed rock bodies. This paper deals with the application of combined gravity-magnetic-electrical explanation method exemplified by the cross section along Z14 line. This technique is of great reference value in the survey of three-dimensional geological structures in other cities.

The accuracy of regional gravity survey is directly affected by the precision of GPS altimetric survey. Using the CQG2000 quasi geoid model developed recently in China, the authors corrected the ellipsoidal height of GPS survey and, as a result, attained a higher accuracy of orthometric altimetric survey. With the method presented in this paper, a better result in 1:200000 regional gravity survey was achieved in the Three-River Drainage Area of Qinghai Province.

The authors calculated the terrain correction of 764 points in 1:200 000 regional gravity survey performed in northwest Qilian Mountain by using 20 m×20 m, 50 m×50 m and 100 m×100 m square grids. Based on a discussion of the gravity terrain correction method, this paper studied the simulation degree and terrain correction precision of every computation method through moving square grids.

The compilation of the aeromagnetic series maps lies in the re-arrangement and collage of aeromagnetic survey results obtained in past years to formulate the basic aeromagnetic maps. Through reduction to the pole, such maps as the upward extension map, the residual magnetic map and the derivative map can be compiled for users. This paper deals with some key technical problems in map compilation.

The gravity field contains the superimposition effect of heterogeneous bodies with different densities. In order to divide the gravity anomaly more effectively, the authors tentatively used the wavelet analysis with the function of multi-scale analysis to separate the gravity fields. Through the wavelet multiple decomposition of the gravity fields in Guixi area, the authors distinguished the sources which had relatively shallower burial depth and smaller scale from those which had comparatively greater burial depth and larger scale. Such a result reflects the heterogeneity of the densities of geological bodies with different burial depths and different scales, and hence can quite effectively delineate tectonic basins and deep concealed rock bodies, with an audiovisual demonstration of their attitude variations. It is therefore concluded that the application of wavelet analysis to decomposing the gravity fields can yield fairly satisfactory result, and thus deserves further popularization.

Previous researches show that organic adsorption can concentrate elements in the sample to some extent. Such an effect becomes stronger with the increasing organic contents and can shield the real undulation of the elements and even form false anomalies. Based on a study of the stream sediments on the western margin of Wulaga fault in Jiamusi uplift zone in such aspects as sample distribution, characteristics of organic matter and supergene geochemical features of major ore-forming elements, the authors hold that the adoption of -10～+60 mesh as the sampling media can meet the need of the work, obtain real and reliable geochemical anomalies and attain fairly satisfactory ore-prospecting result.

Geological activities have intrinsic and logic connection with geochemical activities. Different geological backgrounds correspond to different geological formations and dynamic conditions, and can find expression in different geochemical characteristics. Exemplified by the application of 1:200 000 regional geochemical data to basic geological researches, this paper deals in detail with this problem.