The latest 1:100 000 aeromagnetic data obtained from Hainan Island and the surrounding waters were used in combination with geological, geochemical and remote sensing information and, as a result, 63 concealed and semi-concealed faults were inferred, 12 volcanic apparatuses as well as 188 intrusions were confirmed, and 18 favorable prospecting areas were delineated where 63 prospecting target areas were further delineated.The geological interpretation results obtained have provided the most complete and valuable regional geophysical data for the basic geological survey, marine geological survey and mineral resource exploration arrangement in Hainan Island.

Element concentration and dispersion are decided by atom structure of the element(internal cause)and geological process setting(external cause). Gene profile curve of geochemical elements is geochemical response result of the geochemical system to geological ore formation. The copper and tin polymetallic belt of the central-south Da Hinggan Mountains in Inner Mongolia was selected as the study area. The 1:200 000 stream sediment survey data were processed and analyzed. Based on the result, this paper discusses the structure and the generation of the gene profile curve of geochemical elements. The elements sequence structure information contained in the quasi gene profile curve of geochemical elements generated from stream sediment survey data, such as space-time structure and correlation structure, and its important geological significance are discussed in detail. Based on an integrated analysis of quasi-gene profile curve of the geochemical elements in the study area, the authors point out that the superposition of two epochs of mineralization resulted in the formation of large- and medium-sized polymetallic deposits. This conclusion indicates the orientation for further geological prospecting in this area.

The lithological characteristics of Ordovician strata in the study area can be distinguished by crossplot of porosity logging series.Based on the data and results of conventional logging, FMI logging, core and microscope, the authors found three kinds of reservoirs on the south slope of Central Uplift Belt:fractured reservoir, vugular reservoir and fractured-vugular reservoir, which present different response characteristics.Ordovician carbonate reservoirs on the south slope of Central Uplift Belt in Tarim Basin can be classified into three types:type Ⅲ, consisting of fractured reservoir and vugular reservoir, is most developed in the study area, type Ⅱ, i.e., fractured-vugular reservoir, takes the second place, type Ⅰ, i.e., cave reservoir, is not typically developed.The authors' understanding is helpful to finding high quality Ordovician carbonate reservoir on the south slope of Central Uplift Belt, Tarim Basin.

Through analyzing 1:50 000 aeromagnetic anomalies and other geophysical characteristics, the authors got to know that the Xiarihamu copper-nickel deposit shows weak magnetic anomaly in the aeromagnetic anomaly map, and shows medium strong magnetic anomaly in the geomagnetic anomaly map.The basic-ultrabasic complex has moderate magnetism, whereas pentlandite, pyrrhotite and some other minerals have strong magnetism which is in the main residual magnetism.Copper-nickel ore is the main factor causing the magnetic anomaly, and the magnetic anomaly is a direct prospecting mark in search for such deposits.Aeromagnetic anomaly has important significance in search for magmatic liquation copper-nickel deposits.There are many aeromagnetic anomalies in Eastern Kunlun area, suggesting that this area has the potential to find magmatic liquation copper-nickel deposits.

Based on an analysis of the abundance, type and thermal evolution of the organic matter from wells and cable drilling data of a block in Myanmar, the authors have revealed that the study area has certain hydrocarbon generating potential. The evaluation of 2 source rocks of the Oligocene and Miocene shale by using TOC, S₂, chloroform asphalt "A", Tmax and R_o test data shows that the main source rock is Lower-Middle Oligocene, whereas middle-upper layer of Oligocene has low-middle organic abundance source rock. The type of organic matter is Ⅱ₂ or Ⅲ, gas is produced in the south and oil is produced in the north. Thermal evolution in the south is higher than that in the north, and the maturity is in low-mature and early stage. It is concluded that the study area has a good hydrocarbon potential.

The Shangkumaerke gold deposit is one of the most typical ore deposits in the Central Asian metallogenic domain, and lies in the precious metal metallogenic belt in the middle part of Tajikistan. Metallogenic ore-controlling geological conditions and geophysical characteristics indicate that the orebody is obviously controlled by the structural faults, and is related to the Paleozoic shallow metamorphic sedimentary rock series in time and space. In the 1960s~1980s, the deposit finished a series of geological prospecting exploration work, and found some good mineralization clues that showed a great prospecting potential for this deposit. The previous prospecting exploration work mainly focused on the shallow range of earth's surface to the depth of 300m; however, the deep mineralization should be continued. In this paper, through the test of the geophysical exploration methods, the authors carried out the research on the EH-4 exploration technology of the deep prospecting in this area so as to get a general understanding of the macroscopic geological features within the range of shallow part to the depth of 1 000 m. The authors summarized the ore-prospecting criteria obtained mainly from the EH-4 method, and the prospecting target areas were delineated based on the study. The results obtained by the authors have important guiding significance for the deep prospecting in this area.

Based on the data of 1:200 000 regional geochemical stream sediments in Yuanma Basin, the authors analyzed geological and geochemical characteristics as well as the discrimination and extraction of regional anomaly information of the Jiuquwan copper ore deposit in Yuanma basin. Then the authors established a typical geological-geochemical prospecting model for the Jiuquwan copper ore deposit, and successfully delineated the prediction area. It can thus be seen that the method is feasible and effective.

The determination of the ore-forming elements is one of the main problems of geochemical anomaly evaluation. Based on previous studies, the authors propose a new method of ore-forming elements determination based on geochemical sampling points, in which anomaly mineralization and anomaly contrast are linked to the concentration coefficient. The lower the concentration coefficient of the element, the higher the anomaly mineralization and the lower the anomaly contrast to ore-forming element. The composition of first ore-forming elements based on the sampling point within a certain range reflects the mineral type. The method was successfully applied to the ore-forming elements analysis of the structure-rock sample from the Dabaoshan copper-lead-zinc-tungsten-molybdenum polymetallic orefield in Guangdong Province. It has important practical value for a detailed analysis of the main ore-forming elements of geochemical anomalies and their distribution, and is suitable for a comparative study of mineralization capabilities of elements with different concentration coefficients.

Based on geophysical and geochemical methods such as ground gamma-ray spectrometric survey, soil geochemistry profile survey and audio frequency magnetotelluric sounding survey, the authors investigated the uranium deposits in the shallow coverage areas in Xiwan area of Guyuan County. The surface anomaly information related to uranium mineralization was revealed by the ground gamma-ray spectrometric survey and soil geochemistry profile survey. The faults and the morphology of subvolcanic rhyolite were analyzed by audio frequency magnetotelluric sounding survey in the anomaly sectors. The blind uranium orebody was found, followed by drilling verification of the integrated anomalies. The conclusion of prediction has some indication significance for further ore-prospecting work in this area.

The Banshigou iron deposit in Jilin is a large and typical Anshan-type iron ore deposit controlled by NS-, approximately WE- and NW-trending fold deformations with very complex synclinaria.The authors compared two interpretation methods of upward continuation and wavelet analysis, and reached the conclusion that the wavelet analysis can more accurately reveal the characteristics of the amphibolite iron-bearing formation of the upper Archaean Yangjiadian Formation in the Banshigou iron ore deposit.The results of wavelet analysis also demonstrate that the northern wing is arc-shaped while the southern wing is the second level anticline which continuously extends eastward.The lower anomaly in west-east direction on the southern wing better corresponds with the amphibolite iron-bearing formation of the upper Archaean Yangjiadian Formation in the Banshigou iron deposit, which indicates that the eastern wing has the potential of prospecting for iron ore resources.It is inferred that some iron ore layers may occur under the early Proterozoic Laoling Group and Zhengzhumen Group strata on the southern wing.Magnetic data were also processed by the interactive inversion of the 2.5/3 dimension, and drilling verification along No. 47 line coincides with the drilling results the authors forecast.

Based on an analysis of geological and geochemical characteristics of the Shuangwang gold deposit, this paper holds that there exist different source depths and denudation depths of the gold-bearing breccia. It is worth mentioning that the variation of element Sb indicates denudation, the variation of element As indicates non-denudation, the elements Au, Bi, As, Ag are the main ore-forming elements, Sb, Pb, Zn, Cu indicate the depth of denudation, and Mo, Ba, Hg, Mn contained in surrounding rock can be used in later geological exploration.

A study of the geochemical characteristics of the Gaofeng mining area shows that the gold deposit has the following regularities: (1) The element combination is composed of Au, As, Pb, Zn, Co, the accompanying elements include Ag, Bi Mo, Cu, Sb etc., and the Co/Ni ratios can be used as a basis in search for concealed ore belt. (2) The combinations of trace elements in the two deposits of the Gaofeng mining area are different, the main mineralization of Gaofeng is of the quartz vein type, the combination of trace elements is composed of Au, As, Pb, Zn, Cu, (Co, Ni); the Dengwu gold deposit is of quartz vein complex stockwork mineralization, and the combination of trace elements comprises Au, As, Pb, Zn, Cu, (Co, Ni). (3) The Geligeliang method reveals that vertical zoning of the Gaofeng mining area is characterized by {Pb-Zn-Ag} for pre-ore halo, {As-Au-Cu-Ni} for ore halo, and {Bi-Mo-Co} for post-ore halo. These geochemical characteristics provide a basis for deep and peripheral prospecting.

The Ximole area is located in the iron, gold, copper, titanium, cobalt, nickel prospective zone. In this area, secondary halos are well developed and have relatively high intensity. They are mainly distributed in migmatite strata of 2^nd member of Budaergan Formation in Neo-Archean Seertengshan rock group, Ordovician gabbro bodies, diabase veins and NE-trending faulted shatter zone, with the superimposition of aeromagnetic anomaly. An analysis of the geochemical parameters of elements and anomalies shows that Co, V and Ti exhibit logarithmic positive offset distribution with relatively high mean values and hence belong to elements of extremely uneven differentiation or uneven differentiation whose content values are close to indices of accompanying components of iron ores, indicating that they might have come from the same material source as Fe; therefore, these elements can be regarded as the main accompanying elements as well as the geochemical indicator elements. Secondary halo element association is fairly rich with good correlation, and exhibits characteristics of outer zone and middle zone. Rock geochemical profile verification of some secondary halos led to the discovery of Fe-Co mineralized body, Fe-V mineralized body and Fe-V-Co mineralized body, which are fairly large and are mainly distributed in gabbro intrusive body and NE-trending faulted shatter zone, and show direct correlation with lemonitization, magnetitization, pyritization and hematitization. Ximole area possesses fairly good ore-forming geological and geochemical environment and hence has favorable metallogenic potential for such ore deposits as Fe, Co, V and Ti.

China is rich in coalbed methane resources. The free coalbed hydrocarbon gas and the water-dissolved hydrocarbon gas can migrate to the surface of the earth through the channels such as faults, fractures, cracks and micro pores, and form the near-surface geochemical anomalies. The application of the coalbed methane geochemical exploration technique to Yanchuan south block shows that the geochemical indicators of the headspace methane and the acid-extracted methane have the halo anomaly features over Well Yan 1 coalbed enrichment area, and the main factors controlling the anomalies include deep hydrocarbon source (CBM), cap rocks over the hydrocarbon source, deep faults such as Zhongduo fault and he Baihe fault and other geological elements. The heat-released mercury indicators have the top anomaly features over Well Yan 1 coalbed enrichment area, and the main factors controlling the anomalies include deep coal seams, deep faults such as Zhongduo fault and Baihe fault and other geological elements. Three halo anomalous areas were delineated in the study area according to the coalbed methane effective geochemical indicator of the comprehensive entropy, which are Chengheyuan-Well Yan 1 anomaly area, Zhengshan anomaly area and Jingxiling anomaly area. Chenheyuan-Well Yan 1 halo anomaly effectively indicates the CBM enrichment area of Well Yan 1; Zhengshan anomaly, which is located between the Zhongduo and Baihe faults, and Jingxiling anomaly can also reflect the coalbed favorable areas although they may be partially influenced by the faults.

Coalbed methane is an important part of the natural gas energy, and determination of coal seam gas content is the key to the study of exploration and development of coal seam. In order to improve the capability of coal bed gas content prediction, this paper puts forward a kind of bacteria foraging optimization algorithm and generalized regression neural network (BFA-GRNN) of the coalbed gas content prediction algorithm. Well logging data and core data of coal seam are used by neural network to establish regression model, bacterial foraging algorithm is used to optimize the model parameters, and artificial factor influences on determining the network structure and the process of spreading factor are reduced. According to this algorithm and on the basis of clustering analysis and gray correlation analysis, seven main factors of coal bed gas content are chosen, which include density, resistivity, ash content etc. BFA-GRNN model is set ip by using the data of coal seam, and through the example analysis, the feasibility of this method is verified. The results show that the BFA-GRNN model is a true reflection of the nonlinear relationship between the coal seam gas content and the main control factors, and the relative error between predicted values and the measured values is less than 6%, suggesting that using the model to predict coal bed gas content has a good application prospect.

This paper describes the theory, equipment and applications of airborne natural electromagnetic system (ZTEM) and comparatively summarizes the measuring parameters, exploration results and working efficiency of both airborne natural EM and ground MT methods. The local-regional exploration scheme of combining airborne EM and ground MT method is proposed based on the above discussion. The ZTEM system is used for rapid survey in large area, thus ground MT is used to follow up the interested points in accessible area and provide a reference for data inversion of a ZTEM survey so as to ensure that the final exploration results truly represent the geological bodies in the whole area. It can provide advanced technologies for rapid and effective exploration in high mountainous, forest-cover, water-cover and environmental protection areas in China.

With the purpose of meeting the increasing request for the mineral resources, the present exploration is shifting from the near surface layers to deeper horizons, commonly beyond traditional prospecting methods. To improve the efficiency of explorations, the authors used Controlled Source Audio-Frequency Magneto Telluric Method for the first time in this study to locate deep manganese orebody as well as its hosting structure. The V8 multifunction electrical prospecting system was applied in four CSAMT sections eastward in Shenxi, along the strike of the major manganese deposits. Interpretation of the four CSAMT sections based on a two-dimensional inversion method, combined with geological setting and physical properties of the ore-hosting rocks, shed light on the position of the ore-hosting bed, which agrees well with the results of drilling verification in encountered strata and structures. The CSAMT method thus is of the potentiality in the further exploration of similar ore deposits.

The practices of the exploration and development of shale gas in the Sichuan Basin in recent years show that deep-water shelf facies and good preservation conditions are key factors for shale gas' enrichment and high yields. Meantime, the drilling results of shale gas wells targeting the upper Paleozoic marine shale indicate a phenomenon that high production wells have abnormal high pressure, while low gas production wells have normal to low pressure. Shale gas' production and pressure coefficient show positive correlation. Based on qualitative assessments of shale gas, many researchers concluded that areas where shales are buried moderately, covered and bedded by proper rocks, and are far away from large open faults, uplifts, or erosion areas, as well as the places where there exists short period of tectonic movements and good structural patterns are the places that possess good preserving conditions. Based on the drilling data of marine-shale wells within southeastern Sichuan Basin, the authors revised the Fillippone formula and generated a new formula for predicting pressure coefficient which fits better to this region. With DS area as an example, this paper illustrates the prediction of the pressure coefficient of the Wufeng-longamxi Formation through a high-resolution inversion, and the result turns out to be good.

Statistics based on HS26 abnormal area of 90 drill holes and 3 312 samples of polarizability data show that the polarization rate of metamorphic and intrusive rocks in this region is very low, alteration only slightly changes the polarization rate, but mineralization causes significant increase of polarization incidence, so that the high polarizability is indicative of high mineralization degree. A comparison between the polarizability and metallogenetic elements nickel, copper and cobalt content in the profile distribution reveals the corresponding relationship between the high polarization rate of abnormal center and metallogenic element concentration center, and it suggests that the high polarizability distribution area is the reflection of the orebody. Accordingly, the authors further analyzed the spatial distribution of the polarizability and looked for the end of the closed high polarizability anomaly. It is pointed out that further exploration of HS26 anomaly area should cross diabase dikes and continue to the southwest side of the metamorphic rocks of the coverage area, and it should begin from the end of the closed high polarizability anomalies as well as from ZK2305 and ZK2303 holes and extend westward to trace the deep orebody.

This paper briefly introduces the composition and the main technical parameters of the VTEM^plus system, summarizes the technical advantages, describes the collecting data type and the method of data processing and the maps formed, with a brief description of data interpretation methods. The measurement of massive sulfide mining areas in Hami of Xinjiang and Xiaoyingzias of Inner Mongolia shows the significant application effect of this method in polymetallic ore exploration, and hence this method deserves recommendation for future work. The results obtained by the authors have certain guiding significance for exploration of polymetallic and other mineral resources.

The problem whether compensating actions(roll, pitch and yaw angle)reach the required standard or not in aeromagnetic survey is of crucial importance in that it affects the compensation coefficient directly.In order to evaluate the magnetic field compensation process, the authors present a method to calculate the pose angle of plane using the rotation relationship between three components of magnetic field measured by three axis fluxgate magnetometer under plane coordinates and the three components of geomagnetic field measured under horizontal coordinates, and to evaluate the compensation action quality.The practicability of the method is demonstrated by applying it to aeromagnetic compensation data(with high precision attitude data)of Panshi area in Jilin, where the results of proposed method is close to that of high precision attitude instrument AIRINS within 1 degree, showing that this method can effectively monitor whether the compensation action reaches the requirements or not during the flight.

In July 2009, in Harbin Pingfang airport.The research group of "Research and Development of the Digital Vector Aeromagnetic Exploration System" carried out a series of experiments using the model machine of tri-axial aeromagnetic gradiometer exploration system, which includes the modification of aircraft, compensation flight and exploration flight of 5 000 km.All of the work achieved good results and showed that the system was stable, reliable and reached practical level.The experimental work provides the basis for the improvement and perfection of the system.

Due to the weak energy microseismic events and the characteristics of low SNR data, the quick and accurate first arrival pickup has become the key problem. In view of the low efficiency of manual pickup and the low accuracy energy ratio method in picking up first arrival, the authors proposed entropy and mutual information method. Through studying the features of random variables and correlation degree, the authors proposed a first arrival pickup based on energy and mutual information. First, energy ratio algorithm is used to pick a rough arrival time, and then the mutual information algorithm is used to accurately pick up arrival time. According to the test of the model and the analysis of real data in comparison with conventional methods, the authors effectively verify the accuracy and feasibility of the method. The automatic first arrival pickup is achieved accurately and rapidly.

The hammering small-refraction method was used in the near-surface survey of the Qiharigetu Depression in Erlian Basin.The parameters of geometry which are suitable for the study area were obtained, and the interpretation of practical small-refraction survey showed the close correlations with the interpretation of small-refraction record based on explosive source, borehole data, and the measurement results of high density resistivity method.Meanwhile, the hammering small-refraction method will improve the efficiency of the near-surface survey, and make the job more convenient and the cost lower.This method therefore has higher practical value in this area.

Based on experience acquired in practical work, the authors summarize in this paper the main structure of the ADU-07e and the problem as to how to check the status of the ADU-07e from self test and especially sum up precautions for common trouble phenomena during field work and troubleshooting method for the operation of the GMS-07 comprehensive electromagnetic observation system. Practical examples illustrate abnormal data due to lack of ground electrode or chopper closure during recording data which cannot be checked from self test. The trouble detection method is also applicable to the GMS-07 system used in conventional MT exploration.

There were few drill wells in Qiongdongnan basin, which affected the accuracy of reservoir prediction.In order to solve this problem, the authors applied virtual-well technique to reservoir prediction of drilled A-1 gas bearing structure in the southern part of Lingshui sag in the deep-water area of Qiongdongnan basin, which verified that the virtual-well technique is reasonable.The authors also summarized experience values of wave impedance of the reservoir in A study area.The experience values were used to predict the reservoir of A-2 structure to be drilled.The prediction of A-2 structure coincides with the drilling result, which confirmed that the virtual-well technique is of high feasibility in predicting the exploration targets in the deep-water area of Qiongdongnan basin.

Based on the full azimuthal and high density seismic data in ZG area of Tazhong district in Tarim Basin, the authors detected fractures through the P-wave azimuthal anisotropy with prestack seismic data in OVT domain.After migration in OVT domain, the seismic data which possess azimuth and offset information, are suitable for fast prediction of fractures and hence avoid waste of time.The authors examined different offset ranges and azimuths and the alterable seismic domain and then chose the offset in the range of 100~5500 m and 6 azimuth to predict the fracture.To analyze the relative impendence inversion of every azimuthal datum, the authors determined the fracture orientation and fracture density of carbonate reservoirs in Yingshan Formation.The results are largely consistent with the practical drill hole and can guide the study of well deployment, connectivity of cave-fracture and design of horizontal well.

The thickness of permafrost is an important hydrocarbon accumulation factor for gas hydrate in permafrost areas. There are various exploration methods with different characteristics. In this paper, with the higher cost audio magnetotelluric (AMT) as the detection technology and the Muli area of Qinghai as the study area, AMT forward modeling of numbers of typical models was carried out, then one-dimensional adaptive regularized inversion and analysis were conducted. The results show that the logarithmic derivative curve of one-dimensional regularized inversion (or called the delamination factor curve of stratigraphic interfaces) can be used to divide well the bottom boundary of permafrost. Good results of exploration permafrost thickness application in Muli area were achieved. This means can play an important role in target prediction of gas hydrate in permafrost areas. The study of two cross-sections through the Well DK9 shows that the permafrost thickness near Well DK9 changes little and the permafrost thickness is from 60 meters to 100 m, and these facts provide good conditions for the cap of the gas hydrate concentration. Detection results near Well DK9 are as follows.The permafrost thicknesses of section DK9-2 that is perpendicular to the direction of faults is from 60 meters to 100 m. The permafrost thicknesses of section DK9-1 that is parallel to the direction of faults is from 68 meters to 92 m.

The short-offset transient electromagnetic method (SOTEM) is one of TEM devices with great detection depth and high detection precision. 1-D inversion is the main way of its data processing and interpretation. In this paper, a modified image source inversion scheme is proposed for SOTEM data. Studies indicate that the conversional image source inversion scheme is not completely applicable to the SOTEM and may yield resistivity estimates that are biased at early time region. In this study, all time apparent resistivity was used to modified the inversed resistivity at early stage and a good result was obtained. Synthetic data and an application case both prove the effectiveness of this scheme.

Accurate density inversion is the key to oil and gas prediction, which has been widely used in the offshore seismic exploration. The effect of prestack gathers optimization on the density inversion accuracy is discussed in the paper. Based on the prestack gathers quality evaluation and optimization, the quality of seismic data (signal to noise ratio, amplitude compensation rationality, and frequency difference) has been improved, the wide-angle effective seismic signals have been ensured, and gathers data fidelity has been improved. On this basis, the prestack three parameters inversion method has been adopted to obtain the density parameters for oil and gas prediction. Validated by blind wells, processed gathers data could effectively improve the density inversion accuracy, which will provide new means for oil and gas exploration.

The Yinggehai Basin is a hydrocarbon-rich basin, and in the high-temperature and overpressure strata, there exist numerous large-sized exploration targets.Especially in the high-temperature and overpressure field at the medium and deep depths in the Dongfang area, the natural gas exploration is very promising.The target strata of Huangliu Formation in the Dongfang area serve as the major strata, where a thousand billion cubic meters of gas resources have been proved.The accurate pressure prediction and the establishment of the three-dimensional pressure model constitute the cornerstone for the breakthrough in the exploration, and the establishment of the three-dimensional pressure model is based on the three-dimensional lithologic model.The establishment of this lithologic model breaks through the traditional lithologic prediction method in which the seismic impedance threshold value is used as the only means.In this study, the triple constraint trends lithological model is adopted to establish the lithologic model.The verification based on post-drilling pressure-measuring data and pre-drilling predicted three-dimensional pressure model data has proved the effectiveness of the technology of the three-dimensional pressure model, and demonstrated the extensive development vista of this technology.