Geological Anomaly of China

Geological anomaly is a geological body or geological body combination different from its surroundings in composition, structure, or genetic sequence. If there is a value (value interval ) that works as a valve representing the background field, exceeding or lower than the valve value,it is called a geological anomaly. Geological anomalies can be divided into high geological anomaly and low geological anomaly .The former shows the area that is more complex in composition, Structure or genetic sequence than its surroundings; while the latter just gives an opposite indication, i. e. much simpler. According to their distribution and delimitation markers, geological anomalies can be classified into (1)global geological anomaly; (2)regional geological anomaly; (3) local geological anomaly; (4) minor geological anomaly and (5)micro-geological anomaly .The methods for delimiting geological anomalies include (1)crustal elevation-subsidence coefficieat (G value ) determination; (2) geological complex coefficient (C value ) determination; (3) entropy (H value ) determination; (4) geological similarity coefficient (S value ) determination and (5 ) geological correlation coefficient (R value ) determination. As the result of the movements of Eurasian, Pacific and Indian Plates, the Chinese geological anomalies, including 11 regional ones and 32 main local ones, most Paleozoic in age, are distributed in strip on the margin or the outer and inner folded zones in the east and west arcs of the block symmetric arc tectonic system (BSATS), which controls the distribution of various minerals in China. Thus, geological anomaly theory is of great significance in searching for large, super-large and very large ore deposits.

Theory of Geological Anomaly in Remote Sensing

Geological anomaly is geological body or complex body with obviously different compositions, structures or orders of genesis as compared with those in the surrounding areas. Geological anomaly, restrained by the geological factors closely associated with ore forming process, is an important clue to ore deposits. The geological anomaly serves as a geological sign to locate ore deposits. Therefore, it is very important to study how to define the characteristics of geological anomaly and further to locate the changes in these characteristics. In this paper, the authors propose the geological anomaly based on the remote sensing images and data, and expound systematically such image features as scale, size, boundary, morphology and genesis of geological anomalies. Then the authors introduce the categorization of the geological anomalies according to their geneses. The image characteristics of some types of geological anomalies, such as the underground geological anomaly, are also explained in detail. Based on the remote sensing interpretation of these geological anomalies, the authors conclude that the forecasting and exploration of ore deposits should be focused on the following three aspects: (1) the analysis of geological setting and geological anomaly; (2) the analysis of circular geological anomaly, and (3) the comprehensive forecasting of ore deposits and the research into multi source information.

Geological inferences about the upper crustal configuration of the Medellin-Aburra Valley(Colombia)using strong motion seismic records

In regions of complex geology and tectonic assembly, strong motion seismic arrival time records can be used to test the plausibility of existing hypothesis about the origin of lithological and tectonic features and how they are related in space and time. In this study we use differential travel time residuals at some strong motion accelerographic stations in the Medellin-Aburra Valley, in the northern Central Cordillera of the Colombian Andes, to discuss some aspects of the geological configuration. We based our work on the hypothesis that the differences between seismic travel time residuals among pairs of stations are a function of the differences in the surface geology and the near-surface upper crustal configuration. Our results are consistent with the volcanic rocks of the Quebradagrande Complex being less mafic, more weathered or more tectonically affected than previously thought, with the presence of a relatively thin dunite body on top of the metamorphic basement, and with a large lateral heterogeneity in the mainly mafic San Diego Stock.

Fractal invariable distribution and its application in large-sized and super large-sized mineral deposits

The self-similar is a common phenomena arising in the field of geology. It has been shown that geochemical element data, mineral deposits, and spacial distribution conform to a fractal structure. A fractal distribution requires that the number of objects larger than a specified size have a power-law dependence on size. This paper shows that a number of distributions, including power-function, Pareto, lognormal, and Zipf, display fractal properties under certain conditions and that this may be used as the mathematical basis for developing fractal models for data exhibiting such distributions. The summation method is developed on the basis of fractal models to determine thresholds for Au data in Shandong Province, China. The anomalous area is enclosed by contours which have contour values greater than or equal to threshold （200 × 10^- 9） and contains known large-sized and super large-sized gold mineral deposits.

Expert System for Statistical Prediction of Mineral Deposits on Middle and Large Scales

The expert system for statistical prediction of mineral deposits on middle and large scales takes the system of scientific exploration theories, criteria and methods proposed by Professor Zhao Pengda as the field expert knowledge. At present the developed system focuses on two aspects: synthetic exploration and quantitative exploration. Among the three basic theories for the prediction of deposits, it highlights the applications of seeking anomaly theory. This system is characteristic in the determination of geological background, the study of geological anomalies and the delineation of geological background, the study of geological anomalies and the delineation of mineralization anomalies. The system combines closely the knowledge base, method base and database .integrates the input and output information of multi - sources and mul-ti - variables , data , graphs and imagine processing system and inquiring system as a whole . So the system can meet in general all kinds of demands in statistical prediction of mineral deposits . Since the statistical prediction of mineral resources is a kind of systematic engineering pro ject , a further study should be carried out on the fields of theoretical exploration and ster eo - exploration on the basis of unceasingly perfecting the above-mentioned fields in order to establish a comprehensive intelligent system for scientific exploration , to provide new methods , new techniques and new ideas for fast prospecting appraisal of mineral resources .

"Three-Component" Digital Prospecting Method: A New Approach for Mineral Resources Quantitative Prediction and Assessment

Three-component' method consists of three close-connected aspects: geological anomaly, diversity of mineralization and mineral deposit spectrum. All these three concepts are not new separately, but it is a new approach to combine these three aspects in one single concept for quantitative mineral resources prediction and assessment and it is also the first time to conduct a more detailed study in each aspect. Investigation and clarification of geological anomalies, diversity of mineralization and spectrum of mineral deposits are realized by digitization and quantification of ore forming controlling factors, ore-existing symbols or marks, characteristics of mineralization and regulation of ore-genesis and laws of distribution. These procedures lead to construction of a 'digital model' for mineral resources prediction and assessment.

Important Issues of Sustainable Development:Research of Nontraditional Mineral Resources

Nontraditional resources refer to that potential mineral resources are unconsidered and unutilized under actual condition of technique, economic and environment, or some mineral resources are too difficult to find because of geological complexity. There are some signified problems about discovery and exploration of nontraditional mineral resources to be discussed in this paper. It is a very significant project next century, and makes development bases for offspring, which its research and practice the theory of nontraditional mineral resources need interactive combination.

Gravity gradient distribution in China's Mainland from GOCE satellite gravity gradiometry data

At present, gravity field and steady-state ocean circulation explorer（GOCE） gravity data are always used to compute regional gravity anomaly and geoid height. In this study, the latest GOCE gravity field model data（from Oct. 2009 to Jul. 2010） are used to compute the gravity gradient of China's Mainland according to a rigorous recursion formula（in all the six directions）. The results show that the numerical values of the gravity gradients are larger in the T rr direction than those in the other directions. They reflect the terrain characteristics in detail and correlate with the regional tectonics; however, in the T ql and T r l directions,the numerical values are relatively smaller and the gravity gradients in the T r l direction do not reflect the terrain characteristics in detail.