The Study Of Non-linear Analysis Method Of Geochemical Ore-forming Anomaly

This article is from the Geological Survey projects of China Geological Survey, sub-topics of'the exploration technology research Under the volcanic cover': quantitative evaluation method of Geochemical ore-forming anomaly. Since the closure of volcanic cover is that the body effect on the forming elements of the upward diffusion and micro-infiltration block has a strong ability to evaluate the traditional interpretation of geochemical anomalies become very difficult. To break through the traditional, you need to apply new theories, new methods. n addition to strengthening the deep-penetrating geochemical exploration of new technology and methods of research other than geology and geostatistics from the mathematical point of view, the application of the latest achievements of modern nonlinear science, the re-evaluation of geochemical anomalies, to explain, and further excavation geochemical metallogenic information contained in the data is undoubtedly an important way.This study area is the Dong Gapu copper exploration area in Tibet. From quantitative evaluation method of Geochemical ore-forming anomaly, making use of a variety of modern mathematical methods and nonlinear analysis, mining ore weak anomalies contains in geochemical data. First use of artificial immune algorithm to construct a noise model of geochemical data, geochemical elements data on noise reduction, in order to eliminate high-value brought by special shielding and removing false anomaly. Secondly, based on blind source separation algorithm for establishing anti-evolution geochemical data elements combined model, in order to determine combination of geochemical ore-forming elements. Then, using the fractal concentration-area method to determine single-element geochemistry and elemental composition of the anomaly threshold, re-use content gradient method of fractal delineate abnormal concentration center and to determine the zoning exception. Finally, the elemental characteristics of research and study area with geological characteristics of the combination, compared to single-element anomaly maps and the composite anomaly map of the study area of the geochemical elements to explain the anomaly classification and anomaly evaluation. This study will provide new technical methods for geochemical exploration technical aspects under the volcanic cover.Innovation of this article is:(1)The article in terms of geochemical anomaly identified by a variety of nonlinear analysis method to overcome the traditional methods of geochemical data will be seen as consistent with normal or lognormal distribution brought about irrationality, and the distribution of surface geochemical elements traditionally seen as a continuous smooth surface of the unscientific nature.(2)Artificial immune theory of noise on the geochemistry of the raw data processing, removing the special shielding to bring high-value and false exceptions, to make the data more effective.(3) The surface geochemical element distribution is fractal surface, and thus this article, through analysis of various fractal methods, the use of the content-area model of Chen Qiuming and the Projective covering method of Xie Heping and improved method combined with the fractal method to determine anomaly threshold, and the gradient method used to determine the fractal content of abnormal concentration center, as delineated anomalous zone.(4) The article first attempt to blind source separation technique for geochemical field, blind source separation theory about the FastICA algorithm is applied to regional geochemical data for mineral elements in combination, forming a supergene geochemical method of automatic model to strike a combination of elements, which combined the elements of anti-geochemical characteristics.(5) The article carried a nonlinear information processing science and high technology combined geochemical data processing method of research for multi-scale delineation of geochemical anomalies and deep metallogenic prediction theory provides a new way of thinking, research topics not only novel and practical, but also has a solid work proposed research program based on the existing geochemical exploration will provide a useful supplement.Through research, established geochemical anomaly delineated system under the MAPGIS . after the data processing of 1:1 million soil geochemical survey of Dong Gapu copper in Tibet Autonomous Region, drawing elements of the surveyed area geochemical anomaly maps and the combination of anomalies , and had anomaly interpretation and evaluation. Validated in the survey area was divided into four abnormal. There have two A (1) class anomaly , numbers are Ht-A (1) -1 and Ht-A (1) -2; one is A (2) class anomaly , number is Ht-A (2) -1; one is anomaly B , number is Ht-B -1. The overall distribution of anomalies by overlaying the elements reflected in the situation, unusual intensity reflects the actual situation of the surveyed area. Anomalies and ore bodies found so far, consistent with mineralization. anomaly complete, close is good, that anomaly is an anomaly of mineralization. Where Ht-A (1) -1 andâ…¢of ore-forming anomaly with strong fit, Ht-A (1) -2 anomaly consistent withâ…£orebody, Ht-A (2) No -1 anomaly in the ductile shear belt driveâ‘¢, found in 2004 closeâ…¤orebody.