GIS环境下地质变量自动提取与地质异常的圈定

Geo-variables Extraction and Geo-anomaly Circle Based on GIS

通过对研究区合理的网格单元划分,介绍地理信息系统(GIS)提取地质变量的原理,即利用GIS的空间叠加功能,实现地质变量自动提取。在此基础上,进行变量综合,挖掘隐含信息。过滤与已知矿产有关的变量,圈定地质异常,它是研究致矿异常和发现新矿产地的基础。以云南省维西地区为实例,按上述方法原理,提取其地质变量,圈定其地质异常。已发现的矿体(包括矿化点)中,有76.84%矿体(含矿化点)落入异常区内。

GIS is an effective tool to process and analyze spatial geolog ic al information.Since1980s,with the mature of the GIS technology,GIS is wi dely used in many areas.Although a lot of works has been done for the mineral r esources quantitative appraisal with GIS,few studies are conducted through extr acting,screening and synthesizing geological vari-ables using GIS for the mine ral resources quantitative appraisal.In this paper,some data involving geolog y and geo-chemistry have been collected to establish the database.With the hel p of GIS technology these data are integrated to circling geo-anomaly.When sui table grid cells are ascertained in the research area,GIS spatial overlaying fu nctions are used to extract geo-information,then some geological variables ar e synthesized to burrow implicit geological information such as composite entrop ,beneficial degree of fault and center symmetry degree of fault.The analysis m ethod of ore-finding beneficial degree in linear anomaly and plane anomaly is i ntroduced to filtrate the geological variables relative to mineral resources.Ge o-anomaly model based on GIS is expounded.The geological variables in Weixi a rea in the Yunnan province are taken out ,and the geo-anomaly are circled in t he same area.