基于GIS的地浸砂岩型铀矿预测方法——成矿有利度计算法在伊犁盆地南缘VII_1亚旋回的应用

GIS BASED PREDICTION APPROACH OF IN-SITU LEACHING SANDSTONE-TYPE URANIUM DEPOSITS——APPLICATION OF CALCULATION METHOD OF METALLOGENIC FAVOURABILITY DEGREE ON SEDIMENTARY VII1 SUB-CYCLE IN THE SOUTH MARGINAL REGION OF YILI BASIN

介绍的成矿有利度计算法是一种基于矢量数据的成矿预测方法.与传统的成矿有利度计算法相比,该方法的预测单元采用自然单元(多边形),而不是网格化单元.成矿有利度计算过程是先对2个预测变量(空间图形)进行相交分析,有利因子相乘并进行归一化处理,再与下一个变量进行相交分析,最终得到能反映该预测单元综合成矿地质条件的有利成矿因子值.在详细介绍了成矿有利度计算法的基本原理与工作流程基础上,对伊犁盆地南缘西段水西沟群VII1亚旋回进行了预测评价,圈定了I级、II级铀成矿远景区各1片,III级成矿远景区2片.

The calculation method of metallogenicl favourability degree used in this paper is a metallogenic prediction method based on vector data. Compared with traditional one, the prediction units used by this method are natural polygons rather than grids. The calculation procedure of metallogenicl favourability degree is as following： firstly do intersection analysis of two prediction variables （spatial figures） by multiplying the favourability factor, then normalize the favourabity factor and do the intersection analysis with the following prediction variables, and finally gain the metallogenic favourability factors that can reflect the comprehensive favourability of metallogenic geologic conditions. After introducing the basic principle and work procedure of metallogenic favourability degree method, the essay also discusses the metallogenic prediction on Ⅶ1 sedimentary sub-cycle in the west part of south marginal region of Yili basin and one first-class, one second-class and two third-class metallogenic prospect areas.