青海省祁漫塔格地区1∶5万水系沉积物测量衬值异常圈定实例  

Delineation of Contrast Value Anomalies of 1 ∶ 50000 Drainage Sediment Survey Data: An Example of the Qimantage Area,Qinghai Province

作　　者：赵娟 孙泽坤 贾研慧 马楠 徐博 马正婷 

机构地区：[1]青海省地质调查局,青海西宁810008 [2]青海省地质矿产勘查开发局,青海西宁810008 [3]青海省第五地质矿产勘查院,青海西宁810003

出　　处：《地质与勘探》2016年第3期518-523,共6页Geology and Exploration

基　　金：柴达木周缘成矿带地质矿产调查评价"青海省祁漫塔格地区1:5万矿调多元地质信息集成与找矿预测"(资[2014]01-026-157)(12120114000201)

摘　　要：青海省祁漫塔格地区位于柴达木盆地西南缘,是青海省重要的铁多金属成矿基地之一。利用88442个野外采样点1∶5万水系沉积物测量数据,采用Geo Expl软件圈定了该地区的衬值异常。衬值是指各元素0.5 km×0.5 km网格化数据与其园域搜索半径5km、移动步长0.5km移动平均值的比值。选用自定义累频"90、95、98、100"确定了异常的外、中、内带。通过常规方法和衬值圈定的异常的对比,表明衬值异常能够削弱不同地质背景差异,使异常形态更为规整,浓集中心更为明显,并且可能发现新异常。The Qimantage area in Qinghai Province is located in the southwestern margin of Qaidam Basin, which is one of important iron-polymetallic metallogenic bases in Qinghai Province. Based on data from 88442 field sampling sites for 1：50,000 drainage sediment survey, GeoExpl software was a- dopted to delineate contrast value anomalies in this area. Such contrast values refer to the ratios of each element＇s 0.5 km × 0.5 km gridding data to its moving average value by 5 km searching radius and 0.5 km moving step length. Selecting custom cumulative percentages ＂90,95,98, and 100＂, the outer, middle and inner zones of anomalies were determined. Comparison of the resulting anomalies from the conventional method and the contrast value delinea- tion shows that the latter is able to weaken the differences of different geological backgrounds, making anomaly forms more regular and concentration centers more obvious,and permitting to find new anomalies.

关 键 词：祁漫塔格 1∶5万水系沉积物测量 衬值异常 

分 类 号：P632.3[天文地球—地质矿产勘探]