煤田测井在砂岩型铀矿勘查选区中的应用

摘要

The formation of sandstone type uranium deposit in northern Liaoning coal basins is closely related with coal basin palingene-sis and modification, mostly located on the coal basin marginal and fault slope areas. Through sifted out gamma-ray logging anomalies in 4556 boreholes, have studied to determine optimized exploration targets. In the optimization, based on positive relationship between logging trace gamma-ray anomaly amplitude and uranium content, determined to account anomalous range in study area into 3 seg-ments of 50γ~100γ, 101~350γand>351γ. Through analysis of highγanomalous rocks, have validated the upper Cretaceous Quantou Formation sandstone, sandy conglomerate members are main uranium-bearing strata. According to anomalous boreholes, points, depths, thicknesses andγanomalous values in coalfields, three sandstone type uranium exploration prospect areas have been delineat-ed out, they are Changchengwopu area, Tiefa area and Guyushu-Liangzhong area in northern Liaoning.%辽北煤盆地砂岩型铀矿的形成与煤盆地再生改造密切相关，且多位于煤盆地的边缘及断裂的斜坡区。通过对4556个钻孔自然伽马测井曲线异常的筛选，研究确定辽北煤盆地砂岩型铀矿勘查选区。在选区工作中，依据测井曲线自然伽马异常幅值与铀含量正相关关系，确定研究区内异常范围按50γ～100γ、101γ～350γ、大于351γ三个数值段分别统计；通过对伽马高异常岩性的分析，确认含煤盆地内白垩系上统泉头组砂岩、砂砾岩段为主要含铀岩层；根据各煤田异常孔、异常点、异常深度、异常厚度以及伽马异常值大小，圈定了3个砂岩型铀矿勘查选区，即辽宁北部的长城窝堡、铁法、古榆树--亮中远景区。