块金效应地质意义及其对品位估值影响

Geological interpretation of nugget effect and its constraint on grade estimation

地质(矿化)连续性评价是矿产勘查和资源储量估算的基础。块金效应为变异函数中块金值与基台值的比值,可以用来刻画地质变量空间结构的变异性,并且对品位估值有重要影响。然而,实际操作过程中,对变异函数的拟合与块金效应的地质解释却显得主观随意。在整合前人研究的基础上,重点探讨影响变异函数块金效应确定的主要因素,系统阐述块金效应对地质(矿化)连续性的指示作用及其对克里格和距离幂次反比等品位估值的影响。本研究对于提升矿产勘查评价和资源储量估算的可靠程度有着现实意义。

The continuous evaluation of geology(mineralization)is the basis of mineral exploration and resource estimation.The nugget effect is the ratio of the nugget variance to the total variance in the variogram,which can be used to describe the variability of the spatial structure of geological variables and has important influence on grade estimation.In practice,however,the fitting of variogram and geological interpretation of nugget effect are subjective and arbitrary.Based on the previous studies,the paper mainly discussed the main factors influencing the nugget effect in variogram,systematically elucidated the indication of the nugget effect on geological(mineralization)continuity,and the significance on kriging and IDW grade estimation.The study is practical for mineral exploration evaluation and resource estimation to improve their reliability.