A Kriging-based Estimate of the Survey Quality in Biomonitoring of Trace Element Air Pollution

The present paper addresses Kriging-based approaches to estimate survey quality, thereby using data on biomonitoring surveys of trace element air pollution. Data were used of a 1995 moss monitoring study in The Netherlands, thereby taking sodium (Na), arsenic (As) and bromium (Br) to illustrate the points made. Survey quality was expressed as the survey signal-to-noise ratio (SSNR), with the survey variance as the signal and the local variance as the noise. The Kriging approaches were regarded in parallel to direct approaches where local variances are determined from multi-fold local sampling.The paper addresses the uncertainties in SSNR associated to the uncertainties in local values and variances if based on pooled samples and a limited 5-fold sub-sampling in a restricted number of sampling sites. It further introduces a Kriging approach to SSNR_K (_K for Kriging), by Kriging-assisted recalculation of local values and variances, in turn based on fitted experimental variograms. The outcomes suggest that the Kriging approach may yield reliable SSNR_K values; the approach implies that SSNR_K depends on survey set-up, site density and sampling grid characteristics. The discussion of the paper addresses the points made and further suggests the use of large sample analytical facilities to permit a change in survey approach from mixing and milling of pooled sub-samples to bulk analyses of all sampled material in higher site-density surveys.     

大别造山带核部两处燕山期花岗岩体的成因演化模式

根据对大别山核部牛占鼻和木子店两处燕山期花岗岩体进行的元素地球化学分析和岩浆演化的模拟分析,结果显示,牛占鼻和木子店两处燕山期花岗岩体都具相似的主量和微量元素特征,它们和天堂寨的同期花岗岩具有相似的成因模式和源岩,其主要的形成演化模式可能是增厚的下地壳发生部分熔融所致,源岩可能是太古代TTG片麻岩或奥长花岗岩。同时这样的结果也说明大别山燕山期花岗岩的成因与造山后的地壳叠覆、基性岩浆底侵和随后的地壳拆沉作用具有密切的联系。模拟中也发现有的样品具有异常的地化特征,尤其对是Na2O/K2O>1的花岗岩的模拟结果不理想,暗示可能存在不同的源岩和岩浆演化作用。