Geostatistical evaluation of dimension-stone quarries

This paper addresses the two problems that arise in evaluating dimension-st one quarries: absence of a single quality variable and classification of bl ocks of stone. In constructing the single variable, an approach considering multivariate spatial relations of a number of variables that affect qualit y of dimension-stone is proposed. The multivariate spatial relations are de fined by variogram matrices. In classification of the blocks, a decision an alysis approach that rests on two key concepts, cumulative conditional dist ribution function and loss function, is introduced. The approaches are appl ied to an andesite quarry located in Ankara, Turkey: one level of the quarr y is chosen to be a test area from which 108 rock samples are taken at 20 m regular intervals. The rock samples are tested for some of the mechanical properties of andesite that control the economics of extraction process, an d a quality index is produced using test data. The application area is then divided into 1862 5 x 5 m square blocks, and the conditional distribution functions for these blocks are estimated by indicator kriging. Finally, the blocks are classified as exploitable and non-exploitable on the basis of m inimization of economic losses. (C) 2000 Elsevier Science B.V. All rights r eserved.