Sedimentary Controls of Variograms of Terrigenous Components in Limestones and Limestone-Hosted Deposits

摘要

Knowledge about geological controls of variograms can provide vital decision support for the selection of appropriate models even in case of ambiguous experimental variograms. Observations from the Styran Erzberg sideritic iron ore deposit (Austria) sedimentary controls of the variograms for terrigenous components in limestones and limestone-hosted deposits. Here, the spatial correlation follows a nested structure consisting of a short-range exponential and a long-range linear or, in case of SiO_2, a piecewise linear model. The orientation of the structures' anisotropy ellipsoids suggests that the linear models may be caused by gravity transport while the exponential models may be connected to current transport. These findings are supported by data from La Campana 2 limestone deposit (El Salvador) and the metasomatic magnesite deposit Breitenau (Austria).