DIFFUSIONAL ISOTOPIC EXCHANGE ACROSS AN INTERLAYERED MARBLE-SCHIST SEQUENCE WITH AN APPLICATION TO TINOS, CYCLADES, GREECE Academic Article uri icon

abstract

  • Marble-schist contacts are frequently characterized by fine-scale interlayering which prevents the application of semi-infinite layer width assumptions to advection/diffusion models of isotope profiles. Using a finite layer width boundary condition, we show that the minimum width (w) of a layer required in order that diffusional exchange at both boundaries will not mutually interfere is given by the relation w> k (Dt) 1/2, where D is the effective diffusion coefficient, t is the duration of the diffusion and k is a constant determined by the initial compositional step and the noise (ie, natural homogeneity and/or analytical accuracy). When this condition is not satisfied, a solution of the diffusion equation for a multilayer transition zone containing several schist and marble layers of different, finite, widths is applicable. Application of this refinement of the diffusion model to an oxygen isotope …

publication date

  • January 1, 1991