Geochemical Barriers

Abstract

Perel’man (1966, 1967) defined and illustrated the concept of a geochemical barrier which is of considerable importance in landscape geochemistry and in geology where certain kinds of mineral deposits are known to form as a result of geochemical barriers. Perel’man (1967) defined two general kinds of geochemical barriers of interest in landscape geochemistry: (1) areal barriers which may extend over relatively large areas of country (e.g., in grasslands, forests, and bogs) that are usually isotropic and isometric in plan, and (2) linear barriers which are due to processes which are anisotrophic and cover relatively small areas (e.g., slope discontinuities, fault zones, and spring lines). Perel’man (1966) noted that most environmental scientists tend to concern themselves with areal parts of landscapes (e.g., uniform ecosystem types); however, from the viewpoint of landscape geochemistry, linear features (e.g., transitions between ecosystem types) may often be of greater interest.

“Lithologic boundaries in the supergene zone where conditions of migration change drastically and concentrations of chemical elements begin to rise are called geochemical barriers.”

A. I. Perel’man, Geochemistry of Epigenesis (New York: Plenum Press, 1967), P. 213.