some regions and areas characterized by the predominance of certain chemical elements (in igneous rock termed “specialization” of a chemical element) and a lack of others. Geochemical provinces appear as a deviation from the ratios of the mean contents of chemical elements in the earth’s crust; the greater the deviation, the greater the contrast shown by the particular geochemical province and the more it shows up as localization in a given region of deposits of definite types of minerals, in peculiarities of characteristic soils, and in the mineralization of surface and underground waters and the flora and fauna, sometimes causing specific plant and animal diseases.
Study of geochemical provinces facilitates the solution of a number of problems of regional geochemistry. Knowledge of the specific chemical composition of the predominant elements in a particular geochemical province leads to apposite geological prospecting for mineral deposits. As a rule, the greater the deviation from clarke in the direction of excess, the more likely that there will be deposits of a particular element as long as the ratio of other elements does not prevent its concentration. Unlike complexes without ores, ore-bearing complexes of igneous rock are characterized by uneven distribution of ore elements.
V. V. SHCHERBINA