Physicochemical basis of the analysis of the paragenesis of minerals / Физико-химические основы анализа парагенезисов минералов

An intimate coexistence of minerals in close contact with one another, observed repeatedly in definite geologic settings, is called their paragenesis. The paragenesis of minerals may result from different causes. Usually by paragenesis is meant an association of minerals formed simultaneously as products of a certain stage of a given process. Such, for instance, is the paragenesis of minerals formed at the same time by a metamor-phic process and existing in close contact with one another. In this book we have in mind precisely this kind of paragenesis of simultaneously formed minerals. Some authors use the term paragenesis to designate an association of noncontemporaneous minerals, provided there is regularity in their occurrence together. Such, for example, is the paragenesis of primary minerals with the products of their decomposition, or the paragenesis of minerals which crystallize in a regular sequence from a cooling magma or a hydrothermal solution, forming overgrowths on one another. The term paragenesis will not be used here in this broader sense. <...>