Metamorphic textures / Метаморфические текстуры

METAMORPHISM is the mineralogical and structural (textural) adjustment of (dominantly) solid rocks to physical and chemical conditions which differ from those under which the rocks originated. Weathering and similar processes are conventionally excluded. The type of metamorphism depends on the relative values of temperature ( T ) , confining pressure (/*con)> pressure or chemical activity or fugacity of water (expressed generally as PHJO)* deformation or directed pressures (P^ir) and their variation with time {t). There is only a limited degree of interdependence of these controls and the metamorphic history of a rock is an expression of their mutual interaction with time (Fyfe, Turner and Verhoogen, 1958; Pitcher and Flinn, 1965). <...>