Petrology Petrology Petrology (from the Greek πέτρος, "pétros", "rock" and λόγος, "lógos", "subject matter", see -logy) is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale
Empirical study of literature when it is concerned with questions of reading. In these two areas research and studies based on the framework are steadily growing. Further fields where the framework in various revised and expanded versions attracts scholarship is (comparative) cultural studies and pedagogy. One of several dictionary definitions of the field is as follows: “Movement within the study of literature concerned with the study of literature as a social system of [inter]actions. The main question is what happens to literature: it is written, published, distributed, read, censored, imitated, etc. The empirical study of literature originated as a reaction to, and an attempt