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
What Is This? project while the former was seen as side endeavor. What Is This released their debut EP "Squeezed" in 1984. Around this time, Hillel Slovak had become uncertain of his role in the band and decided to rejoin the Red Hot Chili Peppers. He left What Is This in 1985, and later that year the band would release its only full-length studio album "What Is This?" and its final EP "3 Out of 5 Live". After this, the band broke up. Alain Johannes later met Natasha Shneider and the duo formed Walk The Moon, whose sole studio album featured Jack Irons