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) Love? (What Is) Love? "(What Is) Love?" is a song recorded by American entertainer Jennifer Lopez. Originally entitled "What Is Love?", the song appeared on the soundtrack to "The Back-up Plan" (2010), a film in which Lopez stars. The song was later included on Lopez's seventh studio album "Love?" (2011), as the album's title track. "(What Is) Love?" is a midtempo electropop song written by Diana "Wynter" Gordon, with the song's producer Emile "D'Mile" Dernst II. The song is about "not knowing what love is," according to Gordon. A remix of "(What Is) Love?", entitled "What Is Love? Part II", was