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? the internet on April 20, 2013. According to Jessica Sager of PopCrush, it picks up where the original song left off. Sager wrote that the song "likely isn't about [Marc] Anthony — but for those new to the song, it's surely easy to interpret it as such. Lopez gets pretty revealing in the new song, addressing a divorce directly and explicitly". Credits adapted from the liner notes of "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),