Petrology description of rocks while petrography is the speciality that deals with microscopic details. In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through, and drawn on a log called a mud log. As the cuttings are circulated out of the borehole they are sampled, examined (typically under a 10× microscope) and tested chemically when needed. Petrology utilizes the fields of mineralogy, petrography, optical mineralogy, and chemical analysis to describe the composition and texture of rocks. Petrologists also include the principles of geochemistry and geophysics through the study of geochemical trends
What Is Literature? What Is Literature? What Is Literature? (), also published as "Literature and Existentialism",) is an essay by French philosopher and novelist Jean-Paul Sartre, published by Gallimard in 1948. Initially published in freestanding essays across French literary journals "Les Temps modernes", "Situations I" and "Situations II", essays "What is Writing?" and "Why Write?" were translated into English and published by the Paris-based literary journal Transition 1948. The English translation by Bernard Frechtman was published in 1950. Sartre attempts to devise an understanding of the effect literature has on those who are subjected to it. In the foreword Sartre addresses his critics