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 History? that historians deem unimportant, and "historical facts", information that the historians have decided is important. Carr contended that historians arbitrarily determine which of the "facts of the past" to turn into "historical facts" according to their own biases and agendas. For this reason, Carr argued that Leopold von Ranke's famous dictum "wie es eigentlich gewesen" (show what actually happened) was wrong because it presumed that the "facts" influenced what the historian wrote, rather than the historian choosing what "facts of the past" he or she intended to turn into "historical facts". At the same time, Carr argued that the study