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
A Study of History 23 civilizations identified by Toynbee in vol. Vii. This table does not include what Toynbee terms primitive societies, arrested civilizations, or abortive civilizations. Civilizations are shown in boldface. Toynbee's "Universal Churches" are written in "italic" and are chronologically located between second- and third- generation civilizations, as is described in volume VII. The social scientist Ashley Montagu assembled 29 other historians' articles to form a symposium on Toynbee's "A Study of History", published as The book includes three of Toynbee's own essays: "What I am Trying to Do" (originally published in "International Affairs" vol. 31, 1955); "What the Book is For: