Coal the heat and pressure of deep burial causes the loss of water, methane and carbon dioxide and an increase in the proportion of carbon. Thus first lignite (also called "brown coal"), then sub-bituminous coal, bituminous coal, and lastly anthracite (also called "hard coal" or "black coal") may be formed. The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants—this coal is presumed to
What Really Happened to the Class of '65? What Really Happened to the Class of '65? What Really Happened to the Class of '65? is a 1976 non-fiction book by Michael Medved and David Wallechinsky. Inspired by a 1965 "Time" magazine article, the authors follow up on the people of Palisades High School mentioned in the article, and the book mainly consists of that follow-up. There was at least one sequel, continuing the story from the point of view of a decade or more later. The book was later adapted into an anthology television series of the same name that aired on NBC from December 1977 to July