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
A Star Is Burns A Star Is Burns "A Star Is Burns" is the eighteenth episode of "The Simpsons"<nowiki>'</nowiki> sixth season. It first aired on the Fox network in the United States on March 5, 1995. In the episode, Springfield decides to hold a film festival, and famed critic Jay Sherman is invited to be a judge. The story involves a crossover with the animated series "The Critic". Jay Sherman was the main character on the show. "The Critic" was created by Al Jean and Mike Reiss, who had previously written for "The Simpsons" but left following the fourth season, and produced by James