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 Is This? What Is This? What Is This (known prior to 1980 as Anthym) was a rock band that originated in Fairfax High School in California and would play numerous shows along the coast of California. It was formed by guitarist Hillel Slovak, drummer Jack Irons, vocalist Alain Johannes, and bassist Todd Strassman. Originally named Chain Reaction, the band would later change its name to Anthem, then later to Anthym (as there was already a band using the former moniker), and then finally to What Is This, which was a tongue-in-cheek reference to the reaction they usually received from first-time listeners. During