"Vulcanism" Quotes from Famous Books
... weight of overlying sediments, or to earth movements. In peat condensational changes of this nature are accomplished artificially by the pressure of briquetting machines. Another factor is believed to be the heat developed by earth movements and vulcanism, which presumably facilitates the elimination of volatile materials, and thus accelerates the gradational changes above described. This is suggested by the fact that in places where hot volcanic lavas have gone through coal beds they ... — The Economic Aspect of Geology • C. K. Leith |