Ignimbrite Studies in the Taupo Volcanic Zone

Abstract

This thesis is presented in the form of four independent papers, the first three of which have already been published. Summaries of each of the papers are presented in the general abstract, pages 1-4. Paper I is an introduction to the study of ignimbrites. It deals briefly with their origin and manner of deposition, and the effects of progressive compaction, crystallization, and autopneumatelysis on the cooling deposits. It is essentially a summary paper based partly on existing literature and partly on experience gained during a detailed study of the ignimbrites of the Mangakine area, and observation of ignimbrites in at least four American petrographic provinces, in Nevada-Utah, eastern California, central Oregon, and southeastern Idaho.