Second additional theory of origin of fiamme in ignimbrites

Abstract

Gibson and Tazieff1 have questioned a widely accepted explanation of dense black clots of glass (fiamme) in ignimbrites. A new interpretation of these features is long overdue, for the conventional interpretation of fiamme as flattened and highly compressed lumps of pumice is very difficult to substantiate. As they point out, in many ignimbrites there are few if any lumps of pumice in the upper, uncompacted levels that are large enough to produce the dense glassy clots by compression. © 1968 Nature Publishing Group.