With reference to discussion by G. J. H. McCall of a paper by C. M. Bristow, it is pointed out that fiamme can be found in several volcanologic environments, that ignimbrites devoid of fiamme can also be found, and that the identification of ignimbrites was dependent on a complex of structures and field relationships rather than one particular structure. In the reply McCall asserts that his statements have been given meanings that are not expressed.

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