A geologic, petrographic and geochemical study has been
performed on the pyroclastic flow deposits in the coastal area of
East
Zhejiang
Province,
Southeast
China. This study leads to classification of the
pyroclastic flow deposits into three associations: the extrusive type, the surge
type and the ash flow type welded tuff associations. Through detailed
investigation and comparison of the characteristics of these lithologic
associations, with emphasis on the welded tuffs, a comprehensive model has been
proposed to demonstrate the petrogenesis of the pyroclastic flow
deposits.