ROLE OF GRAIN TYPE IN QUANTITATIVE SURFACE MORPHOLOGY OF PYROCLASTS FROM THE MONTE GUARDIA SEQUENCE ON LIPARI, ITALY.

This paper presents a new quantitative method for examining images of single grains of pyroclasts. The technique can be adapted for quantitative classification, discrimination, or interpretation of several types of pyroclastic deposits. An example is presented using the Monte Guardia sequence, a well-characterized deposit of base-surge origin on the island of Lipari. Samples taken from different types of deposits at various distances from the source represent diverse depositional environments. Cluster analysis shows that clast type dominates over environmental factors in the correlation of grains based on their surface morphology.