Epiclastic processes in volcanic terrains

Abstract

Volcanic eruptions are short-lived and occupy only a small time interval in the total history of a volcano, especially on large volcanoes. Their principal effect is aggradational, building up the surface relief against the base level to which erosional processes work. Repose periods between eruptions occupy the bulk of the time interval covering the history of a volcano. Given the effects of aggradation above erosional base level, the development of high slope angles overall or locally, and the general abundance of loose erodible debris, it is not surprising that the long-lived repose periods are dominated by normal epiclastic surface processes: erosion, transportation and redeposition. In this chapter we review the types of epiclastic processes that are likely to occur in both subaerial and subaqueous volcanic terrains. In particular we examine transportational and depositional processes and the basic principles underlying these processes, and we consider the characteristics of resultant products.