Aeolian Tephra Deposits as a Key to Correlation

Abstract

Though there are no deposits in Japan exactly comparable to the loess deposits, tephra or volcanogenous deposits analogous to the loess in their aeolian origin are widly distributioned, and the chronological studies of them must be urged in Quaternary researches. In this paper, the relations among aeolian deposits, terrace topography, and fluvial or marine deposits are shown; and stratigraphical correlation problems are discussed. In short, horizon markers in tephra deposits (for example, specific pumice or scoria layers, difference in mineral components, plane of unconformity, buried soil bands, etc.) are useful in a relatively small area; but in order to make a chronological table for a wider area, geomorphological correlation of terrace topography is more effective.