Roundness in saturation

the relationship with production process of gravel and sand

Abstract

The concept of "roundness in saturation," i.e., the roundness of no more rounding of detrital grain during transport process had been discussed during the mid-last half of the 20th century. The author reviews the history of "roundness in saturation" had been investigated in the field and in the abrasion experiments, and discusses the phenomenon focusing on the mechanism of grain production, especially abrasion, based on the changes in roundness of grain and sand obtrained from the upper reaches of rivers.