Distinguishing beach cusps from cuspate deposits, descriptions and illustrations are presented based on some beaches of Japan. From the inner structures and evolution of beach cusps, it is considered that both erosion and deposition have influence, and that their differences are related with the conditions under which they are formed. A working hypothesis is proposed to explain the growth and extinction of the beach cusps ; this is intimately related with the line of demarcation in beach slope. This line may be represented by various types of beach ridges, nips, crest lines of berms, low tide terraces, sand banks, a gentle curvature such as the convex and concave beach surface, and the zonal lines deposited by swashing water. From such criteria a new classification for beach cusps in the defined narrow sense is given and explained diagramatically. The preservation of beach cusps in sedimentary formations is also briefly stated.
The science reports of the Tohoku University. Second series, Geology = 東北大学理科報告. 地質学 29 77-A45, 1958-03-22