4.7.5 Cline (Skifte)
4.7.5.1 Cline is the lowest-ranking formal diachronous unit. It designates a brief geological event, but one which nonetheless is reflected in a stratal succession as an important lithological or biological change. A cline may, for example, be the period of time covered by a single retreat with a new advance of an ice-front marked by an ice-marginal deposit, a flood, a storm, or a slide. When used informally, the word "cline" should retain a corresponding meaning of relative time.