also: けんそう
key bed; marker bed
Geological term for a distinctive, widespread rock layer used as a reference for stratigraphic correlation.
We correlated the ages of the strata using a volcanic ash key bed.
In this region, a tuff layer that serves as a key bed is widely distributed.
Standard kanji form; the reading かぎそう is the most common.
Alternate reading; less common but still used in geological contexts.
Compound of 鍵 (key) and 層 (layer, stratum), literally 'key layer'. The term is a direct calque from English 'key bed'.