Coordinates. The Rhynie chert is a Lower Devonian sedimentary deposit exhibiting extraordinary fossil detail or completeness (a Lagerstätte). It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located some 700 m away.The Rhynie chert contains exceptionally preserved plant, fungus, lichen and animal material …

Oolite or oölite (egg stone) is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Ancient Greek word ᾠόν for egg.Strictly, oolites consist of ooids of diameter 0.25–2 millimetres; rocks composed of ooids larger than 2 mm are called pisolites.The term oolith can refer to oolite or individual ooids.