The stratigraphy of the North Esk Inlier, Midlothian

Synopsis The stratigraphic succession in the North Esk Inlier is redescribed and four new formations recognized. These together form the North Esk Group. The lowest (Reservoir) formation is composed of more than 1000 m of alternating mudstones and siltstones, generally poorly fossihferous. The overlying Deerhope Formation is a sequence, up to 155 m thick, of cross-stratified sandstones, including one major conglomeratic interval. The 250 m thick sequence of highly fossiliferous siltstones forming the third (Wether Law Linn) formation contains several beds of volcanic ash, one of which is used to provide time-correlation throughout the inlier. The uppermost (Henshaw) formation is a red bed succession at least 740 m thick: apart from two fish beds it is unfossiliferous. With the exception of the Henshaw Formation which is, at least in part, Wenlock in age, the whole North Esk Group is considered to be of Upper Llandovery (Telychian) age.