An Occurrence of Regionally Metamorphosed Pre-Cambrian Schists in South-West Pembrokeshire

Abstract

Recent research work has revealed an area of regionally metamorphosed Pre-Cambrian schists (previously undescribed) in south-west Pembrokeshire. The name “Dutch Gin Schists” is proposed for this newly described group of rocks. The Johnston Plutonic Series (Dimetian) are seen to be intruded into these schists, and the nature of the intrusive contact is described. The structure and petrology of the schists, and the nature of diorites adjacent to the contact and that seen elsewhere in the igneous mass is compared, and a suggestion made regarding the age of the foliation. A comparison is made with the Pre-Cambrian metamorphosed rocks of Malvern, Shropshire, and Anglesey.