New evidence for the age of the Manx Group, Isle of Man

Abstract

Summary Acritarch assemblages which are sufficiently well preserved to date the rocks in which they occur have been obtained from five formations in the Manx Group of the Isle of Man. The acritarch evidence indicates that the Niarbyl Flags, Glen Dhoo Flags, and Lonan Flags are most probably Tremadoc in age, the last two very late Tremadoc. The Maughold Banded Group is probably Arenig and the Lady Port Banded Group is probably either late Arenig or early Llanvirn. The minimum time interval represented by the Manx Group is late Tremadoc to late Arenig and a correlation of the Manx Group with the Skiddaw Group in NW England and the upper part of the Ribband Group in SE Ireland is proposed. The contemporaneous volcanic rocks in the Manx Group at Peel, here named the Peel Volcanic Formation, are probably upper Arenig in age.