Synchroneity of folding and crosscutting cleavage in the Newfoundland Appalachians?

Abstract

Cleavage that cuts obliquely across folds is relatively common in the Appalachians/Caledonides and this has been interpreted as evidence for regional transpression, an interpretation which is only valid if contemporaneity of folding and cleavage formation can be demonstrated. Crosscutting cleavages in folds of the Early Silurian and older Exploits Group of the northeastern Newfoundland Appalachians are axial planar to rare, mesoscopic F 2 fold in the unconformably overlying Botwood Group on Change Islands. As an alternative to transected folds, it is argued that crosscutting cleavage relationships in the Exploits units are composite D 1- D 2 structures that represent fold superimposition.