The geological development of the southern part of the New England Fold Belt

Abstract

Two major divisions of the New England Fold Belt, Zone A and Zone B, are separated by the Peel Fault. Deposition in these two zones was probably contemporaneous (Lower Palaeozoic ‐ Lower Permian). Terminal orogenesis in both zones was also contemporaneous (Middle Permian) but whereas in Zone A deformation was only moderate, metamorphism was of burial type, and granitic emplacement was uncommon, in Zone B many rocks were severely deformed and regionally metamorphosed, and both syn‐tectonic and post‐tectonic granites are widespread. Pre‐orogenic palaeogeography is envisaged in terms of an evolving volcanic chain ‐ fore‐chain basin ‐ trench system, with an outer non‐volcanic arc developed in the Carboniferous. Cessation of movement on a subduction zone dipping westward beneath the volcanic chain is believed to have caused the Middle Permian deformation, but neither metamorphism nor the granitic rocks are directly related to subduction.