Short Paper: Low grade metamorphism of the Welsh Basin Lower Palaeozoic succession: an example of diastathermal metamorphism?
- 16 May 1988
- journal article
- Published by Geological Society of London in Journal of the Geological Society
- Vol. 145 (3) , 363-366
- https://doi.org/10.1144/gsjgs.145.3.0363
Abstract
The Lower Palaeozoic succession of the Welsh Basin has suffered the effects of low grade metamorphism which shows features that do not accord with classical models of regional or burial metamorphism. Textural evidence demonstrates the development of greenschist facies metamorphism prior to deformation and cleavage development, while mineralogical characters indicate a low pressure facies series. In order to accommodate these features it is suggested that the area has suffered diastathermal metamorphism, in which an enhanced thermal flux develops early in the tectonic cycle in response to an extensional setting. Temperatures remained relatively high during final closure, associated with deformation of the basin sediments and consequent cleavage development. Such a model adequately resolves previously conflicting interpretations of burial- and deformation-related metamorphism.This publication has 24 references indexed in Scilit:
- Compositional controls on coexisting prehnite‐actinolite and prehnite‐pumpellyite facies assemblages in the Tal y Fan metabasite intrusion, North Wales: implications for Caledonian metamorphic field gradientsJournal of Metamorphic Geology, 1988
- Prehnite-Pumpellyite to Greenschist Fades Transition in the Karmutsen Metabasites, Vancouver Island, B.C.Journal of Petrology, 1987
- Electron microscope and microprobe analysis of chlorite–mica stacks in the Wenlock turbidites, mid Wales, U.K.Geological Magazine, 1986
- Transition from the Zeolite to Prehnite-Pumpellyite Facies in the Karmutsen Metabasites, Vancouver Island, British ColumbiaJournal of Petrology, 1986
- Grade and time of metamorphism in the Caledonide Orogen of Britain and IrelandGeological Society, London, Memoirs, 1985
- Spreading-subsidence and generation of ensialic marginal basins: an example from the early Cretaceous of central ChileGeological Society, London, Special Publications, 1984
- Petrology and geochemistry of lower to middle Ordovician igneous rocks in Wales: a volcanic arc to marginal basin transitionProceedings of the Geologists' Association, 1984
- Low‐grade metamorphism within the Welsh sector of the paratectonic CaledonidesGeological Journal, 1983
- Chlorite-mica stacks in low-strain rocks from central WalesGeological Magazine, 1982
- Pumpellyite-bearing basic igneous rocks from the Lower Ordovician of North Pembrokeshire, WalesMineralogical Magazine, 1978