Resetting of the Rb–Sr whole-rock isotope system of an ordovician microgranite during Devonian low-grade metamorphism
By: Evans, J. A
.
Material type: 
ArticleDescription: 675-681p ; Illustration.Subject(s): Reset - Rock isotope system - Ordovician microgranite - North Wales | Geological evidence - Rock isotope system - Volcanic rock - North Wales | Isotope evidence - Volcanic rock - North Wales | Absolute age - North Wales | Microgranite - Devonian low grade metamorphism
In:
Geological magazine : Vol. 126 Iss. 1-6 Year. 1989Summary: Abstract
The Bwlch y Cywion microgranite intrudes an Ordovician sedimentary sequence in northeast Snowdonia, North Wales. Its age is recorded by hornfelses within its metamorphic aureole which give an Ordovician age of 454 ± 20 Ma. The whole-rock Rb–Sr isotope systems of the intrusion, however, and of an associated ash-flow tuff and a rhyolite of the Llewelyn Volcanic Group (Caradoc), were reset during low-grade metamorphism and give Devonian ages of 392±11 Ma, 392±5 Ma, and 405 ± 6 Ma, respectively.
| Item type | Current location | Collection | Call number | Status | Date due | Barcode |
|---|---|---|---|---|---|---|
Article
|
Library and Information Centre Periodical Section | Bound Journal Collection | Not for loan | 002528_151 | ||
Serials/Scientific Journal
|
Library and Information Centre Periodical Section | Bound Journal Collection | 550 GEO (Browse shelf) | Available | 002528 |
Abstract
The Bwlch y Cywion microgranite intrudes an Ordovician sedimentary sequence in northeast Snowdonia, North Wales. Its age is recorded by hornfelses within its metamorphic aureole which give an Ordovician age of 454 ± 20 Ma. The whole-rock Rb–Sr isotope systems of the intrusion, however, and of an associated ash-flow tuff and a rhyolite of the Llewelyn Volcanic Group (Caradoc), were reset during low-grade metamorphism and give Devonian ages of 392±11 Ma, 392±5 Ma, and 405 ± 6 Ma, respectively.
There are no comments for this item.