Do Neoproterozoic tuffs (Moine) calc-silicate rocks represent metamorphosed tuffs? A geochemical re-appraisal
Abstract
Following the identification of grey quartz–albite–chlorite–calcite–muscovite rocks in Meso- to Neo-proterozoic sequences in Scotland as metamorphosed tuffs of intermediate composition, it has been shown that this lithology will generate calc-silicate rocks at higher metamorphic grades. Both rock types occur as thin beds with sharp contacts with their host, occur as multiple beds in isolated suites, and share chemical compositions suggestive of volcanic sources with tholeiitic andesite affinities. The failure to recognise calc-silicate rocks as tuffs might explain the apparent scarcity of volcanogenic material through c. 220 million years of early Earth history in Scotland.
Citation
Batchelor , R A 2018 , ' Do Neoproterozoic tuffs (Moine) calc-silicate rocks represent metamorphosed tuffs? A geochemical re-appraisal ' , Earth and Environmental Science Transactions Of The Royal Society Of Edinburgh , vol. 107 , no. 4 , pp. 333-349 . https://doi.org/10.1017/S1755691018000063
Publication
Earth and Environmental Science Transactions Of The Royal Society Of Edinburgh
Status
Peer reviewed
ISSN
1755-6910Type
Journal article
Description
This work was carried out during the tenure of a Leverhulme Emeritus Fellowship (Grant No. EM/20343) held by the author. The grey tuffs were sampled by the author while employed as a Research Fellow funded by a Leverhulme Trust Research Grant (Grant No. F/00268/AB) awarded to Dr. Tony Prave, University of St. Andrews.Collections
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