Synthesis of the Caledonian Rocks of Britain

355 Pages·1986·13.41 MB·English

by  R. E. Bevins, W. Gibbons, A. L. Harris (auth.), D. J. Fettes, A. L. Harris (eds.)

Synthesis of the Caledonian Rocks of Britain
NATO ASI Series
Advanced Science Institutes Series
A series presenting the results of activities sponsored by the NATO Science Committee,
which aims at the dissemination of advanced scientific and technological knowledge,
with a view to strengthening links between scientific communities.
The series is published by an international board of publishers in conjunction with the
NATO Scientific Affairs Division
A Life Sciences Plenum Publishing Corporation
B Physics London and New York
C Mathematical D. Reidel Publishing Company
and Physical Sciences Dordrecht, Boston, Lancaster and Tokyo
D Behavioural and Social Sciences Martinus Nijhoff Publishers
E Engineering and The Hague, Boston and Lancaster
Materials Sciences
F Computer and Systems Sciences Springer-Verlag
G Ecological Sciences Berlin, Heidelberg, New York and Tokyo
Series C: Mathematical and Physical Sciences Vol. 175
Synthesis of the
Caledonian Rocks of Britain
edited by
D. J. Fettes
British Geological Survey, Edinburgh, U.K.
and
A. L. Harris
Department of Geological Sciences,
University of Liverpool, Liverpool, UK
D. Reidel Publishing Company
Dordrecht / Boston / Lancaster / Tokyo
Published in cooperation with NATO Scientific Affairs Division
Proceedings of the NATO Advanced Study Institute on
Synthesis of the Caledonian Rocks of Britain
United Kingdom
August 19-5eptember 2, 1984
Library of Congress Cataloging in Publication Data
NATO Advanced Science Institute on Synthesis of the Caledonian Rocks of Britain, U.K.
(1984: Cardiff, South Glamoren, etc.)
Synthesis of the Caledonian rocks of Britain.
(NATO ASI series. Series C, Mathematical and physical sciences; vol. 175)
"Proceedings of the NATO Advanced Study Institute on Synthesis of the Caledonian
Rocks of Britain, U.K., August 19-5eptember 2, 1984"-T.p. verso.
Includes index.
1. Geology, Stratigraphic-Paleozoic-Congresses. 2. Geology-Great Britain-Con-
gresses. I. Fettes, D. J. II. Harris, A. L. (Anthony Leonard) III. Title. IV. Series:
NATO ASI series. Series C, Mathematical and physical sciences; vol. 175.
QE654.N37 1984 551. 7'2'0941 86-4972
lSBN-13: 978-94-010-8568-7 e-1SBN-13: 978-94-009-4654-5
001: 10.1007/978-94-009-4654-5
Published by D. Reidel Publishing Company
P.O. Box 17, 3300 AA Dordrecht, Holland
Sold and distributed in the U.S.A. and Canada
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D. Reidel Publishing Company is a member of the Kluwer Academic Publishers Group
All Rights Reserved
© 1986 by D. Reidel Publishing Company, Dordrecht, Holland.
Softcover reprint of the hardcover 1st edition 1986
No part of the material protected by this copyright notice may be reproduced or utilized
in any form or by any means, electronic or mechanical, including photocopying, recording
or by any information storage and retrieval system, without written permission from the
copyright owner.
CONTENTS
Preface vii
List of Contributors xi
List of Participants xiii
The Caledonian Rocks of Britain / R.E. Bevins, W. Gibbons,
A.L. Harris and G. Kelling 1
A Geotraverse through the Caledonides of \~ales / M. G. Bassett,
R.E. Bevins, W. Gibbons and M.F. Howells 29
Field Guide to the Lake District and Southern Uplands /
G. Kelling, W.S. McKerrow and P. Stone 77
The Caledonian Geology of the Scottish Highlands / A.L. Harris,
D.J. Fettes, W.G. Henderson, J.L. Roberts, J.E. Treagus,
A.J. Barber, M.P. Coward and R. Strachan 113
A Comparison of the Lower Palaeozoic Volcanic Rocks on Either
Side of the Caledonian Suture in the British Isles /
C.J. Stillman 187
The Tectonic Setting of the Southern Uplands / W.S. McKerrow 207
The Contribution of the Finnmarkian Orogeny to the Framework
of the Scandinavian Caledonides / D.M. Ramsay and
B.A. Sturt 221
The Moine Thrust Zone: A Comparison with Appalachian Faults
and the Structure of Orogenic Belts / R.D. Hatcher Jr. 247
The 110ine Thrust Structures / M.P. Coward 259
Some Aspects of Geophysics in the Caledonides of the UK /
R.T. Haworth 281
The Caledonian Geology of the Scottish Highlands / D.J. Fettes,
A.L. Harris and L.M. Hall 303
Subject Index 335
PREFACE
The Advanced Science Institute on which this publication is based
took the somewhat unusual form of a geological field symposium held
during late August 1984. It was designed to demonstrate to experienced
earth scientists from the North Atlantic area the full range of
geological phenomena encountered in the British Caledonian rocks.
The ASl travelled from South Wales to the far northwest of Scotland
by the route shown on the map and in doing so examined sedimentary,
igneous and metamorphic rocks from Pembrokeshire (Dyfed), Cardigan
(Ceridigian), Snowdonia, Anglesey, the English Lake District and the
Southern Uplands and Highlands of Scotland. Thus the fifty or so
participants in the ASl studied the geological history and major
structures of rocks exposed on either side of the supposed Lower
Palaeozoic Iapetus Ocean the British sector of which closed to the
south of the present Southern Uplands.
Wales (1-5) afforded insight into the nature of the late
Precambrian basement of England and Wales and the relationship of
sedimentary and volcanic cover sequences to this basement. The
Ordovician sequence in Wales is a sample of the volcanic rocks typical
of a marginal basin, and were examined in Pembrokeshire and Snowdonia.
The English Lake District (6) displays rocks from an island arc also
of Ordovician age.
To the north of the suture where the two sides of the ocean came
together is an accretionary prism of turbiditic and pelagic sediments
locally resting against slivers of the ocean crust on which they were
laid down in the late Ordovician and early-mid Silurian. These rocks
now compirse the Scottish Southern Uplands (7-8) which on their north-
west side are flanked by the Ballantrae Complex which occurs near
Girvan and which is thought by some workers to be a fragment of an
obducted ophiolite complex.
Whereas the rocks of Wales, the Lake District and the Southern
Uplands comprise the paratectonic Caledonides, those to the north of
the Highland Boundary Fault comprise the orthotectonic zone. The
metamorphic rocks of the Scottish Highlands (9-14) offer a strong
contrast to the rocks in the paratectonic zone although many of the
geological events affecting the opposite sides of the ocean were
viii PREFACE
approximately contemporary.
The orthotectonic zone comprises strongly metamorphosed and
deformed rocks of the Dalradian (late Precambrian to mid Cambrian) and
Moine (mid to late Proterozoic) which were deposited on a basement of
Archaean (Lewisian) >2500 Ma rocks, comparable with the ancient
basement of Greenland and Laurentian North America.
To the northwest the Caledonian rocks are limited by a major
thrust zone the study of which formed the final stage of the field
symposium. The traverse made by the symposium across the Highlands
towards the thrust zone extended from the Highland Boundary Fault,
a major fracture, across classic outcrops of metamorphic Dalradian
rocks and major granites and beyond the Great Glen Fault into the
Northern Highlands, where complexely deformed and highly metamorphosed
Moine rocks are splendidly exposed.
The field symposium was particularly appropriate because it
brought together earth scientists from the USA, Canada, France, the
British Isles, Spain, Belgium, Norway and Sweden - all countries in
which Caledonian rocks are of major importance. Thus an opportunity
was offered for discussions between, say, geologists skilled and
experienced in Appalachian problems and those conversant with similar
problems in Europe. They came together in Britain where Caledonian
rocks were first described and were exposed to the stimulus of type
localities and classic relationships.
Part of this publication comprises the guide to the various
localities visited by the field symposium while the remainder, in the
form of written papers, e·mbodies the several lectures and discussions
which were a feature of every evening during the symposium. All the
field guides and the papers have been extensively revised in the light
of the experience and discussions during the field symposium, a process
which to some extent accounts for the delay in the publication of this
work.
All the participants and particularly the director of the
symposium and the editors of this volume are appreciative of the
unique opportunity offered by the NATO Scientific Committee which
enabled this meeting to take place. The editors would like to record
their appreciation of the help and support not only of the contributors
but of all the participants. It is a matter of great sadness that
they record the death of Professor David Wones of the Virginia
Polytechnic Institute whose friendship and contributions during the
meeting did much to make the symposium a success.
D.J. Fettes A.L. Harris
(3) l1ineraries
~---~ Fault
-....--....-- Thrust
-_ ••• -_ CINHNsaoeolreruntcdthyhoenen~ririanann n le i lmdidmgeietefi fot o ororfmfm fs a~siaguilt\.doljnonlninifafi cl0r a.dan ntB tl ock
-
Map showing the main divisions of the British Caledonides and the
generalised route of the field itineraries.
LIST OF CONTRIBUTORS
Dr. A.J. Barber, Department of Geology, Royal Holloway and Bedford
Colleges, Egham Hill, Egham, Surrey, U.K.
Dr. M.G. Bassett, Department of Geology, National Museum of Wales,
Cathays Park, Cardiff CFl 3NP, U.K.
Dr. R.E. Bevins, Department of Geology, National Museum of Wales,
Cathays Park, Cardiff CFl 3NP, U.K.
Professor M.P. Coward, Department of Earth Sciences, University of
Leeds, Leeds LS2 9JT, U.K.
Dr. D.J. Fettes, British Geological Survey, Murchison House, West
Mains Road, Edinburgh EH9 3LA, Scotland.
Dr. W. Gibbons, Department of Geology, University College of Wales,
Cardiff CFl 3NP, Wales.
Professor L.M. Hall, Department of Geology and Geography, University
Of Massachusetts, Amherst, Mass. 01003, U.S.A.
Dr. A.L. Harris, Department of Geology, University of Liverpool,
P.O. Box 147, Liverpool L69 3BX, U.K.
Professor R.D. Hatcher, Dept. of Geology, University of South
Carolina, Columbia, South Carolina 29208, U.S.A.
Dr. R.T. Haworth, British Geological Sciences, Nicker Hill, Keyworth,
Nottingham NG12 5GG, U.K.
Dr. M.F. Howells, British Geological Survey, Bryn Eithyn Hall,
Llanfarian, Aberystwyth, Dyfed SY23 4BY, Wales.
Professor G. Kelling, Department of Geology, University of Keele,
Keele, Staffs St5 5BG, U.K.
Dr. W.S. McKerrow, Department of Geology & Mineralogy, University of
Oxford, Parks Road, Oxford OXl 3PR, U.K.
Professor D.M. Ramsay, Department of Geology, University of Dundee,
Dundee DDl 4HN, Scotland.
Dr. J.L. Roberts, Department of Geology, University of Newcastle,
Newcastle upon Tyne NEl 7RU, U.K.
Professor C.J. Stillman, DepartmentofiGeology, Trinity College,
Dublin 2, Eire.
Dr. R. Strachan, Department of Geology, Oxford Polytechnic, Oxford, UK
Professor B.A. Sturt, Geologisk Institutt Avd. A., Bergen University
Allegt 41, 5014 Bergen, Norway.
Dr. J. Treagus, Department of Geology, University of Manchester,
Manchester, U.K.
Dr. W.G. Henderson, British Geological Survey, Murchison House, West
Mains Road, Edinburgh EH9 3LA, Scotland.
Dr. P. Stone, British Geological Survey, Murchison House, West Mains
Road, Edinburgh EH9 3LA, Scotland.
LIST OF PARTICIPANTS
Dr. T.B. Anderson, Department of Geology, Queen's University of Belfast
Belfast BT7 lNN, Northern Ireland.
Dr. P.G. Andreasson, Department of Mineralogy & Petrology, University
of Lund, Solvegatan 13, S-233 62 Lund, Sweden.
Dr. A.J. Barber, Department of Geology, Royal Holloway and Bedford
Colleges, Egham Hill, Egham, Surrey TW20 OEX, U.K.
Dr. M.G. Bassett, Department of Geology, National Museum of Wales,
Cathays Park, Cardiff CFl 3NP, Wales.
Dr. D. Bates, Department of Geology, University College of Wales,
Aberystwyth, Dyfed, Wales
Dr. R.E. Bevins, Department of Geology, National Museum of Wales,
Cathays Park, Cardiff CFl 3NP, U.K.
Dr. D. Bruton, Palaeontologisk Museum, Universitetet i Oslo,
Sars Gate 1, Oslo 5, Norway.
Dr. I. Bryhni, Mineralogisk-Geologisk Museum, Universitetet i Oslo,
Sars Gate 1, N-Oslo 5, Norway.
Dr. B. Cabanis, Universite Paris VI, Lab de Geochimie Comparee et
Systematique, Tour 16-26 3 Etage, 4 Place jussieu, 75320 Paris
Cedex OS, France.
Professor M.P. Coward, Department of Earth Sciences, University of
Leeds, Leeds LS2 9JT, U.K.
Dr. D. Dallmeyer, Department of Geology, University of Georgia,
Athens 30334, Georgia, U.S.A.
Dr. A.A. Drake Jr., United States Geological Survey, Mail Stop 926,
Reston, Virginia 22092, U.S.A.
Dr. D.J. Fettes, British Geological Survey, Murchison House, West
Mains Road, Edinburgh EH9 3LA, Scotland.
Dr. L. Fyffe, Dept. of Natural Resources, Mineral Resources Division,
College Hill Road, P.O. Box 6000, Fredericton, N.B., Canada E3B5Hl
Dr. D.G. Gee, Geological Survey of Sweden, Box 670, S-75l 28 Uppsala,
Sweden.
Professor F. Geukens, Katholieke Universiteit Leuven,
Redingenstraat 16, 3000 Leuven, Belgium.
Dr. W. Gibbons, Department of Geology, University College of Wales,
Cardiff CFl 3NP, Wales.
Dr. P.L. Guillot, Dept des Sciences de la Terre, University d-Orleans,
45046 Orleans cedex, France.
Dr. L. Gunderson, United States Geological Survey, Denver, Colorado,
U.S.A.
Professor L.M. Hall, Department of Geology and Geography, University
of Massachusetts, Amherst, Mass. 01003, U.S.A.
Dr. A.L. Harris, Department of Geology, University of Liverpool,
P.O. Box 147, Liverpool L69 3BX, U.K.
Professor R.D. Hatcher, Dept. of Geology, University of South Carolina,
Columbia, South Carolina 29208, U.S.A.
xill