Trewin, N. H. and Hurst, A. (Eds.) 2009. Excursion Guide to the Geology of East Sutherland and Caithness. Dunedin Academic Press, Edinburgh The text for this demonstration page was provided by the Aberdeen Geological Society. Find out more information about the Aberdeen Geological Society's field guides on their website.
Excursion guide to the geology of East Sutherland and Caithness
Edited by N. H. Trewin and A. Hurst
Second Edition
Aberdeen Geological Society
Published by Dunedin Academic Press Ltd Hudson House 8 Albany Street Edinburgh EH1 3QB Scotland www.dunedinacademicpress.co.uk
ISBN 978–1-906716–01–1
© 2009 Aberdeen Geological Society
The first edition of this book was published for The Geological Society of Aberdeen in 1983 by Scottish Academic Press (ISBN 0 7073 0731 7)
The rights of Nigel Trewin, Andrew Hurst and the named contributors to be identified as authors of this Work has been asserted by them in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means or stored in any retrieval system of any nature without prior written permission, except for fair dealing under the Copyright, Designs and Patents Act 1988 or in accordance with a licence issued by the Copyright Licensing Society in respect of photocopying or reprographic reproduction. Full acknowledgment as to author, publisher and source must be given. Application for permission for any other use of copyright material should be made in writing to the publisher.
British Library Cataloguing In Publication Data
A catalogue record for this book is available from the British Library
Design and pre-press production by Makar Publishing Production, Edinburgh
Printed and bound in Poland, produced by Hussar Books
Contents
Acknowledgements and Society information
Editorial introduction
Geological history of East Sutherland and Caithness — N.H. Trewin
Excursion Planner
Excursions
1. The Triassic and Lower Jurassic of Golspie N.H. Trewin
2. Bathonian to Oxfordian strata of the Brora area A. Hurst
3. The Upper Jurassic of the Helmsdale area A.C. McDonald & N.H. Trewin
4. The Lower Old Red Sandstone and Helmsdale Granite of the Ousdale area N.H. Trewin
5. The Old Red Sandstone of Caithness N.H. Trewin
6. Kildonan gold C.M. Rice
References
Acknowledgements
The Aberdeen Geological Society is pleased to thank the following for their support of the Society and for generous financial contributions towards the production of this guide; the Petroleum Exploration Society of Great Britain, Senergy through David Harrison, and HRH through Henry Allen.
The sustaining members of Aberdeen Geological Society, HRH, Senergy and BP are also thanked for their support of the annual programme of lectures and other activities of the Society.
Rob Strachan and Ian Alsop are thanked for discussion on basement geology, and making available relevant sections of the Moine excursion guide (currently in press). Phil Gurr for information on the Caithness flagstone industry. Barry Fulton for redrafting many of the figures from the first edition of this work, and creating figures for new excursions. Walter Ritchie for assistance with photography.
The Geological Society of Aberdeen
Membership of the Society is open to all with an interest in geology. A programme of lectures, excursions and social events is organised each year. For further details visit the Society website or write to:
The Secretary Aberdeen Geological Society c/o School of Geoscience Department of Geology and Petroleum Geology Meston Building King's College Aberdeen AB24 3UE
The Petroleum Exploration Society of Great Britain
The Petroleum Exploration Society of Great Britain (PESGB) was set up in 1964 as a non-profit making organisation and is a registered charity. It has a membership of 5,500 individual members and over 80 Sustaining (company) members.The object of the Society is to promote, for the public benefit, education in the scientific and technical aspects of petroleum exploration.
Monthly meetings are held in London and Aberdeen. Distinguished represen-wwtatives from industry and academia are invited to present a talk on a wide variety of topics associated with petroleum exploration.
In addition to organising the biennial PETEX Conference and Exhibition, the PESGB holds other conferences, seminars and courses, some in conjunction with the Society's Special Interest Groups (SIGs), and others jointly with other similar Societies. Regular events include: Geophysics seminars, Data Management conferences and courses; North Sea courses; DEVEX Conference & Exhibition; HGS/PESGB Africa Conference; PROSPEX Fair and the Petroleum Geology Conferences (PGC).
The PESGB also sponsors and supports other activities relevant to its objectives. In 2008 it introduced a Scholarship Award Scheme for MSc students studying an Earth Science degree course.
The Society runs field trips to areas of petroleum and geological interest, both in the UK and abroad, and organises occasional core workshops.
The Society produces a monthly Newsletter and an annual Membership Directory, which are distributed to all members. Recent additional benefits to members include: each new edition of The North Sea Map, the Millennium Atlas DVD, and DVDs of the PGC IV, V and VI Proceedings.
There are four classes of members — Active, Associate, Student and Sustaining. The annual membership subscription is £25.
For further information about the PESGB, please contact the PESGB Office, 5th Floor, 9 Berkeley Street, London W1J 8DW, Tel: +44 (0)20 7408 2000, Fax: +44 (0)20 7408 2050, email: pesgb@pesgb.org.uk; web: www.pesgb.org.uk.
Addresses of authors
A. Hurst, C.M. Rice and N.H. Trewin Department of Geology and Petroleum Geology School of Geosciences University of Aberdeen Meston Building King's College Aberdeen AB24 3UE
A.C. McDonald Roxar Oslo Hoffsveien 1C 6th Floor, PO Box 165 0275 Oslo Norway
Editorial introduction
The Jurassic rocks of the Brora–Helmsdale area form a coastal strip from Golspie in the south to Helmsdale in the north and are bounded on the landward side by the Helmsdale Fault. To the west of the fault the country rocks consist of Moinian metamorphics intruded by the late Caledonian Helmsdale Granite, and these rocks are overlain unconformably by the Old Red Sandstone of Devonian age.
This area has an interesting and varied geological history and has been the focus of considerable geological research from the early work of Murchison (1827) right up to the present day. Early interest was stimulated by the presence of Jurassic coal at Brora, which was mined from as early as 1598 until 1974. Bricks were made from Jurassic clays at Brora but the site of the brickpits has now been landscaped. A brief 'gold rush' to Kildonan took place in 1868, and gold can still be panned at Baille an Or.
Numerous geological field parties visit the area each year, usually to look at the spectacular Upper Jurassic 'Boulder Beds' which were deposited in deep water on the downthrow side of the Helmsdale Fault at a time when the fault was active. Other geologists are drawn to the area to see the lower part of the Jurassic succession, which has affinities to the rocks of the Beatrice Oilfield whose production platforms can be seen some 12 miles off Helmsdale on a clear day. To the north of Helmsdale lie the famous Old Red Sandstone deposits of Caithness, dominated by cyclic lake deposits with spectacular faunas of fossil fish.
The purpose of this volume is twofold; the first being to introduce the reader to the geology of the area by means of a chapter on the geological history of the region, and the second to provide a series of excursions to illustrate the geology. Some previous knowledge of geology is generally assumed, but all excursions are intended to provide interest for the amateur geologist, student and professional geologist. A checklist of major topics covered in the excursions, together with details of restricted access to some localities, is given in the Excursion Planner section of this guide. A geological map of the area is included as
A range of excursions is provided which would occupy a party for a week or more. There are good hotels, guest houses, caravans, youth hostels and camping sites in the area, details of which can be obtained from the Tourist Information outlets. The towns of Golspie, Brora and Helmsdale are convenient for the Jurassic outcrops, and Wick and Thurso for the Devonian, but all excursions are within day-trip range of Helmsdale. Mention must be made of the excellent geological exhibition at the Orcadian Stone Company in Golspie. The Timespan Heritage Centre exhibition beside the old bridge in Helmsdale has good exhibits relating to local historyand the history of the gold rush of 1868.
In following the enclosed excursions, always heed the Country Access Code by sensible parking, closing gates and avoiding growing crops and lambing ewes. Also follow the Scottish Fossil Code published by Scottish Natural Heritage. Seek permission to visit exposures in farmland and quarries, and take extreme care crossing the railway line. Do not hammer needlessly at any outcrops, or excavate exposures in a search for fossils; others will come after you wishing to see and photograph outcrops. Specimens can usually be obtained from loose material. In particular, do not hammer or remove bedrock at any Sites of Special Scientific Interest; SSSI — these are noted in the text. Never ignore personal safety, particularly in cliff and moorland areas. The weather in the area can be severe and change very quickly.
Since the publication of the first edition of this guide in 1993 there have been a number of changes in the area affecting access and exposure. Hence some of the original localities have been omitted and others added.
We hope that some of the different views and emphasis provided in the excursions will prove stimulating for the reader. Individual authors are responsible for the scientific content of each excursion, and excursions should be referenced under the author's name.
Nigel H. Trewin, Andrew Hurst — April 2009