Scottish Journal of GEOLOGY Volume i, Part 3, pages 221-312 September 1965 Published for the Geological Societies of Edinburgh and Glasgow by OLIVER & BOYD LTD The Scottish Journal of Geology is a new Journal continuing and amalgamating the Transactions of the Edinburgh Geological Society and the Transactions of the Geological Society of Glasgow, and is sponsored by the councils of the two Societies. The Societies gratefully acknowledge financial help from the Carnegie Trust and the Royal Society. Certain back numbers of the Trans. Edinb. geol. Soc. and the Trans, geol. Soc. Glasg. are still available. A list of prices and parts may be had on application to Oliver & Boyd Ltd., Tweeddale Court, 14 High Street, Edinburgh 1. Editors G. Y. CRAIG R. A. EDEN W. E. TREMLETT A. C. MCLEAN DOUGLAS GRANT Front Page Illustration Hutton's unconformity, Siccar Point Copyright © Scottish Journal of Geology 1965 Reproduction of authors' summaries is authorised Prices for non-members Volume Subscription £4 Single copies 30s. or $12 or $5 Scottish Journal of GEOLOGY Editors G. Y. CRAIG R. A. EDEN W. E. TREMLETT A. C. MCLEAN DOUGLAS GRANT Volume I 1965 Published for the Geological Societies of Edinburgh and Glasgow by OLIVER & BOYD LTD The Scottish Journal of Geology is a new Journal continuing and amalgamating the Transactions of the Edinburgh Geological Society and the Transactions of the Geological Society of Glasgow, and is sponsored by the councils of the two Societies. The Societies gratefully acknowledge financial help from the Carnegie Trust and the Royal Society. Copyright © Scottish Journal of Geology 1965 Reproduction of authors' summaries is authorised Printed in Great Britain by Oliver and Boyd Ltd., Edinburgh CONTENTS VOLUME I, PART 1 HARRY, w. T. The form of the Cairngorm Granite Pluton ... 1 MYKURA, w. The age of the lower part of the New Red Sandstone of South-West Scotland 9 O'HARA, M. J. Primary magmas and the origin of basalts ... 19 WEEDON, DOUGLAS s. The layered ultrabasic rocks of Sgurr Dubh, Isle ofSkye . 41 READ, w. A. Shoreward facies changes and their relation to cyclical sedimentation in part of the Namurian east of Stirling, Scotland . 69 MILLER, j. A. AND p. A. MOHR. Potassium-argon age determinations on rocks from St Kilda and Rockall ....... 93 VOLUME I, PART 2 RUST, B. R. The stratigraphy and structure of the Whithorn area of Wigtownshire, Scotland 101 LUMSDEN, G. I. AND A. DAVIES. The buried channel of the River Nith and its marked change in level across the Southern Upland Fault . 134 BROWN, P. E., D. YORK, N. J. SOPER, J. A. MILLER, R. M. MACINTYRE AND E. FARRAR. Potassium-argon ages of some Dalradian, Moine and related Scottish rocks ... 144 MUNRO, M. Some structural features of the Caledonian granitic complex at Strontian, Argyllshire .152 MYKURA, w. White trap in some Ayrshire Coals . .176 NEVES, R., W. A. READ AND R. B. WILSON. Note on recent spore and goniatite evidence from the Passage Group, of the Scottish Upper Carboniferous succession ........... 185 MORTON, NICOL. The Bearreraig Sandstone Series (Middle Jurassic of Skye and Raasay) 189 JOHNSON, M. R. w. AND A. L. HARRIS. Is the Tay Nappe post-Arenig? . 217 IV CONTENTS VOLUME I, PART 3 JARDINE, w. G. Note on a temporary exposure in central Glasgow of Quaternary sediments with slump and load structures . 221 WTLSON, c. D. v. A marine magnetic survey near Lerwick, Shetland Isles 225 RUST, B. R. The sedimentology and diagenesis of Silurian turbidites in South-east Wigtownshire, Scotland ...... 231 SISSONS, j. B. AND D. E. SMITH. Peat bogs in a Post-glacial sea and a buried raised beach in western Carse of Stirling ..... 247 CHEENEY, R. F. AND D. w. MATTHEWS. The structural evolution of the Tarskavaig and Moine nappes in Skye ...... 256 MERCY, E. L. P. AND M. j. O'HARA. Websterite from Glenelg, Inverness-shire 282 BRAND, p. j. New Lower Cambrian fossil localities in North-west Scotland 285 BOWES, D. R. The West Glasgow Earthquake—7 March 1964 . 288 BOWES, D. R. AND s. G. KHOURY. Successive periods of basic dyke emplace­ ment in the Lewisian complex, south of Scourie, Sutherland . 295 GIBB, FERGUS G. F. A note on the age relationships between Sgurr Dubh Ultrabasic Laccolite and Cuillin Gabbros ..... 300 DALZIEL, IAN w. D. AND RICHARD L. BROWN. The structural dating of the sillimanite-grade metamorphism of the Moines in Ardgour (Argyll) and Moidart (Inverness-shire) . 304 .