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., 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 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 , 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, 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 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