The Late-Glacial History of the Firth of Clyde: A Reply

Abstract

The 'flaws' in the paper by Gemmell (I973) commented on by Gray are examined and assessed. A close reappraisal of the results obtained in Arran using Andrews's (1970) nomogram is carried out, particular attention being paid to the assumptions of a reference level dated at 5500 years B.P. and of a continuous uplift since c. 13 500 years B.P. The probable errors resulting from these assumptions are suggested to be of a maximum size of 600-700 years, the original nomogram tending to underpredict the age of late-glacial shorelines. It seems likely that the errors in the proposed lateglacial chronology are rather lower than Gray implies, low enough at least for future workers to use the chronology as a framework for further study. GRAY'S comments on the author's recent paper (Gemmell, I973) question several aspects of that publication, particularly the use of a nomogram produced by Andrews (1970) to derive a tentative dating sequence in the Island of Arran. Gray's paper gives the author the opportunity to clarify some points and to rectify some minor omissions in his paper. It is proposed to consider various aspects of the original paper in the same order as they are raised by Gray. ANLEY, G. (I95I) 'The ra ge of variation of the British climate', GeogrlJ. II7, 43-68 ARTHINUSSEN, M. (1960) 'Coast and fiord area of Finmark (with remarks on other districts)' in HOLTEDAHL, O. (ed.) e logy of Norway, 416-29 (Oslo and London) ORNER, N. A. (1969) 'The Late Quat rnary history of the Kat egatt Sea and the Swedish west coast: deglaciation, shorelevel displacement, chronology, isostasy an eustasy', Sver. geol. Unders. Afh. C., 640 HOTTON, F. W., BLUNDEL , D. J. and WILLIAMS, R. E. G. (1970) 'Birmingham University radiocarbon dates IV', Radioarbon 12, 385-99 HOTTON, F. . and WILLIAMS, R. E. G. (1973) 'Birmingham University radiocarbon dates VII', Radiocarbon 15, 451-68 I SONS, J. B. (I962) 'A rein erpretation of the literature on late-glacial shorelines in Scotland with particular reference o the Fo th rea', Trans. Edinb. geol. Soc. I9, 83-99 I SONS, J. B. (1965) 'Quaternary' in CRAIG, G. Y. (ed.) Geology of Scotland, 467-503 (Edinburgh) I SONS, J. B. (i967 ) 'Glacial stages and radiocarbon dates', Scott. J. Geol. 3, 375-81 I SONS, J. B. (i967b) The evolution of Scotland's scenery (Edinburgh) I SONS, J. B. (I967c) 'Comments on the paper by F. M. SYNGE and N. STEPHENS in Transactions no. 39', Trans. Inst. r. Geogr. 42, 163-8 I SONS, J. B. (I969) 'Drift stratigra hy nd buried morphological features in the Grangemouth-Falkirk-Airth area, central cotland', Trans. Inst. Br. Geogr. 48, 19-50 I SONS, J. B. (1972) 'Dislocation and non-uniform uplif of aised shore ines i the western part of the Forth valley', Trans. Inst. Br. Geogr. 55, 145-59 I SONS, J. B. (1974) 'A L te-gla ial ice-cap in he central G ampians, Scotland', Trans. Inst. Br. Geogr. 62, 95-114 I SONS, J. . and BROOKS, C. L. (I971) 'D ti g of early post-glacial land and sea level changes in the western Forth valley', ature Phys. Sci. 234, 124-7 TEPHE S, N. (I968) 'Late-gl cial and post-glacial s orelines in Ireland and south-west Scotland' in MORRISON, R. B. and RIGHT JR., H. E. (eds) Means of co relati of Quaternary successions, 437-56 YNGE, F. M. and STEPHENS, N. (I967) 'A reply to J. B. Sissons's comments', Trans. Inst. Br. Geogr. 42, I69-73 he late-glacial histo y of the Firth of lyde: a reply 132 J.M.GRAY This content downloaded from 157.55.39.120 on Mon, 05 Sep 2016 05:53:51 UTC All use subject to http://about.jstor.org/terms Late-glacial history Of the tirtn oJ (lyae I33