Further Observations on a

Quaternary Deposit at Bowleaze

Cove, near Weymouth, Dorsetby the late A. G. DAVIS; and J. N. CARRECK

Received 31 May 1957

CONTENTS

I. INTRODUCTION

2. THE EARLY HOLOCENE LoAM

3. CONCLUSIONS

ACKNOWLEDGMENTS

REFERENCES

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ABSTRACT: Some new faunal records for the Early Holocene Loam of BowleazeCove, described by the authors in 1955, are listed, together with new molluscan recordsfrom the Holocene tufa of Blashenwell, Dorset, with which the Bowleaze deposit hasbeen compared and contrasted. Conclusions are drawn, confirming those of the formerpaper, and the similarity between the Bowleaze fauna and that of the early Post­Glacial deposits at Nazeing, Essex, is noted.

1. INTRODUCTION

SINCE THE publication of a detailed account of the Quaternary deposits atBowleaze Cove near Weymouth, Dorset, by the present writers (Carreck &Davis, 1955), additional evidence has become available, permitting somefurther inferences to be made concerning one of these deposits, the EarlyHolocene Loam (op. cit., 78-82).

2. THE EARLY HOLOCENE LOAM

Recent collecting from this horizon, at the original site in the cove, hasresulted in the discovery of important additions to the faunal list, as follow.

(a) Mammalia

Clethrionomys sp. One right m 2• This confirms the tentative recognition ofa species of Bank Vole from the deposit, published in 1955 (op. cit., 80).

(b) Mollusca

Acicula fusca (Montagu). Five examples. The species is very rare in the

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QUATERNARY DEPOSIT AT BOWLEAZE COVE 121

living state in Dorset; fossil examples were known previously from theBlashenwell tufa (most probably of Atlantic age) and Bronze Age burialsat Stockbridge, Hants.

Delete Columella edentula (Draparnaud) (ibid., 80) and substituteColumella columella (Benz). Six further examples. These more completespecimens show that the earlier identification was in error. C. columella,which is perhaps a sub-species of C. edentula, is extinct in Britain and hasnot been recorded previously from the Dorset Quaternary, but is knownto occur in the Late Pleistocene or earliest Holocene of Portfield, nearChichester. It is best known from its occurrence in the 'Arctic' Beds ofPonder's End (Middlesex), Nazeing (Essex) and Barnwell Station,Cambridge. At Nazeing it is found to have lived from the Late Pleistocene(Last Glaciation), C14 dating >- 20,000 years B.P., to the Early Boreal,Zone Y, during which it died out (Allison, Godwin & Warren, 1952, 190and 235). Burchell & Davis (1957, 167) consider, on the basis of molluscanevidence, that at Aylesford, Kent, this form ranges from Late Glacial(Older Dryas Time) to the end of the Boreal. Therefore, although character­istic of sub-arctic climatic environments in Britain during the Last Glacia­tion, it persisted in this country during progressive amelioration of climate,into the BoreaLVertigo substriata (Jeffreys). Two examples. A species previously known inDorset only from the Blashenwell tufa. At the present it is typical of themore humid north-western parts of the British Isles.V. genesii Gredler (? = V. parcedentata (Braun) ). Three examples. Thereare no previous records of this for Dorset, but it is present in the Pleisto­cene of West Wittering, Sussex. It occurs in some Pleistocene and EarlyHolocene deposits but became extinct in Britain, probably by Bronze Agetimes, although it still lives in Ireland.Lauria anglica (Ferussac), Three examples. L. anglica has not been recog­nised previously in the county, but occurs in the Holocene of Box (Wilt­shire), and the Holocene tufa of Totland Bay, Isle of Wight, both probablyof Atlantic age. Like Vertigo substriata, L. anglica is now characteristic ofthe humid north-western areas of the British Isles.Clausilia rolphi Turton. Two examples. This species has not been recordedpreviously from any Quaternary deposit in the county, but was foundliving at Liscombe Bottom, about seven miles NNE. of Dorchester.shortly before 1898, and by the senior author (A.G. D.) in 1956 at CreechGrange, near Creech Barrow, in Purbeck. C. rolphi is rarely found fossil.and is unknown in the British Pleistocene.Pisidium subtruncatum MaIm. Three examples. In addition, this has beenidentified recently by Mr. S. P. Dance, as yet without publication, amongmaterial collected by the authors from the tufa at Blashenwell.P. personatum MaIm. Four examples. Also determined recently by Mr.

122 A. G. DAVIS AND J. N. CARRECK

Dance from the authors' material from the Blashenwell tufa, but notpreviously published.

3. CONCLUSIONS

When these additional molluscan occurrences are considered in relationto those recorded by the authors in 1955 from this deposit, it is seen thatthe fauna as a whole does not reflect cold conditions but resembles those ofthe Nazeing series (Allison, Godwin & Warren, 1952, 190-1) as the latterpasses up into the deposits of Mesolithic age, in which the sub-arcticfauna becomes modified, no longer stunted, and is accompanied by thearrival of forms indicative of a warmer climate. The forms recorded in thepresent note suggest damp woodland or damp and shady ground, withsome standing water, and therefore support the conclusions reached in1955 (op. cit., 81). Columella columella does not indicate a cold climate inthis instance, for it is known to have persisted in a temperate climate intothe Boreal phase of Post-Glacial time, and probably to the end of thatphase.

A comparison of the entire molluscan fauna of the Early Holocene Loamwith those of similar age elsewhere, and the occurrence of C. columella,shows that there can be little doubt that the deposit was laid down duringpart of Mesolithic times. The molluscan evidence also clearly indicates thata temperate climate existed in the region during the time of deposition.

ACKNOWLEDGMENTS

The writers wish to extend their grateful thanks to Mr. S. P. Dance forthe above determinations of the Pisidia obtained by them at Bowleaze andBlashenwell. The younger author is indebted to Mr. M. P. Kerney foradvice and information regarding the completion of the paper, after thedeath of Mr. Davis.

REFERENCESALLISON, J., GODWIN, H. & S. H. WARREN. 1952. Late-Glacial Deposits at Nazeing in

the Lea Valley, North London. Phil. Trans., Ser. B, 236, 169-240.BURCHELL, J. P. T. & DAVIS, A. G. 1957. The Molluscan Fauna of some Early Post­

Glacial Deposits in North Lincolnshire and Kent. J. Conch., 24, 164-70.CARRECK, J. N. & DAVIS, A. G. 1955. The Quaternary Deposits of Bowleaze Cove,

near Weymouth, Dorset. Proc. Geol. Ass., Lond., 66, 74-100.