The Suffolk Crag

215

MYXOMATOSIS IN EAST SUFFOLK

No major outbreaks have been reported this year, but one diseased rabbit was pickedup in the HerringswellareainMay, 1955.

No evidence has been found of foxes doing more damage than usual but the public, in particular poultry keepers, appear to be far more fox conscious than before the spread of myxomatosis.

N . W. NEWELL, August, 1955.

THE SUFFOLK CRAG By

D.

F.

W.

BADEN-POWELL,

M.A., B.Sc.,

F.G.S.

As all Suffolk geologists know, the Crag is a much-investigated deposit. The history of research on the subject has been somewhat uneven, as spurts of activity and new discovery have alternated with periods of quiescence. In recent decades there has been an acceleration in our work on these beds, and the purpose of this article is to summarise what has been found out in the last 30 years or so, and to indicate what might be done in the future.

Before the nineteenth Century, many writers alluded to the Crag mainly in connection with its importance in agriculture, and it was not until the 1830's that geologists began to pay detailed attention to this formation. About this time Lyell published his famous recognition of the great antiquity of the Crag, based on the presence of extinct shells, and Charlesworth (1835) realised that " the Crag " is not all of one age, and gave the names Coralline Crag, Red Crag and Norwich Crag to the three main divisions ; these designations have been used ever since his time. This period of initial activity was followed by less eventful work which included attempts by Prestwich to identify detailed layers over wide areas. By 1866, Searles Wood had shown that Prestwich's sub-zones could not be followed in the way he suggested, and established three divisions of the Red Crag which could be recognised by their shells ; these are now known to us as the Walton, Newbourne and Butley Crags. The various Monographs of the Palaeontographical Society by Wood, Harmer and others are a record of the diligent collecting of fossils which was carried out between the 1870's and the 1920's ; as early as 1872 (in the " Supplement to the Crag Mollusca ") the main faunal lists had been recorded. No attempt will be made here to give references to the numerous papers on the Crag, a mere list of these would occupy more space than the whole of this article : however, in the following paragraphs a few references will be given to papers which deal with recent research, so that geologists may have some idea of contemporary work.

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THE SUFFOLK CRAG

CORRELATION WITH THE M A R I N E

BEDS OF THE

MEDITERRANEAN

While local work was being done on the Crag fauna mainly

by Wood and Harmer, a number of French and Italian geologists were making similar investigations on marine beds in the Mediterreanean regions. By about 1918 the following succession of marine beds had been established there : Youngest

Sicilian (cold climate with few extinct shells).

Calabrian (cold climate with some extinct shells).

Oldest

Astian (warm climate with many extinct shells).

Later than this series came the Tyrrhenian and other raised beaches with shells which prove the return of a warm fauna. One of the most interesting problems connected with the Crag now is the correlation with the Mediterranean series.

Wood had shown in 1853-1856 and in 1872 that some shells, especially those belonging to the genus Teilina, had a zonal value, and in fact the species belonging to this genus can be used for dating the main subdivisions of the Crag. The " arrival " of Teilina balthica in the Weybourne Crag of Norfolk is especially well known. Harmer showed later (1914-1925) that the genera Turritella and Purpura could also be used in a similar way. So far these shells had only been used as typical of certain layers in the English Crag, and in fact Wood wrote (1874, p.199.) that he did not know the Mediterranean fossils well enough to attempt correlation with the Continent. Clement Reid tried to rectify this position by travelling to Italy specially to study the foieign fauna, and as a result he expressed the opinion that the Calabrian beds of Monte Mario near Rome are in general the same age as part of our Red Crag (Reid, 1890, p. 215). In Harmer's monograph on the Crag Mollusca (1914-1925) correlations were suggested between our Crag and that of Belgium and Holland, but Harmer did not commit himself definitely about the relation to the Mediterranean deposits.

In 1953 I had the luck to visit Sicily and Italy and was able to collect enough fossils to make a useful comparison with the Suffolk deposits.

The results of this work were published in " Nature " (Baden-Powell, 1953) and may be summarised t h u s : MEDITERRANEAN

BRITAIN

Sicilian (Erosion) Calabrian Astian

North Sea Drift (Cromer Forest Bed) Norwich and Red Crags Coralline Crag

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217

These correlations were based partly on the varieties of Turritella and Nassa which are common to both areas, and partly on the sequence of climatic change from the warm Astian to the cold Sicilian in the Mediterranean area compared with change from the warm conditions of the Coralline Crag to the intense cold during the formation of the North Sea Drift in this country.

The gradual change of climate during the Crag, as shown by the fauna, was first emphasised by Harmer ; more recently Boswell (1931) has confirmed Harmer's work by a thorough revision of the fauna from the various beds and the temperatures indicated by the shells. Many years ago Deperet (1921, p. 161) had correlated the " Bridlington Crag " of Yorkshire with the Sicilian, and Wood had placed the " Bridlington Crag " in his Lower Glacial formation together with the North Sea Drift.

This type of research work on the Crag is more than a simple matter of trying to make correlations with similar deposits abroad ; it helps geologists to decide on a world-wide scale where the distinction between the Pliocene and the Pleistocene should be made. When the Survey Memoirs were being written at the end of the last Century, all the Crag was automatically described as Pliocene and all the overlying glacial drift and later marine layers were called Pleistocene, the division between the two Coming somewhere near the Cromer Forest Bed. Recently, however, geologists have been considering more and more that in the Mediterranean area the Calabrian beds should be taken as the base of the Pleistocene ; there is much to be said for this decision, because the first known immigration of northern shells into the Mediterranean basin took place at this stage, indicating the beginning of the deterioration of climate which led to the Ice Age. If we are right in considering the whole of the Red Crag as Calabrian, the Walton Crag now becomes the base of the Pleistocene in this country. This opinion has been defended by Boswell (1952) in his latest publication on the Crag, and I am in fĂźll agreement with him.

T H E CRAG ELEPHANTS. It is well known that the base of some of the Crag layers contains vertebrate fossils, some of which are derived and some indigenous. Owing to the lack of sections our knowledge of the base of the Coralline Crag is extremely scanty, and because the Red Crag is no longer dug for phosphatic material, the base of this formation is seldom seen now. In spite of these difficulties, fossils which were collected when the Red Crag was being excavated to its base show us that the derived material came partly from the London Clay, also from the base of the Pliocene, with Mastodon longirostris and Hipparion (Reid, 1890, pp. 8 and 226): the fauna which is considered indigenous to the beginning of the Reg Crag includes Mastodon arvarnensis and Elephas meridionalis, and these two extinct animals survived

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THE SUFFOLK CRAG

until the time of the Norwich Crag (Reid, 1890, and E. T. Newton, 1891). Of these two, only Elephas meridionalis is found in the Cromer Forest Bed. A useful summary of these data will be found in Boswell's paper already quoted (1952). There is much confusion in the literature about the earliest date of arrival of Elephas antiquus, the extinct elephant which lived on long into the glacial period, but it does not appear to be known for certain before the Cromer Forest Bed. T h e recognition of these fossils and others which accompany them is interesting, because it helps us to understand the sort of land fauna which was living in Britain in Crag times, but these fossils are also important for long-distance correlation and they act as a most useful check on similar work done with the marine fossils. The French geologist Gignoux discovered that in the Mediterranean area the most typical elephant found with the Calabrian beds was Elephas meridionalis, whereas Elephas antiquus was not found until the Sicilian and later deposits. It is clear that the finding of Elephas meridionalis in and beneath the Red Crag and Norwich Crag confirms these beds as Calabrian, and the first appearance of Elephas antiquus in the Cromer Forest Bed does not contradict the idea that the overlying North Sea Drift is Sicilian. The name Villafranchian is used by Continental geologists for the non-marine equivalent of the Calabrian, and indeed Hopwood (1940, p. 18) has already dated the Red Crag as Villafranchian because Elephas meridionalis occurs in both deposits.

Correlations of this kind enable us to understand some of the geographical conditions of Europe before the beginning of the Ice Age : they have further importance as they throw light on the origin of mankind, as I shall explain in the next section of this paper.

THE E O L I T H PROBLEM. DĂźring the nineteenth Century, archaeologists were intensely interested in the antiquity of man.

At first the Stone Age was divided into the Palaeolithic and Neolithic stages, and later several sites in Suffolk, such as Hoxne, played their part in the long argument about whether Palaeoliths could be of interglacial age or not. DĂźring the present Century it is accepted by all archaeologists that palaeoliths can be interglacial, and now the argument has shifted to the question of the probability of the existence of Pre-Glacial Man. The main evidence on this point lies in the flaked stones known as eoliths, and the doubt about them is whether they were made by man or by some natural process. The arguments on this question have mostly been pointless, because many archaeologists seem to have forgotten what an eolith really is. To many people eoliths are simply flat stones with a few chips along their edges.

It is obviously difficult to decide whether such objects have been intentionally flaked or not, but fortunately for those who

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219

want to reach a definite conclusion about them, they were originally defined by the de Mortillets with much greater precision (G. and A. de Mortillet, 1903, plate V,figs.23-27). The examples chosen were from the Auvergne in Central France, and included tabular cores of chert up to 4 inches thick, from the upright sides of which definite percussionflakeshave been removed, and these flakes show good bulbs of percussion, normal scars and often secondary edge-work. If we accept the de Mortillets' deflnition, eoliths must be considered as percussionflakesaccompanied by the cores from which they were Struck ; in other words, we are dealing with a Pre-Palaeolithicflakeindustry. It is clear that Professor Sollas had a similar interpretation in mind when he described the Auvergne eoliths as Struck off tabular blocks (1924, p. 96), and an unpublished manuscript by the late Mr. Reid Moir also describes these specimens as aflakeindustry. The Auvergne specimens have been dated by the presence of Hipparion and other fossils as Coming from the base of the Pliocene ; in terms of East Anglian geology, that would be older than the Coralline Crag.

Some archaeologists objected to the idea that these eoliths and further examples from other parts of Europe could be intentionally flaked, because they thought that no intermediate stages had been found between these and true palaeoliths. This argument was quelled by discoveries in East Anglia, first by Lewis Abbott (1897, p. 90) and later by Reid Moir (1911, p. 39), offlakesand cores which are intermediate in type between the Auvergne specimens and the early palaeolithicflakeindustries. As these eoliths are found together with occasional Abbevillian bouchers (hand-axes) below and in the Red Crag, there is no doubt that some primitive form of man was living at that time. If the interpretation of these eoliths as an earlyflakeindustry is correct, it will be seen that some of the " choppers " and " rostrocarinates " which have been described as implements may rather have been the cores from whichflakescould be obtained, although some of these cores may have been used as implements in their own right. It would take up too much space here to give an account of the long arguments which were aroused by these discoveries : presumably most Suffolk archaeologists will remember the details of them. It is sufficient for me to say that through the kindness of Dr. Westlake, I have been able to examine an enormous collection made by his father of specimens from the Auvergne, and a comparison of these with the Crag eoliths leaves me in no doubt that they represent a Pre-Palaeolithicflakeindustry of Pliocene age, and that early Pleistocene (Calabnan) specimens from the Crag represent an advance in technique compared with those from the Auvergne. This summary of what is known so far about the Crag eoliths would not be complete without mention of the discovery by Reid Moir of the Darmsden pebble tools (1916 and 1936). Although the age of the gravel at Darmsden

220

THE SUFFOLK CRAG

is unknown, these implements have also been found beneath the Crag, and a comparison of them with the Early Soan of India and with the Kafuan and Oldowan industries of East Africa should be both interesting and important.

FUTURE RESEARCH. It will be realised from this account that research on the Crag during the nineteenth Century consisted largely of the discovery of the main subdivisions and their faunal characters. Investigation in recent years has had a more worldwide and less parochial aspect; in other words, our responsibility is now not only to understand the nature of the Crag as fully as possible but to establish its position in the stratigraphy and palaeogeography of Europe as a whole.

One of the least known facts about the Crag is the amount of submergence represented by each stage, and the allied problem of any crustal movements which may have altered the original levels. We know that as the Crag consists of marine beds tnere must have been rises of sea-level of certain amounts, and one way of finding out these quantities would be the investigation of any shorelines which might be discovered, like the one at about 200 feet found by Mr. H. E. P. Spencer near Hascot Hill recently.

An excavation here to study the fauna should show whether tms shore-line is connected with the Newbournian or with some other division of the Crag. The question of subsequent disturbance of levels by tectonic movement could be answered by studying the age and height of the Lenham Beds in Kent and by a continuation of Harmer's work on the equivalents of the Crag layers in Belgium and the Netherlands.

One interesting piece of research now in progress is an attempt to find out the temperature in which Crag shells lived by an analysis of the isotopes of oxygen in their composition. The work is being done in Chicago by Dr. Emiliani, to whom I sent sets of Crag for investigation. Unfortunately the results have not yet been worked out.

T h e " Suffolk Bone Beds " at the base of the Red Crag, and especially at the base of the Coralline are in urgent need of excavation and renewed investigation.

Confirmation (or the contrary) of the Villafranchian age by study of the fauna at the base of the Red Crag would be one result of such work, and further investigation of the flaked flints in their new interpretation as a flake industry would be most valuable. In addition to special expensive excavation, there is much to be done on the marine fauna which can be collected from existing sections ; the accumulation of complete faunal lists for each subdivision is needed, and even more important work would be the study of the Variation and evolution in the more abundant species; in fact, this article seems to show us that we are at the beginning rather than the end of our investigation of the Suffolk Crag.

T H E SUFFOLK CRAG

221

REFERENCES Abbott, W. J. Lewis

1897.

Baden-Powell, D. F. W. 1953.

Boswell, P. G. H.

1931.

Boswell, P. G. H.

1952.

Charlesworth, E.

1835.

Deperet, C.

1920.

Harmer, F. W.

19141925

Hopwood, A. T .

1940.

Moir, J. Reid

1911.

Moir, J. Reid

1916.

" Worked flints from the Cromer Forest Bed." Natural Science, 10, (pp. 8996.). " Correlation of Pliocene and Pleistocene marine beds."

Nature, 172 (p. 762). " The Stratigraphy of the glacial deposits of East Anglia in relation to Early Man." Proc. Geol. Assoc. vol. 42 (pp. 87-111.). " The Pliocene-Pleistocene boundary in the East of England." Proc. Geol. Assoc., vol. 63 (pp. 301-315.). " Observations on the Cragformation and its organic remains : with a view to establish a division of the Tertiary strata overlying the London Clay in Suffolk."

Phil. Mag., ser. 3, vol. 7, (p. 81.). " Essai de coรถrdination chronologique des temps quaternaires." Comptes Rendus, vol. 170. (pp. 159-163.). " The Pliocene Mollusca of Great Britain."

Mon. Palaeontogr. Soc., (900 pp.). " Fossil mammals and Pleistocene correlation."

Proc.

Geol. Assoc., vol. 51, (pp. 7988.). " The flint implements of Sub-Crag Man." Proc.

Prehist. Soc. East Anglia, vol. 1, part 1, (pp. 17-43.). " A series of Pre-Paloeolithic implements from Darmsden, Suffolk." Proc. Prehist. Soc. East Anglia, vol. 2, part 2, (pp. 210-213.).

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THE SUFFOLK CRAG

Moir, J . Reid

1936.

" The Darmsden flint implements." Proc. Prehist. Soc. for 1935, New Series, vol. 1, (pp. 93-97.).

Newton, E. T .

1891.

" The Vertebrata of the Pliocene deposits of Britain."

Mem. Geol.

Survey.

Reid, Clement

1890.

" Pliocene deposits of Britain."

Mem. Geol. Surv. (326 pp.).

Wood, S. V.

1866.

" On the structure of the Red Crag." Quart. Journ. Geol.

Soc. Lond., vol. 22, (p. 538.).

Wood

1848- " Monograph of the Crag 1882.

Mollusca." Mon. Palaeontogr. Soc., with Supplements.

S. V.

De Mortillet, G. & A.

1903.

CRAG PITS IN

" Musee prehistorique."

Edition.

2nd

CHILLESFORD-BUTLEY-

SUTTON AREA CHILLESFORD CHURCH

PIT

This is the type section of the Chillesford Beds which consist of layers of clay—or layers of clay and sand. In this section the latter condition prevails and it is the only section which contains typical fossils. These beds rest on the Butleyan Red Crag as members saw last year at Aldeburgh where these beds are not fossiliferous. The late Mr. Harmer considered the Chillesford beds to have been deposited in the delta of the Ancient Rhine which formerly had its course extending thus far to the West, the sea bed having been choked by the accumulated Red Crag and Norwich Crag Sands. Harmer claimed to have traced the deposit from Walton-on-Naze to Aldeby and Bramerton in