Field meeting in the New Forest, Hants

Field Meeting in the New Forest, Hants 11 May 1969 Report by the Director: F. C. STINTON Received 1 October 1969 THIRTY-FIVE MEMBERS assembled at Southampton Central Station, where a coach was boarded. The object of the meeting was to study the Tertiary outcrops of the New Forest, ranging from the Oligocene Middle Headon Beds down to the Eocene Upper Bracklesham Beds. The probable correlation of these outcrops with others in the Hampshire Basin and in continental Europe would be discussed in the light of the faunal findings at each site. It was mentioned that a possible future revision of the EoceneOligocene boundary in Britain might extend the Eocene to the Bembridge Limestone instead of it ending at the base of the Brockenhurst Bed, as is the present situation. It was suggested that this would conform with the successions occurring in France, Belgium and Germany. The localities visited (National Grid 100 km. square SU) were Park Hill Enclosure (320059); Lyndhurst Hill (289078); Warwick Slade, Highland Water (275067); Studley Wood Enclosure, Latchmore Brook (227156); Brook Golf Course, King's Gam Gutter (265135); Coalmeer Gutter, Brook (266132); Shepherd's Gutter, Bramshaw (261155). All the available sections are in drainage trenches or stream banks.

Park Hill Enclosure This section in the Middle Headon Beds was discovered during the excavation of drainage trenches for a reafforestation project. Variegated light green to grey marly and sandy clays containing many fossils were revealed. In particular, the typical Sinodia suborbicularis Goldfuss (= Venus incrassata of early authors) was found by several members of the party and all were able to collect many examples of Corbicula obovata J. Sowerby, which abounds at this site. The presence of frequent examples of Cerithidea ventricosa J. Sowerby, suggests that the clays are near the top of the Middle Headon Beds. A teleost otolith, Pagel/us oligocenicus (Frost), was found by one member. The Director explained that these strata were mainly estuarine in character, hence the very restricted fauna, but that they became more marine in outcrops at the eastern end of the Isle of Wight. 269

270

F. C. STINTON Lyndhurst Hill

Although no exposures are now visible at this famous locality, the construction of a reservoir on the south-west face of the hill in 1961 enabled the Director to see a section, perhaps complete, of the Middle Headon Beds. It was considered that a detailed description of the section would be of interest to the party and a halt was made on the crest of the hill for this purpose. The descending section seen in 1961 was: MIDDLE HEADON BEDS

Topsoil F. Unfossiliferous streaked clay... E. Very fossiliferous, stiff, greenish clay turning brown on exposure. Numerous small, iregularly shaped concretions. Sinodia suborbicularis common. = The 'Venus' Bed of early authors D. Unfossiliferous greenish and brownish streaked clay passing down into stiff greenish clay with many fossils and a prominent band of large septaria. This marks the Voluta geminata Zone and the type fossil occurs commonly together with rare Venericardia deltoidea J. Sowerby C. Unfossiliferous brownish streaked, green clay becoming uniformly brown and more sandy. Selenitecrystals in seams ... B. Sparsely fossiliferous, brown sandy clay with Athleta dunkeri (Speyer) (= Voluta suturalis Nyst contabulata (Edwards MS.) R. B. Newton), and Ostrea ventilabrum Goldfuss

metres 0.75 0.12

3

2.1 0.15

LOWER HEADON BEDS (BARTONIAN)

A. Light green clay with Melania at base of section.

seen to 1 m.

Almost immediately after the discovery of this section the contractors laid a concrete raft for the base of the reservoir and this prevented any extensive collecting from beds A and B. Detailed collecting was carried out from beds E and D while the section was open and the following faunas were 0 btained : PISCES

Odontaspis acutissima Agassiz Physodon sp. Myliobatis aquila Linne-Gmelin oligocaena Leriche Dasyatis sp. 'Sparus' sp, (palatal teeth) Scomberomorus sp. (teeth)

E R F

D R

NC

NC

F R R

R

F F

R

Otoliths: Apogon sp. Argentina sp Cetengraulis sp. Cymatogaster sp. Dentex sp. .. .

C R R

F

NC

C R

R

R

FIELD MEETING IN THE NEW FOREST

Chanda sp . .. . Moena sp . Pagellus oligocenicus (Frost) Palaeogadus shepherdi (?) (Schubert) Pt erothrissus sp. . . .

E C R F

271 D

F R R R R

BIVALVIA

Trigonodesma (Area) lissa Bayan Nucula Iissa Wood Venericardia deltoidea J. Sowerby Tr inacria cf. deltoidea Lamarck ... Ne m ocardium hantonlense von Koenen .. . Corb ieula deperdita Lamarck C. obovata J. Sowerby C. obtusa Morris .. . Circe edwardsi von Koenen Sinodia suborbicularis Goldfuss Psammotaea aestuarina Edwards (MS) , R. B. Newton Panopaea intermedia J. Sowerby. .. Mactra fastigiata Edwards (MS), R . B. Newton Corbula cuspidata J. Sowerby C. pisum J. Sowerby Neaera cf. inflexa von Koenen Lentidium ta wneyi Curry .. .

NC

VR R R

C C VC C C F F

F F F

C F

F R R R

NC

C

F

R R

GASTROPODA

Rimella rimosa Solander . .. Turricula transversaria Lamarck eypha Edwards Bathytoma hantoniensis Edwards Gemmula odontella Edwards (= G. plebeia Forbes) Turris sp. . .. Genota headonensis Morris Athleta geminatus J. Sowerby Mitra gracilenta Edwards (MS.) R . B. Newton Marginella aestuarina Edwards Pollia labiata J. Sowerby ... Uxia elongata Nyst Bonellitia pyrgota (Edwards) Ob eliseus sp . Odostomia sp , Turbonilla pulehra Deshayes Polygyreulima truneata (J. Sowerby) Bayania fasciata J. Sowerby Pyrgula pulehra De Raincourt dentieulata Edwards (MS.) R. B. Newton ... Stenothyra lubrieella Braun S. par villa (Deshayes MS.) Morris Melania (Tarebia) acuta J. Sowerby Natica epiglottina Lamarck Euspira dilatata Philippi ... E. headonensis Wrigley E. oligoeaeniea Wrigle y .. .

R

C F C

NC

F

R NC

F

R

F F R R R

C F F F F R R R R

R R

F R NC R

R R

R

F C

272

F. C. STINTON E

Actaeon limneiformis Sandberger Ringicula sandbergeri MorIet Bullinella conoidea 1, Sandberger Atys lamarcki Deshayes, variety Atys sp,

R R F

D

R R C

VR

CRUSTACEA

Callianassa batei Woodward Callianassa sp. Maia sp. Balanus unguiformis J. Sowerby ...

NC NC

VC F NC R

ECHINODERMATA

R

Starfish ossicles FORAMINIFERA

Quinqueloculina hauerina d'Orbigny

R

C

ANlHOZOA

Graphularia cf. wetherelli Milne-Edwards & Haime

C

The frequency of each species is indicated as follows: VC: Very common; C: Common; NC: Not common; F: Frequent; R: Rare; VR: Very rare. Species listed above as sp. are new species which have yet to be described.

Warwick Slade A section in the Upper Barton Beds (Chama Bed) was seen in the banks of the stream Highland Water. It is a blue sand, the matrix being identical with that seen on the coast at Barton. The visible part of the bed has no macrofossils but borings have shown that it is very fossiliferous near the base of the bed below stream level.

Studley Wood Enclosure The next exposure to be visited was in the banks of the headwaters of the Latchmore Brook. The stream rises in swampy ground and starts to cut into the substrata just before entering Studley Wood. The following descending section is seen as one proceeds downstream: metres C. Coral Bed. Blue, sandy clay with many specimens of an eupsammid coral and large calcareous annelid tubes B. Huntingbridge Bed. Dark green, glauconitic, very sandy clay, unfossiliferous above but becoming very fossiliferous below with an abundance of large specimens of Turritella sulci/era Deshayes, Thylacodes ornatus J. de C. Sowerby, Dentalium grande Deshayes and numerous other molluscan species including Bicorbula gallica Lamarck and Spondylus rarispina Deshayes... A. Nummulite Bed. Dark grey, very sandy clay with numerous Nummulites cr. prestwichianus T. R. Jones and frequent, wellpreserved small molluscs, fish-remains and other fossils .. ,

0.45

2 0.45

FIELD MEETING IN THE NEW FOREST

273

It was noted that many of the molluscan species are confined to these strata in England and that some of these species are also found in the Bartonien inferieur of France. The Coral Bed (C) is found on the foreshore at Lee on Solent, Hants, but the Huntingbridge and Nummulite Beds (B, A) have not been recognised either there or in the foreshore exposures at Selsey, Sussex. However, beach and/or Pleistocene deposits cover the areas where this bed should be exposed. In Whitec1iff Bay the highest Bracklesham Beds are practically unfossiliferous dark green, sandy clays which offer little correlative evidence. Curry (1942) proved the existence of the Huntingbridge and Nummulite Beds in the old brickyards of Afton and Gunville on the Isle of Wight. Lunch was taken at Brook, Hants, followed by a visit to the site of the original excavations of Keeping and Wise, so graphically described by Wise (1867, 245). No section is now visible in this immediate area but a typical exposure of the 'Brook' Bed (Fisher, 1862) was seen in the bank of the nearby Coalmeer Gutter, just above its junction with King's Gam Gutter. Here members were able to collect many typical Upper Bracklesham fossils and to observe the abundance of Corbula pisum J. Sowerby wemmelensis E. Vincent, a particular feature of this bed.

Shepherd's Gutter, Bramshaw Members first assembled at the road-bridge over the stream where the Director described the sequence of the Upper Bracklesham Beds in this neighbourhood and mentioned that, at about 30 metres upstream, the presence of the Nummulite Bed (A, p. 272) has been proved in a trial boring. The following section, in descending order, and visible at intervals as one goes downstream, was then seen: metres 5. Light grey clay, very sparsely fossiliferous at the top but more fossiliferous in the lower part, where a seam of Turritella carinifera Deshayes, occurs. At its base the clay is blue, shaly and contains beautifully preserved shells and other fossils among which specimensof Sassiafiandrica Koninck, are frequent 4. Glauconitic, very sandy, dark green clay packed with Nummulites variolarius Lamarck, an extensive, well-preserved molluscanfauna, fish-remains and other fossils indicating that this bed may be correlated with Fisher's (1862) bed XVII, Whitecliff Bay, Isle of Wight = Fisher's (1862) bed 22(b), Bracklesham Bay, Selsey, Sussex ... 3. Compact dark greyclaywithfewfossils 2. Compact dark grey clay with numerous Amussium corneum J. Sowerby, and thin intermittent seams of sand packed with broken shells,perfectsmall gastropods, many fish otoliths, echinoid spines and other fossils. A small coral, Paracyathus sp., often attached to shellfragments, occurscommonlyand smallseptaria are frequent.

3.5

I 1.6

2

274

F. C. STINTON

metres This bed was seen in the section revealed during the excavation for the Fawley transmission tunnel (Curry, Hodson & West, 1968) and may also be recognised on the foreshore at Lee on Solent. It is probably the equivalent of the 'Hard' Bed (Fisher (1862) bed 2l(c» ofSelsey, Sussex, where it has become indurated. I. Unfossiliferous dark green, glauconitic sandy clay fossiliferous toward the base where fine, adult specimens of Turricula attenuata J. Sowerby are frequent amongst the abundant fossils in which Corbula pisum J. Sowerby variety wemmelensls E. Vincent predominates. Belosepia sepioidea Blainville is not uncommon and occasional large single valves of Venericardia planicosta Lamarck may also be found

2

This bed probably represents Fisher's (1862) bed 19(d), the Brook Bed, at Selsey, Sussex. Below is greyish-brown clay with no visible macrofossils passing into very shelly, clayey silty sand with Pinna in the lower part, proved by boring to 5 metres. This is the lowest bed visible at this locality and may well be correlated with the upper part of a similar bed formerly visible in the disused Brook Brickyard which lies about a mile to the south-east of Shepherd's Gutter. The lower part of the latter bed contained numerous specimens of Pinna sp., fish-remains, well-preserved Chlamys trigintaradiata J. de C. Sowerby, and a small oyster, Ostrea cf. plicata Solander. All other molluscs were very soft and rotten. The same bed was encountered in the Fawley Transmission tunnel (Curry, Hodson & West, 1968). Members collected many typical Bracklesham fossils before taking tea at a restaurant overlooking the Forest at Stoney Cross. After tea the coach returned to Southampton and the party dispersed.

REFERENCES CURRY, D. 1937. The English Bartonian Nummulites. Proc, Geol. Ass., 48,229--46. - - - , 1942. The Eocene Succession at Afton Brickyard, Isle of Wight. Proc. Geol. Ass., 53, 88-101. - - - , F. HODSON & I. M. WEST. 1968. The Eocene Succession in the Fawley Transmission Tunnel; with an Appendix on the Clay Mineralogy of the Strata by R. J. Gilkes. Proc. Geol. Ass., 79, 179-206. FISHER, O. 1862. The Bracklesham Beds of the Isle of Wight Basin. Q. II geol. Soc. Lond., 18, 65-94. WISE, J. R. 1867. The New Forest: Its History and its Scenery. London. i-viii and 1-336.

F. C. Stinton 51 Craigmoor Avenue, Strouden Park Boumemouth, Hants