Excursion to Sheppey

EXCURSION TO SHEPPEY. 459 Heath, where there is a fine section in an outlier of Blackheath Beds. Towards the base the pebbles had become cemented by iron oxide into a hard conglomerate. Sand occurred below the pebble beds, and between the two was a thin band of allophane ; numerous specimens of this mineral were obtained. The amount of oxide of iron present gave the section a vivid red appearance. In spite of a long search, nothing beyond flint pebbles was found although on previous occasions a few quartzite pebbles of unknown derivation had been obtained by Dr. Hinde. Above the Blackheath Beds was to be seen a quantity of drift material, derived from Blackheath Beds and Thanet Sand. A short walk through a picturesque plantation brought the members to the edge of the dry Chalk valley, and the magnificent view there obtained was thoroughly enjoyed by all. A steep descent was made to the main road, and Upper Warlingham was again reached. Here the members enjoyed the hospitality of the Rev. T. T. Griffith, M.A., amidst the sylvan beauties which surround his home. Hearty votes of thanks to the Director and to the Rev. Mr. Griffith concluded an instructive excursion. REFERE~CES. Geological Survey Map, Sheet 6 (Drift). Price 8s. 6d. Ordnance Survey Map, New Series, Sheet 286. Price IS. 1872. WHITAKER, vV.-" Geology of the London Basin." Man. Geot, Survey, vol. iv. 1896-7. HINDE, G. ].-" Notes on the Gravels of Croydon." Trans. Croydon Microscop. and A'at. Hist. Cluh. 1898. SALTER, A. E.-" Pebbly and other Gravels in Southern England," P,'Of. Geoi. Asscc., vol. xv, pp. 275-276. EXCURSION TO SHEPPEY. SATURDAY, JULY 16TH, 1898. Directors: W. WHITAKER, F. R.S., PRES. GEOL. Soc., T. V. HODIES, F.G.S., AND W. H. SHRUBSOLE, F.G.S. Excursion Secretary: A. E. SALTER, B.Sc., F.G.S. (Report by THE DIRECTORS.) ABOUT forty members left London by the 9.56 a.m, train, arriv ing at Sheerness at noon, and drove thence to East End Lane, where the vehicles were left and the journey continued by the cliff path on foot. Near at hand was the only remaining Coast guard Station of four which had been erected; the other three have been entirely swept away by the erosion of the coast, and their sites are now well out on the foreshore. In the cliff section, above the London Clay, the Lower Bag shot Beds were seen, standing almost perpendicularly, and capped NOVEMBER, 1898.] EX CURSION TO SHEPPEY. irregularly by false-bedded sand and gravel. Where slips had recently occurred the line of junction with the London Clay was very clearly defined. Although a passage bed is generally seen in sectio ns elsewhere, a sharp line of demarcation has been observed in the se cliff sections for many years. At a spur-like projection of the cliff, Mr. Whitaker took the opportunity of drawing attention to the various strata to be seen in the cliffs. On looking over the fields hereabout, the presence of gravel in considerable thickness could be noted by the stu nted an d unhealthy appearance of large patches of the growing crops. At Hensbrook Gap the party descended to the beach. At the mouth of the gap a large heap of partially-decomposed pyrites -r;"t g ~ ~ . ~~ .,; j ] ..; ~ ~ ~ g i:' ,. 0 -"<.> ,;, 't ~ c .~ ~" e ,D s: c c, ~~ u ~ -o c -e ~ c, ~ :cee c '"e "c '0 '"« ~ 0 o 0 -"'" ....:....-, Z'" i>:'" ~ :x: ,..l B:: 0 (fJ IDEAL S ECTION OF LONDON C LAY ( P RESTw rCH) . B. Bagshot Series. LI'. Ts. Lower Te rtiar ies. L.C. London Clay. CH. Cha lk. was seen. Its presence in that position showed that there is now no demand for iron pyrites as an article of commerce. It was pointed out that the heap probably represented many months of hard toil by the women who had transported the heavy materia l from a cons iderable distance, over the slippery shingle, in bags carried on their backs. Passing eastward along the beach, a diligent search was made for fossils ; but from some cause not easily ascertainable, the quantity found was much less than on former occasions. There were many logs of fossil wood bored by Teredo, and several of the party secured specimens of Nipadites ; these are always in evidence, even when no otber fossils are to be found. At Barrowsb rook was seen a small natural bridge formed by fallen masses of clay, beneath which the brooklet had cut its way. Just beyond this, and extending past Warden Point, the lower part of the cliff presented a precipitous face which could not be scaled, EXCURSION TO SHEPPEY. SO the ascent took place a little to the east of the point itself. When the old road was reached, the part of the churchyard which still remains intact was seen about 100 ft. below its former level, tilted at an angle of about 40°. The site of the church is now covered by the beach. The only vestige of the church remaining is a stone bearing an inscription in a cottage garden near by. The vehicles were now made use of to convey the party to Minster, where a hasty survey of the interior of the Abbey Church was made. Mr. Parker discoursed on the local ecclesiastical history, to the general gratification of the members, and the party returned to Sheerness. A substantial meal was provided at the Royal Hotel, and afterwards the President moved a vote of thanks to the Directors of the Excursion, and especially men tioned some of the services which had been rendered to geological science by Mr. Shrubsole. The vote of thanks was carried by acclamation, and in reply, Mr. Shrubsole gave further informa tion respecting some of the discoveries which had been alluded to. The remarkable mineralised Diatoms* occurred in a zone (having a considerable range) near the base of the London Clay, and therefore only to be reached in Sheppey by deep excavation. Radiolaria,t in a pyritised condition, had also been found in clay from a well near Queenboro' Railway Station. The only freshwater shells, Camptoceras priscul1I,t known to occur in the London Clay he found in a septarian nodule. The skull and other portions of the skeleton of the toothed bird, Argillorllis IOllgipellllis§ were found at different times among the shingle on the beach, unobscured either by limestone or pyrites. The immense skull of Chelo1le gzgasll (Eosphargis gigas) was enclosed in a septarian nodule, the outline of which furnished the only clue to something organic within. Interesting reference was made to its skilful exhumation at the British Museum, and the delight of Sir Richard Owen at finding such complete evidence of a gigantic Chelonian, the existence of which was foreshadowed forty years before by a small fragment of bone, on which the name had been bestowed. The most recent discovery was the skull of another bird in 1897. Unlike the Argillomis, it was enclosed in a limestone nodule of oval form, at one end of which the base of the cranium was slightly exposed. The expert mason of the British Museum soon revealed what appears to be a perfect avian skull. A description of this interesting specimen is in course of preparation. As usual Mr. Shrubsole has added this skull to the National Collection at South Kensington. The Director concluded his remarks by the ,., See f ourn, R()YIlI1l1icr(JscopicaISoc.~1881. t See Quart.jIJurn. Geot. SOC. I vel, xlv, 188g, p. 121. :t: ibid., vol. .xxxviii, r882) p. 218. § Ihid' j vols • xxxiv and xxxvi. II/bJd., vol. xlv ; "Cat. Fossil Reptilia, Brit. Museum," part 3; '" Owen's Palreon- tologv," and edition, pp. 317, 3t8. EXCURSION TO SHEPPEY. statement that the first visit of the Geologists' Association to Sheppey in 1871, was made at his suggestion, and led him to become a student of geology. Mr. T. V. Holmes called attention to some matters of interest in connection with the ancient physical geography of the district. Looking at the action of the sea, it became evident that the North Foreland stood out because of the superior hardness of the Chalk, while the softer Tertiary and later beds of Essex had been eaten away much more rapidly. Some years ago he discovered in a railway cutting close to Romford, the remains of an old silted-up stream-course, covered by Thames Valley Gravel. This stream, before the intrusion of the ancient Thames, had apparently flowed to the north-east and joined the Blackwater below Maldon, the valleys of the Mardyke and the Crouch having evidently come into existence at a much later date." As regards the old deposits of the lower Thames, gravel and loam were shown on the Geological Survey Map extending from Southend to Burnham-on-Crouch, and thence to the mouth of the Blackwater at Bradwell. These beds were considered by Mr. Whitaker to be old Thames Valley beds, deposited when there was a considerable breadth of land east of them, where there is now sea. A chart of the Thames Estuary illustrated very strikingly a former state of things. In it could be seen a series of channels, separated by shoals and sandbanks, ranging from the Nore in a north-easterly direction, and evidently marking the positions of the Thames and Medway at former periods when the two rivers occupied independent valleys, east of what is now the coast of Essex, and entered the sea somewhere off Harwich. The shoals and sandbanks now separating rhe channels east of Essex, marked the planing down action of the sea on the higher ground once separating them, as the broad shoals north of Sheppey and Herne Bay indicated similar action on the soft strata of northern Kent.

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