View source for Excursion to Caterham, Godstone, Tilburstow, and Nutfield. Monday, June 4th, 1877 - Geologists' Association excursion

{{Template:GA excursions1860-1890}}

'''Director: J. Logan Lobley, F.G.S. (Report by The Director.) (Proc. Vol. v. p. 155.)'''

Note: [Tilburstow and Nutfield. A brief report of an excursion to Tilburstow and Nutfield,  on May 28th, 1870, is given in Proc., vol. ii., p. 35. An account of another on June r3th, 1874, J. Logan Lobley, Director, may be seen in Proc., vol. iv., p. 153. Another visit to the above places, Mr. Lobldy again being Director, was made on June 4th, 1877. The same ground was traversed on both these last-named visits, but the report of the latter being much the fuller is alone given here. On June 23rd, 1888, there was an excursion to Caterham, Godstone, Tilburstow, and Nutfield, the Director being Prof. G. S. Boulger. A report of it will be found in the Proceedings, vol. x., p. 496.]

Before arriving at Caterham the party were much interested by seeing the Bourne flowing along the bottom of the usually stream-less Kenley Valley. This intermittent river flows only after unusually wet seasons, the Chalk of the district absorbing ordinary rainfalls. In recent years there had been flows in 1866; 1873, and a small flow in 1876. This year (1877) the flow is large, and is the subject of much comment and speculation amongst the residents of the locality, some of whom even now ascribe the appearance of the river to a mysterious or supernatural agency, although in 1660 the true cause was known. Childrey, in the Britannia Baconica of that year, says : "The rising of a Bourn or stream near Croydon (as the common people hold) presageth death or the plague; and it bath been observed to fall out so. The rising of Bourns in places where they run not always, we have before proved to be caused by great wet years, which (according to Hippocrates' observation) are generally the most sickly; and if they prove hot as well as wet (because heat and moisture are the greater disposers to putrefaction) they prove also malignant and for the most part pestilential. and the reason why the using [? rising] of this Bourn doth not always presage the plague, is because all wet years do not presage hot."<ref>See W. Whitaker, Geol. London Basin (Geol. Surv.), 1872, p. 391.</ref>

Mr. Baldwin Latham, in a letter to the Croydon Chronicle, dated January 25th, 1877, gives the following particulars of the flow of the present year : " The flow of the Bourn from Marden Park and that at Riddlesdown joined each other on Monday, the 22nd inst., and now form one continuous stream, and the flow is making rapid progress towards Croydon, having this day (Thursday) reached to a point north of Caterham Junction. The Bourn now makes its appearance at the highest point a short distance below Bughill Farm, and from this point to a considerable distance below the Rose and Crown Inn, under Riddlesdown, the water continuously receives considerable accessions to its bulk. The volumes of water flowing from Marden Park, at Wapses Lodge, have been as follows

:On the 19th, at the rate of 1,516,000 gallons in 24 hours.

:On the 20th, at the rate of 2,567,000 gallons in 24 hours.

:On the 23th, at the rate of 4,425,000 gallons in 24 hours.

:On the 24th, at the rate of 4,623,000 gallons in 24 hours.

"At this latter date the water below the Rose and Crown was flowing at the rate of 20,584,000 gallons in twenty-four hours, while at Warlingham Station, a point intermediate between Wapses Lodge and the Rose and Crown, the volume flowing was at the rate of 6,855,000 gallons in twenty-four hours. From my last letter it will be seen that the volume of water flowing out of the Bourn Culver, at Croydon, on the 25th inst., was at the rate of 9,300,000 gallons in twenty-four hours. On the 21st it was at the rate of 8,837,000 gallons in twenty-four hours; and on the 24th inst. at the rate of 8,761,000 gallons in twenty-four hours. The falling-off of the quantity is no doubt due to local effects arising from the diminution of the rainfall."

On alighting from the train at Caterham the members found a collection of the fossils of the Chalk of the neighbourhood had been brought by Mr. Cluse, of Caterham Junction, not only for inspection, but also for distribution. At a short distance from Caterham Station, on the road to Godstone, a visit was paid to a quarry in the Lower Chalk, and here the Director explained that from Caterham Junction to Caterham, lower and lower beds of the Chalk had been traversed, the section at the Junction showing Mr. Caleb Evans Upper Kenley, or Riddlesdown, Beds of the Upper Chalk, while this quarry was in the Lower Marden Park Beds of the Lower Chalk. These beds are characterised by ''Belemnites plenus'' and ''Holaster suhglobosus''.

Rain arrested progress for a little time, but on its cessation the party made their way to the great Firestone Quarries in the Upper Greensand, on the Godstone road, which have been worked underground for a long period, though they are not so ancient as others a little distance to the west, from which stone for Windsor Castle was obtained in the time of Edward III. Although at the ends of the workings there are places in which a considerable quantity of water lies, the galleries, along which trams are laid, are comparatively dry. The Firestone is quarried from a calcareo-siliceous bed of the Upper Greensand, which has an extension not limited to Surrey. Curiously enough, however, near to the opening to the quarries another excavation had been made, but no Firestone had been met with. At this place some fossil sponges (''Siphonia'') were found. Under the guidance of the manager of the Quarries a visit was paid to a quarry near Marden Park, in which a harder stone, used for hearthstones, occurs. Proceeding southwards, an exposure of the Gault was found in a field to the east of the Godstone road, and a few fragments of the characteristic ''Belemnitella minima'' were extracted from the clay. After passing a pit in which a fine white sand is worked, an exposure of Lower Greensand, the pretty village of Godstone was reached.

After luncheon the road to Tilburstow Hill was taken, and a " head-water" of the Medway, Broad Mead Water, having been crossed, the ascent of the commanding elevation of Tilburstow commenced. A deeply-cut, disused lane, almost covered by tangled vegetation, opens on to the hill-side, and here the party paused and, turning to the north, surveyed the beautiful valley they had just crossed, lying between Tilburstow Hill on which they stood and the Chalk Hills of the North Downs. The' bare but green Chalk hills on the opposite side of the valley, diversified with white patches where excavations occur along their sides, contrasted with the darker green and well-wooded lower ground of the Upper Greensand and Gault. The Lower Chalk of Caterham had given place to the Upper Greensand of the Firestone Quarries, and this had been succeeded by the Gault of the bottom of the valley and the Lower Greensand, of which the whole of Tilburstow Hill was composed, and the commencement of which had been seen at the Godstone sand-pit. Thus a regular and continued sequence of beds had been traversed from Caterham Junction to the spot on which they stood.

Continuing the ascent, the party soon reached the summit of the road, where a fine section of the ferruginous sands of which the Lower Greensand so largely consists is exposed. The tendency of the oxide of iron to separate from the sand and form " boxes " is well exemplified at this place, and some good specimens of these structures were obtained. The top of the hill is much higher thati the summit of the road, and is only gained by a very steep and. difficult path; but the difficulty was soon overcome, and the-members stood on the little plateau under the trees which crown the summit of Tilburstow, and were struck with the extent and extreme beauty of the landscape which met their eyes, for, stretching to the east, to the west, and to the south, as far as the eye could see, lay before them the great Wealden district. With the aid of the Geological Survey Maps of the Wealden Area, the Director described its physical features, and explained the theories held to account for the denudation of the great mass of Cretaceous strata which had been removed. Mr. Boulger having said a few words on the plants of the neighbourhood, the party left the hilltop, and after visiting some Kentish Rag quarries in the Lower Greensand, made their way westward along the hill, through the villages of Bletchingley and Nutfield, to the well known Fuller's Earth pits, also in the Lower Greensand. The argillaceous earth here worked is finer than that of the Fuller's Earth (Jurassic), and is largely used in the arts. Masses of barytes occur in these pits, and, when broken up, show fine brown crystals, sometimes having small cubical crystals of iron-pyrites attached. Nearly every member of the party succeeded in carrying away a good specimen.

A further walk of about a mile brought the party to Redhill. Mr. C. J. A. Meÿer, F.G.S., kindly furnished the following list of fossils obtained from the Nutfield Lower Greensand.
==Footnotes==

[[Category:Geologists' Association excursions]]