View source for Excursion to Hayward's Heath and Ditchling Beacon. Saturday, June 70th, 1882 - Geologists' Association excursion

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[[File:GA Image 0481.jpg|thumb|Figure 47 Section of the southern valley of the Weald (Length of section about 4 miles)  Vertical scale greatly exaggerated.]]

'''Director''': J. Logan Lobley, F.G.S. (Report by The Director.) (Prot Vol. vii. p. 395.)

The third of this Weald series of Excursions between London and Brighton was devoted to the district between Hayward's Heath and Ditchling Beacon (the summit of the eastern section of the South Downs) comprising a southern Weald Clay Vale.

The ground crossed is, therefore, geologically similar to that traversed between Redhill and Three Bridges in May, (see p. 116), but with the difference that we get upon higher, not lower beds as we go southward. One of the minor Wealden anticlinals occurs at Hayward's Heath, where brickyard-sections show Cuckfield Clay at the surface; the ground is then formed of Tunbridge-Wells Sands nearly to Wivelsfield, where a depression on Weald Clay is met with. This is, however, very narrow, and Wivelsfield itself stands on what is almost an inlier of Hastings Beds. This is soon crossed, and then the Weald Clay vale is reached. Ditchling Common is a very extensive tract, entirely on the Clay, which here forms ground more or less undulating, the highest part having a considerable elevation. A divergence was made so as to enable the party to visit the very extensive brickyards near Keymer Junction. The section of the Weald Clay here is one of the best in the entire Wealden area, being some fifty feet deep. The Clay at this place is used solely for brick-making, the terra cotta being made at Ditchling Pottery, about a mile distant, from a finer clay. To this pottery the party proceeded, and the interesting process of terra cotta manufacture was explained to them by the manager. After seeing the Clay the southern part of the common was crossed, and as the village of Ditchling was approached the changed character of the ground indicated the presence of the Lower Greensand, and at the village itself a section of the Folkestone Beds was found behind the hotel, and the ancient church stands on a small hill of these Beds. There does not appear to be any representative of the Atherfield Clay in this neighbourhood, but the Hythe Beds, the Sandgate Beds, and the Folkestone Beds are present, though forming features comparatively insignificant when compared with those which fringe the North Downs. The outcrop of the Gault, too, is narrow, and is indicated by the dark colour of the ploughed land above it, locally called "Blackland." The Upper Greensand also is crossed at the base of the hills, and the Grey Chalk is shown by fine sections at a little elevation. Continuing the ascent the higher beds of the Chalk are successively passed over until the summit of the Downs is reached, consisting of a bed of the Upper Chalk with flints. Ditchling Beacon is 814 feet above the sea-level, and, as it is the highest point in the Sussex Downs, affords a magnificent view on all sides. The southern part of the Weald crossed during the day was looked over on the north, while to the south the view extended across the Downs and far out to sea. A route due west along the summit of the Downs was next taken, and a descent made near Combe Down, when a visit was paid to the new waterworks, where a deep well had been sunk through the Lower Chalk. Passing through Keymer village, at which a section of the Folkestone Beds was seen, the party hastened to Hassock's Gate station for the return journey to London.
References

=== Maps ===
Ordnance Survey. Geological. Sheet 9. 8s. 6d. New Ordnance Survey. Sheets 302, 318. is. each. Booxs.—W. Topley, Geology of the Weald, 8vo, London (Geol. Surv.). 1875. 285.

F. Dixon, Geology of Sussex. 1850; and ed. 2, 1878.


G. A. Mantell, Fossils of the South Downs. 1822. G. A. Mantell, Illustrations of the Geology of Sussex. 1827.

G. A. Mantell, Geology of the South-East of England. 1833.

See also " Weald Series of Excursions," pp. 35-44.

[[Category:Geologists' Association excursions]]