Westcombe Park, Greenwich, and Loampit Hill, Lewisham. April 7th, 1883 - Geologists' Association excursion
| From: A record of excursions made between 1860 and 1890. Edited by Thomas Vincent Holmes , F.G.S. and C. Davies Sherborn, F.G.S. London: Edward Stanford [For the Geologists’ Association], 1891. Source: Cornell University copy on the Internet Archive (Public domain work) |
Note: [The sections at Westcombe Park are described in Proc., vol. viii., 1883, p. 59. The extension of the London and Greenwich Railway to Maze Hill and to Charlton caused the cutting up of Westcombe Park for building purposes. The Lower Tertiary escarpment almost coincides with the northern boundary of Westcombe Park, most of the surface of which consists of the Blackheath Pebble-Beds; the roads then cut across the brow or along the strike of the Tertiary escarpment affording the sections seen. The letters A B and C on the plan, (Figure 7) mark the position of the sections shown in Figure 8. Perhaps it is better (1888) that all the strata above the shell-beds should be classed as Oldhaven or Blackheath. In 1883 it seemed preferable to group the sand with clayey partings with the Woolwich Series.]
Westcombe Park, Greenwich, and Loampit Hill, Lewisham. April 7th, 1883
Director—T. V. Holmes, F.G.S. (Report by The Director). Proc., Vol. viii., p. 112.
After leaving the chalk-pits Westcombe Park was entered from its eastern boundary, and its sections viewed in the order in which they are described in Proc., vol. viii., p. 59. Since their examination by the Director in November, 1882, they had been cut further back and modified in various ways, the result showing the great variability as regards minute detail of the Woolwich and Blackheath Beds. A word of caution may perhaps be useful on the way in which the Blackheath Pebble Beds mask the beds beneath them along the brow of the Lower Tertiary escarpment.
The, pebbles roll down the hillside in vast numbers, and give the impression that it is entirely made up of pebble-beds, where no road or railway-cutting exists to show the true state of things. Thus in a guide-book to Greenwich and its neighbourhood, published in 1882, is a remark about "One Tree Hill" in Greenwich Park, to the effect that "owing to a peculiarity of its geological formation it is composed principally of loose pebbles." One Tree Hill is simply a part of the westerly extension of the Westcombe Park escarpment.
Leaving Westcombe Park by Foyle Road, the party, after leaving Greenwich Park by the Blackheath gate, crossed the Heath, and descended the hill towards Lewisham. On reaching the immediate neighbourhood of the Loampit Hill sections, it became evident that great alterations were in progress there. Much building is going on close to the most easterly pit, that in which the shell-beds of the Woolwich Series and strata immediately below them are displayed. This pit is now enclosed, and used as, a store yard. But as it is, fortunately, nearly semicircular in shape, a good view of the strata was obtained from the top of the pit. The oyster-bed, 2 feet thick, separating the two Cyrena-beds, was pointed out and contrasted with the mere trace of an oyster-bed at Westcombe Park. Below the shell-beds and that containing "race" and concretions, a thick pebble-bed was seen; but, above the shell-beds, the thick pebble-beds of Westcombe Park were represented at Loampit Hill by a pebble band of 2 to 3 inches at the base of the London Clay. Fortunately at Loampit Hill on this occasion a new and very clear section of the strata .between the Woolwich shell-beds and the London Clay was exposed. They consist, as described by Whitaker (Geol. London, i., 1889, pp. 149, 150), of laminated clay with partings of sand, and sand with partings of clay, having a total thickness of about 25 feet.
[On July 7th, 1888, there was an excursion to Loampit Hill, Lewisham, and Westcombe Park, T. V. Holmes, F.G.S., Director (Proc. Vol. x. p. 501).]