Excursion to Perivale. Saturday, May 26th, 1883 - Geologists' Association excursion

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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)

Director: Rev. Prof. Henslow, M.A., F.G.S. (Report by The Director and Prof. T. Rupert Jones, F.R.S.). (Proc. Vol. viii. p. 141.)

The members were met at Ealing Station by Prof. Henslow and Mr. J. Allen Brown, under whose guidance the party proceeded . to the New Reservoir now in course of construction on the Mount. Here cuttings were visible, showing waved and banded loamy strata with deep grooves in them, the strata bending under the grooves. The latter run in a northerly direction, and were believed by Mr. Brown to be due to ice-action, as several specimens of rocks of various kinds had been found scattered about the surface of the field; but the grooves themselves appeared only to contain water-worn flints, and not rocks indicative of ice-action. A discussion arose as to their truly glacial character, Prof. Rupert Jones inclining to the idea that the upper beds had sunk over subterranean watercourses, and that the grooves were not due to ice at all.

The party proposed going to the most elevated point in the district, Horsenden Hill, but the weather proved so rainy and unfavourable that, after having visited Perivale Church and Churchyard, where the altar-tomb of Robert, son of Richard Cromwell, contains some fine Orthocerata, and where another old altar-tomb and its wrought iron railings have been curiously pushed and twisted out of shape by an ash, a thorn, and an ivy, they did not proceed further than the little bridge over the Swilley half-a-mile on the road beyond, where Prof. Rupert Jones gave an exposition of the physiography of the district.

He pointed out that valleys are the leading characters of a district, being the indications of the great denuding agents, rain, rivers, and ice, which modified plateaux and plains, leaving the hills as wrecks and relics of once broad flat lands. Such a land once existed throughout a great part of south-east England and north-west France, and, after the final elevation of the Weald area, wide level tracts, consisting of Tertiary strata variously eroded and coated with gravel, remained to be acted on by the retreating waters (whether the land rose, or the sea was withdrawn by its being evaporated and stored up as ice at the poles). Bagshot Heath, and other such small plateaux, and Highgate, Hampstead, and other such hills, are local remnants, their isolation having been made more and more distinct, after tidal action ceased to affect them, by rain and rivers, aided by arctic winters; derivative or secondary gravels, thus formed in the valleys, were again and again worn down or moved away, as the hill-sides and valley-bottoms were modified; and such successional deposits of gravels, with or without the barns of flood-muds, are traceable, and have been traced as well in the Ealing as in other districts. The animals inhabiting the lands bordering the sea-creeks, lakes and rivers were drowned and imbedded there and then, and tell of warmer or colder climates, as the case may be; and in many cases the flint tools and weapons of man are found in the gravels along certain stages or horizons of these diluvial and alluvial deposits; Mr. Allen Brown and Mr. R. W. Cheadle have found such archaic implements near Ealing, and others are abundant at Acton and elsewhere.

Map

See Excursion to Hampstead (p. 144).

Books

See Excursion to Hampstead (p. 144).

J. Allen Brown, The Water-bearing Strata of the Ealing District, 8vo, Ealing. 1882.

J. Allen Brown, Evidence of the Action of Ice, near Ealing, Proc. Geol. Assoc., vol. viii., 1883, pp. 173–181.

J. Allen Brown, Working Sites and Inhabited Land Surfaces of the Palaeolithic Period in the Thames Valley, Trans. Middlesex Nat. Hist. Soc., 1888-9, pp. 40–73.