The Section at Worms Heath (Surrey). With Remarks on Tertiary Pebble-Beds and on Clay-with-Flints

Abstract

I. History and Literature of the Worms-Heath Outlier The occurrence of outliers of the Lower London Tertiaries far away from the main mass, in the Chalk-tract of Surrey, was known to Prestwich, and the sites of some of them were noted by him, though not in his papers read to the Society. 1 But, presumably because he was then dealing with distance from the main mass and not with size, these sites included only small patches, at the top of the Chalk-escarpment of the North Downs and not the much larger outlier with which we are especially concerned, roughly a square mile in area and some way inward from the Chalk-escarpment. All these outliers consist wholly of the uppermost of the three divisions of the Lower London Tertiaries, to which the name Blackheath Beds has been given, the underlying Woolwich Beds and Thanet Beds being absent. This was not mentioned by Prestwich, who was dealing with the Lower London Tertiaries as a whole and not with the divisions thereof, the details of which, moreover, had not been then fully worked out, his third paper on the Series not appearing until 1854. The first recognition of the Tertiary tract of Worms Heath was on Sheet 6 of the Geological Survey Map, published in 1864, though the Surveyor (who need not be named) was mistaken as to the age of the deposit when he first saw the place, some years before that date, the pebble-beds being taken as a peculiar kind of Drift,