The Quarterly journal of the Geological Society of London . rtford gravel J, which I refer to the same period of re-elevation. 5. Near the chalk-escarpments overhanging the Wealden area, andon the highest tabular summits of the chalk hills, the pipes are filledwith cledge §, a mixture of clay, sand, and unabraded and unfrac-tured flints. This I refer to part of the same period of re-elevation,considering it to have been laid dry somewhat sooner than the Dart-ford gravel. 6. When any member of the erratic tertiaries, or the chalk onwhich they rested, has been so exposed by denuding action as to
The Quarterly journal of the Geological Society of London . rtford gravel J, which I refer to the same period of re-elevation. 5. Near the chalk-escarpments overhanging the Wealden area, andon the highest tabular summits of the chalk hills, the pipes are filledwith cledge §, a mixture of clay, sand, and unabraded and unfrac-tured flints. This I refer to part of the same period of re-elevation,considering it to have been laid dry somewhat sooner than the Dart-ford gravel. 6. When any member of the erratic tertiaries, or the chalk onwhich they rested, has been so exposed by denuding action as to bethe bed nearest the surface, it is worn into furrows and pipes of smalldimensions, and these are filled with the loamy deposit which I callthe warp-drift ||, and which contains, and occasionally passes into,masses of sharply-fractured flints and heaps of chalk-rubble. This ispart of the angular flint-drift of Sir Roderick Murchison**. I refer the Fig. 1.—Section near Portobello Inn between Farningham andWrotham, Kent-. N. Scale 12 feet to 1 inch. Talus. a. Dark ferruginous clay with flints. c. Seams of rounded eocene pebbles. A, b. Light-coloured sandy loam. ri. Red and yellow ochraceous sand, e. Clay, sandy loam, and eocene pebbles, in irregular alternations, horizontally stratified ;becoming obscure towards the south part of the section. /. Chalk. * The Lower Erratic Tertiaries comprise the Boulder-clay; the superincum-bent gravels, &c. with erratic blocks being the Upper Erratics. See Geol. Soc. vol. vii. p. 21; and ibid. vol. ix. p. 295. f See Table, Quart. Journ. Geol. Soc. vol. ix. p. 295. % See Quart. Journ. Geol. Soc. vol. ix. pp. 287, 295. § Quart. Journ. Geol. Soc. vol. viii. p. 275. || Quart. Journ. Geol. Soc. vol. ix. Table, p. 295. ** Quart. Journ. Geol. Soc. vol. vii. p. 349. TRIMMER ON SAND-PIPES. 235 o 2 ~ c o o^ ISoSb - B&Ebl3 fracture of the flints, not to movementsof disturbance in the chalk, which tookplace, I conceive, durin
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