Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/124

 tertiaries nearest the surface became elevated with their gravel covering, and cut back by the denudation into the form of scarped brows. While, however, the high brows of the Hampshire gravel are thus, I contend, coeval, or nearly so, with the high-brow gravel of the Thames, East-Essex, and Canterbury sheets, the lower-terrace beds of the Thames gravel formation are not, I venture to suggest, coeval with the Elephant-gravels of Mr. Codrington, but are considerably

Fig. 2. — Theoretical Section connecting the Thames and Hampshire Gravel Brows.

Mr. Codrington's inlet. The western extremity of the Weald.

1. Weald clay. 2. Lower Greensand. 3. Gault, Malm Rock, and Upper Greensand. 4. Chalk. 5. The Lower Tertiaries. a. The sea-bottom on which the high-brow gravel of the Thames and Hampshire sheets accumulated. b. The sea-level of that period, c. The sea-bottom of the inlet wherein the lower Hampshire marine gravels accumulated, d. The sea-level of that period. The XXX mark the high brows of gravel of the London and Hampshire areas.† The part over which the sharply broken flint accumulations of Sir R. I. Murchison occur. indicates the foci of preglacial upheaval.‡ indicates those of postglacial upheaval. (N.B. The Needle Down should in the upper representation have been drawn free of Tertiaries and near the sea surface.)

anterior to them, and possess a well-known older and somewhat different fauna, both mammalian and molluscan, though of course posterior to the highest-brow gravels of either area. In other words, the great slope of gravel which Mr. Codrington shows as stretching from low levels (where it inosculates with the Elephant- gravels of the valleys) up to brows where it is cut off by denudation at elevations of 400 feet, represents, according to my view, that long postglacial period during which, over Surrey, Sussex, and Kent, those extensive changes of land and water were proceeding which resulted in the denudation of the Weald — the Selsey deposit (which I have correlated with the retirement of the sea within the Wealden escarpment) being covered by the lowest-level portion of the Hampshire sheet.

Discussion.

Mr. Godwin-Austen thought that the author had done his theory injustice in presenting only a portion of the Wealden area for consideration. He remarked that phenomena similar to those of the Weald were to be found in various parts of Western Europe. He was glad to find that Mr. Searles Wood did not regard the escarp-