394 MR. G. W. LAMPLUGH ON THE 



being sometimes clearly defined and sometimes irregular and sug- 

 gestive of passage (see PI. XIII. fig. 4). This rubble is a curious 

 hard cement-like mass of small subangular chalk-debris mixed with 

 a little marly clay, and with, very rarely, a small erratic pebble. It 

 shows obscure flowing lines of stratification, which are not, how- 

 ever, suggestive of deposition in water. A large limb-bone of Bo>i 

 or Bison was recently found in it, probably derived from the under- 

 lying Blown-sand. 



The thickness of this bed where it first appears at the cliff-foot 

 was proved by a boring * to exceed 21 feet, but as it rises it thins 

 rapidly, so that there is not more than 12 feet of it in the cliff 

 when its base is first seen ; and before reaching the Chalk on the 

 crest of the buried cliff it has dwindled to less than one foot, and 

 indeed in one place disappears entirely. Its extension southward 

 beneath the Basement Clay at some depth below sea-level was 

 proved by its occurrence at a depth of 22 feet in a boring on the 

 foreshore at Bridlington Q,ua5\ 



(d) The Buried Cliff (PI XIII. fig. 4).— The solid Chalk appears 

 suddenly in the cliff just opposite the village of Sewerby, fronting the 

 drifts in an abrupt wall 30 or 40 feet high ; this has been formed by 

 marine action prior to the deposition of any of the above-described 

 Glacial beds, and afterwards buried and obliterated by the accumula- 

 tion of materials banked against it (fig. 4). These materials differ 

 from anything found elsewhere on the coast, and are altogether a 

 most interesting series. They consist of the following members : — 



(A) An old sea-beach of rounded pebbles, chiefly of chalk, which 

 rests on a sea-cut platform of solid Chalk, and is piled up at the 

 foot of the old cliff to a depth of four or five feet. The upper 

 surface of this beach is not much above the present level of the 

 highest tides. 



(B) A rainwash of marly clay and fallen chalk, containing land 

 shells and bones, which rests on the old beach close under the cliff, 

 being there about five feet thick, but disappears at less than 7 yards 

 from the cliff. \ 



(C) A thick mass of fine wind-drifted yellow sand, with a few 

 blocks of fallen chalk, which rests on the rainwash, or, where 

 that is absent, on the old beach. This bed has a thickness in one 

 place of over 25 feet, and reaches quite to the top of the old cliff 

 (as shown in the section, fig. 4), where it is cut out by the chalky 

 rubble and Basement Clay. The cliff-face behind this blown sand 

 has been beautifully smoothed and rounded by the friction of the 

 wind-driven particles, and has an aspect quite unlike that of the 

 recent Chalk-cliff adjoining. 



The great value of this series f is that all the beds are fossili- 



* ' Report on Ancient Sea-beach, &c.' Brit. Assoc. Rep. (1888) p. 336. 



t The general resemblance of this section to the buried cliffs of the South of 

 England is very striking, especially in the arrangement of the beds, in the 

 presence of ' landwasli ' over the beach, and of local rubble above the land- 

 wash. See A. Tylor, Quart. Journ. Geo!. Soc. vol. xxv. (1869) p. 79, and 

 Prestwich, ibid. vol. xxxi. (1875) p. 36. 



