﻿Yol. 64.] SUBDIVISIONS OF THE CHALK OF TRIMINGHAM. 405 



The next block (B) to the south is almost entirely, perhaps 

 entirely, composed of the same or of some of the same beds as Block 

 A, and like that area forms an anticlinal ridge running more or 

 less from east to west (see PI. XLYII). The only part of it which 

 deserves any comment, or which may represent beds not already 

 described, is the spur which runs up to the cliff-line (/). This spur 

 is cut off from the main mass by a fault filled with clay (g). It 

 consists of an anticlinal ridge 'formed by a very thick pseudotabular 

 band (h) of flint, with O.-lunata Chalk immediately above and below 

 it. This 'pseudotabular' band is as continuous as any ordinary 

 tabular flint-band ; but it is undoubtedly interbedded, and presents 

 an extremely rugged surface, being apparently formed by the con- 

 solidation of the lower part only of a close -set line of flints of the 

 ordinary type. As this ridge rises westward, that is, slantwise up 

 the beach, at a lower angle than that of the beach, Chalk is preserved 

 at the western end above the pseudotabular flint ; while farther down 

 the beach to the south the pseudotabular flint and the Chalk below it 

 have been cut through to some depth, but without another line of 

 flints being reached. Quite recently, on the exposure in the lower 

 part of the ridge of a considerable part of the surface of the pseudo- 

 tabular band, Pliocene beds {i) full of well-preserved marine shells 

 were found in the interstices of the pseudotabular band and cropping 

 out between it and the Glacial clay. These beds are dealt with in 

 an appendix (p. 411). This ridge was traced in patchy exposures 

 up to the foot of the cliff, and appeared to continue into the base 

 thereof. There is nothing by which this pseudotabular band can 

 be identified with any line of flints elsewhere exposed, but I strongly 

 suspect that it is identical with the highest line of flints visible in 

 the South Bluff (Block A). The seaward edge of this block (B) 

 and the south side of the pseudotabular ridge are the only two in- 

 stances known to me at Trimingham of the surface of the Chalk 

 dipping gently under the clay. 



The small strip of Chalk still farther south appears as a line (D) 

 on the plan (fig. 1, p. 402). It was described by me in Geol. Mag. 

 1906, p. 78. 



We now come to the northernmost block (C), the largest and by 

 far the most important (PI. XLYIII). Here only a relatively small 

 space at the northern end is occupied by beds {d' e) which may 

 be identical with any previously described ; but the correspondence 

 in detail down to the nature of the flint-band forming the boundary 

 between the Chalks with and without 0. lunata is so exact that 

 the identity is practically beyond doubt. The boundary of this 

 area, so far as it has yet been traced, is a fault; and no guidance can 

 be obtained as to the relative ages of the Chalk of the first two 

 blocks (A, B) and the Chalk which forms the greater part of the 

 block (C) now to be described. The beds in this block which are 

 new to us are all disposed more or less in an anticlinal ridge running, 

 as in the case of the other areas, east and west. From the lowest 

 tide-level for a considerable way up the beach, the beds run with 

 perfect regularity from one end of the block to the other, unbroken 



