1868.] C0DR1>'GT0N WniTECLlFF BAT. 51 U 



14. Notes to Accompany a Section of the i^TuxTX from the Chalk to 

 the Bembridge Limestone at Whitecliff Bay, Isle of Wight *. 

 By T. CoDRiNGTON, Esq., F.G.S. 



(Abridged.) 

 The section is drawn from measurements made on the shore at low 

 water during the autumn of 1867. In consequence of the dip of 

 the beds being nearly vertical, the horizontal section exposed on the 

 shore at low water is a section nearly at right angles to the strati- 

 fication ; and advantage was taken of favourable tides to measure a 

 continuous section from the basement-bed of the London Clay to the 

 Bembridge Limestone, always exactly at right angles to the strike 

 of the beds. 



The dip of the lower part, or the London Clay, is in a direction 

 parallel to the line of the cliffs, so that the section exhibited in the 

 cliff is at right angles to the beds ; but the alteration in the direc- 

 tion of the dip, and in the line of the coast, both tend to make the 

 section seen in the cliff more oblique in the higher beds ; and in the 

 Headon beds the obliquity is as much as 45°. 



In bed VII f. of the Bracklesham series the junction of a bed of 

 compact clay with a bed of shaly laminated clay was observed, 

 which indicated a denudation of the laminated clay before the de- 

 position of the compact clay on its edges. 



No detailed examination of the fossils was attempted, except in 

 the case of the Headon beds, where, at the suggestion of Mr. Jenkins 

 (Assistant Secretary of the Geological Society), fossils were carefully 

 sought for, in order to verify the opinion expressed by the Kev. 0. 

 Fisher in a note to his paper on the Bracklesham beds (Quart. Journ. 

 Geol. Soc. vol. xviii. p. 67), to the effect that the equivalent of the re- 

 markable Brockenhurst bed, which has been correlated by Yon Konen 

 with Dumont's Lower Tongrian formation of Belgium, occurs here 

 near the bottom of the Middle Headon beds:J:' 



The beds marked L and M in the section, which are those 

 described in plate 4 of the Memoir of the Geological Survey of the 

 Isle of Wight as " brown clay, abounding in marine shells," and 

 "brown clay, with irregular fracture, shaly in places, with clayey 

 nodules," are those referred to by Mr. Fisher. 



A list of the shells § obtained from these beds, comprising upwards 

 of 30 species, will be found on the section, and is appended to these 

 notes. Ostreaprona and Cardita deltoidea, both distinctive Brocken- 

 hurst shells, are very abundant in bed L, and the latter occurs very 

 frequently in bed M. The shells from bed M were all obtained from 

 that part of the bed exposed only at low water spring tides. 



The ironstone band P and the double band B will serve as guides 



* The section referred to is deposited in the Society's Library. 



t The beds distinguished by Roman numerals are the divisions described by 

 the Rev. O. Fisher ; those marked by Arabic numerals are in accordance with 

 Mr. Prestwich's section. 



:j: See Pal. Soc. Mon. Brit. Foss. Corals, 2nd series, part 1. p. 40. 



§ I am indebted to the Rev. O. Fisher, Mr. Etheridge, and Mr. Jenkins for 

 r?eis(anc-e in naming the shells. 



