96 



H. KEEPING AND E. E. TAWNEY ON THE EEDS AT 



they are traceable ; but though the vertical scale is more than twice 

 the horizontal, it is not possible to show the details ; for these 

 we must refer to the vertical sections. 



Lower Heaclon Beds of the cliffs between Weston and WiddicJc 

 Chines. — We left off with the Potamomya-sands, 8J feet below the 

 How-Ledge limestone ; these are easily traceable through the grass- 

 slopes, exposures of a few feet occurring at intervals all the way to 

 Widdick Chine, about 230 yards distant. There good sections are 

 seen on each side of the roadway ; here the sands have in the upper 

 part more clay mixed with them, as in Warden Cliff. Whiter sands 

 are below ; above are alternating whity-brown sands with bluish 

 silts. Melania turritissima occurs in the latter, a shell which occurs, 

 indeed, in the Bembridge Marls at Hamstead, but which, in this 

 district, we only know at one horizon, viz. the Unio Solandri bed, 

 and one above that, at Warden Cliff and Colwell Bay ; we remark 

 its analogous position at Widdick Chine. Below the sands, again, is 

 pale greenish clay, 3 inches ; in descending order, soft buff Limnaea- 

 limestone, 1 foot ; brownish sands with Potamomya and reptile 

 dermal ossifications : these occupy the position of the Crocodile-beds 

 in the Lower Headon at Hordwell ; they continue along the cliff as 

 we walk northwards. Below is a carbonaceous band or impure lig- 

 nite, 6 inches, then a repetition of clays with carbonaceous layers, fol- 

 lowed by another Limngea-liuiestone, 10 inches, Potamomya-clays, 

 4 feet, another Limnsea-limestone, 1 foot, greenish clays with Palu- 

 dina lenta, Potamomya plana, Melanosis brevis, Limnaia &c. ; 

 another Limnasa-limestone, 8 inches, full of Oyrogonites, below that 

 clay with carbonaceous layers passing to drab sands, about 2 feet ; 

 then a lignite layer and impure Limnaea-limestone, soft and crumbling 

 at the outcrop. The limestone full of Gyrogonites is noteworthy, as 

 it occurs only low down in the Lower Headon, and serves to mark 

 our position in the series at this spot. Now this Chara-limestone is 

 exposed again at the back of the Reading Booms, where there are 

 the same five limestones seen as near Widdick Chine, the Chara-bed 

 being the lowest but one ; this is well seen behind the Beading 

 Booms, where there has been a cutting through the Lower Headon 

 beds for a new pathway. It will be noticed that we have passed 

 five thin Limnaea-limestones in the lower part of the Lower Headon 

 in the cliffs immediately north of Widdick Chine, and again behind 

 the Beading Booms ; we see them again as they rise from beneath 

 the sea-level beyond the new pier under Warden Cliff ; they are 

 seen also in the recent scarping under Totland Bay Hotel. The 

 continuity, then, of the section from the five lower limestones under 

 Warden Cliff through Weston Chine to Widdick Chine is undoubted ; 

 and from there we continue through the sands above to the How- 

 Ledge limestone in Headon Hill. The beds in the cliff here belong- 

 entirely to the Lower Headon*. 



* The top of the cliff at the back of the Reading Eooms has a capping 

 of about 7 feet of Post-tertiary sand ; at the base of this is a layer of flints and 

 derived marine fossils, Cytherea incrassata, Ostrea velata, &c, showing that 

 the marine Middle Headon series existed here above this level. This Post- 

 tertiary sand lies on the (Lower Headon) Warden sands. 



