Vol. 67.] WEST, MID, AND EAST SOMERSET. 69 



The section in the road- cutting near Old Down Inn is quite 

 overgrown ; but portions of that in the railway-cutting, which, 

 has been described by the Rev. H. H. Winwood l and by Mr. H. B. 

 "Woodward, 2 are still visible. 



(D) The Hinton-Blewet Area. 



In this ' outlier' the Tea-green Marls are about 11 feet thick, and 

 the Pteria-contorta Shales about 10 feet. 



In the lane leading from Hinton-Blewet to Shortwood Common, 

 the Cotham Marble and other deposits composing the Cotham Beds 

 can be seen, together with the underlying black shales and associated 

 limestones and sandstones composing the. Westbury Beds, and then 

 the Tea-green and Red Marls ; but the best exposure of the Pteria- 

 contorta Shales in the outlier is in the steep bank on the west side 

 of the lane that leads from the Cross Roads on Burledge Hill to 

 Bishop's Sutton. Here was discovered a fine development of the 

 Cotham Marble, and a limestone-bed comparable with the Pecten- 

 Limestone of Chilcompton, only in places pyritic and full of fish- 

 Temains. 



(E) The Harptree Area. 



At Harptree Hill, Triassic, Rhaetic, and Liassic deposits occur 

 in a hollow that was excavated out of Old Red Sandstone and 

 Carboniferous Limestone. The Old Red no doubt furnished the 

 arenaceous material of which the Rhaetic deposits are here mainly 

 composed, and most likely percolating waters with silica in solution 

 have brought about the partial silification of the superincumbent 

 Liassic deposits. 



These abnormal facies of the Rhaetic and Liassic strata here 

 occasioned considerable difficulty in their early correlation. Thus 

 Thomas Weaver regarded them as being of the same age as the 

 Blackdown Beds (Selbornian) 3 ; Buckland & Conybeare thought 

 them possibly comparable with the Dolomitic Conglomerate 

 (Keuper) 4 ; but De la Beche detected their partial Liassic age, 5 

 and Mr. H . B. Woodward separated them as Rhaetic and Liassic. 6 



There is only one section open now (1905), and that is the 

 celebrated ' pot ' or ' swallet-hole/ about half-way between East 

 Harptree and the Castle of Comfort. 



' It is about 60 feet in diameter at the mouth, is funnel-shaped, and about 

 20 to 30 feet in depth. It is evidently a natural "pot" or " swallet-hole." 

 The section consists almost entirely of massive bedded chert, occurring in 

 layers of from 1 to 3 feet in thickness, standing out sharply, but sometimes 

 weathering sandy at the exterior, and separated by thin clayey beds an inch or 

 two in thickness. The beds are coated here and there with quartz crystals.' 7 



1 Proc. Bath Nat. Hist, & Ant. R C. vol. iii (1874-77) pp. 300-304. 



2 ' Geology of East Somerset & the Bristol Ooal-Fields ' Mem. G-eol. Surv. 

 1876, p. 79 & pi. iv. 



3 Trans. Geol. Soc. ser. 2, vol. i (1824) p. 365. 4 Bid. p. 294. 



5 Mem. Geol. Surv. vol. i (1846) p. 277. 



6 * Geology of East Somerset & the Bristol Coal-Fields' Mem. Geol. Surv. 

 1876, p. 105; see also p. 108. 



7 ' The Jurassic Rocks of England: the Lias of England & Wales ' vol. iii 

 (1893) p. 124. 



