162 Mr. De la Beche on the Geology 



sandstone, shale, quartz, grauvvacke, and red quartziferous porphyry, ce- 

 mented by a red paste, generally argillaceous, and frequently very compact ; 

 so that the mass affords a very good building stone. This fine-grained con- 

 glomerate often contains small earthy crystals of felspar. 



Besides the preceding, there is a large-grained conglomerate containing' 

 fraoments that are sometimes a Ion or more in weight. In this the cement 

 varies, being principally loose and sandy, and seldom containing crystals of 

 felspar. Interstratified with these are red sandstones and marls. These con- 

 glomerates may, for more easy description, be divided into three small dis- 

 tricts : I . That of St. Mary Church and Watcombe ; 2. That of Tor Moham, 

 extending up to King's Kerswell ; and 3. That of Paington. 



1. Red Congloinerate of St. Mary Church and Watcombe. 



The range of cliffs extending west from the Ness-point at Teignmouth, 

 exposes a section of this rock^ which varies from fine-grained to coarse, the 

 latter greatly predominating: the most abundant fragments are pieces of the 

 limestones, on which the conglomerate here frequently rests ; pieces of red 

 quartziferous porphyry are, however, by no means rare, as in the east of 

 Teignmouth. These porphyritic fragments are most decidedly rolled pieces, 

 derived from some other rocks than the conglomerate that now contains them. 



The only interruption to the continuation of these conglomerates to their 

 termination at the fault at Oddicombe-sands, is caused by the carboniferous 

 limestones of Petit Tor*. These limestones are nearly isolated, being- 

 bounded on all sides but the sea by red conglomerate. The conglomerate 

 would appear to rise to the carboniferous limestone on both sides. 



A short distance further south, the conglomerate abuts against trapf . This 

 fault seems to continue through the village of St. Mary Church, where the 

 conglomerate abuts against carboniferous limestone. The church stands on 

 the latter rock, sections of which are seen in the village on the new road to 

 Torquay; nevertheless, close to these places, a mason sunk a well 100 feet 

 deep without going through the red conglomerate. 



A porphyritic conglomerate, resembMng that of Heavitree, is seen on Hollo- 

 way Hill, over which both the roads from Torquay to Teignmouth pass. 



2. Red Conglomerate of Tor Moham. 



This portion is joined to that previously noticed by a kind of isthmus of the 

 same rock, passing round from Holloway Hill by King's Kerswell. The con- 

 glomerate stretches from King's Kerswell south-west to Tor Abbey-sands, re- 



* Coast section, Plate XVIII. Hg. 1. t Plate XVIII. fig. 1, 



