382 W. A. E. T7SSHEE OK THE TRIASSIC 



The Pebble-beds of Budleigh Salterton and of Burlescombe, and the 

 Conglomerates of Milverton. 



This division affords 3 distinct lithological types, passing from one 

 to the other, I believe horizontally ; but, owing to this being the 

 thinnest member of the Trias of Devon and Somerset, it is the most 

 affected by faults, so that the changes in composition cannot be 

 always traced. 



We will commence with the coast, as the conglomerate in the 

 Williton district is so much faulted where present and so often ab- 

 sent, owing to the same cause, as well as so similar to that of 

 Milverton and Wiveliscombe, that it would form a bad starting- 

 point. 



The following are general characteristics of all three types — well- 

 worn nature of contained fragments, imp ersistent strips and beds of 

 rock-sand and sandstone intercalated, and general thickness of 

 beds. 



At Budleigh Salterton the pebble-beds form, for nearly 20 chains, 

 the substratum of the beach, dipping conformably under the Upper 

 Sandstones and overlying Marls which dip towards the north-east at 

 an angle of 5°. They consist of about 100 feet of large ellipsoidal 

 quartzite pebbles of foreign derivation (as far as at present known)* 

 in red sand, and containing impersistent strips and beds of rock- 

 sand. As far as I have yet seen, the quartzite pebbles seem to 

 give way gradually to grit and quartz, and to become smaller 

 north of Aylesbere Hill, between Whimple and Ottery St. Mary. 

 Between Tallaton and Uffculm, though the feature is generally 

 persistent, the pebble-beds are present only at intervals along the 

 line of feature, but sufficiently close to justify me in considering 

 their absence due to faults. Thus they are shown at Blue Anchor, 

 Higher Tale, Clist, "William's Cross, Kentisbere, Pirzwell, Higher 

 South Hill, and Bull Moor, near Uffculm. In most of these patches 

 the pebbles are smaller than those south of Tallaton. At Uffculm 

 and Uffculm Down they consist of pebbles of grit and quartz (in 

 some places compacted by ironstone into comparatively hard beds), 

 in a red-sand matrix, and containing strips of sand. At Burlescombe 

 they exhibit the appearance of a loose gravel of small quartz 

 pebbles in sand. Between Uffculm and Whitehall Hill their ab- 

 sence in one or two places is manifestly due to faults. Near Thorn 

 St. Margaret, they appear to be passing into a hard rock, but the 

 immediate change into the conglomerates, faulted against them, 

 cannot be observed. The conglomerates of Thorn St. Margaret, 

 Milverton, Castle Hill, near Wiveliscombe, Combe Ulorey, &c. con- 

 tain pebbles (generally large) of limestone and Old Bed Sandstone, 

 and smaller ones of quartz (the limestone pebbles being in excess 

 of or less than the others in different places) in a matrix of 

 hard red sandstone, generally slightly calcareous. The beds are 

 generally massive; but those at the top of sections often appear 

 much thinner than the rest. Subangular fragments of grit and 



* Mr. Peach adyocates their derivation froin certain quartzites in Cornwall. 



