ROCKS OF SOMERSET AND DEVON". 383 



quartz sometimes occur in the matrix, and give the beds the slightly 

 hybrid character of a breccio-conglomerate, as at Yellow near 

 Stogumber. 



It is possible that the thick-bedded breccias of Wembdon, overlain 

 as they are by sandstones, and containing intercalated beds of 

 sandstone, may prove to be the representative of the conglomerate 

 division in the Bridge water area. 



Thickness. — As the conglomerates and pebble-beds seldom exceed 

 100 feet in thickness, and both contain intercalated beds of sand- 

 stone, so that in some places a section might display more sand- 

 stone than conglomerate, it is probable that the local absence of 

 this division may be due to replacement, and the sandstone beds 

 traced from Otterton Point (between the conglomeratic bed there 

 and the pebble-beds) pass into conglomerate in other parts of the 

 district. 



Mr. Pengelly noticed the feature made by the pebble-beds of 

 Budleigh Salterton, being the line of hills running thence to 

 Tallaton. In tracing the conglomerates from Wellington south- 

 wards, I found that feature maintained, even where the beds them- 

 selves were absent, indicating a fault junction between Upper 

 Sandstone and Lower Marls. 



Economic Uses. — The pebble-beds of Uffculm and Burlescombe 

 are quarried for gravel*. The conglomerates of Milverton, between 

 Thorn St. Margaret and Alcombe, near Minehead, are quarried out 

 for building-purposes, but more often for the sake of the contained 

 limestone pebbles to burn for lime. 



I have not found seams of clay in either the conglomeratesf or 

 the pebble-beds. In one instance (east of Whimple) at Straightway^ 

 Head, I was informed that they had worked out a bed of clay in 

 excavating the gravel. 



In mapping the conglomerates west of Milverton I noticed clay, 

 but concluded it was merely a soil or beds in the conglomerate. 

 Near Tiverton Junction, however, the extent of ground it occupied 

 led me to a better understanding ; but it was not till the summer of 

 1873, in making a rapid survey of the coast section, that I recog- 

 nized the true nature of the loamy clays in 



The Second Series of Marls. 



Underlying the pebble-beds conformably, we find red marls, varie- 

 gated greenish grey in bands, and slightly calcareous in the upper 

 beds. They seem to continue only for | mile from their outcrop, 

 under the pebble-beds on the top of the cliffs, in unbroken succession, 



* P. O. Hutchinson, Esq., of Sidmouth, informs me that manganese was 

 worked in the pebble-beds at Yattington (or Yettington), a hamlet to the 

 north of Budleigh. In sheet 22 of the Ordnance map. 



t Except where the base of the overlying sandstones consists of intercalated 

 beds of clay and sandstone, when the top beds of conglomerate may occur in 

 or with clay. 



\ Straightway Farm is called by the inhabitants Straightgate Farm. 



Q. J. G. S. No. 128. 2 e 



