A HISTORY OF DEVONSHIRE 



liers on the north of the Tiverton valley. In the intervening distance 

 of 30 miles the Minette dyke of Rose Ash * occurs. 



MIDDLE NEW RED 



On the coast a series of red marls with thick even beds of red and 

 whitish sandstone, displaced by numerous faults, are succeeded on the 

 north of Straight Point by red marls (probably about 500 feet thick) 

 with a bed or two of sandstone ; these pass under the Budleigh Salterton. 

 Pebble-beds on Westdown Hill. The Straight Point sandstones seem to 

 be near the top of the intercalated series ; in occasional brecciation they 

 strongly resemble Lower New Red beds, but they also contain an irregu- 

 lar bed of dolomitic aspect, not found in the lower series. The marls 

 in their cuboidal fracture resemble the Keuper marls, but do not contain 

 gypsum or the thin calcareous and sandy bands found in that series. No 

 continuous development of sandstones can be traced northward from the 

 coast. Disconnected and frequently faulted patches of sandstone occur 

 near Exmouth, Littleham, Withycombe, Lympstone, Woodbury, White- 

 cross, Aylesbeare, and east of Rockbeare. North of Whimple sandstones 

 have not been detected in the marls. Faults preclude any certain esti- 

 mate of the thickness of these beds which on the coast from Exmouth 

 to Westdown Hill can scarcely be less than 800 feet, but they attenuate 

 northward and at the Somerset boundary may not exceed 200 feet. 



Their junction with the sandstones and breccias of the Lower New 

 Red is so anomalous as to suggest unconformable overlap ; whilst in their 

 relation to the overlying Pebble-beds nothing of the kind has been 

 proved. The slight irregularities in junction and occasional seams of 

 marl in the base of the Pebble-beds ' are the least that could be expected 

 from the change in physical conditions. Whether the marl series should 

 be classed with the Nottingham Permian Marls (as suggested by Irving), 

 the Upper Zechstein of the Harz, etc., or with the upper beds of the 

 Upper Rothliegende of the Nahe sections, or whether they represent 

 the whole or part of the Bunter, is open to question. 



UPPER NEW RED SANDSTONE 



Pebble Beds. — The Budleigh Pebble-bed is the thinnest member of 

 the New Red series, rarely exceeding 80 feet in thickness. Its marked 

 character enables the presence of faulted relations to the beds above or 

 below to be easily detected. There are many breaches in its continuity 

 owing to faults, especially between Sidmouth Junction and Kentis- 

 beare. 



The percentage of Silurian and Devonian quartzite pebbles,' which 

 forms so distinguishable a feature on the coast, decreases northward 

 towards UfFculme. The pebbles from Talaton northward are on the 



^ Downes, 'Mica Trap Rose Ash,' Tram. Devon Assoc. 1884. 

 * Rev. A. Irving, ^art. Journ. Geol. Soc. May, 1888, p. 156. 



' Vicary and Salter, ibid. August, 1864, p. 283 ; Davidson, ibid. Feb. 1870, p. 70 ; Thomas, 

 ibid. Nov. 1902, pp. 620-32. 



30 



