ROCKS OF SOMERSET AND DEVON. 387 



and to a great extent concealed by Lower Marls, as, between the 

 western extremity of Grabbist Hill and Horner (south-east of Por- 

 lock) the Lower series is developed principally in the form of breccia. 

 South and west of Luckham sandstones occur either resting on or 

 faulted against the older rocks. 



Character of Lower Sandstones. — These beds consist of red-rock 

 sands and hard sandstones, and differ from the Upper division in 

 being almost uniformly red. They are stained blaokish at Lower 

 Welshford, near Thorn St. Margaret, near Gaulden Farm, south of 

 Tolland, and in the neighbourhood of Luckham ; though sometimes 

 slightly calcareous, the network of concretionary veins and the 

 calcareous nodules, often locally distinctive of the Upper Sandstones, 

 are generally wanting*. They are also found passing into, inter- 

 calated with, and containing seams and beds of breccia, and at 

 Bradninch associated inseparably with a gravelly breccio-conglo- 

 merate. In distinguishing them from the Upper Sandstones by 

 colour I should have made a notable local exception in the light- 

 coloured and banded sands and sandstones of Torbay. The Lower 

 Sandstones, where the Lower division is developed, are found over 

 the area treated of to occur at almost any horizon with reference to 

 the other varieties, and also inseparably associated with them. 



Breccias. 



In describing the different purely lithological varieties of breccia 

 we will first consider the apparently uppermost form exhibited 

 in the coast -section. In the Shrubbery at Exmouth we find 

 red sandstones brecciated with numerous angular grit- fragments, 

 generally of a uniform size ; the same general character is dis- 

 played by the breccias of Langstone Point and Dawlish, and, in a 

 less degree, by breccia at the Docks in Exeter f. North of Exeter 

 in many places brecciated rock-sands and sandstones occur, differing 

 from the Dawlish breccias either by the fragments contained being 

 closer and the matrix more impure, as shown in some of the rail- 

 way-cuttings north of Stogumber, by a difference in the material, 

 as displayed in the breccias containing shale and grit-fragments 

 resting on Culm-measures on the north of the Tiverton Valley, or by 

 resemblance to a gravel in containing rounded as well as angular and 

 subangular fragments close together and of various sizes, as in the 

 neighbourhood of Bradninch and Boundham Head, near Paignton, 



* I have hitherto failed to detect the presence of gypsum in the Lower 

 Marls ; though it is possible that marls containing veins of gypsum near WithyT 

 combe (Williton district) may belong to this division, I am inclined upon other 

 grounds to ascribe them to the Upper-Marl division, 



t Fragments of igneous rocks are numerous in the Teignmouth and Dawlish 

 breccias ; and in parts of the Crediton valley the breccia is almost wholly made 

 up of them. 



Murchisonite is most plentiful in the breccia south of Exeter and in the 

 Crediton valley. The crystals when found singly, as is often the case in the 

 last-named locality, exhibit signs of attrition on their edges. 



So far as I am aware, few, if any, fragments of igneous origin are found in 

 the conglomerate and pebble-bed division 



