Basin of the Eden and north-western Coasts of Cumberland, S^c. 395 



new tunnel, now excavating for the purpose of a ready communication with 

 the hills west of Dissington, where the main coal seam is about to be worked. 

 Its structure is therefore very well exposed. 



Close to the north end of Whitehaven comes in another fault, producing a 

 downcast to the north-east, of eleven fathoms ; but if we follow this fault into 

 the interior, the quantity of dislocation produced by it is enormously increased. 

 By this and two other faults, elevating the strata in the same direction, we 

 may explain the high position of the quarry sandstone in the hills immediately 

 south of the town. At Saltom, as is seen in the section, are two faults, pro- 

 ducing downcasts in opposite directions : their joint effect is to bring the 

 great sandstone once more to the level of the sea, after which it is continued 

 nearly a mile in a lofty cliff; and its component beds are carried by their dip 

 (with the interruption of one fault) in regular succession towards the base of 

 St. Bees Head. 



The general character of this sandstone is the same as in the tunnel cliff, 

 north of Whitehaven ; but it is of a much redder colour, contains many small 

 ferruginous nodules, and in mineral character is perfectly identical with many 

 portions of that peculiar red sandstone which separates the Yorkshire coal 

 measures from the magnesian limestone. It is generally without any trace of 

 fossils : the very extensive excavations carried on in it on both sides of White- 

 haven, have> however, brought to light a few obscure impressions of Equiseta 

 and Calamites. It makes, therefore, a very near approach to a true coal grit; 

 and in the surveys hitherto published, as well as in the estimation of the coal 

 viewers of the neighbourhood, it has, I believe, always been regarded as a 

 true member of the coal measures. 



Under Barrowmouth this sandstone is surmounted by a conglomerate, 

 exactly like the magnesian conglomerates of our south-western coal fields, but 

 only two or three feet in thickness. Its lower part is of a reddish colour, and 

 contains, among other fragments, rolled masses of mountain limestone mixed 

 with hydrate of iron. The upper parts of it have a calcareo-magnesian ce- 

 ment; and it is surmounted by, or rather graduates into, a yellow, foliated, 

 cellular, magnesian limestone. This limestone is not well exposed at the 

 sea-side, being almost buried under the overlying red marls ; but some of its 

 upper beds are mixed and striated with red ferruginous matter, and seem to 

 pass into a singular, red, siliceous sandstone containing jasper and chalcedony. 

 It is, however, extensively worked at Barrow and Preston How quarries, and 

 shows in great perfection most of those peculiarities of structure which so well 

 mark the formation . I do not know of any section where all its beds are exposed ; 

 but it probably never exceeds 60 feet in thickness. Of its relations to the coal 



VOL. IV. SECOND SERIES. 3 F 



