214 Dr, H. A. Nicholson — Geology of Ingleton. 



and liave a decidedly conglomeratic appearance. As no rocks of this 

 kind can be found in situ, it is impossible to speak exactly as to the 

 nature of these isolated boulders. 



III. After passing over an interval of about one third of a mile in 

 which there is no rock-exposure, a great series of greenish-gray 

 slates and interbedded felspathic traps is reached. The slates retain 

 their N.W. and S.E. strike, and have a nearly vertical cleavage, but 

 the bedding can scarcely be made out. Some of the traps are of 

 considerable thickness, others are mingled with slaty bands, and all 

 are much intersected by veins of quartz. Some are dark-gray in 

 colour, but they are mostly of a light greenish gray. They are all 

 very fine-grained, and are devoid of distinct crystals. 



IV. These are succeeded by a very thick band of ordinary Green 

 Slates, containing a few small bands of trap. 



V. A massive felspathic trap, of great thickness, and intersected 

 by numerous quartz-veins. In mineral characters this is exactly 

 similar to those already described, being fine-grained, greenish-gray 

 in colour, slightly hornblendic, containing scattered flakes of mica, 

 weathering brown, and effervescing faintly on the weathered surfaces 

 and in the minute fissures of the stone. 



VI. This trap is overlaid by a second great band of slates, which 

 has been largely worked on both sides of the river. They form a 

 fine-grained, greenish-grey slate, sometimes micaceous, and having a 

 nearly vertical cleavage, which appears to coincide with the bedding, 

 as shown by the existence of ripple -marking upon many of the 

 cleavage-planes. 



VII. Close below the slate quarries, by the side of the stream, the 

 slates are seen to be surmounted by a light-brown granular felspathic 

 trap or felstone, gritty-looking, and of small thickness. 



VIII. Above this there comes on a band of gray, cleaved, flaggy, 

 and calcareous shales, with a few obscure organic remains upon the 

 cleavage-planes, amongst which are a species of Orthis and a large 

 Orthoceras (probably 0. Brongniarti)} These shales are in parts 

 nodular, and they eifervesce freely when treated with acids. 



The further continuance of the section ujDwards is here interrupted 

 by a fault, running parallel to the Craven fault, whereby the Scar- 

 Limestone is brought down against the Silurian Eocks. 



Correlation with the Green Slates and Porphyries of the LaTce- 

 District. — "When we compare the Green Slates of the neighbour- 

 hood of Ingleton with those of the typical area in the Lake- 

 district, many points of resemblance are observable, and a few 

 notable differences. In both regions the series of rocks in question 

 consists essentially of alternations of bands of felspathic ashes, with 

 cotemporaneous igneous rocks, or traps, the ashes being usually 

 cleaved, and being sometimes replaced by flaggy shales containing 

 fossils. In the Ingleton section, on the whole, the slates are more 

 largely developed in relation to the thickness of the traps, than is 



' In the excellent paper by Professor Sedgwick already referred to, the following 

 fossils are stated to occur in this band of shales : — Stenopora Jibrosa, Goldf. ; Raly- 

 sites catenularius, Mart. ; Orthis Actonice, Sow. 



