272 THE SHAP GRANITE AND ASSOCIATED ROCKS. 



*' porcellanized " condition ; they are lighter than in the unaltered 

 state, and break with a conchoidal fracture, but the planes of 

 lamination are clearly shown. The Middle Coldwell Eeds occur as 

 white or cream-coloured laminated porcellanous beds on the summit 

 of Packhouse Hill, and immediately below them, above the road from 

 Kendal to Shap, the Lower Coldwell Beds crop out as quartzite, 

 though there is a fault between the Middle and Lower Coldwell 

 Beds marked by a breccia composed of fragments of the two rocks, 

 and itself altered by the granite. These are in turn underlain 

 by the Brathay Flags, which strongly resemble the Upper Coldwell 

 Beds in general appearance, though they have undergone greater 

 alteration. 



On the north side of Wasdale Beck the Upper Limestone band of 

 the Coniston Limestone occurs in a small stream coming from the 

 north, immediately west of Wasdale Head Farm. It is greatly 

 altered but clearly recognizable, though changed into a white 

 saccharoidal rock, for it has more finely-laminated beds inter- 

 stratified with it, and at its base passes into the breccia with 

 fragments of rhyolite seen weathering out on the exposed surfaces. 

 Beneath this the rhyolite is readily recognizable, nodular at the 

 summit, and fissile below, and underneath this comes the Lower 

 Limestone, with the original calcareous patches occurring as white 

 nodular masses embedded in a less pure rock. The presence of the 

 Coniston Limestone at this point was recognized by Profs. Harkness 

 and Nicholson so long ago as 1868 *. 



Ascending the hill from this point, a series of rhyolitic ashes and 

 agglomerates in a state of considerable alteration is traversed until 

 the summit of Wasdale Pike is reached, and immediately north of 

 this the vesicular andesites and interbedded banded ashes crop out 

 on the moorlands between this point and Sleddale Pike. We may 

 here state that we assume the presence of vesicles to be sufficient 

 evidence that the rocks in which they occur are true lavas and not 

 ashes, as we cannot conceive the production of vesicles of this 

 nature throughout the whole mass of a fragment al accumulation, 

 and the microscope fully confirms our view. Li this manner we 

 are often enabled to distinguish between lavas and ashes even 

 when the rocks have undergone great change near the contact with 

 the granite. 



The third section (fig. 3) is drawn from the Coniston Flags of 

 Wasdale Beck, through the grounds of 8hap Wells Hotel, in a 

 direction generally parallel with the course of Blea Beck to the 

 Andesitic Group west of the high road, on the southern flanks of Low 

 Fell (Tewsett Pike). 



The Brathay Flags are here hardened and splintery, and of a 

 dark colour ; they contain graptolites allied to JSlonograptus 

 vomerinus. Between Wasdale Beck and the Spa Well in Blea Beck 

 the lower rocks are covered by red conglomerate, but there is not 

 sufficient room in the interval lor the Stockdale Shales, the Ashgill 



* Quart. Journ. Geol. Soc. vol. xxiv. p. 296. 



