276 On the Geology of Northumberland and Durham. 



Yds. Ft. 



Clay 5 



Freestone (sandstone) 1 1 



Plate (argillaceous shale) 18 



Plate, white 2 



Plate 21 



Brown limestone 7 



Brown post 7 



Coal mixed with stone 2 1 



66 2 

 This may convey some general idea of the rocky beds 

 passed through, but evidently is not to be relied upon like the 

 other sections, which were procured from gentlemen em- 

 ployed in the higher departments of mining. 



At Guilsland in the Vale of Irthing, three miles to the west 

 of Blenkinsop, the strata consist of limestone, sandstone, coal, 

 and shale; the latter peculiarly rich in nodules and thin sub- 

 ordinate strata of clay ironstone. One peculiar bed of blue 

 limestone, about half a mile below the Spa, is intimately blend- 

 ed with minute fragments of coal. A seam of coal, two feet 

 thick, crops out in the cliffs on the Wardrew side of the river : 

 it has a good roof of sandstone, and is worked at the surface 

 by the farmers on the estate. Near Baron House, a mile and 

 a half south-west of Wardrew, a seam of coal, three feet eight 

 inches thick, crops out: from its situation, and the inclination 

 of the strata in which it is imbedded, it must be lower in the 

 series than the Blenkinsop seam. The course of the Irthing 

 from Narworth to Guilsland is in the limestone formation ; 

 but at Leonard coast the new red sandstone of Cumberland 

 makes its appearance. The limestone has been quarried on 

 the banks of the river a little to the east of the bridge, and 

 the red sandstone not far above it. The Abbey is chiefly 

 built of this material, which, like the same description of stone 

 at Melrose, seems, from its durability, well adapted to the 

 purpose. Immense blocks of fine-grained gray granite are in 

 this neighbourhood scattered over the face of the country, 

 both on the encrinal limestone and on the new red sandstone. 

 To return to the vicinity of Glenwhelt : a mass or irregular bed 

 here crosses the rivulet, and is probably connected on the one 

 hand with the well-known Walltown crags to the eastward, 

 and on the other with the basalt quarried on the top of 

 Windy-law Hill, close to the Carlisle turnpike road, to the 

 westward. In the quarry the basalt assumes a rude columnar 

 structure, and beautiful crystals of purple amethystine quartz 

 are occasionally found in its interstices. In the vicinity of 



