Mr. Tate on Basaltic Rocks. 207 



occupying nearly the same position, it is on the north bank 

 of the Font near Ritton, and next, northward of Green 

 Leighton, and then near to Gallow Hill, and away by Hart- 

 ington to Kirkwhelpington, where on the banks of the 

 Wansbeck are sections of some interest near to Kirkwhelp- 

 ington Mill, in the bed and in the banks of the Wansbeck ; 

 the basalt is overlaid by limestone, about fifteen feet thick, 

 and altered at the point of contact, and this is covered by 

 shale beds about twelve feet in thickness. Another Section, 

 on the north bank of the river, shews the basalt divided by a 

 thin bed of metamorphosed shale. In Section 11 we have, 

 dipping S.E. 



Feet. 



b. Columnar basalt 20 



sh. Metamorphic shale 1 



V Columnar basalt 12 



s. Sandstone — 



From Hartington to Little Swinburn, a distance of seven 

 miles, there are two outcrops of basalt, in some parts one and 

 a half mile apart. The westerly outcrop ranges by Col well, 

 Horncastle, Hawick, and Throckrington, to near Little 

 Swinburn*. The easterly outcrop curves away from Hart- 

 ington to Kirkwhelpington, and thence to West Harle, Great 

 Bavington, Humbleton, and Little Swinburn; from whence 

 there is but one range south westward to Gunnerton and 

 Haughton Strother, where it crosses the North Tyne. 



On the slope of the south bank of the Tyne at Cocklaw, 

 the basalt appears, and it extends to Towertye, where it 

 crosses the line of the Roman Wall, and whence its course in 

 a W.S.W. direction is to Glenwhelt, a distance of fourteen 

 miles. Along the whole of this range, it is intruded among 

 the middle beds of the calcareous division of the Mountain 

 Limestone. 



At Towertye, the ditch of the great Roman barrier has 

 been cut out of the basalt, which is here seven hundred and 

 seventy-six feet above the sea-level ; and on its side are still 

 lying large blocks, which had been excavated by the Roman 

 workmen, and which though little changed during seventeen 

 centuiies, shewing the durability of the rock, yet still bearing 

 the marks of time ; for the iron in the basalt has oxidised in 

 some places, and partially destroyed the rock, giving a 

 tendency to the outer surface to peel off in flakes. From 

 Towertye the basalt curves away southward and then north - 

 * Hutton, Trans, of Nat. Hist. Soc. of Northd. and Durham, vol. ii., p. 198. 



