Northumberland and Durham. 1 3 



thus that the Five Quarter coal seam of the mines on the Wear is 

 divided into the Metal and Stone-Coal seams of Sheriff Hill, and 

 that the Low-main seam of the Wear becomes the Five Quarter and 

 Six Quarter seams of the Tyne and Gateshead Fell. Thus also in 

 Brandling and Hebburn collieries a parting of stone first divides 

 and afterwards usurps the place of the High Main coal seam ; and 

 thus the two upper coal seams that are well worth working (see 

 the section of Montague colliery north) at Kenton, are no longer 

 so in the neighbouring colliery of Killingworth. The following is 

 an account of a similar occurrence in Montague colliery, abridged 

 from an unpublished Memoir, by Mr. Thomas, of Denton, on the 

 dykes found in that mine. Within the Newbiggin Stone-Coal 

 seam, at 20 inches from the floor, there is a band of a soft clayey 

 substance \\ inch thick : but the band encreasing in thickness to- 

 wards the east, the coal is divided into two distinct seams, whose 

 aggregate thickness is less than that of the original seam. At the 

 distance of 1000 yards to the east, and 300 yards north of the 

 main dyke,* the band is 24 feet thick ; the upper coal seam 6 inches ; 

 the lower 16 inches. The band decreases towards the north at 

 the rate of something more than 1 inch per yard ; and the coal at 

 the same time increasing, the upper and lower parts are so nearly 

 united at the distance of 160 yards, as to form again a workable 

 seam. The upper coal then measures 21 inches, the lower 24, 

 and the band 15. 



It is useless therefore to attempt any general section of the Coal 

 formation ; and it will be seen in the sections subjoined to this 

 paper, how difficult it is from want of uniformity in the beds to 

 identify the coal seams in the vicinity of Newcastle. I refer to the 



* The Ninety-fathom Dyke described hereafter. 



