72 Postcript to Mr. IIutton's Notes, ^c. 



Postcript to Mr. Hutton's Notes on the New Red Sandstone, of the 

 County of Durham, below the Magnesian Limestone. 



Read May 18, 1830. 



During the progress of the foregoing Notes through the press, we were 

 induced to examine the effects upon the strata caused by the 90-fathom 

 Dyke, at the point of its greatest depression, certain appearances having 

 led us to suppose that the lower New Red Sandstone existed some- 

 where near Killingworth, and we found it accordingly in one spot, 

 called the Clowsden or Closing Hill Quarry, situate about 950 yards to 

 the south of Killingworth House, and immediately adjoining the Kil- 

 lingworth Railway. It is of inconsiderable extent, and forms a small hill, 

 which slopes gently on every side, except where it has been broken in 

 upon for quarrying the stone. There are two quarries, that on the 

 northern slope of the hill has been extensively worked ; it is now full of 

 water, but is said to be 60 feet deep. The southern quarry was drained 

 by means of a drift, from the bottom of the hill ; this was driven north- 

 ward entirely in Sand, until the face of the rock was suddenly and ab- 

 ruptly come upon, which was no doubt the northern cheek of the Dyke. 

 I am informed by my friend, Mr. Nicholas Wood, that a seam of Coal 

 20 inches thick, with a Shale bed above it, appeared in the north quarry ; 

 this Coal stratum is higher than any bed we have been hitherto ac- 

 quainted with in this Coal field. The highest known is in Hebburn, 

 Jarrow, and South Shields collieries, from their pits being sunk at the 

 point of the greatest depression of the strata, or at the bottom of the 

 Coal Basin, as it is termed ; it is 114 fathoms above the High Main, 

 whilst this is 190 fathoms at least. 



The Red Sandstone exhibits here its usual characters, but the Ruddle 

 is in greater abundance than common, particularly in the lower part of 

 the bed, where it exists in large masses, all the farmers in the neigh- 

 bourhood supplying themselves from this quarry with Keel (as it is 

 termed, and the spot the Keel Quarry), for marking their sheep. Its 



