308 Mr. N. Wood on the Geology of Northumberland, ^c. 



this Limestone lies a bed of very white Sandstone, through which a 

 Basaltic Dyke passes without altering the position of the beds. The 

 direction of this Dyke is N. 83 W., and it passes through the beds of 

 Limestone and Sandstone, nearly at right angles to the line of stratifica- 

 tion, or 70°. Upon the Sandstone rests another thick bed of dark blue 

 Limestone, very much contorted and wavy, with thin beds of Shale in- 

 terposed between the planes of stratification. 



This bed of Limestone abuts against a confused mass of Basalt and 

 displaced Sandstone, the position of which will be best comprehended 

 by a reference to the Section. This broken and confused mass of Ba- 

 salt and Sandstone, is terminated by a great body of Whin or Basalt, 

 which forms a nearly perpendicular cliff, about 120 feet in height, 

 stretching into the sea, and dipping and diminishing in height in that 

 direction. The Sandstones and Shale, in contact with the Basalt, are 

 altered and affected in a similar way to that which usually takes place 

 from the influence of Whin Dykes. 



The mineralogical character of the Basalt, corresponds with that of 

 the Whin Sill of Aldston and Teesdale ; consisting of Felspar and Horn- 

 blende, and, where exposed to the sea, it assumes an apparently colum- 

 nar appearance. 



This mass of Basalt, diminishing in height from the south face, then 

 forms a platform of rocks, varying from 12 to 20 feet in height, stretch- 

 ing along the coast for about two miles, dipping into the sea and 

 presenting a rugged escarpment to the west, the line of direction being 

 N. 21 E. At the north extremity, the Basalt again forms a high mount, 

 on which the ruins of Dunstanburgh Castle stand. It here rests upon 

 thin beds of gritty Sandstone, Plate, and Shale, which lie upon a thick bed 

 of black Limestone much contorted, and every way resembhng the thick 

 bed near Howick, at the southern point of the Basalt. Tf these two 

 beds of Limestone are identical, we must suppose that the Slip Dykes 

 near Hotvick have elevated the strata on the north side, so as to throw 

 in the Basalt and accompanying Limestones, as shewn in the Section 

 No. 1, Plate XXVII. 



From Dunstanburgh, underlying the Basalt, we find a series of low 



