PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY OF LONDON. 



1831—1832. No. 24. 



Jan. 4, 1832. — A paper "On the stratiform basalt associated with 

 the carboniferous formation of the North of England," by William 

 Hutton, Esq., F.G.S., begun at the meeting of the 14th of Dec. 1831, 

 was concluded. 



The author's object in this memoir is to detail the range, con- 

 nexion, and phenomena of the whin sill, which occurs in the lead mea- 

 sures or carboniferous limestone of the North of England. 



He commences his observations by enumerating the points at 

 which the basalt is visible within the escarpment of the limestone 

 between Knaresdale and Lunehead ; then traces it along the outcrop 

 of that formation from Murton to the Roman wall, near Haltwhistle; 

 next along the wall itself; and afterwards by Gunnerton Crags, 

 Little Swinburne, Hartington, Newbigging, Shield's Dykes, Rugby, 

 and Greenfield, to the Aln near Den wick. Besides the whin thus 

 traced along the escarpment of the limestone, the author includes in 

 this sill or stratum the basalt which occurs in the series of beds dis- 

 played on the coast of Northumberland from the Aln to Bamborough 

 Castle; likewise that which appears in the interior between the last 

 point and Belford and Kyloe; and the basalt of the Fern Islands and 

 Holy Island. During the course of this extensive survey the author 

 made the following observations : — 



That the basalt within the escarpment, as on Alston Moor and the 

 neighbouring mining districts, dips regularly with the strata of the 

 metalliferous limestone. 



That the whin sill in general constitutes but one bed, though 

 sometimes two, and near Bavington three beds ; and is found in 

 contact with every stratum belonging to the limestone formation. 

 He noticed that great irregularity prevails in the thickness of the 

 whin ; and states that it varies from one to thirty or forty fathoms, 

 sometimes swelling out into dome-shaped masses, though without 

 producing any disturbance in the strata in contact with it. 



The igneous action of the basalt he observed to be principally ex- 

 hibited on the subjacent strata ; but he mentions four instances where 

 the incumbent beds of shale or limestone had assumed the same al- 

 tered characters as the beds below; and one, Gallows-hill near Hat- 

 lington, where the limestone above the whin is much contorted. 



Lastly, the author draws the following conclusions : — 



That the whin is a stratum included in the limestone series, and 

 was deposited subsequently to the beds on which it rests, but ante- 



