PROCEEDINGS 



OF 



THE GEOLOGICAL SOCIETY OF LONDON. 



1832-1833. No. 28. 



Nov. 7, 1832. — The Society assembled this evening for the session. 



Woodbine Parish, Jun. Esq. F.R.S. of Upper Harley Street ; Henry 

 Troliope, Esq. of Harrow } Whitlock Nichol, M.D. F.R.S. & L.S. of 

 Curzon Street Mayfair ; and Herbert Mayo, Esq. F.R.S. Professor of 

 Anatomy in King's College, London, were elected Fellows of this 

 Society. 



A paper was first read, " On some Intersections of Mineral Veins 

 in Cornwall," in a letter to Davies Gilbert, Esq. M.P. F.G.S. F.R.S. 

 &c, by William John Henwood, Esq. F.G.S. 



The chief object of this communication is to lay before the reader 

 particular facts bearing upon certain theories respecting the disloca- 

 tion of veins ; and the author in pursuance of his intention first states 

 the theory as a question, and then adduces his facts. The following 

 are the principal propositions. 



1. When one vein is dislocated by another, is it to be found on the 

 side of the smaller or larger angle ? 



At Bulls, in the Herland mine, two veins are heaved by a cross- 

 course j and one of them was rediscovered on the side of the smaller 

 angle, and the other on the side of the larger angle. 



2. When one vein dislocates several others, are all the latter to be 

 found on the same hand ? 



In the Weeth mine, two cross-courses are traversed by the same 

 E. and W. lode. One of them is heaved to the left, the other to the 

 right, but both to the side of the larger angle. 



3. When the same vein is dislocated by several others, do they all 

 heave it to the side of the greater, or all to the side of the smaller 

 angle ? 



In Huel Friendship mine, a lode has been heaved by three cross- 

 courses, in each instance to the left ; but in two, on the side of the 

 smaller, and one on the side of the greater angle. 



4. When a vein is dislocated by several others, do they all heave it 

 to the right, or all to the left ; or some one way, some the other ? 



In Carharrack mine the lode is heaved by two cross-courses, and 

 by both of them to the side of the larger angle ; but in one instance 

 to the left, and in the other to the right. 



5. When a vein is thrown or dislocated by a slide, is it to be redis- 

 covered on the side of the greater or smaller angle ? 



In South Huel Towan mine, the vein was rediscovered on the side 

 of the smaller angle 3 but at Bulls on that of the larger angle. 



