180 J. D- KENDALL OX HAEMATITE IN THE SILURIANS. 



20. H-ematite in the Silttbians. By J. D. Kendall, Esq., F.G.S. 

 (Bead March 8, 1876.) 



In a paper read last session before the Society, I pointed out some 

 of the most important features of the Haematite deposits that occur 

 in the Carboniferous Limestone of Cumberland and Lancashire. 

 Amongst other things I showed that the direction of the deposits 

 was invariably parallel to that of the meridional divisional planes 

 by which the rocks are intersected ; and as an explanation of that 

 fact I suggested that the haematite had probably been deposited in 

 caverns which had been hollowed out by chemical action along the 

 meridional planes, or that the haematite had replaced the Limestone 

 along those lines. 



The paper also briefly referred to the deposits of haematite in the 

 Silurians of the same districts, and went to show that these deposits 

 (which are in the form of veins), like those in the Carboniferous 

 Limestone, were in direction parallel to the divisional planes. There 

 was, however, this difference between these Silurian deposits and 

 those in the Carboniferous Limestone, that whereas all the deposits 

 in the latter were parallel to one another, and had a direction nearly 

 north and south (that is the same as the meridional divisional 

 planes), those in the Silurian had two directions, some being parallel 

 to one set of divisional planes and some to the other. 



Since the delivery of that paper I have had an opportunity of 

 examining a Silurian deposit which appears to me to be altogether 

 unlike (as regards the relation between the direction of the deposit 

 and the divisional planes) either those deposits to which I before 

 alluded in the same scries of rocks, or those in the Carboniferous 

 Limestone. I therefore deem it may be interesting to the Society 

 if I give an account of my observations on that deposit. 



The deposit to which I refer is in the parish of Millom and 

 county of Cumberland, and is now being worked by the Water- 

 Blean Mining Co., their works being known as the Water-Blean 

 Mines. 



The geological structure of the district in which the deposit 

 occurs is somewhat as shown in the following plan and section 

 (figs. 1 and 2). 



The Silurians are all conformable, and strike about 65° N.E. and 

 S.W., with a dip of about 80° to the N.W. Their order is thus 

 inverted, the Limestone appearing to dip in below the Ash-beds, 

 and the Flags below the Limestone, whereas in reality the Ash- 

 beds underlie the Limestone, which in its turn forms the base of the 

 Flags. 



The Limestone is part of that narrow band which stretches through 

 the country in a nearly straight line from Millom to Shap, a distance 

 of about thirty miles. It is in this rock that the haematite occurs 

 to which I wish to call attention. The form of the deposit (or, 



