WATSON — THE HEMATITE DEPOSITS OP GLAMORGANSHIRE. 241 



THE H^^MATITE DEPOSITS OF GLAMORGANSHIRE. 



By Dr. J. J. W. Watson, F.G.S., F.S.A., Member of the North 

 of England Institute of ^Mining Engineers. 



During the last few years, the native iron -making resources of 

 South Wales have received considerable assistance from the re-dis- 

 covery and working of some very remarkable deposits of hsematite in 

 the county of Glamorganshire. I propose in the present article to 

 describe two of the most important, perhaps, of those veins of ore, 

 which are found in the districts of Llautrissant and Llanharry, near 

 Cowbridge, and at Newton Nottage, near Bridgend; — the iron-ore in the 

 latter locality being associated with a very large and curious deposit 

 of manganese, chiefly psilomelane. Prefatory to this description, it 

 may not be out of place to give a few remarks on the physical geology 

 of the surrounding country, inasmuch as this district possesses ample 

 materials to engage the attentive and careful examination of the 

 geologist, particularly in relation to the origin of the mineral deposits 

 in question. The exploitation of these hsematite-mines will have the 

 effect, commercially, of giving a great development and increased 

 prosperity to the iron-manufacture in the district south of Cardiff ; 

 while, as a social result, their being worked will probably bring back 

 to a population, at present agricultural, the mining and metallur- 

 gical occupations of the ancient fore-dwellers on the soil, and, what 

 is most desirable, give constant occupation to a very large number 

 of the working classes. 



The stratigraphical position, as well as mode of occurrence of the 

 ore, is similar in all three localities, being confined to the uppermost 

 beds of the carboniferous limestone, immediately below where, in 

 ordinary cases in this district, it is overlaid by the sub-dolomitic or 

 calcareo-magnesian conglomerate, of equivocal age, which occupies the 

 hollows and overlaps the edges of the limestone. 



Starting from the shores of the Bristol Chaimel, the limestone- 

 strata roll forward to form a series of east and west anticlinals, before 



