256 



THE GEOLOGIST. 



The manganese-ore is singularly free from iron, and its position 

 between the beds of hasmatite forms altogether a most remarkable 

 association of minerals. The character of the veinstone of the haema- 

 tite at Newton differs from that at Llantrissant by the absence of 

 silica and its replacement by calcareous minerals. Small leaders of 

 ore, called " blowers/' run up into the magnesian conglomerate at right 

 angles to the general mass, and are analogous to the "joints " which 

 intersect the " mine-measures " in the Forest of Dean. The ore dips 

 fast to the south at the crop, but would seem to " flat " as it passes 

 towards the centre of the basin. Near Pyle, traces of the haematite 

 are to be seen at low-water occupying the flank of the limestone 

 basin immediately under the magnesian conglomerate ; and both there 

 and at Newton the deposits course in an east and west direction. 

 Besides the psilomelane, which forms the chief bulk of the ore, there 

 is a small admixture of pyrolusite, but the vein may be considered 

 "massive grey manganese," such as occurs at Upton Pyne and 

 Dodscomb Leigh, in Devonshire. 



In the Newton District the ploughshare has brought up the 

 evidence of former workings of the ore, as near Llantrissant, and 

 iron-cinders, old slag's, and even pieces of ore, are to be found scattered 

 over the fields. The borough of Kenfig, in this district, consists of a 

 solitary house ; and this fact is significant of the place having once 

 been of importance, arising, no doubt, from the metallurgical opera- 

 tions formerly carried on by the Romans, or some other people, in 

 the neighbourhood, — the ancient town having disappeared with the 

 removal of that industry which had created the settlement. 



Antiquarian matters do not properly fall within the province of 

 this article, but those of my readers who have curiosity in these 

 m'atters had better repair to the locus in quo, where they may find an 

 abundance of material : — the geologist will have an opportunity of 

 examining there som.e of, perhaps, the most wonderful phenomena in 

 connexion with the petrology of the British Isles. 



