CARBONIFEROUS DISTRICT OF COLCHESTER AND HANTS. 273 



" Pyroliisite. — This species is found at numerous localities in different 

 l^arts of the province, and is now being mined in considerable quantity 

 at one of them, viz., at Teny Cape in Hants Co., about five miles from 

 Walton, where about a thousand tons have been got out within the 

 last two years, the bulk of which has been readily sold in England. 

 It occurs here in the form of nodules of irregulax', generally rather 

 flattened shape, of all sizes, from that of a bean up to that of a man's 

 head, or even twice as large, and weighing proportionately up to about 

 twenty-five pounds. These masses lie loose in a bed of ' soil ' about 

 a foot thick and a foot below the surface : they consist of pyrolusite 

 and psilomelane. Some feet below this bed, in a gray and brick- 

 coloured limestone containing magnesia, the ore is found, in very thin 

 deposits, which, from the easily separable nature of the rock, can be 

 laid bare in sheets, and also in ' pockets ' or interrupted chains of 

 deposits of very variable dimensions, sometimes but a few inches in 

 depth, and thickening out to several feet. I have seen one egg-shaped 

 mass exposed in situ estimated to be of three tons weight. One of 

 these 'pockets,' running east and west at a depth of 15 feet from the 

 surface, was about 72 feet in length, varied in thickness from 6 inches 

 to 14 feet, and was practically exhausted on the removal of about 130 

 tons of ore. A second runs parallel with this, at a depth of 30 feet 

 from the surface, and has been found to extend at least 105 feet : it 

 had yielded up to August last about 300 tons of ore ; and a large 

 quantity remained. Below this, again, at a depth of 50 feet from the 

 surface, other deposits have been met with, the form and dimensions 

 of which have not, so far as I know, been fully made out, but which 

 have afforded many tons of good ore. The whole thickness of the 

 limestone holding manganese is estimated at about 300 feet. 



" The minerals associated with pyrolusite at Teny Cape are iron ore 

 (brown hematite, I believe), barytes, and calcite. The first of these 

 is occasionally found at the line of junction of the ore and rock, which, 

 as before mentioned, is sometimes red. The barytes is of pure white 

 colour, is often disseminated in varying quantity through the pyro- 

 lusite, and is probably constantly present in all but the pure crystals 

 of the species. The calcite is also occasionally imbedded, in trans- 

 parent crystals, but more often exists as an incrustation ; it sometimes 

 forms specimens of great beauty, when it lies in opaque snow-white 

 mammillary masses of finely crystalline structure, or in piles of nail- 

 head crystals, half an inch or an inch across, of gray or snow-white 

 colour, on black lustrous masses of well crystallized pyrolusite. 



"The pyrolusite found at Walton is sometimes attached to brown 

 hematite in a reddish limestone resembling that at Teny Cape. 



