Clifton College Scientific Society. 47 



large pit has been opened in which these Tiiassic beds become 

 much more important, as their bottom has not been reached at a 

 depth of over 50 feet, while at 30 to 40 feet a great horizontal 

 bed of hsematite is being worked 10 or 12 feet thick. This bed, 

 however, rapidly thins out to the west, and must do the same to 

 the east, so that it forms a lenticular mass. 



These Triassic beds are evidently the debris of the millstone 

 grit beds containing haematite which have been denuded. 



Mr Lewis's mine is a pit about 60 feet long by 40 feet wide ; 

 the length being measured along the strike of the beds, and the 

 breadth at right angles to this in the direction of the dips, south 

 10° W. 



The beds at present exposed on the floor of the mine are eight 

 in number. 



No. 8. The highest of these beds in stratigraphical order is 

 found at the lower part of the quarry, and consists of red 

 sandstone with large cavities filled with haematite. 



No. 7. Bed of haematite, 4 feet, in sandstone matrix. 



No. 6. Laminated sandstone, red, with large nereites and shells. 



No. 5. Bed of haematite, 4 feet, in sandstone matrix. 



No. 4, Eed clayey shale. 



No. 3. Sandstone. 



No. 2. Thick bed of sandstone with some haematite. 



No. 1. Sandstone. 



There are thus two beds of nearly solid haematite which, I have 

 no doubt, will yield 50 per cent, metallic iron. The clay bed, 

 No. 4, is also rich in iron, and is said to be of use for mixino- 

 with the harder and purer ore. The sandstone is of no use and 

 is thrown away. 



At the west end of the quarry the rocks come up to the recent 

 surface soil. 



The value of the deposit depends on three things : — 



1st. The depth below the surface to which the beds of haematite 

 already found extend. This is a very uncertain problem ; in the 

 Carboniferous Limestone of the north of England in the Pennine 

 range are large deposits of lead and other minerals, but they are 

 never — or hardly ever — found below a certain depth. 



2d. When the Triassic beds to the north are removed, it is 

 quite possible that new beds of haematite may be found parallel 

 to those already described. 



3d. It is a question how far these beds extend to the east and 

 west along the line of strike. As the ore is iuterstratified with 

 the sandstone beds, and does not merely fill up a pocket or a 

 fissure in the rocks, there seems to be no reason why it should 

 not extend to a considerable distance each way. 



