Hydrated Sesquioxides. 



Under this head comes the important ore of iron known as 

 LiMONiTE, Brown Haematite, hydrated Iron Sesquioxide, or Ferric 

 Hydrate. Mention has already been made of the occurrence of 

 this ore amongst the vein-stuff associated with the lead ores along 

 the higher parts of the district around Cross Fell. 



Its mode of occurrence suggests that, in this case, at least, it is 

 simply Haematite altered in situ. The ore graduates into the 

 surrounding limestone in the same way that much of the Haematite 

 does, and the individual masses frequently present the peculiar 

 mammillated and botiyoidal forms, and the radiating fibrous 

 structure observable in the Haematite itself. Indeed, although 

 the characteristic brown streak of the Limonite is easily obtained, 

 these Cross Fell deposits are sufficiently like the West Cumberland 

 ore to have been described more than once as genuine Haematite. 

 I have elsewhere expressed my belief that the great upland tract 

 where these occur is merely the modified descendant of the great 

 plain that, before its continuity was interrupted by the Faults, once 

 extended beneath the New Red over a very large part of the North 

 of England. And just as I regard the Haematite occurring in the 

 low ground of Edenside as the result of infiltration from the lately- 

 denuded New Red still represented in the neighbourhood, so I 

 would refer the origin of these deposits of Limonite to infiltration 

 from part of the eastward extension of these same beds, and would 

 regard their present hydrated condition as being due to the greater 

 length of exposure they have undergone. 



Another form of hydrated iron oxide occurring in Cumberland 

 and Westmorland is Turgite. Part of the ore occurring at Aral 

 Head, or Ardale Head, near Cross Fell, is referable to this species, 

 as are also some botryoidal masses with a radiating fibrous structure 

 occurring in the haematite mines near Harcla, Westmorland. 



GcETHiTE, the Rhombic Monohydrated Ferric Oxide, frequently 

 occurs in association with Haematite and Limonite. I have not 

 yet noticed it myself; but it has been found in West Cumberland 

 by our Association Secretary, Mr. Kendall. 



