384 Correspondence — Mr. W. Gunn. 



JNbrth shore of Lake "Winnipeg, the section exposed being a natural 

 one, and is as follows : — 



1. Loam, 3ft. 



2. Hard rock (Limestone?) 10ft. 



3. Pyritiferous sand, silvery to the eye when fresh, 4ft. (exposed). 



The pyrites forms so large a portion of the sand that it might be 

 worth while to work the deposit ; mere washing would probably 

 separate the ore readily from its matrix. The composition of the 

 pyrites is said to be Fe 46*4 S 53*6. 



With regard to the origin of the pyrites, can it have been formed in 

 situ in the sand, or is it as well as the sand the product of the disin- 

 tegration of an older rock ? I can find no account of any similar 

 deposit elsewhere ; the nearest approach to such a bed in character 

 seems to be met with in beds containing diminutive spherical nodules 

 of iron ore in Manitoba, but these are not pyrites ; they are chalybite 

 and much larger ; and it is said in the report of the Survey of the 49th 

 Parallel, that a thin film of pyrites in the Lignite deposits near Porcu- 

 pine Creek was the first appearance of that mineral in connexion with 

 those deposits. J". Magens Mello. 



The Rectory, Brampton, S. Thomas, 

 Chesterfield, June 28, 1879. 



GLACIATION OF THE WEST YORKSHIRE DALES. 



Sir, — Will Mr. J. W. Davis kindly tell us what evidence he has 

 to show that either the Scotch or Lake Country ice, after traversing 

 the valley of the Eden, passed clown Wensleydale, Arkendale, and 

 Swaledale, as stated by him in your last Number, p. 315 ? I think 

 the statement must be new to most of your readers, unless they have 

 seen a somewhat similar one in Davis and Lee's West Yorkshire. 

 Surely if the ice took this course, these dales should abound in 

 erratics. Yet so far as I know there are no foreign boulders in 

 "Wenslejrdale — only local ones. There are no erratics in Arkendale 

 and none in Swaledale, except in the lowest part of the dale near 

 Richmond, where it can be shown clearly that they came over the 

 watershed from the north, out of Teesdale. Mr. Davis must have 

 entirely misunderstood Mr. Goodchild's paper on this matter. It 

 may look at first sight to an outsider as if the ice ought to have 

 behaved differently, especially when it did not pass from the Eden 

 Valley over the low watershed into Wensleydale. " But facts are 

 chiels that winna cling." Perhaps it is not generally known that 

 the Lake Country ice in passing over Stainnioor did not take the 

 direction of the lowest pass, 1378 feet above the sea, and so cross 

 where the Stainmoor railway goes over into the valley of the Greta, 

 but it passed over higher ground further north into Deepdale, Balder- 

 dale, and Lunedale, and erratics have been found by Mr. Goodchild 

 and myself at various heights up to 1800 feet on the watershed 

 between the Eden and the Tees. W. Gunn, 



Berwick-on-Tweed, Geol. Surv. of Eng. and "Wales. 



July 12, 1879. 



