Gypsum Deposits in Northern Manitoba. 357 
Saskatchewan Band, who live on the western shore of 
Lake St. Martin, informed me that similar rock was to be 
found in several places further north, and they have named 
a lake on a tributary of Warpath River, which flows into 
Lake Winnipeg north of the mouth of the Little Saskatche- 
wan, Ka-ka-wusk Sa-ka-higan (translated in English as 
Mica Lake) from the alleged presence of selenite in its 
vicinity. 
Towards the south-west, at a distance of ninety miles in 
a straight line, in the bore that was sunk on the bank of 
Vermilion River by the Manitoba Oil Company, a bed of 
gypsum fifteen feet in thickness was struck between 550 
and 565 feet, at approximately the same geological horizon 
as that of the gypsum beds above described. Gypsum 
deposits are therefore in all probability very widely dis- 
tributed throughout Northern Manitoba. 
As far as examined they preserve a pretty constant 
character. Where they immediately underlie the surface 
the country is very rough and hilly, and the prevailing 
poplar of the region is mixed with birch, or the spruce of 
the adjoining low-lying land is replaced by Banksian pine. 
The gypsum itself is generally very pure, of adead white 
colour, and usually stratified in rather thin beds, which are 
either horizontal or dipping at a low angle. Among the 
massive beds, however, are many others, composed of 
crystals or crystal-masses, in which the crystals usually 
stand transverse to the plains of bedding. Some plates 
could doubtless be obtained from the crystal-masses 
sufficiently clear for optical purposes. No anhydrite was 
seen mixed with the gypsum, but one of the hills, as above 
stated, appeared to be composed entirely of it. It is much 
harder and tougher than the gypsum or hydrated sulphate 
of lime, is considerably heavier, has a roughly nodular, 
rather than a distinctly stratified structure, and is of a 
decidedly bluish tint. 
Of the exact geological age of the deposit it is difficult to 
speak as yet with certainty, as the strata have not been 
continuously traced into any others, and no beds im- 
