39

in the boulder clay and have been deposited close to the surface at the base
of the humus line. The nodules appear to have “grown’’ from certain
favourable foci forcing the soil sideways and upwards rather than penetrat-
ing it. The force of crystal growth is sufficient to accomplish this.

The nodule above referred to is situated on the slope of the hill at a
point where a moderate slope changes below into a sharper one (Figure 3,
locality 7). . The main hydromagnesite deposit (No. 3) lies directly below it.
At Kelly lake such nodules of gypsum with calcite are numerous and form
small humps on the sides of the hills. They lie within the bedrock as well
as on top of it in the drift. These nodules clearly were formed at or near
the surface by upward moving waters.

The distribution of the main deposits in the flats at Clinton, Meadow —
lake, and Watson lake indicates deposition at certain focal points or areas
in the flat land rather than as sheets covering the bottom of a lake, that is,
they were formed at the points’ where underground waters reached the
surface of the ground and spread out therefrom. The hydromagnesite
patch (Figtire 3, locality 3), at Clinton, for instance, lies at the foot of the
hill about 4 feet above the general level of the flat to the west and 8 feet
above the creek level. If it had been precipitated by the evaporation of |
the waters of a saline lake the deposit would originally have covered all of
the flat land to an approximately equal depth and its presence now at but
one point could have resulted only from the carrying away of large parts by
erosion. The same may be said of the other deposits. | Evidence exists
to show that they have been formed since glaciation and since the glacial
period there has been no erosion of any account in the Meadow Lake flat.
Moreover, the hummocky portions of the stirfaces of the deposits (Plate IV)
do not resemble mounds left by erosion but, rather, structural forms due
to growth outward from a centre. The stone craters at Meadow lake are
in plan exactly like the interstices between a set of closely spaced circles.
These craters contain large stones only and extend several feet in depth
below the tops of the circular hydromagnesite masses alongside. Such a
condition could not have arisen if the hydromagnesite had been deposited
as a precipitate from lake water.

Granting that the waters carrying these salts rose as springs, the finding
of shells at the base of the deposits at Meadow and Watson lakes indicates
that the springs in many places reached the ground surface at the bottom
of ponds, but their growth has in these cases also been around certain
focal points or areas. Freshwater shells have, moreover, been found in
deposits of carbonates of magnesium and calcium lying on the slopes of a
hill below a mineral spring near 141 Mile House.

The action of underground waters with reference to such deposits as
those in question, is illustrated by the appearance of a white efflorescence
on the hill-sides below the irrigation ditch at Clinton. The water soaks
downward from the ditch line, dissolves the salts disseminated through
the soil and deposits them on the surface.

The following analyses of the waters of two springs and of the lime and
magnesium carbonates deposited around them are given as an example
of the manner in which the calcite, gypsum, and hydromagnesite are formed.
The spring whose water is. represented by analysis No. | is situated a short
distance east of the railway track opposite 141 Mile House; the second
spring (analysis No. 2) occurs beside the north fork of Riske creek three-
quarters of a mile above the main deposit of hydromagnesite.