27
- Shape of the Deposits.

The larger deposits are thin, flat-lying sheets of nearly uniform depth
from’ the surface to the underlying sand or clay. The surfaces, which are
from 1 to 2 feet higher than the surrounding valley floors, are broken up
into nearly circular humps full of radiating cracks resembling the_top of a
cauliflower (Plate IV). The tops of these humps are, as a rule, from 1

'Geolog ical Suryey, Canade

Areas with hydromagnesite
of 00d quality.
1,2,3- Exposures of hydromagnesite of good quality. 4,5,6.- Exposures of calcite with gypsum.

7- Exposure of gypsum with calcite. &- Exposure of conglomerate overlain by travertine.
> Tunnels % Prospects

Areas with deposits of
impure hydromagnesite.

Scale of feet
2000

° 41000 3000 4000

Approximate magnetic declination, 27 “Fast

Figure 3. Hydromagnesite deposits near Clinton, Lillooet district, British Columbia.

to 2 feet higher than the ground between them. In certain places along
the edges of the deposits, as at Meadow lake and elsewhere, lunar or cusp-
shaped cavities filled with large basaltic boulders, but with practically no
fine-grained material, lie between the cauliflower-like humps. The shapes