basis, and occasionally interspersed carbonaceous matter. Some
of the beds are a foot and a half thick, and have sufficient tenacity to
be fitted for making grindstones; most of the sandstone is, however,
rather friable. Near the summit there is interposed a bed of
fine-grained dolomite, and a friable sandstone, which forms the crest of
the cliff, and exhibits in its weathering battlement-shaped projections
and pinnacles. [Sidenote: 29] Covering this sandstone, but not quite to
the margin of the cliff, there is a layer of slaty limestone, having a
bluish or blackish-gray colour, a dull fracture, and rather compact
structure. [Sidenote: 30] In the lower beds of the cliff there are some
globular and disk-shaped concretions, of an indurated iron-shot
slate-clay, or poor clay-iron-stone, containing pyrites. They vary in
magnitude from six inches to a foot and a half in diameter, and appear
to be formed of concentric layers, which are rendered apparent by the
weathering of the stone. The sandstones and shales of the rapid have a
strong resemblance in appearance to those of the coal measures; but
pitch-coal was not detected at this place. Several distinct concretions
of indurated slate-clay, assuming the appearance termed _cone in cone_,
were picked up among the boulders on the banks of Bear Lake River, some
way below the rapid, but they were not traced to their parent beds. They
effervesce with acids.

Between the walls of the rapid and the limestone ridge there is a piece
of meadow-ground, having a soft, clayey soil, in which, near the base of
the hill, a small rivulet flows to join the river. The bed of this
rivulet presents accumulations of boulders of large size, arranged so as
to form two terraces, the upper of which is considerably above the
highest level either of the rivulet, or of Bear Lake River. The boulders
consist of varieties of granite, gneiss, mica-slate with garnets,
greenstone and porphyry. [Sidenote: 50] One of the porphyries is a
beautiful stone, composed of hyacinth-red felspar, and irregular
crystals of milky quartz, with a few specks of a dark green mineral,
and very much resembles a rock which is not uncommon in the gneiss
districts about Fort Enterprize. [Sidenotes: 45, 47, 50, 51, 49] Many of
the boulders consist of conglomerates and sandstones that strongly
resemble those of the old red sandstone formation, which forms the
height of land between Dease Bay and Coppermine rivers. Also some flinty
sla