similarity with the schist and limestone association on Anderson Creek, but the two
could not be correlated.

Limestone-beds are few in number, and the other rocks are for the most part non-
calcareous. The largest limestone-bed, about 100 feet in thickness, is exposed in the
canyon on lower Anderson Creek in the north-west corner of Lot 11404. The limestone
is light grey, thinly bedded, and dips south-westward beneath bright-green chlorite
schist. A limestone-bed about 25 feet thick is exposed on both sides of Last Chance
Creek at and south of the west fork, where it is displaced by a fault that runs along
the creek.

One might expect, because of their strike, that the limestone on Anderson Creek
and that on Last Chance Creek would be the same. Any correlation between the two is
uncertain because of the lack of intervening outcrops and of the differences in succes-
sion of beds at the two places. Should the two correlate, it would mean that there has
been a considerable thinning of the limestone between Anderson and Last Chance
Creeks, and also a change in the overlying rocks from chlorite schists to more quartzitic
rock on Last Chance Creek.

A few boulders of grey limestone seen along Van Winkle Creek up-stream from the
intake of the lower Grub Gulch ditch suggest that a bed of limestone crosses the creek
at some unobserved point higher up-stream.

Several thin limestone-beds are exposed in the west end of the Ketch hydraulic pit
and in a bluff 300 feet to the south. The limestone is interbedded with pale greenish-
grey chloritic schists and quartzites. These limestone-beds were not traced to the east
and could not be found on the west side of the fault that runs along Devils Lake Creek.
Despite the general association of limestone and chloritic beds at the two places, there
appears to be no correlation of the limestone at the Ketch with that on Anderson or
Last Chance Creeks.

Another limestone-bed, about 75 feet thick with thin interbeds of grey schist, out-
crops on the north side of and near the mouth of Coulter Creek. Its eastward projec-
tion is presumably faulted to the position occupied by similar limestone on the south
side of Coulter Creek near the foot of the canyon. This limestone dips northward and
is overlain by largely medium- to dark-grey quartzite.

A few thin limestone-beds are interbedded with argillaceous rocks at the east end of
the trestle crossing Burns Creek.

The presence of one or more limestone-beds on Burns Mountain is suggested by
finding a succession of limestone boulders on Perkins Creek extending from the mouth
to the top end of the placer-workings, and by a few limestone boulders in the placer-
workings on Burns Creek. A few thin limestone fragments were seen in rock from
the dump from the long crosscut adit on the south-east side of Burns Mountain. No
limestone-outcrops were seen on the mountain.

There are few known intrusive rocks in the area. Those present are correlated
with either the pre-Mississippian Prosperine intrusives or the more basic, Jurassic,
Mount Murray intrusives.

The only recognized Prosperine-type intrusive is exposed in several places in the
canyon of Lightning Creek, about 600 feet down-stream from the junction of Houseman
Creek. The rock is hard, medium grey, slightly schistose, and spotted with small grains
of red-brown weathering ankerite. For the most part the rock appears to be conform-
able with the adjacent quartzite, but one outcrop suggests minor transgressing of the
beds. Examination of a thin section of the rock reveals both quartz and feldspar
phenocrysts lying in a fine-grained ground-mass of the same minerals. The rock is a
slightly schistose fine-grained quartz feldspar porphyry or rhyolite porphyry. Ankerite
in small grains and irregular patches replaces the phenocrysts and ground-mass. The
ankeritization evidently is the same that has affected various members of the Cariboo
schists.

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