abt

that their origin is independent of the age of the formations
involved, which range from-late Precambrian to Triassic. With
this opinion as appligd to the Wolverine complex the present
writers and A.H. Lang> are in accord. They believe that the

if
Geol. Surv., Canada, Papers. 41-5 and 42-2..

metamorphism of these rocks resulted from processes related

to the Omineca batholithic intrusions of Mesozoic age, and that
the constituent formations, though probably mostly Permian or
older, may range in age from Proterozoic (Late Precambrian) to
Jurassic. Although most of the rocks of the Wolverine complex
are separated by a fault from those of the adjacent Cache Creek
group, those at the head of Boulder Creek appear to lie
structurally conformably below Cache Creek formations. The main
area of the Wolverine complex lies along a northwesterly
projection of the belt of Proterozoic (Late Precambrian) rocks
of the Cariboo district, and, presumably, may be in part of the
same age.

Cache Creek Group

The Cache Creek group appears to represent a con-
formable succession, not less than 10,000 feet thick, of
interbedded limestone, argillite, slate, chert, greenstone,
and their-derived schists. The constituent formations are
closely folded in a general northwesterly direction, but in
places the folds trend nearly due west. Most of the limestone
is contained in three northwesterly trending bands, one north
of Omineca River and two southwest of Manson River. Thickness
determinations are uncertain, as in general the limestone
exhibits no definite bedding, but the maximum accumulation for
any single locality is probably in excess of 3,000 feet.
Smaller, irregular bands, as much as 500 feet thick, occur at
intervals throughout the sedimentary part of the Permian
section, but have not been mapped separately. The limestone
bands pinch and swell along their strike and at depth,. and
are discontinuous. The normal limestone is blue-grey, grey
weathering, medium-grained to dense, and massively bedded.

It is commonly veined by stringers of calcite up to half an
inch wide.

The argillites and slates are grey to black, rusty
weathering, carbonaceous rocks in beds that are rarely more
than 6 inches thick. Near fault and shear zones they have
been altered to lustrous graphite schists.

The greenstones include altered andesitic and

' basaltic flows, tuffs, breccias, and agglomerates. The flows
are fine-grained to dense, green rocks composed mainly of
chlorite and amphibole with minor amounts of feldspar. In
part they are spherulitic and amygdaloidal. The tuffs are
dense, cherty, grey and green rocks that exhibit good bedding
on weathered surfaces. Breccias and agglomerates consist
mainly of fragments of the greenstone flows, up to 5 inches
in diameter, embedded in a flow or tuffaceous matrix.
Fragments of limestone up to 8 feet in diameter are contained
in bodies of greenstone.

Thin beds of pink, white, grey, and green chert-are
intercalated with the argillite and greenstones.