Whitesail Lake Map-Area

Most of the faults in the Hazelton group described above are adjacent
to the main contact with the Coast Intrusions, and it is probable that faults
are exceedingly common close to this contact throughout its length within
the map-area.

External Structural Relations

The Hazelton group rocks are in faulted contact with rocks of the older
Takla group in the northeast corner of the map-area. Elsewhere in the
vicinity the Hazelton group is in erosional contact with the Takla group.
South of Eutsuk Lake, Hazelton group and Takla group rocks outcrop on
opposite sides of a wide, southeasterly trending valley that may be the locus
of a fault.

To the west of Kasalka Butte, upper Lower Cretaceous marine beds are
in contact with greenstones of the Hazelton group. The actual contact was
not seen due to overburden and snow, but it is certainly non-conformable
and may be faulted.

On Mosquito Hills rocks of the Hazelton group are overlain uncon-
formably by basalt flows of Tertiary age. Elsewhere along Ootsa Lake and
on the flanks of Mount Wells rhyolites and basalts of Upper Cretaceous or
Tertiary age unconformably overlie volcanic rocks of the Hazelton group.
Near Goodrich Lake flat-lying Miocene basalts overlie disturbed sedimentary
and volcanic rocks of the Hazelton group.

All main intrusive bodies in the map-area are younger than the Hazelton
group. Some of the contacts are. faulted, others are typically intrusive
and sharp, still others are gradational and do not suggest crosscutting
characteristics. Due to the large amount of intrusive material affecting them,
the Hazelton group rocks are generally metamorphosed and not uncommonly
have reached a high stage of alteration.

Age

Fossil remains of marine invertebrates are common in the middle division
of the Hazelton group. The remains are poorly preserved, and good specimens
are difficult to obtain. Fossils were found in argillite, greywacke, impure
limestone, and tuff. Pelecypods and brachiopods are common but belemnites
or their remains are present wherever sedimentary rocks occur. The fossils
collected are all confined to the Bajocian (Middle Jurassic) and no fossils
of definite Lower Jurassic or Upper Jurassic affinities were found, though
it is possible beds belonging to these epochs are present.

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