General Geology

Table of Formations (cont.)

Era Period or epoch Formation Lithology

Relations not known; intrusive contact with younger granitic rocks

Middle Jurassic (Bajocian) | Hazelton Group Greywacke, argillite, conglomerate tuff,
breccia, andesite, and arkose; minor
| (So rhyolite

| Andesite, related tuffs and breccias, chert-
| pebble conglomerate, shale, and sand-
| stone

Unconformity; erosional interval

Mesozoic Lower Jurassic mainly or Topley Intrusions Granite, granodiorite, diorite, and quartz
cont. entirely. | diorite

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Intrusive contact with lower part of Takla Group

Upper Triassic and Takla Group Red and brown shale, conglomerate, and

Lower Jurassic greywacke
IGO Andesitic and basaltic flows, tuffs, and
breccias; interbedded argillite and minor

|

| limestone

Not in contact; intrusive contact with Topley Intrusions

Post-Upper Permian- Serpentinized peridotite, talc schists,
pre-Lower Jurassic anthophyllite schists

Not in contact; intrusive contact between Topley Intrusions and Cache Creek Group

Paleozoic Pennsylvanian (>) and Cache Creek Group | Limestone
Permian Zoo -2$e

Sedimentary and Volcanic Rocks
Cache Creek Group

Rocks assigned to the Cache Creek Group occur in the southeast quarter
of the area, south of Kluskoil Lake. They consist of massive grey limestone and
banded grey limestone; contact with younger rocks is not exposed. These rocks

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