Era

Cenozoic

Mesozoic and
Cenozoic

Mesozoic

Palzozoic

60920—3

23

TABLE OF FORMATIONS

Period or epoch

Tertiary

Upper Cretaceous
and later

Lower Cretaceous

Formation or

group
(Thickness in feet)

Lithology

Sifton

Lignite, clay of Coal River

Rhyolite flows, tuffs, and
breccias; west of Rocky
Mountain Trench

Non-marine conglomerate,
sandstone, shale, coal; in
Rocky Mountain Trench

Beds on Petitot
River

Non-marine sandstones,
shales, conglomerate with
Equisetum arcticum

Wapiti

Smoky group
500 + to 1,000 +

Non-marine sandstone,
shale, coal seams

Marine shale and sand-
stone

and non-marine

Dunvegan 500+ {Marine
to 1,000 + sandstone and shale
Fort St. John

group
4,000 to 5,000

Mostly marine shale and
sandstone

Lower Cretaceous
and earlier ?

Jurassic or Lower
Cretaceous

Jurassic

Triassic

Bullhead group
100 +

?

Non-marine sandstone,
shale, and coal above,
and mostly marine sand-
stone and shale below

Cassiar batholith

Granite, granodiorite,
quartz diorite; intrusive
into formations west of
Rocky Mountain Trench

Fernie group

?

Marine shales, some sand-
stone

Pardonet beds
‘Grey beds’
‘Dark siltstone’
‘Flagstones’
Toad, Grayling
4,500+ to 8,000

Marine, lithological units
of dark siltstones, lime-
stones, and shales, alter-
nating with massive, grey,
calcareous sandstones
and grey limestones

Disconformity

Permian

Carboniferous (?)
and Permian

Marine calcareous sand-
stone, near Stott Creek,
Peace River Valley

Marine chert, shale, sand-
stone, and limestone, on
Mount Merrill