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Ministry of Energy Mines and Responsible for Core Review

092HSW Geological Legend

 

LAYERED ROCKS

CENOZOIC

TERTIARY

Miocene to Pliocene

MPSv

Skagit Formation: felsic and intermediate pyroclastic rocks

Late Oligocene to Early Miocene

OMCv

Coquihalla Formation: intermediate and felsic pyroclastics and flows

Eocene

Princeton Group

Es

Sandstone, conglomerate and argillite; includes Allenby Formation

MESOZOIC

CRETACEOUS and/or TERTIARY

MSL

Slollicum Schist: mainly greenschist-grade mafic to intermediate volcanics, phyllite, minor volcanic and carbonate-clast supported conglomerate; metamorphosed in the Cretaceous

MS

Garnet-biotite, staurolite, kyanite and sillimanite schist, local amphibolite, minor ultramafic rocks and siliceous schist, metamorphosed in Cretaceous; includes Settler Schist and Brokenback Hill Formation

KTC

Custer Gneiss: Granite gneiss with abundant pegmatite dikes, pelitic schist and amphibolite, minor marble and ultramafic rocks, probably derived mainly from Lower Mesozoic and possibly Paleozoic and Precambrian(?) rocks. Metamorphosed in Late Cretaceous and early Tertiary time, the Custer Gneiss may be a deeper level metamorphic equivalent of the Settler Schist (Cayoosh Formation) or Cogburn Schist. Custer Gneiss is the suspected source of the anatectic melts which produced the Needle Peak and Outram plutons (Egd)

CRETACEOUS

Lower to Upper Cretaceous

Pasayten Group

KP

Undifferentiated sandstone, chert-grained sandstone, conglomerate, argillite, arkose, minor red beds and tuff; in part probably the non-marine facies equivalent of the Jackass Mountain Group (KJ)

Lower and Middle Cretaceous

Jackass Mountain Group

KJ

Sandstone, argillite, conglomerate; upper part is likely the facies equivalent of the Pasayten Group

Lower Cretaceous (Berriasian to Albian)

Gambier Group

lKG

Undifferentiated Gambier Group volcanic and sedimentary rocks include thick bedded basaltic andesite, dacitic and rhyolitic tuffs, flows and volcanic breccia, greenstone, pillowed basalt, argillite, greywacke, shale, siltstone, basal conglomerate with plutonic clasts and arkose; includes Monarch Volcanics, Fire Lake Volcanics and Goat Mountain, Britannia, Helm, Empetrum, Cheakamus, Brokenback Hill and Peninsula formations

JURASSIC

Upper Jurassic

Thunder Lake Sequence

uJTs

Sandstone, conglomerate and argillite

JK

Kent Formation: conglomerate, sandstone and argillite

Lower Oxfordian

JBC

Billhook Creek Formation: intermediate volcaniclastics

Lower and Middle Jurassic

Ladner Group

JL

Argillite, slate, siltstone, tuff and minor amounts of Upper Jurassic sandstone and conglomerate

JD

Dewdney Creek Formation: sandstone, argillite, local mafic and intermediate volcanics; part of the Ladner Group

Early and Late Toarcian and Younger

JHL

Harrison Lake Formation: intermediate, locally felsic flows and pyroclastics; local argillite and conglomerate; includes Callovian age Mysterious Creek Formation

TRIASSIC / JURASSIC

Late Triassic and/or Early Jurassic

TRJC

Cultus Formation: argillite, sandstone, siltstone, minor carbonate

TRIASSIC

TRSP

Spider Peak Formation: mafic volcanics

Middle Triassic (Ladinian)

TRCC

Camp Cove Formation: siliceous argillite, mafic volcanics; possibly the base to the Harrison Lake Formation (JHL)

PALEOZOIC to MESOZOIC

PMu

Ultramafic rock, local gabbro

PMCS

Cogburn Schist: Schist, metachert, pelite, amphibolite, marble, ultramafic rock; possible correlative of Hozameen and Bridge River complexes; metamorphosed in Cretaceous

PERMIAN to JURASSIC

Hozameen Complex

PJH

Undifferentiated chert, pelite, mafic volcanics, minor limestone, gabbro and ultramafic rock

PJHv

Mafic volcanic rocks of the Hozameen Complex

Permian (to Mesozoic?)

Vedder Complex

PMV

Amphibolite, gneiss, minor ultramafic rock

PALEOZOIC

Devonian to Permian

Chilliwack Group

DFC

Undifferentiated pelite, sandstone, minor conglomerate, mafic and felsic volcanic rocks; Permian and Pennsylvanian carbonate

Pennsylvanian to Permian

PPc

Carbonates in the Chilliwack Group

PROTEROZOIC and PALEOZOIC

Yellow Aster Complex

PPY

Metadiorite and gabbro; includes Baird Diorite on Old Settler Mountain

INTRUSIVE ROCKS

CENOZOIC

TERTIARY

Miocene

Mgd

Zoned granodiorite, quartz monzonite, tonalite, includes Mount Barr Batholith

Oligocene and/or Miocene

OMgd

Zoned granodiorite, diorite, tonalite, quartz monzonite, alaskite; probably the plutonic roots to the Coquihalla Formation (onCv); includes Chilliwack Batholith

EARLY TERTIARY

ETgd

Granodiorite and lesser quartz diorite; includes Yale Intrusions, Sheemahant, Machmell and Clendenning plutons

ETi

Intrusions of intermediate composition; includes Yale Intrusions

MESOZOIC

CRETACEOUS

Middle Cretaceous (105-85 Ma)

MKg

Granite; includes Falls Lake Suite of the Eagle Plutonic Complex

MKqd

Variably foliated quartz diorite; lesser granodiorite; includes Malaspina, Howe Sound, East Sechelt and Spuzzum plutons

JURASSIC

Late Jurassic

LJt

Tonalite; Eagle Tonalite of the Eagle Plutonic Complex (includes Eagle Gneiss)

Middle to Late Jurassic

MLJd

Hornblende diorite and metavolcanics of the Zoa Complex

Middle Jurassic

MJgd

Granodiorite

 

Geological map and legend adapted from:

Bellefontaine, K. and Alldrick, D. (1994): Geological Compilation of the Mid-Coast Area, Southwest British Columbia (Vancouver to Bella Coola), (NTS 92F,G,H,J,K,L,M,N; 93D; 102P; 103A); B.C. Ministry of Energy, Mines and Petroleum Resources, Open File 1994-17, 1:250 000.

Monger, J.W.H. (1989): Geology, Hope, British Columbia; Geological Survey of Canada, Map 41-1989, sheet 1, 1:250 000.

See CHILLIWACK LAKE (092HSW) Summary Sheet for an overview of the map area and additional regional references.

Positions of all geological contacts are approximate. In the case of an apparent disagreement between an occurrence’s geological location on the map and its stratigraphic setting given in the MINFILE documentation, the latter should be given priority.