Appendix VI - Terrane Codes, Descriptions and Legend

Terrane Map Description

The data has been compiled by J.O. Wheeler, A.J. Brookfield, H. Gabrielse, J.W. H. Monger, H.W. Tipper, and G.J. Woodsworth from Terrane Map of the Canadian Cordillera, Geological Survey of Canada, Open File 1894, 1988.

"Terranes are bodies of rock, each preserving a geological record different from those of neighboring terranes (Monger and Berg, 1984). Plutonic and metamorphic rocks and mineral deposits may be integral parts of terranes. Terrane boundaries are important faults, although in places these may be concealed by younger cover rocks or intrusions. Paleontological and paleomagnetic data suggest that some currently juxtaposed terranes were originally separated by distances of up to thousands of kilometres." (DNAG, Chapter 2)

Terranes are categorized according to their relationship to ancestral North America. Tectonic assemblages and plutonic suites which make up each terrane are listed using symbols and names from Tectonic Assemblage Map of the Canadian Cordillera and adjacent parts of the United States of America, compiled by J.O. Wheeler and P. McFeely, Geological Survey of Canada, Open File 1565, 1987.

Middle Proterozoic to Carboniferous passive and offshelf continental margin sediments, Devonian to Carboniferous clastic wedges, Pennsylvanian to Jurassic passive continental margin prism, and Permian clastics.

mPCM Cap Mountain, mPM Mackenzie, mPMu Muskwa, mPPW Purcell-Wernecke, uPW Windermere, uPWR Rapitan, uPPI Pinguicula, PCG Gog, PCH Hyland, mCr rift assemblage, CDR Rocky Mountains, DMB Besa River, DME Earn, DMI Imperial, DCR Rundle, CM Mattson, CL Lisburne, CPO Outer, PPI Ishbel, PJ Jungle Creek, TRJS Spray River, JKp Parsons

plutonic rocks: MPgH Hellroaring Creek, MPdM Moyie, LPqD Deserters, LPdM Macdonald, LPdR Rackla, LPdT Thundercloud, Sy Bearpaw Ridge.

Craton-related metasedimentary rocks overlying basement paragneiss and orthogneiss of Early Proterozoic age.

lPM Monashee Complex

plutonic rocks: EPnMo Monashee, LPYC Mt. Copeland

Upper Proterozoic and lower Paleozoic miogeoclinal sedimentary, volcanic and granitic rocks unconformably overlain by Lower Carboniferous to Triassic continental margin deposits and displaced along the Kaltag Fault.

uPN Neruokpuk, PCHA Hyland, CDRA Rocky Mountains, DMIA Imperial, CMA Mattson, CLA Lisburne, PTRS Sadlerochit, JKPA Parsons

plutonic rocks: DMqA Ammerman, DMqF Fitton, DMqOC Old Crow, DMqSH Schaeffer, DMqSe Sedgwick.

uPWCA Windermere, PCGCA Gog, CDRCA Rocky Mountains, DMECA Earn,
PPICA Ishbel, TRSCA Spray River

Metamorphosed Proterozoic to lower Paleozoic (?) passive continental margin assemblage and partly metamorphosed carbonaceous and siliceous offshelf sediments.

PCN Nisling, CDN Nasina

Continental margin sediments comprising upper Proterozoic clastics overlain by Paleozoic carbonates and clastics intruded by Devonian syenodiorite, and bounded by the Yukon and Kaltag faults.

PCHP Hyland, CDRP Rocky Mountains, CLP Lisburne, CPOP Outer, PJP Jungle Creek, TRJSP Spray River, JKpp Parsons

plutonic rocks: DMYDL Dave Lord

Intensely deformed, variably metamorphosed and poorly dated Proterozoic to Triassic, siliceous clastic sediments, subordinate volcanics, and limestone, locally intruded by Ordovician, Devonian, and Mississippian granitoid plutons. Some of the deformed lowest Paleozoic rocks appear to be stratigraphically related to ancestral North American whereas the younger, less deformed rocks do not.

PPzEK Eagle Bay, CMK Milford

plutonic rocks: OSnL Little Shuswap Lake, DMqF Mt. Fowler, DMqC Clachnacuddain.

Proterozoic continental margin sediments and basement gneiss separated from North American strata by the Purcell and Esplanade thrust faults

lPM Malton, uPW Windermere

plutonic rocks: EPnM Malton, LPgH Hugh Allan, DyI Ice River

Proterozoic and Paleozoic strata which are thrust bounded with and may be a facies equivalent of the Cariboo Subterrane

PPzEK Eagle Bay

plutonic rocks: DMqQ Quesnel Lake

Metamorphosed and intensely cataclastized sedimentary, volcanic and intrusive rocks of Late Proterozoic, Paleozoic and possibly early Mesozoic ages

PTRNK Nisutlin

plutonic rocks: DMgS Simpson Range Suite, EpqSC Sulphur Creek

Muscovite-biotite granite and leucogranite augen gneiss and biotite quartz monzonite orthogneiss of S-type affinity; in part fault bounded. Pelly Gneiss is in fault contact with Nisutlin Subterrane and in an unknown relationship with the Nisling Terrance. It may be included with the Nisutlin Subterrane if correlated by age with the Simpson Range Suite although Pelly Gneiss is compositionally different.

DMgM Mink Creek Suite

Oceanic marginal basin volcanics and sediments of Devonian to Late Triassic age which are basement to Quesnellia in southern B.C.. Included are chert, argillite, sandstone, conglomerate, mafic intrusions, basalt, alpine-type ultramafic rocks, carbonate rocks and local occurrences of blueschist and eclogite. In northern B.C. Permian fusulinids are not found in coeval, co-latitudinal cratonal rocks suggesting terrane movement from the south.

DTRS Slide Mountain

plutonic rocks: DTRuo oceanic ultramafics, DTRd, EPtF and EMtF Four Mile.

Carboniferous marginal basin chert and clastics with similar lithology to Slide Mountain Terrane but lacking ultramafics, containing less volcanics and including important conglomeratic units. The terrane may represent a facies of either Quesnel or Slide Mountain terrane.

CD Dorsey

Upper Triassic and Lower Jurassic arc volcanics, volcaniclastics and comagmatic intrusive rocks overlain by Jurassic arc-derived clastics. Triassic and Jurassic faunas differ from those in coeval, co-latitudinal cratonal rocks.

TRJN Nicola, JHA Hall

plutonic rocks: LTRup Polaris Suite, EJgG Guichon Suite, EJYCM Copper Mountain Suite

SUBTERRANES: basement to Quesnellia

Upper Devonian to Triassic arc clastics, volcanics and carbonate.

Carboniferous to Permian oceanic volcanics and sediments.

OTRS Shoemaker, CPA Anarchist

Mississippian to Upper Triassic oceanic volcanics and sediments, Upper Triassic island arc volcanics and local accretionary prism melange. Included are radiolarian chert, argillite and basalt, shallow water carbonate and alpine-type ultramafics. The terrane is bounded on the east by the Teslin and Pinchi faults. Permian fusulinid and coral faunas of Tethyan affinity are not found in coeval, co-latitudinal cratonal rocks suggesting an exotic origin.

MTRC Cache Creek, TRKU Kutcho

plutonic rocks: DTRuo oceanic ultramafics

Devonian to Permian arc volcanics and platform carbonates form the basement to Stikinia. They are overlain by Triassic and Lower Jurassic arc volcanics, volcaniclastics, and arc-derived clastics, which are intruded by comagmatic plutonic rocks. Permian, Triassic and Jurassic faunas differ from co-latitudinal cratonal rocks indicating northward terrane displacement.

DPA Asitka, TRS Stuhini, TRL Lewes River, JH Hazelton, JT Takwahoni
plutonic rocks: LTRup Polaris Suite, LTRdS Stikine Suite, TRJgK Klotassin Suite, EJqB Black Lake, EJqCM Copper Mountain Suite, EJq unnamed plutons in Coast Mountains, EJqL Long Lake Suite, EJqT Topley Suite, MJdgT Three Sisters Suite.

Devonian oceanic sediments and volcanics; Cretaceous blocks

DKWR White River

Variably metamorphosed upper Paleozoic and Triassic basalt, local acid volcanics, carbonate, pelite and Permian crinoidal limestone. Jurassic to Cretaceous metamorphosed sediments and volcanics are similar to the Gambier (Gravina-Nutzotin) Assemblage. The stratigraphic base of the terrane is unknown and relationships with other terranes are obscured by intrusions and metamorphism.

PKT Taku

Upper Triassic island arc clastics and volcanics (regarded in part by some workers as Stikinia) overlain by Jurassic arc clastics and volcanics, and Jura-Cretaceous easterly derived continental margin clastic wedge of shale and siltstone in Tyaughton Trough.

TRC Cadwallader, JL Ladner, JKR Relay Mountain

Upper Triassic basalt overlain by Lower Jurassic arc clastics and volcanics, and Jurassic and Cretaceous easterly derived clastic wedges shed from Quesnellia

JL Ladner, JKR Relay Mountain, KS Skeena

Accretionary prism and oceanic crust of Permian to Middle Jurassic age disrupted and variably metamorphosed radiolarian chert, argillite, basalt, alpine-type ultramafics and minor carbonate and diorite.

PJB Bridge River

Jurassic island arc volcanics and clastics. Carbonate clasts in Toarcian conglomerate contain Permian fossils similar to those in the Chilliwack Terrane

JHL Harrison Lake

Devonian to Permian arc volcanics and clastics overlain by Upper Triassic to Lower Jurassic arc clastics. Permian fusilinid faunas resemble those in Quesnellia and Stikinia. The Yellow Aster may in part by basement to the Chilliwack Terrane.

DPCH Chilliwack, TRJC Cultus

plutonic rocks: PPnV Vedder, COnY Yellow Aster.

Upper Proterozoic to Triassic volcanic and sedimentary rocks in a variety of depositional settings (ocean arc, back arc, platform, rift, trough, offshelf) and comagmatic intrusions.

PCW Wales, OSD Descon, ODD Donjek, ODK Kaskawulsh, OTRA Alexander, DC Cedar Cove, DK Karheen, DPC Cannery, CI Iyoukeen, PH Halleck, PP Pybus, PTRA Alexander, TRH Hyd
plutonic rocks: COd in St. Elias, OSg, OSd, Sy and Sum in S.E. Alaska, PPgI Icefield Ranges Suite.

Silurian to Permian arc volcanics, clastics and platform carbonates form the basement to Wrangellia; they are overlain by Triassic oceanic rift tholeiitic basalt, carbonate and Jurassic arc volcanics, and intruded by comagmatic plutons. Paleomagnetic data suggest displacement from low latitudes.

DPS Sicker, PPS Skolai, TRK Karmutsen, JB Bonanza

plutonic rocks: DgS Saltspring, EJdW, EJnW Westcoast Complex, MJgV Vancouver Island Suite, MJg Chichagof Island

Cretaceous accretionary prism of greywacke, argillite, and melange of Triassic to Lower Cretaceous blocks in a Lower Cretaceous matrix.

KV Valdez

Upper Cretaceous turbidite and melange of Upper Triassic to Lower Cretaceous blocks in a Cretaceous matrix.

uKY Yakutat, pTM Metchosin, pTC Carmanah, nTY Yakataga

Melange and chert-volcanics assemblage on Upper Triassic calc-alkaline arc volcanics

JKPR Pacific Rim

Pull-apart basin ridge-island Eocene volcanics cut by gabbro and diabase intrusions

pTM Metchosin

plutonic rocks: ETgC Catface Suite