G E O L O G I C A L S Y M B O L SS T R A T I F I E D A N D I N T R U S I V E R O C K S

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« Quartz +/- carbonate extension veins

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Megascopic fold axial surface trace

Structure symbols

F antiform, upright

M synform, upright

P synform, overturned

Limit of mapping

Change in level of stratigraphic detail

Stratigraphic or intrusive contacts

defined

approximate

inferred

Faults

approximate

reverse motion, teeth on upper plate

defined

strike-slip motion

inferred

undifferentiated sedimentary rocks

chert pebble to cobble conglomerate, interstratified sandstone

fine- to coarse-grained sandstone, minor interstratified conglomerate or mudstone

thinly-bedded mudstone and siltstone

unnamed dioritic plutons and stocks

felsic dykes and stocks, unnamed

sedimentary and volcanic rocks, undifferentiated

undifferentiated sedimentary rocks

clast-supported granitoid pebble to boulder conglomerate

undifferentiated andesitic volcanic and epiclastic rocks

epiclastic rocks: red to green coarse-grained sandstone to conglomerate;medium- to thickly-bedded, cross stratification common

andesitic volcanic breccia/block tuff; hornblende+plagioclase-phyric clasts,some interstratified epiclastic rocks

undifferentiated felsic volcanic and epiclastic rocks

fine-grained crystal tuff; epiclastic conglomerate, well-bedded

flow-banded dacite to rhyolite lavas

lapilli tuff, variably welded

undifferentiated sedimentary rocks

volcanic sandstone, conglomerate, local bioclastic sandy limestone intervals

turbiditic mudstone to siltstone

thinly-bedded to massive limestone

bimodal volcanic rocks and interstratified sedimentary rocks

felsic volcanic rocks, undifferentiated

massive, aphyric flow-banded lavas, minor flow breccia

ash, lapilli tuff, non-welded to densely-welded; aphyric toquartz+k-feldspar-phyric

volcanic breccia, monolithic to slightly heterolithic

epiclastic breccia to subangular volcanic conglomerate

mafic volcanic rocks

massive andesitic to basaltic lavas; plagioclase+/-clinopyroxene-phyric

pillow lavas, broken pillow breccia, interbedded mudstone

volcanic breccia , hyaloclastite, interbedded mudstone

rhyolite lavas, autoclastic breccias

intercalated sedimentary rocks

thinly-bedded carbonaceous mudstone, turbiditic mudstone to siltstone,locally chert

Harrymel Ridge diorite

Inel porphyry

Iskut River stock: k-feldspar megacrystic monzodiorite

John Peaks Pluton hornblende diorite

Brucejack Lake k-feldspar megacrystic porphyry

Lehto Pluton: k-feldspar+porphyritic monzodiorite; monzonite and quartz diorite

k-feldspar megacrystic porphyry phase

equigranular phase

Melville pluton: hornblende+biotite diorite to quartz diorite

Mitchell/Sulphurets suite: granite, monzonite, quartz monzonite, monzodiorite

k-feldspar+plagioclase+hornblende porphyry (includes Eskay porphyry)

quartz diorite, unnamed

quartz monzonite, unnamed

Red Bluff porphyry

white crinoidal limestone

limestone clast breccia with medium-grained wacke matrix

phyllite, siliceous siltstone, minor chert

foliated plagioclase porphyry, phyllitic and tuffaceous siltstone and wacke

felsic tuff, breccia, minor lavas

unconsolidated fluvial and glacial sediments

Stikine volcanic suite: olivine+plagioclase-phyric basaltic lavas, tephra,and scoria deposits

biotite+hornblende granite, minor quartz diorite; associated dykes

Nickel Mountain olivine gabbro and related stocks

Lee Brant stock: hornblende-biotite quartz monzonite

Bronson stock diorite

diorite, locally agmatitic texture

volcanic and sedimentary rocks, undifferentiated

undifferentiated andesitic volcanic lavas, tuffs and volcanic breccia

andesitic clinopyroxene/hornblende+plagioclase-phyric block tuff,volcanic brecciaheterolithic conglomerate, mainly andesitic clinopyroxene/hornblende+plagioclase-phyric clasts

amphibole schist or gneiss

undifferentiated basaltic volcanic lavas, tuffs and volcanic breccia

basaltic clinopyroxene+plagioclase-phyric lapilli to block tuff

mafic schist or gneiss (hornblende, plagioclase; relic clinopyroxene cores)

undifferentiated sandstone, mudstone, conglomerate, limestone

thinly- to medium-bedded argillite, siltstone turbidites; interstratifiedsandstone and wacke

phyllitic metasandstone, phyllite

pale green thinly-bedded siliceous siltstone, mudstone

thinly- to medium-bedded feldspathic fine-grained sandstone/wacke;interstratified siltstone to mudstone

phyllite, siliceous phyllite

medium- to thickly-bedded coarse-grained feldspathic sandstone andtuffaceous heterolithic conglomerate

massive dark green sandstone/wacke

limestone white to grey coarsely crystalline marble

green andesitic boulder conglomerate

orange weathering, medium to coarse fossiliferous wacke phyllitic fossiliferous metasandstone

chert pebble conglomerate

phyllite to phyllitic schist

undifferentiated volcanic rocks

k-feldspar megacrystic syenite

Motion

Type

# #

normal motion, D = downthrown sideD

U

Compiled by Peter D. Lewis

Geological Legend

Geoscience BC Report 2013-05

Suggested Reference:Lewis, P. D. (2013): Iskut River Area Geology, Geological Legend; Geoscience BC Report 2013-05.

January 2013

Iskut River Area Geology

GEOLOGICAL LEGEND FOR ISKUT RIVER AREA GEOLOGY ISKUT PROJECT

vertical

inclined

vertical

inclined

fold axis

axial surface, vertical

axial surface, inclined

vertical

inclined

Flow - banding, inclined

Eutaxitic foliation, inclined

crenulation lineation

crenulation cleavage, vertical

crenulation cleavage, inclined

vertical

inclined

vertical

overturned

inclined

Fault plane

Slaty cleavage/schistosity, phase I

Slaty cleavage/schistosity, phase II

Gneissic layering

Mesoscopic fold

Crenulation fabric

Bedding, facing unknown

Bedding, facing determined

Slickenside lineation

Mineral orientation lineation

Intersection lineation

kink band boundary, inclined

kink band axis

Jurassic

BOWSER LAKE GROUP biostratigraphic limits: post-Middle Bajocianknown biostratigraphic range: Middle Bajocian to Kimmeridgian

biostratigraphic limits: post-Rhaetian, pre-Middle Bajocianknown biostratigraphic range: Hettangian-Sinemurian to Middle Bajocian

HAZELTON GROUP

biostratigraphic limits: post-Upper Aalenian, pre-Middle Bajocianknown biostratigraphic range: Bajocian

Salmon River Formation

Bruce Glacier Member John Peaks Member

biostratigraphic limits: post-Hettangian/Sinemurian, pre-Middle Bajocianknown biostratigraphic range: Upper Pliensbachian to Upper Aalenian

Betty Creek Formation

Treaty Ridge Member

Brucejack Lake Member Unuk River Member

biostratigraphic limits: post-Rhaetian, pre-Upper Pliensbachianknown biostratigraphic range: Hettangian/Sinemurian Boundary

Jack Formation

Triassic

STUHINI GROUP biostratigraphic limits: post-Permian, pre-Hettangian/Sinemurianknown biostratigraphic range: Carnian-Rhaetian

Permian

Lower Permian and Older

STIKINE ASSEMBLAGE biostratigraphic limits: pre-Upper Triassicknown biostratigraphic range: Devonian-Permian

Sedimentary unit

Felsic volcanic rocks Andesitic volcanic and epiclastic rocks

Mafic volcanic rocks

Intermediate volcanic rocks

Sedimentary rocks

Metamorphic Equivalents of Stuhini Group Rocks

Basal sedimentary unit

JrB1

JrB2

JrB3

JrDi

JrF

JrH

JrH1

JrH1a

JrH2

JrH2b

JrH2c

JrH3

JrH3a

JrH3b

JrH3c

JrH4

JrH4b

JrH4c

JrH4d

JrH5

JrH5F

JrH5Fa

JrH5Fb

JrH5Fc

JrH5Fd

JrH5M

JrB

JrH5Ma

JrH5Mb

JrH5Mc

JrH5R

JrH5S

JrH5Sa

JrHd

JrI

JrIR

JrJ

JrK

JrL

JrLb

JrLc

JrMe

JrMi

JrP

JrQd

JrQm

JrR

Pc

Plb

Pp

Pvp

Pvt

Qs

Qv

TC

TJrN

TL

TrB

TrDi

TrS

TrSi

TrSi1

TrSi2

TrSim

TrSm

TrSm1

TrSmm

TrSs

TrSs1 TrSs1m

TrSs2

TrSs3 TrSs3m

TrSs4

TrSs5

TrSs6 TrSs6m

TrSs7

TrSs8 TrSs8m

TrSs9

TrSsm

TrSv

TrSy

Stratified Rocks

Tertiary and Quaternary

COAST PLUTONIC SUITE

Intrusive Rocks

Tertiary

TEXAS CREEK PLUTONIC SUITE

Jurassic

STIKINE PLUTONIC SUITE

Triassic

Uncertain

Eskay Rhyolite Member

Troy Ridge Member