GEOLOGICAL SYMBOLS STRATIFIED AND INTRUSIVE ROCKS . Ç X Ö ½ Ü 7 J Ý y « Quartz +/- carbonate extension veins Ð 6 8 ! % , x < @ V ® H Ï Ò 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 to quartz+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 breccia heterolithic 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; interstratified sandstone 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 and tuffaceous 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 side D 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 Bajocian known biostratigraphic range: Middle Bajocian to Kimmeridgian biostratigraphic limits: post-Rhaetian, pre-Middle Bajocian known biostratigraphic range: Hettangian-Sinemurian to Middle Bajocian HAZELTON GROUP biostratigraphic limits: post-Upper Aalenian, pre-Middle Bajocian known biostratigraphic range: Bajocian Salmon River Formation Bruce Glacier Member John Peaks Member biostratigraphic limits: post-Hettangian/Sinemurian, pre-Middle Bajocian known 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 Pliensbachian known biostratigraphic range: Hettangian/Sinemurian Boundary Jack Formation Triassic STUHINI GROUP biostratigraphic limits: post-Permian, pre-Hettangian/Sinemurian known biostratigraphic range: Carnian-Rhaetian Permian Lower Permian and Older STIKINE ASSEMBLAGE biostratigraphic limits: pre-Upper Triassic known 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