LIST OF MAP UNITS

    QUATERNARY SURFICIAL DEPOSITS
.1
Qd     Quaternary deposits undivided (Holocene  
            and Pleistocene)
.2
Qa     Alluvium undivided (Holocene)
.3
Qf     Alluvial-fan deposits (Holocene)
.4
Ql     Landslide and related deposits (Holocene)
.5
Qm     Glacial deposits undivided (Pleistocene)
.6
Qtr    Travertine (Pleistocene)

    MIOCENE VOLCANIC AND SEDIMENTARY ROCKS 
.7
Tcb    Columbia River Basalt group
.8
Tpa    Payette Formation

    EOCENE CHALLIS VOLCANIC GROUP
    SEDIMENTARY AND INTRUSIVE ROCKS

    Thunder Mountain Cauldron Complex
    Intrusive rocks
.9
Trd    Rhyolite dikes
.10
Tqp    Quartz porphyry intrusions
.11
Tr     Rhyolite intrusions
.12
Tmi    Mafic intrusions

    Granitic rocks of Casto Pluton
.13
Tg       Granite
.14
Thg      Hornblende granite
.15
Tgp    Gray porphyry

    Extrusive and sedimentary rocks
.16
Tla    Latite of Lookout Mountain
.17
Tds    Beds of Dewey Mine
.18
Tss    Sunnyside Tuff of Shannon and Reynolds (1975)
.19
Tsu      Upper Tuff
.20
Tmx      Megabreccia
.21
Tslu     Uppermost tuff that has mineralogy of 
              lower tuff
.22
Tsrl     Rhyolite lava or tuff
.23
Tsl      Lower tuff
.24
Tbr    Buff rhyolite
.25
Tpl    Perlitic rhyolite
.26
Tdq    Dime-and-quarter size lapilli tuff
.27
Tdql   Lower densely welded tuff
.28
Tll    Lower latite lava
.29
Tcv    Challis volcanic group, undivided

    Northern part of Van Horn Peak cauldron complex
         and Panther Creek graben
    Intrusive rocks
.10
Tqp    Quartz porphyry intrusions
.11
Tr     Rhyolite intrusions
.12
Tmi    Mafic intrusions
.30
Tvp    Tuff of Van Horn Peak

    Granitic rocks of Casto Pluton
.13
Tg       Granite
.14
Thg      Hornblende granite
.15
Tgp    Gray porphyry
.31
Tdi    Dikes and plugs of intermediate composition

    Extrusive and sedimentary rocks
.32
Toc    Colluvium of Panther Creek

    Tuff of Castle Rock and related rocks
.33
Tmt      Monolith-forming tuff
.34
Tck      Tuff of Castle Rock
.35
Tfl      Flow-layered rhyolite
.36
Tb       Basaltic lava
.37
Tqb      Quartz-biotite tuff
.38
Tap    Alkali feldspar-plagioclase tuff
.39
Tdt    Dirty tuff

    Tuffs of Camas Creek-Black Mountain and 
             related rocks
.40
Tc       Tuffs of Camas Creek-Black Mountain
.41
Ttm      Tuff of Table Mountain
.42
Tcs      Tuff of Camas Creek-Black Mountain and 
              bedded strata, undivided
.43
Tp       Tuff of Pennal Gulch
.44
Trb    Rhyolite of Red Butte
.45
Tpq    Quartz-phenocryst perlite
.46
Tem    Tuff of Eightmile Creek
.47
Tl     Potassium-rich andesite, latite, 
            and basalt lava
.48
Te     Tuff of Ellis Creek
.49
Tdf    Dacitic and rhyodacitic lava
.50
Tmz    Intermediate lava and breccia of mixed zone
.51
Tlt    Lithic tuff of Corral Creek
.52
Tfr    Flow-laminated rhyolite or quartz latite lava
 
    Corral Creek cauldron segment and area north 
         and east of Challis
    Intrusive rocks
.12
Tmi    Mafic intrusions
.53
Tinm   Intermediate and mafic intrusions
 
    Extrusive rocks
.54
Tcr    Tuff of Challis Creek, outflow unit
.41
Ttm    Tuff of Table Mountain
.43
Tp     Tuff of Pennal Gulch
.46
Tem    Tuff of Eightmile Creek