METASEDIMENTARY AND METAVOLCANIC ROCKS
Xsv   METASEDIMENTARY AND METAVOLCANIC ROCKS
      METASEDIMENTARY ROCKS
Xlc     Libby Creek Group
Xdl     Deep Lake Group
Wgn   GRANITE GNEISS
WVsv  METASEDIMENTARY AND METAVOLCANIC ROCKS
Ws      Metasedimentary rocks
Wmu     Metamorphosed mafic and ultramafic rocks
Ugn   OLDEST GNEISS COMPLEX--Overprint pattern indicates area of 
           migmatite related to emplacement of 2,600-Ma granite

                            PLUTONIC ROCKS

Ys    SHERMAN GRANITE
      LARAMIE ANORTHOSITE COMPLEX
Yls     Pyroxene and hornblende syenite
Yla     Anorthosite and norite
Yd    RHYOLITE TO DIABASE PORPHYRY DIKES
YX    MAFIC INTRUSIVE ROCKS
Xgy   GRANITIC ROCKS OF 1,700-Ma AGE GROUP
Xqd   QUARTZ DIORITE
Xm    MAFIC INTRUSIVE ROCKS
Xgo   GRANITIC ROCKS OF 2,000-Ma AGE GROUP
!W    MAFIC INTRUSIVE ROCKS
Wp    PERIDOTITE INTRUSIVE ROCKS
Wg    GRANITIC ROCKS OF 2,600-Ma AGE GROUP
Wgd   GRANODIORITE OF THE LOUIS LAKE PLUTON
Wqm   QUARTZ MONZONITE OF NORTH YELLOWSTONE
WVg   PLUTONIC ROCKS