DESCRIPTION OF MAP UNITS
                                    
The geologic map for the Craig and Dixon Entrance quadrangles, upon which this report is based, is simplified from the
publications and maps cited in the CDE-Bibliography.  All the major geologic units in those reports are represented in the
map units used here or are used in the descriptions of the units that follow. However, certain units used here combine
units used by previous workers, and their maps should be consulted for more detailed information. Those reports also
include considerably more details about the petrology, structure, and ages of the rock units in the area.

              SEDIMENTARY, METAMORPHIC, AND VOLCANIC ROCKS
                                    
          Qtv       Extrusive volcanic rocks (Quaternary? and Tertiary)-- Mainly rhyolite to basalt in a variety of breccia
          bodies, tuff layers, flows, small plugs and dikes

          MzPzm     Metamorphosed sedimentary, volcanic, and intrusive rocks (Mesozoic and (or) Paleozoic)--Dark gray
          phylllite and fine-grained semischist., greenschist facies metamorphosed andesite and basalt flows on southern
          Cleveland Peninsula; amphibolitic and quartzo-feldspathic schist and gneiss to north; and few small bodes of
          metamorphosed diorite, quartz diorite, and gabbro

          Trh       Hyd Formation (Triassic)-- Polymictic breccia that consists of pebbleto boulder-sized clasts of a
          heterogeneous suite of plutonic, metamorphic, and sedimentary rocks; possibly a submarine talus
          deposit. Age enigmatic; alternatively, may be Devonian

          |Pkl      Klawack Formation and Ladrones Limestone, undivided (Middle and Early Pennsylvanian)-- Klawack
          Formation consists mainly of sandstone and siltstone-, the Ladrones Limestone is massive limestone.
          Both locally contain chert pebbles and nodules

          Mp        Peratrovich Formation (Late and Early Mississippian)-- Bedded limestone with chert nodules that
          gradationally overlies bedded chert

          Dpsc      Port Refugio Formation (Devonian), St. Joseph Island VoIcanics (Devonian?), and Coronodos
          VoIcanics (Devonian)--Mainly graywacke, mudstone, siltstone, and shale rich in volcanic material,
          accompanied by basalt flows and fragmental basalt. Locally, includes fossiliferous limestone

          Dw        Wadleigh Limestone (Late, Middle and Early Devonian)-- Massive to bedded limestone with minor
          argillaceous limestone and calcareous shale

          Dk        Karheen Formation and related rocks (Middle? and Early Devonian)-- Mainly redbed- and turbidite-
          facies sandstone, mudstone, shale, and polymictic conglomerate. Minor limestone. Scattered rhyolite and
          andesite flows, and small plugs of andesite, dacite, and diorite

          DSs       Sedimentary rocks of the Staney Creek and Tuxekan Passage area (Early Devonian? and Late to
          Early Silurian)-- Limestone, sandstone, mudstone, and polymictic conglomerate in order of abundance

          Sh        Heceta Limestone (Late to Early Silurian)-- Reef limestone with minor limestone breccia, mudstone, and
          polymictic conglomerate

          SOd       Descon Formation and related rocks (Silurian and Ordovician)-- Volcanic graywacke, siltstone, and
          mudstone turbidites with interlayered volcanic breccia, extrusive domes, flows, and tuffs that consist
          mainly of andesite and basalt with some dacite and rhyolite. Includes the andesitic breccia of Luck
          Creek. On northern Prince of Wales Island, includes small area of the partly correlative Bay of Pillars
          Formation which consists mainly of graywacke and mudstone turbidites.

          Wales Group (Early Cambrian and Late Proterozoic)-- Divided into:

          CZwg      Greenstone, greenschist, black phyllite, quartz-sericite schist, meta-keratophyre, and greenschist- to
          amphibolite-facies schist and gneiss

          CZwm      Marble

                         PLUTONIC IGNEOUS ROCKS
                                    
          Tm        Migmatitic granitic rocks (Miocene and/or Oligocene)-- Heterogeneous suite of granitic rocks that vary
          in composition from granite to diorite and from migmatites to massive and unfoliated

          Kg        Granitic plutonic rocks (Cretaceous)-- Mainly tonalite, diorite, quartz diorite, quartz monzodiorite, and
          quartz monzonite, with several bodies of gabbro

          Zoned mafic-ultramafic complex of Union Bay (Early Cretaceous)-- Divided into:

          Kugb      Gabbro

          Kudp      Dunite, pyroxenite, and peridotite

          Jp        Plutonic rocks (Middle Jurassic)-- Peralkaline granite of Bokan Mountain and syenite at Dora Bay

               P|Psy          Syenite (Early Permian and Late Pennsylvanian)-- Syenite near Klawock and leucosyenite on Sukkwan
               Island

          SOg       Granitic to rnafic plutonic and metarnorphic rocks (Late to Early Silurian and Late Ordovician)--
          Heterogeneous unit that includes granite, syenite, quartz monzonite, leucodiorite, diorite, quartz diorite,
          gabbro, hornblendite, trondhjemite, and pyroxenite. Also includes correlative metamorphic rocks at
          Kendrick Bay that consist mainly of gneiss, schist, and amphibolite

          Og        Granitic plutonic rocks (Late and Middle Ordovician)-- Mainly quartz diorite, granodiorite,
          leucogranodiorite, and quartz monzonite. Also includes small body of foliated metagabbro and
          metadiorite with minor metavolcanic and metasedimentary rocks on southern Prince of Wales Island

          Cg        Foliated granitic to mafic plutonic rocks (Early Cambrian)-- Foliated quartz diorite, granodiorite, diorite,
          and gabbro