Candle
Kcg
Calcareous graywacke and mudstone
Cretaceous
Rhythmically interbedded, medium-gray, yellowish-orange weathering, fine-grained to gritty highly calcareous graywacke and micaceous, calcareous mudstone.  Abundant carbonized plant debris.  Unit coarsens westward.  Estimated more than 5,000 feet thick.
abundant carbonized plant debris
CA002
Sedimentary
Qf
Flood-plain deposits
Quaternary
Flood-plain deposits.  Gravel, sand, and silt along flood-plains of major stream valleys
Unconsolidated
Qt
Terrace deposits
Terraced alluvial silt deposits with minor peat and gravel
Klc
Limestone conglomerate
Pebble to boulder limestone conglomerate, poorly sorted, locally derived, non-marine
plant fossils of Cretaceous age
Kcc
Poorly sorted nonmarine and shallow-water shelf deposits consisting  of carbonate-rich conglomerate (calcirudite), sandstone (calcarenite), and shale (calcilutite).  Unit contains abundant plant debris and thin seams of bituminous coal.  Clast-supported
CA003
Cyclically interbedded sequence of fine to coarse grained, calcareous graywacke, fine to medium grained carbonaceous, volcanic graywacke, and carbonaceous mudstone.  This unit has been lumped with the eastern part of unit Kcv on the source map and re-lab
Pzl
Limestone and schist -- Limestone and dolomite
middle Paleozoic
Chiefly light-gray, massively bedded recrystallized limestone and dolomite, containing subordnate calcareous mica schist and dark phyllite
Tentatively assigned middle Paleozoic age based on correlation with fossiliferous carbonate rocks in the Solomon quadrangle
Metamorphic
Pzs
Limestone and schist -- Quartz-mica schist, mica schist, and quartzite
Paleozoic
Quartz-mica schist, mica schist, and quartzite.  Locally includes calcareous, graphitic, and feldspathic schists, amphibolite schist, phyllite, and thin limestone.  Age and stratigraphic relationship with unit Pzl uncertain, contact may be gradational.
Pzls
Limestone and schist
Undivided limestone and schist in areas of poor exposure
Kvg
Volcanic graywacke, conglomerate, and mudstone
Andesitic volcanic graywacke and mudstone with local amounts of granitic rock detritus and fine-grained tuffaceous material and conglomerate
Lead-alpha and K/Ar ages of 90 +/- 10 m.y. to 120 +/- 15 m.y.
Hard, fine-grained to conglomeratic, locally tuffaceous, graywacke and dark-gray finely laminated mudstone. The graywacke is composed of matrix-supported clasts of intermediate and mafic volcanic and intrusive rocks and chert.  Clasts of quartz and of me
Marine mollusks of late Early Cretaceous (Albian) age  were identified in this unit in the Bettles, Hughes, and Kateel River quadrangles
QTb
Basalt
Tertiary (?) and Quaternary
Flows of vesicular olivine basalt.  Minor glassy basalt.  Believed to be correlative with Imuruk Volcanics of Bendeleben quad
Igneous
Ksy
Granitic rocks
Granitic rocks of hornblende and pyroxene monzonite and syenite.  Minor biotite quartz monzonite.  Unit subdivided by Patton (1999, 2000)
lead-alpha age of 90 +/- 10 m.y. and 100 +/- 15 m.y.  K/Ar age of 102 +/- 5 m.y. and K/Ar age of 100 +/- 5 m.y.
KJv
Andesitic volcanic rocks
Jurassic (?) and Cretaceous
Wide variety of andesite volcanic flows and volcaniclastic crystal and lithic tuffs.  Mainly andesitic and trachyandesitic crystal and lithic tuffs, tuffaceous volcanic graywacke, masssive andesitic breccia, agglomerate, and conglomerate
Simbirskites ammonite of Early Cretaceous
K/Ar age of 120 +/- 3 m.y.
Selawik
Qga
Undifferentiated older glacial drfit, alluvium, and eolian deposits
Quaternary, Illinoian
Chiefly highly modified till and outwash gravels mantled by wind-blown and water-laid silt and fine sand.
SE002
Qft
Silt, sand, and gravel along flood plains of major drainages.  Locally includes some fan and terrace deposits along narrow tributary valleys
Qs
Chiefly sand deposits
Modified and dissected deposits of wind-blown and water-laid sand with subordinate amounts of silt
Qws
Chiefly wind-blown and water-laid silt
Chiefly wind-blown and water-laid silt.  Locally includes glacial outwash.
Pleistocene or Late Tertiary
Dissected, nearly horizontal flows of gray to dark-red vesicular olivine basalt.
Knc
Nonmarine conglomerate, sandstone, mudstone, and coal
Late Cretaceous
Conglomerate composed chiefly of well-sorted white quartz pebbles in quartzose and micaceous matrix; also has pebbles of phyllite, schist, greenstone, and chert in subordinate amounts.  Interbedded quartzose and micaceous sandstone and mudstone.
Abundant well-preserved plant fossils of probable Cretaceous age
Age based on correlative rocks in the Baird Mtns.and Selawik quadrangles dated by K-Ar.
Kc
Igneous pebble-cobble conglomerate
late Early Cretaceous (Albian)
Massive poorly stratified and poorly sorted conglomerate composed of pebble- to cobble-sized clasts of mafic extrusive and intrusive rocks in a graywacke and mudstone matrix.
Kv
Volcanic graywacke and mudstone
Poorly sorted dark greenish-gray volcanic graywacke and mudstone.  (Unit replaced by NSA = 1820, per Patton, 2000)
Shallow-water marine mollusks locally abundant but poorly preserved, probably of Early Cretaceous (Albian) age.
Km
Metasedimentary rocks
Small patches of high-grade metamorphic rocks within Selawik Hills pluton.  Likely to have been of unit Kv in part
K-Ar age of 110 Ma on biotite from metapelite
HFS
Khe
Felsic hypabyssal and extrusive rocks
Cretaceous(?)
Small widely scattered bodies of fine-grained intrusive and extrusive rocks including soda rhyolite, quartz latite porphyry, sanidine trachyte, and quartz diorite.  Some welded tuff at eastern end of Selawik Hills.
earliest(?) Cretaceous and Jurassic(?)
Chiefly andesitic crystal-bearing lithic tuff, volcanic breccia, and volcanic conglomerate with subordinate intercalated andesitic flows.
Abundant Buchia sublevis of earliest Cretaceous locally.
Kns
Nepheline syenite
Early Cretaceous
Chiefly leuco- to melanocratic, medium-grained nephelene syenite and malignite, with subordinate ijolite, shonkinite, and pyroxenite.
K-Ar age of 107 Ma
Kgi
Syenite and monzonite
Chiefly leuco- to mesocratic, medium-grained gniessic syenite and monzonite
K-Ar age of 100 Ma
Kqi+
Quartz monzonite and alaskite
Chiefly leucocratic, fine- to medium-grained cataclastic-textured, monzonite and alaskite
K-Ar age of 99 Ma
Jv
Altered mafic volcanic rocks
Jurassic (?)
Dark-greenish gray altered basalt and diabase; commonly altered or partially altered to aggregate of chlorite, epidote, and sodic plagioclase
K-Ar ages of 155 and 168 Ma in the Christian quadrangle.
Limestone
Light-gray, recrystallized, limestone and dolomite containing minor intercalated phyllite and mica schist.  Arctic Alaska terrane, northern part of quadrangle
Schist and phyllite
Chiefly light- to dark-gray fine-grained quartz-mica schist and grayish-black phyllite.  Subordinate calcareous schist, limestone, chlorite schist, and amphibolite schist.  May locally include metasedimentary rocks of middle Cretaceous age.
DOtu
Metasedimentary and metavolcanic rocks of Tukpahlearik Creek, undivided
Devonian to Ordovician
Black carbonaceous quartzite and silicieous argillite with lenses of dolostone and marble, silvery gray to silvery green pelitic schist, gray chert pebble metaconglomerate, green calc-schist, micaceous marble, dark green mafic metavolcanic rocks, gray or
Ordovician conodonts and Devonian to Ordovician conodonts
SE003
Pzkm
Marble of Klery Creek
White-weathering, medium- to light-gray marble having subordinate intercalated gray to green quartz-chlorite schist, black carbonaceous quartzite, and tan calcareous mica schist.
Early Devonian to Late Silurian conodonts and earliest Mississippian conodonts
PzpCku
Mixed schists of the Kallarichuk Hills, undivided
Paleozoic and (or) Proterozoic
Silvery green and gray quartz-mica schist, brown calcareous schist, gray marble, and black quartzite.  Carbonaceous rocks compose 20 percent of unit, marble less than 1 percent.  Indicate blueschist metamorphism followed by retrograde greenschist facies
Mississippian to Silurian conodonts
Proterozoic U-Pb age on zircon from granodiorite intruding marble, and K-Ar cooling ages of 114 Ma on muscovite and 91.6 Ma on biotite.
Norton Bay
Flood-plain and estuarine deposits
Holocene
NR002
Terrace and slope deposits
Holocene and Pleistocene
Pleistocene or Pliocene
Ta
Andesite and basalt
Eocene
TKi
Shallow intrusive rocks
early Tertiary and Late Cretaceous
Shallow intrusive rocks of silicic and intermediate composition.
Shallow intrusive rocks - Complex
Shallow intrusive rocks of silicic and intermediate composition.  Complex of many small intrusive bodies
Kcm
Granitic rocks of Christmas Mountain pluton
Ts
Shale, sandstone, and coal
Miocene? or Oligocene?
MzPzq
Quartzite-metachert, carbonate rocks, phyllite
Mesozoic? and Paleozoic?
MzPzr
Reindeer Hills complex
Thermally altered and metasomatized carbonate rocks, schist, and quartzite intruded by numerous small felsic and mafic bodies
Pzc
Carbonate rocks
Early Paleozoic
Pelitic schist, calc schist, and quartzite
Paleozoic and Proterozoic?
Quartz-muscovite-graphite schist, calc schist, quartzofeldspathic schist, phyllite, and quartzite.  Unit is locally interlayered with unit Pzcs and is therefore, at least in part, Paleozoic in age.  Some of the unit may be as old as Proterozoic.
Samples of the schist yielded a metamorphic mineral K/Ar isotopic cooling age of 124 Ma
NR003
Pzu
Carbonate rocks and schist
Undivided carbonate rocks and schist in areas of poor exposure
Carbonate-rich conglomerate and sandstone
Late and Early Cretaceous
Nonmarine and marine carbonate-rich conglomerate and sandstone deltaic deposits.
Kvc
Volcanic conglomerate and breccia
Massive, poorly stratified pebble to boulder conglomerate, interbedded with dark graywacke and dark finely laminated mudstone.  Unit composed of debris flows and alluvial fan deposits.  Consists chiefly of andesitic volcanic rock detritus, but locally in
A granitic clast from conglomerate yielded a K/Ar cooling age of 113 Ma
Kct
Carbonate-rich sandstone, siltstone, and shale turbidite deposits
Kcvg
Carbonaceous volcanic graywacke and mudstone turbidite deposits
Ks
Sandstone and shale deltaic deposits, undivided
Nonmarine and marine sandstone and shale deltaic deposits, undivided
Ksm
Marine deltaic deposts
Kcs
Calcareous sandstone, siltstone, and shale turbidite deposits
Volcaniclastic graywacke and mudstone turbidite deposits
Kcv
Mixed sequence of calcareous graywacke, calcareous mudstone, volcanic graywacke, and volcanic conglomerate.  Transitional between Kvg and Kcg.  Small area of unit in northeast part of quadrangle reassigned and lumped with unit Kvm by W.W. Patton, Jr. (19
Mixed sequence of calcareous graywacke, calcareous mudstone, volcanic graywacke, and volcanic conglomerate.  Transitional between Kvg and Kcg.  Unit added by Patton, 1999 by sub-division.  Consists of carbonaceous volcanic graywacke and mudstone turbidit
Calcareous graywacke and mudstone -- conglomerate
Conglomeritic facies of a mixed sequence of calcareous graywacke, calcareous mudstone, volcanic graywacke, and volcanic conglomerate.  Transitional between Kvg and Kcg.  An area of unit Kcv in the south west part of the quadrangle has been reassigned by
Volcanic conglomerate and breccia -- conglomerate
Conglomeritic facies of  volcanic conglomerate and breccia.
Conglomeritic facies of carbonate-rich sandstone, siltstone, and shale turbidite deposits.
Andesitic volcanic graywacke and mudstone with local amounts of granitic rock detritus and fine-grained tuffaceous material and conglomerate.  Western outcrops of this unit changed to unit conglomeratic facies of unit Kvc by W.W. Patton, Jr. (1999).
Conglomerate facies -- Carbonate-rich conglomerate and sandstone
Conglomerate facies -- Nonmarine and marine carbonate-rich conglomerate and sandstone deltaic deposits.
Intricately intruded areas of Volcanic conglomerate and breccia
Intricately intruded areas of Volcanic graywacke and mudstone, late Early Cretaceous (Albian)
Solomon
Qb
Beach deposits
Pleistocene
SO002
Qe
Dune sand deposits
Bendeleben
Silt and peat
BN002
Qlt
Lake terrace deposits
Qd
Glacial drift
Late Quaternary
Qc
Silty colluvium, undivided
Silty colluvium, undivided; includes slope deposits, glacial deposits highly modified by weathering, and volcanic rocks covered by a thick mantle of silt
Qal
Alluvium, undivided
QTkg
Kougarok Gravel
Quaternary, Tertiary
Qlj
Lost Jim Basalt
Lost Jim Basalt; single basaltic lava flow and vent deposits undisrupted by frost brecciation
Qv
Volcanic rocks, undivided
Basalt and basaltic andesite flows and associated vent deposits slightly to strongly fragmented by frost riving and locally overlain by windblown silt
QTv
Quaternary and Tertiary
Volcanic rocks, undivided; Basalt and basaltic andesitic flows and associated vent deposits thoroughly fragmented by frost action
TKv
Felsic volcanics
Tertiary, Cretaceous
Felsic volcanics; sericitized, limonitized tuff, flow, flow-breccia or vent-breccia
ALT-SER
Ddm
Dolostone and marble
Devonian
Black to dark gray dolostone and marble with relict sedimentary structures and megafossils
"megafossils"
Sd
Dolostone
Silurian
Light to dark gray fine-grained dolostone
Od
Ordovician
Pink to light gray weathering, gray to tan fine-grained dolostone with distinct color mottling
Cd
Cambrian
Light or medium gray to pinkish orange dolostone which weathers gray to orange; may contain a few percent quartz and white mica
DCbm
Black marble
Devonian through Cambrian
Black to dark gray marble and subordinate impure fissile marble; may show rhythmic alteration of purer, coarse crystalline marble and more impure, fine crystalline layers; mafic dikes and plugs common
Oim
Impure chlorite marble
Buff to orange weathering impure marble characterized by lenses and layers of chlorite-albite schist
Ocs
Casadepaga schist
Light green and greenish-brown mafic- and calcareous-rich schist
OCx
Mixed unit
Ordovician, Cambrian
Interlayered pure and impure marble, quartz-graphite schist, and lesser pelite, calc-schist, and mafic schist
CpCs
Solomon schist
Cambrian, preCambrian
Solomon schist; Tors of resistant, well-foliated quartz-rich pelitic schist, locally containing chloritoid, glaucophane and garnet; minor calc-schist
Pzim
Impure marble
Buff to orange weathering impure marble containing white mica, chlorite, albite, quartz and graphite; probably facies equivalent of the impure chlorite marble unit (Oim)
Pzwm
White marble
Pzm
Marble, undivided
Pzd
Dolostone, undivided
Dg
Granitic orthogneiss
Light gray to orange-weathering fine-grained orthogneiss of Kiwalik Mountain
Pzg
PzpCf
Felsic schist
Paleozoic, Precambrian
Oimh
Orange-weathering, well-foliated marble; upgraded equivalent of the impure chlorite marble unit (Oim); above biotite grade
Ocsh
Calcareous and mafic schist
Brown to green weathering mafic, calcareous, and feldspathic schist; above biotite grade; upgraded equivalent of Casadepaga schist (Ocs)
OCxh
Interlayered marble and quartz-graphite schist
Predominantly marble and quartz-graphite schist above biotite grade; upgraded equivalent of mixed unit (OCx)
CpCsh
Pelitic schist
Pelitic schist with centimeter-thick lenses and layers of quartz; above biotite grade; upgraded equivalent of Solomon schist (CpCs)
PzpCsh
High-grade schist, undivided
Paleozoic to Precambrian
Metasedimentary and metaigneous schist and gneiss above biotite grade; contains rocks which may be equivalent to units described above (Ric- on the map, I believe this unit was labelled PzpCh)
PzpCm
High-grade marble, undivided
Light-gray weathering coarse-grained pure and impure marble
PzpCg
Migmatite
PzpCs
Metasediments
Amphibolite facies metasediments of various lithologies associated with the Windy Creek pluton and Oonatut Granite
PzpCa
Amphibolite
Garnet amphibolite rubble crop in western Bendeleben Mountains
PzpCo
Orthogneiss
TKs
Sandstone
Rocks of the Kugruk fault zone; Siltstone, sandstone, and pebbly sandstone with locally abundant coal seams
TKc
Conglomerate
Rocks of the Kugruk fault zone; Conglomerate composed predominantly of carbonate and mafic clasts
MzPzm
Mylonitic metabasite
Mesozoic, Paleozoic
Rocks of the Kugruk fault zone; Fine-grained, medium bluish-gray metabasite with fine, laminar foliation and rounded, light-green clinopyroxene grains; contains blue amphibole and lawsonite where exposed in the Bendeleben quadrangle
Tectonite
MzPzb
Metabasitic rocks
Dark red, green and gray vesicular basalt and basaltic pyroclastic rocks metamorphosed to lower greenschist facies
MzPzs
Serpentinite
MzPzt
Spruce Creek Tonalite
Tm
Mafic dikes
Tertiary
Quartz Latite
Quartz Latite; Light tan to orange weathering dikes, sills and plugs of rhyolitic to andesitic composition
Kog
Oonatut granite
Oonatut granite; Monzogranite and lesser syenogranite
69.2 +/- 2 Ma and 71.2 +/-  Ma K-Ar in biotite
Kp
Pargon pluton
Pargon pluton; Granodiorite and quartz monzonite
Kb
Bendeleben pluton
Bendeleben pluton; Monzogranite, granodiorite, quartz monzonite, and quartz monzodiorite
81.8 +/- 2 Ma K-Ar in biotite
Kkz
Kuzitrin pluton
Kuzitrin pluton; Monzogranite
93.0 +/- 1.4 Ma K-Ar in biotite Age may be mis-reported, a late report is 83 Ma
Kku
Kugruk pluton
Kugruk pluton; Quartz monzonite to quartz monzodiorite
94.9 +/- 2.9 Ma K-Ar in hornblende
Kae
Asses Ears stock
Asses Ears stock; Monzogranite to syenogranite
Kcb
Crossfox Butte stock
Crossfox butte stock; Monzogranite to quartz monzonite
Kvb
Virginia Butte stock
Virginia Butte stock; quartz monzonite to syenite
94.8 +/- 1.9 Ma K-Ar in biotite
Knh
Nimrod Hill stock
Nimrod Hill stock; monzonite
Kd
Darby pluton
Darby pluton, monzogranite, locally granodiorite
94 Ma K-Ar in biotite and horneblende
Kwc
Windy Creek pluton
Windy Creek pluton; Quartz monzonite
Kkd
Diorite
Hybrid diorite of Kachauik pluton
Kkgm
Gneissic monzonite
Gneissic monzonite of the Kachauik pluton
Kkg
Granodiorite
Granodiorite to quartz monzonite phase of the Kachauik pluton
Kkms
Monzonite-syenite
Monzonite-syenite phase of the Kachauik pluton
99.3 +/- 3 Ma K-Ar on horneblende
Kdc
Dry Canyon stock
Dry Canyon stock; Nepheline syenite
108 +/- 3 Ma K-Ar in hornblende
Kpg
Pegmatite
Pegmatite [Digitized as arcs]
Kfg
Foliated granite
Foliated granite; Leucocratic syenogranite, locally monzogranite
Kgu
Granitic rocks, undivided
Teller
Cover
Tundra; shown only where it completely mantles bedrock.
TE002
Alluvium
Includes spits, offshore bars, and lagoonal deposits.
Silt
Includes loess and fine-grained sediment near steams and over coastal terrace.  Generally covered by tundra but numerous exposures in thaw lakes.
Qss
Silt and sand
Stratified deposits related to changes of base level (Imuruk Basin only).  Generally covered by tundra but numerous exposures in thaw lakes.
Qm
Moraine deposit
Qo
Outwash
Quaternary, Pleistocene
Qtr
Terrace gravels
Alluvial-fan deposits
Large fans on marine terrace of Sangamon age.
Qyb
Younger beach deposits
Low-level deposits related to sea level of Sangamon age.
Qob
Older beach deposits
High-level deposits related to sea level of an early Sangamon age, or a pre-Sangamon age.
Qpc
Lithified deltaic gravels on the York terrace of Yarmouth(?) age.
Tertiary or Quaternary
Alkalic basalts, locally nepheline bearing.
TKd
Dikes
Cretaceous and Tertiary(?)
Rhyolite, rhyolite porphyry, granite, diabase, and lamprophyre dikes.  Only larger dikes shown.
TKa
Altered equivalents of rhyolite, rhyolite porphyry, granite, diabase, and lamprophyre dikes.  Only larger dikes shown.
ALT
Kg
Granite
Medium to coarse grained, unfoliated biotite granite; includes biotite hornblende granite of King and Little Diomede Islands
Kgh
Hypersthene granite of Fairway Rock.
Kgf
Medium to fine-grained, unfoliated biotite granite; may include biotite-hornblende quartz monzoite
Kgn
Gneissic or markedly foliated garnet-bearing biotite granite and related rocks.
Ml
Limestone, dolomitic limestone, and shale
Mississippian
Intensely deformed medium-dark-gray limestone and marble and interbeds of silicious shale; local chert; sparse fossils.
Dl
Dark-gray medium-bedded sugary-textured limestone with sparse fossils.
Sl
Middle Silurian
Light-brownish-gray, medium-bedded sparry limestone grading downward to medium- to light-gray medium bedded limestone at base; abundant fossils (Sainsbury, 1996a).
SOdl
Limestone and dolomitic limestone
Late Ordovician and Silurian
Principally meduim- to dark-gray meduim- to thick-bedded sparry limestone, locally includes cherty layers and nodules; weathers to dark-gray, hackly plates with numerous white fossils that are largely silicified; for common fossils see Sainsbury (1969a).
Oum
Undifferentiated limestone and dolomized limestone
Late and Middle Ordovician
Undifferentiated limestone and dolomized limestone.  West of Don River may include some rocks of Silurian age.
Oshl
Limestone and shale
Middle Ordovician
Dark thin- to meduim-bedded limestone with local chert nodules; weathers to pale orange to pale yellowish brown and forms subdued slopes.  At base contains thin (50-100 feet) unit of fissile black shale and minor interbedded black limestone.  Shale conta
Graptolites
Oshd
Dolomitzed equivalent of Oshl.
Ol
Limestone and argillaceous limestone
Early Ordovician
Massive to thick-bedded micritic limestone containing interbeds of argillaceous limestone; sparse chert nodules in thick-bedded limstones which are entirely calcitic.  Sparse fossils include cephalopod siphuncles and brachiopods of late Canadian age (Sai
Cephalopod sphuncles, brachiopods, and trilobites
Olu
Undifferentiated limestone and argillaceous limestone
Oal
Argillaceous limestone and limestone
Thin-bedded ruditic argillaceous and silty limestone and dolomite limestone, carbonaceous limestone, and subordinate massive micritic limestone which locally contains chert; abundant ripple marks, swash marks, casts of worm tubes, crossbedding, and limes
Worm tubes
Intensely deformed limestone of undifferentiated Paleozoic age.
Marbleized equivalent of Pzl.
OpCl
Limestone, argillaceous limestone, and dolomitic argillaceous limestone
Late Precambrian and earliest Ordovician
Limestone, argillaceous limestone, and dolomitic argillaceous limestone of undifferentiated late Precambrian and earliest Ordovician age.
pCl
Late Precambrian
Thin-bedded, rhythmically interbedded dolomitic limestone and argillaceous limestone.
pCld
Large areas of dolomitized pCl; probably near a thrust fault.
pCt
Metmorphosed equivalent of pCl converted to tactite.
pCg
Gabbro
Includes coarse-grained gabbro, diabase and altered equivalents which locally are garnet-glaucophane rocks.  Of two ages (see accompanying text).
pCs
Slate of the York region
Slightly to moderately metamorphosed graphitic siltite, slate, graywacke, and calcareous siltite.
pCsg
Green-weathering chloritic graphitic siltite (pCs) near mafic intrusives.
pCn
Nome Group
Nome Group undifferentiated; chloritic schists and marble schists.
pCnc
Chlorite-epidote-amphibole schists, intensely deformed, locally graphitic; retograded blueschist facies rocks locally (Sainsbury, Coleman, and Kachadoorian, 1970); subordinate schistose limestone.
pCnl
Dark schistose limestone intercalated with subordinate chloritic schist.
pCmu
Kigluaik Group
Precambrian
Metamorphic rocks undifferentiated.
pCgn
Biotite-quartz-orthoclase gneiss; locally includes small areas of undifferentiated metamorphic rocks (pCmu).
pCb
Tigaraha Schist
Biotite-garnet schist; near granite (Kgn, Kgf) contains andalusite.
pCbm
Marble and calc-silicate rocks intercalated in schist (pCb).
pCgu
Upper gneiss
preCambrian
Biotite-hornblende-quartz-plagioclase paragneiss.
pCm
Marble
Coarse-grained marble, locally contains mica and either olivine or monticellite; at places converted to brown-weathering tactite.
pCgl
Lower gneiss
Quartz-biotite-plagioclase-hornblende paragneiss and local calc-silicate rock.
Interbedded white to light-gray banded quartzite, dark phyllite, and gray laminated limestone. Thin sections show the quartzite to be composed of as much as 99 percent interlocking quartz grains.  Thin layers of white mica folia give the quartzite a fain
In the Nulato quadrangle the limestone is partly recrystallyzed and silicified and locally contains unidentifiable coral and crinoid fragments.  In the Melozitna quadrangle, thin marble beds contain conodonts and crinoids of Devonian age
Nonmarine and marine carbonate-rich conglomerate and sandstone deltaic deposits
SE004
Carbonate and volcanic clast graywacke and mudstone
Cyclically interbedded fine- to coarse-grained highly calcareous graywacke; hard, fine- to medium-grained, carbonaceous, volcanic graywacke; and dark carbonaceous mudstone.  Graywacke is typically graded and sole-marked. Carbonized plant debris is abunda
Kgr
Knsy
Kmc
Contains marine mollusks of Early Cretaceous(?) age in the Selawik quadrangle
PzZu
Chiefly light- to dark-gray fine-grained quartz-mica schist and grayish-black phyllite.  Subordinate calcareous schist, limestone, chlorite schist, and amphibolite schist.  May locally include metasedimentary rocks of middle Cretaceous age.  Subdivison a
MzPzma
Metabasite
Mesozoic or Paleozoic
Varies from thinly layered greenschist to more massively layered greenstone bodies representing altered mafic and intermediate volcanic and  shallow intrusive rocks. The characteristic minerals are chlorite, albite, actinolite, and epidote.  Unit may inc
Dark-greenish gray altered basalt and diabase; commonly altered or partially altered to aggregate of chlorite, epidote, and sodic plagioclase.  Separated from rest of unit; occurs only in southwest part of quadrangle.
Light-gray, recrystallized, limestone and dolomite containing minor intercalated phyllite and mica schist. Seward terrane, southwest part of quadrangle
Qbm
Modern beach deposits
DCks
Calc-schist
Medium-grained calc schist interlayered with DObm and DCbm
Metasedimentary and metaigneous schist and gneiss above biotite grade; contains rocks which may be equivalent to units described above
94 Ma K-Ar in biotite and hornblende
Kad
Alkaline dikes
Alkaline dikes; Nepheline syenite and pseudoleucite porphyry [Digitized as arcs]
96.3 +/- 3 Ma K-Ar
BN004
PzpCh
Oc
Light green and greenish-brown mafic- and calcareous-rich schist
Appears as unit Ocs in source BN002.
Kbg
Bendeleben pluton and Kuzitrin plutons
Bendeleben pluton; Monzogranite, granodiorite, quartz monzonite, and quartz monzodiorite (Unit Kb in source BN002), Kuzitrin pluton; Monzogranite  (Unit Kkz in source BN002)
81.8 +/- 2 Ma K-Ar in biotite
93.0 +/- 1.4 Ma K-Ar in biotite
QTk
Kougarok Gravel
Unit QTkg in source BN002
Kng
Stocks
Asses Ears stock; Monzogranite to syenogranite  (Unit Kae in BN002);
Crossfox butte stock; Monzogranite to quartz monzonite (Unit Kcb in BN002); Virginia Butte stock; quartz monzonite to syenite  (Unit Kvb in BN002); Nimrod Hill stock; monzonite (Unit Kn
Pegmatite.  No polygons on map.  Lines have an arc-para2 value of 340.
Quartz Latite; Light tan to orange weathering dikes, sills and plugs of rhyolitic to andesitic composition.  No polygons on map.  Lines have an arc-para2 value of 341.
SO004
99.3 +/- 3 Ma K-Ar in horneblende
Alkaline dikes; Nepheline syenite and pseudoleucite porphyry
No polygons on map.  Lines have an arc-para2 value of 342.
Pzca
Ranges from light gray to white partly recrystallized limestone  to coarsely crystalline marble. Dark finely crystalline dolomitic marble.  Interbedded calc schist, chloritic schist, and quartzite in subordinate amounts.  Unit ranges in age from Ordovici
Contains scattered fossils, chiefly conodonts, from map area and from exposures of the unit in contiguous parts of the Arctic Alaska terrane north of the map area
PzZsa
Paleozoic and Proterozoic
Quartz-mica schist and lesser amounts of calc schist, quartzite, graphitic  schist, chlorite schist, and quarto-feldspathic schist. Polydeformed greenschist-blueschist-facies characterized by quartz-muscovite-chlorite-albite±glaucophane assemblages. A re
K/Ar isotopic analyses of the schist yielded Early Cretaceous metamorphic mineral cooling ages
PzZua
Pelitic schist, calc schist, and quartzite (PzZsa) and carbonate rocks (Pzca), undivided
Gravel and sand
A small cutbank exposure of moderately dipping gravel and sand at north edge of Selawik Hills on eastern tributary of Mangoak River.  Composed chiefly of poorly sorted granitic rock detritus that appears to have been derived from nearby granitic rocks
Qua
Alluvial, colluvial, glacial, and windblown terrace and slope deposits, undivided
Chiefly  silt and very fine sand including thick deposits of micaeous silt in the Koyukuk Flats and Nowitna and Innoko Lowlands.  Local deposits of alluvial fan and glacial outwash gravels
Alluvial, colluvial, glacial, and windblown  terrace and slope deposits, undivided
Chiefly silt and very fine sand including thick deposits of micaeous silt in the Koyukuk Flats and Nowitna and Innoko Lowlands.  Local deposits of alluvial fan and glacial outwash gravels
Chiefly  silt and very fine sand including thick deposits of micaeous silt in the Koyukuk Flats and Nowitna and Innoko Lowlands.  Local deposits of alluvial fan and glacial outwash gravels.
Basalt flows
Pleistocene and Pliocene
Vesicular tholeiitic and alkali basalt flows. In Candle and Selawik quadrangles unit includes several alkali basalt cones and flows that contain abundant peridotite inclusions.
K/Ar isotopic cooling ages from the volcanic field in western part of Unalakleet quadrangle range  from 3.25 Ma to 1.39 Ma.
Carbonate-clast graywacke and mudstone
Fine-grained to gritty graywacke and laminated micaceous mudstone turbidite deposits composed largely of carbonate detritus and lesser amounts of quartz, chert, volcanic rock, and mica clasts.  Contains abundant carbonized plant debris. The mudstone inte
A single collection of palynomorphs from the Norton Bay quadrangle is Cretaceous in age, possibly late Early or early Late Cretaceous (Albian or Cenomanian).
MzPzum
Mafic-ultramfic complexes
Mesozoic and Paleozoic?
The complexes consist of: 1) a cumulate magmatic suite composed of interlayered dunite, wehrlite, olivine clinopyroxenite, and gabbro, 2) a mantle suite composed of harzburgite, dunite, and minor clinopyoxenite, and 3) a metamorphic sole consisting of a
K/Ar isotopic cooling ages from the magmatic suite average 159 Ma and two 40Ar/39Ar determinations yielded a plateau age of 162 Ma.  K/Ar isotopic cooling ages from the metamorphic sole at the base of the complexes range from 172 to 155 Ma and one 40Ar /
Flood-plain and tidal flats deposits
Gravel, sand, silt, and peat. Floodplain deposits in Koyukuk Flats and along Yukon River composed mainly of light gray micaceous silt
Conglomerate facies -- Carbonate-clast conglomerate, sandstone, and shale
Nome
Qa
Floodplain alluvium
Elongate deposits of pebble-cobble gravel and sand with few to numerous boulders beneath modern floodplains; well sorted wand medium to thick bedded, locally crosssbedded; surface smooth, except for local low scarps
NM002
Qaf
Fan shaped, heterogeneous mixtures of pebble-cobble gravel, sand and silt with few to numerous, subangular to subrounded boulders, especially in proximal areas; may include deposits of slushflows and debris flows in proximal areas; thick to thin bedded;
Qat
Terrace alluvium
Elongate deposits of pebble-cobble gravel and sand with trace to some silt and few to numerous boulders comprising stream terraces bordering modern floodplains; includes strath terraces; higher, older terraces are covered with up to 1 m of undifferentiat
Undifferentiated colluvium
Irregular, heterogeneous blankets, aprons, and fans of angular to subanglular rock fragments, gravel, sand, and silt up to estimated 3 m thick that are left on slopes, slope bases, or high-level surfaces by residual weathering and complex mass-movement p
Qca
Snow-avalanche debris
Tongue-shaped, heterogeneous mixture gravel, sand, and silt deposited at the mouths of bedrock couliers by snow avalanche; surface typically covered with numerous boulders
No polygons could be found on the map.
Qcd
Debris-flow deposits
Fan- and cone-shaped, heterogeneous mixtures of sand and silt with some gravel and few to numerous angular rock fragments deposited at the mouths of gullies and on lower slopes by debris flows; surface has numerous discontinuous channels and numerous sub
Qcf
Undifferentiated colluvium and alluvium
Fan- and tongue-shaped and elongate, heterogeneous mixtures of subangular rock fragments and pebble-cobble gravel with some sand and silt deposited in upper stream courses; surface smooth to covered with numerous boulders, except for local low scarps and
Qcl
Landslide deposit
Oval to tongue-shaped, heterogeneous mixtures of fractured bedrock, pebble-cobble gravel with trace to some sand and silt deposited by near-surface flowing and sliding due to instability of failed bedrock and unconsolidated surficial deposits; surface sl
Qcp
Protalus rampart deposits
Arcuate ridges of angular fragments of local bedrock and pebble-cobble gravel with trace to some sand and silt; surface littered with rock fragments
Qct
Talus
Cone- and apron shaped, heterogeneous mixtures of angular rock fragments with trace to some gravel, snad and sitl deposited at mouths of steep bedrock couliers; surface steep, slightly irregular, and covered with numerous angular rock fragments, expecial
Qd4
Unmodified drift of Salmon Lake Glaciation
Heterogeneous blankets of pebble-cobble gravel with some sand and trace to some silt and few to numerous subangular to subrounded boulders of Kigluaik Mountains lithologies deposited directly from glacial ice; includes glaciolacustrine silt and clay with
Qd3
Slightly modified drift of Stewart River Glaciation
Heterogeneous blankets of pebble cobble gravel with some sand and trace to some silt and few to numerous subangular to subrounded boulders of Kigluailk Mountains lithologies deposited directly from glacial ice and slightly reworked by mass-movement proce
Qd2
Modified drift of Nome River Glaciation
Heterogeneous blankets of pebble-cobble gravel with trace to some snad and silt and few to numerous subangular to subrounded boulders deposited directly from glacial ice and reworked by mass-movement processes; generally massive bedded
Qd1
Greatly modified drift of Sinuk Glaciation
Heterogeneous blankets of pebble-cobble gravel with trace to some sand and silt and few to numerous subangular to subrounded boulders deposited directly from glacial ice and greatly modified by mass-movement processes; massive bedded
Qo4
Outwash of Salmon Lake Glaciation
Elongate and fan-shaped deposits of well-sorted pebble-cobble gravel with trace to some medium to coarse sand and trace silt deposited by proglacial meltwater streams; medium to thick bedded, locally crossbedded
Qo2
Ice-marginal deposits of Nome River Glaciation
Elongated deposites of well-sorted pebble-cobble gravel with trace to some medium to coarse sand and few to numerous subangular to subrounded boulders deposited by meltwater stream in ice-marginal channel just south of Rocky Mountain Creek on lower easte
Qes
Dune sand
Homogeneous blankets of well-sorted snad deposited by wind in the vicinity of Hazel Creek in lower Nome River valley; thin to medium bedded
Qmb
Elongate deposits of well-sorted medium to coarse sand and shingled pebble gravel deposited and extensively reworked by wave action; locally fossiliferous and auriferous and mined for placer gold; fine to medium bedded, locally crossbedded
Qme
Estuarine deposits
Elongate to blanket deposits of silt with trace to some clay and ifne to medium sand deposited in estuarine reaches of tidewater streams; overlain by 1 to 2 m of surface peat; laminated to thick bedded
Qmt
Terrace deposits of Pelukian Transgression
Upper Pleistocene
Blankets of marine gravel, sand, and silt overlain by variable thicknesses of peat and reworked in upper part during thaw-lake cycles; perennially frozen and ice rich; complexly bedded
Undifferentiated swamp deposits
Upper Pleistocene and Holocene
Elongate to blanket deposits of peat, organic silt, and organic sand accumulated as surface deposits downslope of springs and seeps, in former stream channels, or in thaw-pond and thaw-lake basins; saturated and discontinuously to continuously frozen, lo
Qh
Primarily placer-mine tailings
Water-washed pebble-cobble gravel with trace to some sand; moderate to well sorted
pCPzmsb
Interbedded marble, schist and metabasite sills, Casadepaga Schist (?)
Precambrian to Paleozoic
Heterogeneous, well stratified, sequence composed of: chlorite rich, locally calcareous muscovite schist; graphitic muscovite, chlorite, quartzo-feldspathic schist; tremolite bearing marble; and garnet, glaucophane bearing, actinolite rich metabasite.  G
pCPztcb
Calcareous porphyroblastic schist, Casadepaga Schist (?)
Calcareous, albite, chlorite (pennine) schist with minor garnet amphiboite.  Calc-shcist difficult to distinguish from schist (pCPzct) of mixed unit
pCPzsm
Coarse grained, albite mafic schist, Casadepaga Schist (?)
Coarse grained, porphyroblastic schist and phyllite with distinct plagioclase porphyroblasts up to 1 cm in long dimension rolled in fabric.  Mafic minerals are actinolite-hornblende, largely retrograded to pennine chlorite and opaque oxides, and anhedral
pCPzspp
Porphyroblastic epidote schist, Casadepaga Schist
Generally coarse grained, light to medium green, feldspar rich, chlorite, epidote porphyroblastic schist.  Subhedral feldspar porphyroblasts up to 0.5 mm long are inclusion charged with secondary muscovite, chlorite, and opaques.  Chlorite is pennine ric
pCPzd
Dolomite
Fine grained sugary dolomite.  Where of mappable extent pCPzd occurs in association with larger marble units (pCPzmp, pCPzmm, pCPzm).  Thin sections show more than 90 percent dolomite with several percent each of albite, white mica, epidote, and quartz
pCPzmp
Platey marble
Light to medium gray, medium to coarse grained, with grains 0.25 to 1 mm, hackly weathered, marble composed largely of 85 percent calcite and subordinate amounts of quartz anhedra (5 percent), tremolite (3 percent), locally diopside in disequilibrium (1
pCPzm
Massive marble
Massive, blocky, medium to coarse grained marble composed almost entirely of calcite rhombehedrons.  Locally unmapped lenses or crosscutting dikes of chlorite-amphibole-garnet metabasited found in outcrop. pCPzm unit thought to be in thrust cntact with u
pCPzsc
Calcareous schist, felsic schist, and chlorite schist
Heterogeneous unit composted of distinctly brown weathered, medium grained, calcareous chlorite-white mica schist, albite rich muscovite felsic porphyroblastic schist, and mica bearing dolomitic marble.  The felsicporphyroblastic schist contain zircon an
pCPzspm
Pelitic, porphyroclastic, micaceous, graphitic schist
Distinctively dark gray, massive to layered, medium to coarse grained, biotite, chlorite, muscovite, porphyroclastic "lumpy" schist, the provenance of which is thought to be pelitic, coarse metasandstone and metaconglomerate.  Composed of up to 15 percen
pCPzb
Metabasite, Nome Group
Fine to medium grained, nonfoliated to moderately foliated, rutile and sphene-rich metabasite.  Prograde minerals include garnet, hornblende, chloritoid, calcic plagioclase, and sphene-rutile.  Retrograde minerals include pennine chlorite, albite, epidot
pCPzf
Feldspathic orthogneiss and metavolcanic schist
Fine to medium grained, subfoliated to phaneritic, K-spar rich, felsic orthogneiss.  Contains abundant white mica, feldspar, albite, quartz, and subordinate chlorite, carbonate, and sericitic alteration products
pCPzsf
Felsic, muscovite, metavolcanic schist
Heterogeneous unit of zircon rich, muscovite quartzose schist; feldspar-rich, porphyroblastic muscovite schist with minor quartz; and tourmaline enriched, muscovite-chlorite-feldspar schists, referred to as "tourmalite" beds
pCPzsg
Graphitic schist and quartzite
Massive to laminated, blocky graphitic quartzite.  Composed of laminated layers of interlocking quartz anhedra, and graphite.  Occasionally thin sections contain 1-2 percent white mica.  represents either (1) carbonaceous fine grained mudstones; or (2) m
pCPzt
Chlorite rich, metaturbidite schist, and marble
Medium grained, well foliated, locally banded, chlorite, muscovite, feldspathic, quartzose schist and phyllitic schist.  Locally contains thin marble beds, and up to 3 percent calcite in groundmass.  Also contains variable amounts of clinozoisite, garnet
pCPztc
Calcareous metaturbidite schist
Usually banded, calcareous, micaceous, feldspathic schist typically containing calcite, white mica, chlorite, inclusion charged feldspar, quartz, and opaque minerals.  Similar to interbedded pCPzt unit, but more calcareous.  Thought to be gradational wit
pCPzspb
Garnet, biotite, pelitic schist, Solomon Schist (?)
Biotite rich, graphite bearing quartzose schist with numerous small anhedra garnets, largely retrograded to leucoxene and chlorite, and opaque oxides.  Similar to pCPzspm unit but coarser grained and with lower quartz content.  Exposed in Twin Creek Anti
pCPzspc
Calcareous, biotite, porphyroblastic schist, Solomon Schist (?)
Porphyroblastic (albite grains) biotite rich calcareous pelitic schist, chiefly distinguished by high biotite content, which comprises up to 40 percent of rock.  Also contains distinctive quartz-graphite lamina ranging from 5 to 50 cm thick
pCPzsgb
Biotite, graphitic schist and quartzite, Solomon Schist (?)
Blocky to massive, moderately foliated, muscovite-biotite, graphitic schist and black laminated quartzite.  pCPzsgb forms, along with pCPzss unit, the major lithologies of the Solomon Schist in the study area.  Distinguished from other pelitic units by c
pCPzsa
Albite chlorite schist and quartite
Porphyroblastic, feldspathic, chloritic schist and very light gray to bleached, laminated quartzite, both highly schistose
pCPzss
Muscovite, quartzose schist and paragneiss, Solomon schist
Medium grained, foliated, massive to laminated, garnet bearing, white mica, quartziose schist and paragneiss.  Dominant lithology of Solomon Schist north of Stewart River.  Locally contains porphyroblasts of andesine, chloritoid, and pseudomorphs (?) of
pCPzspi
Iron rich, biotite, pelitic schist, Nome Group
Medium to coarse grained, well foliated, pyrite rich, garnet, mica schist.  Contains abundant garnet, pyrite and its alteration products goethite and limonite, pennine after both white mica and biotite, epidote, quartz, and undetermined feldspar.  Pyrite
Mzdg
Metadiorite
Mesozoic (?)
Medium graained phaneritic, slightly foliated, andesine, hyperstene (?) metadiorite or metagabbro.  Mafic minerals completely altered to pennine chlorite, leucoxene, and undetermined opaques.  Quartz poor.  Observed only in core of Twin Creek anticline o
pCPzg
Granite and granodiorite gneiss
Subfoliated to massive, blastoporphyritic, white mica rich orthogneiss variety, granite gneiss and granodiorite gneiss.  Contains numerous and complexly folded inclusions of host rock Nome Group lithologies, including pelitic and mafic schists.  White mi
g
Ferricrete gossan
Ferricrete gossan
Only information given is the name shown in the map symbols.
Surficial sedimentary deposits, undivided
Frost-rived rubble on slopes and broad low ridges; glacially deposted sand, gravel, and boulders; fluvial gravel and sand; terrace deposits.
SE005
Conglomerate, sandstone, and shale
Conglomerate and finer grained sedimentary rocks that grade from massive, poorly stratified rocks rich in mafic intrusive and extrusive clasts at the base of the unit to a well-sorted sedimentary rock rich in quartz and metagraywacke clasts at the top of
Sparse plant fossils of Early to Late Cretaceous age; Early Cretaceous? marine mollusks
White to gray (less commonly black), fine to coarsely crystalline, massive to platy marble and subordinate metalimestone and dolostone occurs discontinuously in all quadrangles within the map area.  This unit is part of the Central belt.
Conodonts, silicified two-hole crinoid columnals of late Early-early Middle Devonian  (late Emsian-Eifelian) age; brachiopods; possible stromatoporoids; pelmatozoan; trilobites
Pzsg
Mafic schist
Green and greenish-gray schistose to massive irregularly-shaped bodies and lenses of mafic rocks in units Dsq and DPsc large enough to show at the scale of the map occur in the Survey Pass and Chandalar quadrangles.  This unit is part of the Schist belt.
Dsq
Quartz-mica schist
Gray, dark gray, or brownish-gray weathering, dominantly pelitic or semipelitic schist that constitutes a major unit along the length of the Schist belt.  Outcrops vary from blocky and resistant (quartz-rich varieties) to platy and less resistant (mica-r
Youngest detrital zircon population at one locality 370-360 Ma
DpCsc
Calcareous schist, Schist belt
Devonian to Proterozoic
Light gray, brown and locally orange-weathering, lithologically heterogeneous mix of marble and carbonate-rich, quartz-rich, and mafic schist derived from metasedimentary and metaigneous protoliths, one of two major units that extends along the length of
Ghosts of radiolarians, sponge spicules, bivalves, fine graphite laminae, stromatolites, conodonts
PzZcm
Metasedimentary and metavolcanic rocks, undivided
Heterogeneous assemblage of interlayered calcareous, mafic, and siliceous rocks exposed in the central Baird Mountains, Ambler River, and Wiseman quadrangles.  This unit is part of the Central belt.
Conodonts
Undifferentiated alluvial, colluvial, and eolian terrace and slope deposits
Carbonate-rich conglomerate and sandstone; mudstone, siltstone and coal, Kugruk Fault zone
Tertiary and Cretaceous
Two separate sedimentary sequences, of broadly different age: tan to light-gray siltstone, sandstone, and pebbly sandstone, and light-gray-weathering conglomerate composed mostly of marble, metalimestone, and dolostone clasts, probably of mid-Cretaceous
CA004
Andesite and basalt flows and volcaniclastic rocks
Andesite and basalt flows interbedded with volcaniclastic rocks and volcanic greywacke, exposed along the eastern boundary of the map in the Candle quadrangle (Figure 2).   Calcareous tuffs in the upper part of the unit contain abundant shelly material,
K-Ar ages of 137 to 120 Ma (Patton and others, 2005)
Surficial deposits, undivided
Frost-rived rubble on slopes and broad low ridges; glacial moraine; glacially deposited sand, gravel, and boulders; fluvial gravel and sand; marine and fluvial terrace deposits; wetlands
Metamorphosed mafic rocks and serpentinite, Kugruk Fault zone
A tectonic assemblage of metagabbro, metabasalt, amphibolite, serpentinite, and minor chert, exposed in rubble fields and poor outcrops along the trend of the Kugruk fault zone.  Mafic rocks within the fault zone include minor unmetamorphosed (but altere
Marble, Nome Complex
Generally light-gray-weathering, white to medium-gray, medium to coarsely crystalline marble that forms rubble-covered hills and small outcrops which are widely but sparsely distributed through the map area. Marble in this unit is dominantly pure, but lo
Conodonts, stromatoporoids and (or) colonial and rugose corals
DOx
Mixed marble, graphitic metaquartzite, and schist, Nome Complex
Devonian through Ordovician
Interlayered pure and impure marble, graphitic metasiliceous rock, pelitic schist, calc-schist, and mafic schist. Gray and orange weathering marble and dark gray-black weathering graphitic metasiliceous rock are the most common lithologies in the unit, w
Casadepaga Schist, Nome Complex
Light green, silvery green and greenish-brown mafic, feldspathic, and calcareous schist. Typically occurs as frost-riven slabs and flakes that underlie rounded hills and dark greenish-black tors and rubble piles several meters across. Tors of metabasite,
Chiefly light-gray, massively bedded recrystallized limestone and dolomite, containing subordnate calcareous mica schist and dark phyllite.  Sub-division of this unit from Patton (1967) to separate dolomite
Kigluaik granite
Fine- to medium-grained felsic rocks of the upper part of the Kigluaik pluton (Figure 2), including leucocratic biotite granite and granodiorite (Amato and Miller, 2004).  This unit is more extensively exposed than the mafic root (Kdi), and contains mino
BN005
Fine grained equigranular, fine to medium grained seriate granodiorite, monzodiorite, and locally monzogranite exposed in the western Bendeleben Mountains along the Pargon River (Figure 2).  Granodiorite and quartz monzonite are the dominant lithologies.
U-Pb zircon age of 86±1 Ma (Gottlieb and Amato, 2008)
PzZg
Gneiss and orthogneiss, High-grade metamorphic and associated igneous rocks
Paleozoic? and Proterozoic?
Light brownish gray, light orange to gray biotite-plagioclase-quartz gneiss and granitic orthogneiss and minor metasedimentary rocks exposed in rubble crop north of the Oonatut Granite Complex, northwest Bendeleben quadrangle (Hudson, 1979).  The fabric
Df
Felsic schist, Nome Group
Light orange to light green weathering fine to coarse-grained quartz-feldspar-white mica schist. Present on the southwest flank of Kiwalik Mountain, where it occurs as platey rubble-crop of mm-scale laminated, very fine grained schist. Rarely, accessory
U-Pb zircon age 391±5 Ma (J. Aleinikoff, written commun., 2005; Till and others, 2006)
Dcs
Pelitic, calcareous, and graphitic schist, Nome Group
Pelitic, calcareous, and graphitic lithologies interlayered on a scale of centimeters to meters, exposed in the central Nome and Solomon quadrangles.  Interlayering is gradational and intimate. The unit is composed predominantly of pale brown and gray we
Ds
Pelitic schist, Nome Group
Devonian?
Tors of resistant, well-foliated quartz-rich schist. Pelitic rocks are the dominant lithology in the unit; calcareous schist is a minor component. Outcrop appearance of the pelitic schist is diagnostic of the unit, and shows 1- to 2-cm-thick bands of gra
Mixed marble, graphitic metaquartzite, and schist, Nome Group
PzZh
High-grade metasedimentary and metaigneous rocks, High-grade Metamorphic  and associated igneous rocks
Paleozoic  and Proterozoic
Brown, light brown, reddish brown, black, and gray-weathering schist and gneiss exposed in the Kigluaik, Bendeleben, and Darby Mountains. Highest-grade metamorphic assemblages are upper amphibolite to granulite grade; assemblages in all three ranges reco
Zo
Orthogneiss, High-grade metamorphic and associated igneous rocks
Proterozoic
Pale gray-, tan- and orangish-tan-weathering outcrops and rubble fields of foliated and unfoliated metagranitic rocks that form a large, tabular, concordant body within the high-grade rocks of the Kigluaik Mountains.  Called the "Thompson Creek orthognei
U-Pb zircon ages of 555±15 Ma (TIMS; Amato and Wright, 1998) and 565±6 Ma (SHRIMP; Amato, 2004)
Granitic orthogneiss.  Sub-division of unit of Till and others (1986) that outcrops associated with the Nome Complex
Dolostone, undivided.  Sub-division of unit of Till and others (1986) to separate Ordovician dolostone
Zn
Metagranitic rocks, Nome Complex
Late Proterozoic
Pale gray to pale greenish tan, locally green-weathering rubble crop and outcrop of small granitic, granodioritic, and tonalitic orthogneiss bodies.  Weakly- to well-foliated, fine- to coarse-grained, with foliation defined by weak to strong alignment of
669±5 Ma, U-Pb zircon analyses that range from approximately 665 to 685 Ma
Zv
Metavolcanic rocks, High-grade metamorphic and associated igneous rocks
Foliated lens- to sill-shaped bodies in the western Bendeleben Mountains exposed in outcrop and rubble fields.  Up to 50 meters thick. Very fine grain size and variation in the abundance and relative proportion of biotite and hornblende suggest a volcani
U-Pb zircon age of 870 Ma (Gottlieb and Amato, 2007, 2008; Amato and others, 2009)
NM005
Kdi
Kigluaik diorite
Fine- to medium-grained potassic mafic rocks of the lower part of the Kigluaik pluton, including biotite hornblende diorite, quartz diorite, granodiorite, tonalite, and gabbro, exposed in the western Kigluaik Mountains (Figure 2; Amato and others, 1994;
Crystallization age of 90±1 Ma (Amato and Wright, 1998)
Granitic rocks, undifferentiated
Granitic dikes, sills and small plugs at widely scattered localities (Figure 2).  Most commonly these bodies occur within exposures of high-grade metamorphic rocks (|<h), but they are also present in the Nome Complex and on islands off of the south and w
Pzmm
Marble of the Moon Mountains, Nome Complex
Pale gray to white weathering, coarsely crystalline calcite marble exposed only in the western Nome quadrangle, in an area informally called the Moon Mountains due to lack of vegetation.  The marble has a layered appearance due to variations in grain siz
Pelitic, calcareous, and graphitic schist, Nome Complex
Impure chlorite marble, Nome Complex
Buff- to orange-weathering chlorite-, white mica-, and albite-bearing calcite marble that underlies rounded hills. The unit crops out poorly; rare outcrops show well-foliated impure marble to calcareous schist. Impurities are most commonly chlorite and a
NR004
Dolostone, undivided, Nome Complex
Generally light-colored, fine-grained, featureless dolostone that forms rubble-covered hills sparsely distributed through the map area. This unit likely includes rocks of several ages. Conodont faunas, obtained at seven localities, are mostly long rangin
Black marble, Nome Group
Dark gray to black marble and subordinate fissile impure marble, calcareous schist, and mafic schist that crops out in the eastern Solomon and western Norton Bay quadrangles. The unit is best exposed in sea cliffs along Norton Bay and forms rubble covere
Carbonate rocks.  Sub-division of Patton's Norton Bay unit into marble and dolostone units.  This is the marble
Carbonate rocks.  Sub-division of Patton's Norton Bay unit into marble and dolostone units.  This is the dolostone
SE006
SO005
Weathered volcanic rocks, undivided
Basalt lava flows, vent deposits, maar volcanoes and associated pyroclastic rocks exposed in northern, central, eastern, and to a minor extent, southern Seward Peninsula (Figure 2).   
Less weathered rocks are slightly to strongly fragmented by frost riv
40Ar/39Ar whole rock age of approximately 0.8 Ma (Werdon and others, 2006)
Dolostone, metalimestone, and marble, Nome Group
Medium- to dark-gray-weathering, dark-gray to black dolostone, metalimestone and marble, with minor associated chert, that typically weathers to fist-sized rubble but forms outcrops along river banks or sea cliffs. Ddm is widely but sparsely distributed
TE004
OZp
Phyllite, York terrane
Ordovician through Proterozoic
Fine-grained, mainly pelitic and (or) calcareous phyllite exposed in the west-central part of the Teller quadrangle.  Outcrops occur on creeks, weather gray to grayish-brown, and are layered and locally finely laminated. The phyllitic foliation surface i
Granitic dikes, sills and small plugs at widely scattered localities (Figure 2).  Most commonly these bodies occur within exposures of high-grade metamorphic rocks (PzZh), but they are also present in the Nome Complex and on islands off of the south and
K-Ar biotite date of 110.7±3 Ma
TE005
Ktg
Tin-bearing granitic stocks
Stocks of biotite granite exposed in outcrop, rubble, and float in northwestern Seward Peninsula.  Includes stocks at Cape Mountain, Brooks Mountain, Black Mountain, Ear Mountain, and the Oonatut Granite Complex (Figure 2).  The belt also includes bodies
K-Ar biotite ages range from 69.2±2 to 80.2±3 Ma (Hudson and Arth, 1983)
Limestone, York terrane
Intensely deformed limestone that has yielded no fossils but is presumed to be of Paleozoic age (Sainsbury, 1972), exposed in several small outcrops in the central part of the Teller quadrangle, northeast of the York Mountains. Equivalent to western part
Pzp
Phyllite and argillite, Grantley Harbor Fault Zone
Phyllite, argillite, and lesser metasiltstone and fine-grained metacarbonate rocks exposed south and north of Grantley Harbor in the central Teller quadrangle. Outcrops consist of brownish-orange- to black-weathering, silvery-gray to black, locally carbo
Sparse conodont fragments, recrystallized radiolarians and siliceous sponge spicules
Pznp
Metagabbro and metasediments, Nome Complex
Paleozoic?
Massive tors and rubble piles of metagabbro and poorly exposed metasedimentary rocks on the western side of the Kigluaik Mountains.  Metagabbro bodies form flat-topped hills generally less than a kilometer across; one body exposed along sea cliffs is 9 k
Limestone, dolomitic limestone, and marble, York terrane
Intensely deformed and recrystallized medium-dark-gray carbonate rocks, locally cherty and intercalated with subordinate fine-grained siliciclastic strata, exposed on the westernmost tip of Seward Peninsula (Teller quadrangle; Sainsbury, 1972). Ml has be
DSl
Devonian and (or) Silurian
Light-gray-weathering, medium-dark-gray limestone exposed in a small, fault-bounded area in the central Teller quadrangle. Lithofacies include cherty lime mudstone, peloidal wackestone, and lesser coralline packstone. Lower beds in this unit produced rel
Corals thought to be of probable Middle or Late Devonian age by Oliver and others (1975)
DOx, overlay
The part of the unit in the Teller quadrangle shown with the diagonal line overlay is distinct in age and lithology.  Dolostone, dolomitic marble, and marble form an elongate belt, extending for almost 40 km, in the westernmost part of DOx in the eastern
Mainly massive to thick-bedded, light-brownish-gray to medium-gray, fine-grained limestone with local chert nodules and lesser interbeds of argillaceous limestone and shale, widely exposed in and adjacent to the York Mountains in the western and central
Brachiopods, cephalopods, echinoderm debris, gastropods, and trilobites
Dark limestone, York terrane
Silurian and Late Ordovician
Medium- to thick-bedded, light-brown to dark-gray limestone, dolomitic limestone, and dolostone, locally cherty, commonly very fossiliferous, exposed in a fault-bounded area along the Don River in the northeastern York Mountains (Teller quadrangle; Sains
Conodonts, corals, trilobites, brachiopods, cephalopods, gastropods, ostracodes, pelecypods, and stromatoporoids
Ols
Limestone and shale, York terrane
Thin- to medium-bedded, pale-orange- to pale-yellow-brown-weathering, medium-gray to dark-gray limestone, dolomitic limestone, and dolostone with local shale and chert nodules. Ols forms subdued slopes within, north of, and east of the York Mountains; it
Conodonts, cephalopods, graptolites, gastropods, and trilobites
SOul
Limestone and dolostone, undifferentiated, York terrane
Silurian and Ordovician
Carbonate rocks equivalent to Ols and (or) SOdl of this map, but less well studied than those units; exposed in two small fault-bounded areas in the central part of the Teller quadrangle. The western exposure is dolostone with corals of Late Ordovician (
Contains long-ranging conodonts, domal to laminar stromatoporoids, and diverse tabulate and rugose corals of Silurian, probably late Llandovery-Wenlock, age
Thin-bedded, argillaceous, silty and (or) dolomitic limestone, lesser massive micritic limestone, and local chert; rocks are light gray to medium gray and weather light gray to orange to tan. The unit is widely exposed in and adjacent to the York Mountai
Conodonts, brachiopods, gastropods, and trilobite fragments (Sainsbury, 1969b); echinoderm debris, calcareous sponge spicules, and possible calcispheres were noted in thin sections. Stromatolites
OZl
Limestone and dolomitic limestone, York terrane
Light-gray- to grayish-orange-weathering, medium-light-gray to medium-dark-gray limestone and dolomitic limestone that occurs widely in the western, central, and northern parts of the Teller quadrangle. The unit forms low outcrops and extensive areas of
Conodonts, chitinozoans, or acrotretid brachiopods
PzZt
Metasiltstone and phyllite, Grantley Harbor Fault Zone
Metasiltstone, metasandstone, and phyllite that form a small exposure south of Grantley Harbor in the central Teller quadrangle. The unit consists of intercalated grayish-green metasiltstone to medium-grained metasandstone, in layers 1 cm to 1 m thick, g
PzZl
Metalimestone, Grantley Harbor Fault Zone
Thinly layered to laminated, orange and gray weathering, color-banded, white to dark gray metalimestone exposed in a small area south of Grantley Harbor in the south-central Teller quadrangle.  Layers range from a few millimeters to 6 cm thick and reflec
Pzgb
Metagabbro, York terrane
Dark green to black weathering massive bodies of metagabbro exposed in rubble crop and small blocky cliffs associated with units OZt, OZp and OZl (Sainsbury, 1969b).  Throughout the unit, igneous textures are retained in thin section.  In central Teller
U-Pb zircon crystallization 539±11 Ma
OZt
Sandstone, siltstone, and limestone, York terrane
Gray- to orange-weathering, gray to brown, locally calcareous sandstone to siltstone, interbedded with gray to black mudstone and local limestone, exposed in the western Teller quadrangle. Beds are typically ?5 cm thick (20 cm max). Outcrop features, whi
Syenite, monzonite, and nepheline syenite
Syenite, monzonite, and subordinate quartz monzonite, monzodiorite, quartz syenite, nepheline syenite and related mafic alkaline rocks of Patton and others (2005), exposed along the eastern boundary of the map area, in the Candle quadrangle (Figure 2).
Kotzebue
KZ002
DObm
Black Marble
Black to dark gray marble and subordinate dolostone which is commonly well-layered showing rythmic alteration of coarse and fine crystalline layers
KZ003
KZ005
KZ004
Shishmaref
SF002
Barrier islands
SF003