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["nm","Not mapped",null,"Areas not mapped on Saint Matthew and Hall Islands",null,null,"ST002",999,"Saint Matthew",null,98,null,null,98]
["Q","Surficial deposits","Quaternary","Undifferentiated beach, bar, alluvial, and colluvial deposits.  Mostly gravel and sand",null,null,"ST002",1,"Saint Matthew","Unconsolidated",100,null,null,1000]
["Qu","Surficial deposits","Quaternary","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials; eolian sand and silt; and colluvium.",null,null,"BI002",1,"Baird Inlet","Unconsolidated",100,null,null,1000]
["Qu","Surficial deposits","Quaternary","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials; eolian sand and silt; and colluvium.",null,null,"NI002",1,"Nunivak Island","Unconsolidated",100,null,null,1000]
["Qu","Surficial deposits","Quaternary","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials; eolian sand and silt; and colluvium.",null,null,"KB002",100,"Kuskokwim Bay","Unconsolidated",100,null,null,1000]
["Qa","Alluvium","Holocene and Pleistocene","Unconsolidated alluvial, colluvial, glacial outwash, lacustrine, and eolian conglomerate, sand, silt, and mudrock",null,null,"BH002",105,"Bethel","Unconsolidated",100,null,null,1000]
["Qu","Unconsolidated deposits","Holocene","Unconsolidated deposits",null,null,"NI003",110,"Nunivak Island","Unconsolidated",100,null,null,1000]
["Qu","Unconsolidated deposits","Holocene","Unconsolidated deposits",null,null,"CM003",110,"Cape Mendenhall","Unconsolidated",100,null,null,1000]
["Qu","Surficial deposits","Quaternary","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials; eolian sand and silt; and colluvium.",null,null,"KB003",300,"Kuskokwim Bay","Unconsolidated",100,null,null,1000]
[null,"Surficial deposits, undivided","Quaternary?","Areas on map not assigned to bedrock geologic units, assumed to be surficial deposits.  Not described.",null,null,"GO005",501,"Goodnews Bay","Unconsolidated",100,null,null,1000]
[null,"Surficial deposits, undivided","Quaternary?","Areas on map not assigned to bedrock geologic units, assumed to be surficial deposits.  Not described.",null,null,"HG003",501,"Hagemeister Island","Unconsolidated",100,null,null,1000]
[null,"Surficial deposits, undivided","Quaternary?","Areas on map not assigned to bedrock geologic units, assumed to be surficial deposits.  Not described.",null,null,"NG006",501,"Nushagak Bay","Unconsolidated",100,null,null,1000]
["Qc","Colluvium","Quaternary","Chiefly frost-rived rubble, loccally includes stream alluvium, terrace gravels, glacial deposits, and windblown silt",null,null,"HG005",607,"Hagemeister Island","Unconsolidated",100,null,null,1000]
["Qs","Surficial deposits, undivided","Quaternary",null,null,null,"NG007",701,"Nushagak Bay","Unconsolidated",100,null,null,1000]
["Qc","Colluvium","Quaternary","Chiefly frost-rived rubble, locally includes stream alluvium, terrace gravels, glacial deposits, and windblown silt",null,null,"GO008",707,"Goodnews Bay","Unconsolidated",100,null,null,1000]
["Qc","Colluvium","Quaternary","Chiefly frost-rived rubble, locally includes stream alluvium, terrace gravels, glacial deposits, and windblown silt",null,null,"GO006",807,"Goodnews Bay","Unconsolidated",100,null,null,1000]
["Qc","Colluvium","Quaternary","Chiefly frost-rived rubble, but locally includes small amount of bog deposit, flood-plain alluvium, terrace deposit, glacial gravel, and wind-blown silt.",null,null,"BH004",3107,"Bethel","Unconsolidated",100,null,null,1000]
[null,"Tidal flat deposits","Quaternary, Holocene","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials",null,null,"BI001",2,"Baird Inlet","Unconsolidated",103,null,null,1030]
[null,"Tidal flat deposits","Quaternary, Holocene","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials",null,null,"KB001",103,"Kuskokwim Bay","Unconsolidated",103,null,null,1030]
["Qtf","Tidal flats","Quaternary, Holocene",null,null,null,"NG001",103,"Nushagak Bay","Unconsolidated",103,null,null,1030]
[null,"Tidal flat deposits","Quaternary, Holocene","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials",null,null,"HG001",603,"Hagemeister Island","Unconsolidated",103,null,null,1030]
[null,"Tidal flat deposits","Quaternary, Holocene","Undifferentiated fluvial and marine gravel, sand, silt, and mud; organic materials",null,null,"GO001",703,"Goodnews Bay","Unconsolidated",103,null,null,1030]
["Qa","Alluvial deposits","Holocene","Flood-plain alluvium (sand, gravel, and boulders), beach (sand and small pebbles) and estuarine deposits (clay rich silt), and dunes (fine-grained sand).",null,null,"GO002",105,"Goodnews Bay","Unconsolidated",105,null,null,1050]
["Qa","Alluvial deposits","Holocene","Flood-plain alluvium (sand, gravel, and boulders), beach (sand and small pebbles) and estuarine deposits (clay rich silt), and dunes (fine-grained sand).",null,null,"HG002",105,"Hagemeister Island","Unconsolidated",105,null,null,1050]
["Qal","Alluvial deposits","Holocene","Flood-plain alluvium (sand, gravel, and boulders), beach (sand and small pebbles) and estuarine deposits (clay rich silt), and dunes (fine-grained sand).",null,null,"NG002",105,"Nushagak Bay","Unconsolidated",105,null,null,1050]
["Qf","Flood plain alluvium","Quaternary","Alluvium, includes some beach deposits",null,null,"HG005",605,"Hagemeister Island","Unconsolidated",105,null,null,1050]
["Qf","Flood plain alluvium","Quaternary","Alluvium, includes some beach deposits",null,null,"GO008",705,"Goodnews Bay","Unconsolidated",105,null,null,1050]
["Qa","Alluvial deposits","Holocene","Flood-plain alluvium (sand, gravel, and boulders), beach (sand and small pebbles) and estuarine deposits (clay rich silt), and dunes (fine-grained sand).",null,null,"NG007",705,"Nushagak Bay","Unconsolidated",105,null,null,1050]
["Qf","Flood-plain alluvium","Quaternary","Mud, silt, sand, gravel, boulders, and intermixed wood, peat, and other vegetal material.",null,null,"BH004",3105,"Bethel","Unconsolidated",105,null,null,1050]
["Qal","Alluvial deposits","Quaternary","Alluvial ssand, gravel, and silt along major streams and rivers.    Deposits are locally transitional to undivided surficial deposits, estuarine and tidal flats deposits.  Locally older alluvium may constitute the material of marine terraces",null,null,"KB003",3105,"Kuskokwim Bay","Unconsolidated",105,null,null,1050]
["Qal","Alluvial deposits","Quaternary","Alluvial ssand, gravel, and silt along major streams and rivers.    Deposits are locally transitional to undivided surficial deposits, estuarine and tidal flats deposits.  Locally older alluvium may constitute the material of marine terraces",null,null,"BI003",3105,"Baird Inlet","Unconsolidated",105,null,null,1050]
["Qrs","Reworked silt deposits","Quaternary","Silt, sandy silt, and bog deposits",null,null,"GO008",710,"Goodnews Bay","Unconsolidated",113,null,null,1130]
["Qrs","Reworked silt","Quaternary","Chiefly reworked silt, sandy silt, and bog deposits underlying a plain transitional with or slightly above areas of flood-plain alluvium of Recent age and separated from higher plains and residual 'islands' of older silt deposits by an erosional scrap 10",null,null,"BH004",3110,"Bethel","Unconsolidated",113,null,null,1130]
["Qrs","Reworked silt","Quaternary","Derived by extension from adjacent Goodnews Bay quadrangle map.  Chiefly reworked silt, sandy silt, and bog deposits underlying a plain transitional with or slightly above areas of flood-plain alluvium of Recent age and separated from higher plains and r",null,null,"KB003",3113,"Kuskokwim Bay","Unconsolidated",113,null,"Q",1130]
["Qrs","Reworked silt","Quaternary","Chiefly reworked silt, sandy silt, and bog deposits underlying a plain transitional with or slightly above areas of flood-plain alluvium of Recent age and separated from higher plains and residual 'islands' of older silt deposits by an erosional scrap 10",null,null,"BI003",3113,"Baird Inlet","Unconsolidated",113,null,null,1130]
["Qb","Beach deposits","Quaternary",null,null,null,"NG002",114,"Nushagak Bay","Unconsolidated",115,null,null,1150]
["Qb","Beach deposits","Quaternary",null,null,null,"NG007",702,"Nushagak Bay","Unconsolidated",115,null,null,1150]
["Qb","Older beach deposits","Quaternary","Older raised beach ridges on mainland along Kuskokwim Bay.  Derived from interpretation of topographic maps and Google Earth image.  Deposits are locally transitional to undivided surficial deposits, alluvial deposits, and locally may constitute the mate",null,null,"KB003",3115,"Kuskokwim Bay","Unconsolidated",115,null,null,1150]
["Qb","Older beach deposits","Quaternary","Older raised beach ridges on mainland along Kuskokwim Bay.  Derived from interpretation of topographic maps and Google Earth image.  Deposits are locally transitional to undivided surficial deposits, alluvial deposits, and locally may constitute the mate",null,null,"BI003",3115,"Baird Inlet","Unconsolidated",115,null,null,1150]
["Qb","Older beach deposits","Quaternary","Older raised beach ridges on mainland along Kuskokwim Bay.  Derived from interpretation of topographic maps and Google Earth image.  Deposits are locally transitional to undivided surficial deposits, alluvial deposits, and locally may constitute the mate",null,null,"NI004",4115,"Nunivak Island","Unconsolidated",115,null,null,1150]
["Qes","Raised estuarine deposits","Quaternary",null,null,null,"NG002",116,"Nushagak Bay","Unconsolidated",116,null,null,1160]
["Qes","Raised estuarine deposits","Quaternary",null,null,null,"NG007",704,"Nushagak Bay","Unconsolidated",116,null,null,1160]
["Qes","Raised estuarine deposits","Quaternary",null,null,null,"GO006",6116,"Goodnews Bay","Unconsolidated",116,null,null,1160]
["Qmt","Raised estuarine deposits","Quaternary","Underlain be older estuarine and alluvial deposits",null,null,"NG007",706,"Nushagak Bay","Unconsolidated",117,null,null,1170]
["Qmt","Marine terrace","Quaternary","Raised surface underlain by a varity of unconsolidated deposits, especially including older beach, estuarine, alluvial, and probably glacial deposits",null,null,"KB003",3117,"Kuskokwim Bay","Unconsolidated",117,null,null,1170]
["Qmt","Marine terrace","Quaternary","Raised surface underlain by a varity of unconsolidated deposits, especially including older beach, estuarine, alluvial, and probably glacial deposits",null,null,"BI003",3117,"Baird Inlet","Unconsolidated",117,null,null,1170]
["Qb","Older beach deposits","Quaternary","Older raised beach ridges eroded to constitute raised marine terraces on mainland along Kuskokwim Bay.  Derived from interpretation of topographic maps and Google Earth image.  Deposits are locally transitional to undivided surficial deposits, alluvial d",null,null,"NI004",4117,"Nunivak Island","Unconsolidated",117,null,null,1170]
[null,"Late alluvial sediments, mostly sand, St. Paul Island","Quaternary","Late alluvial sediments, mostly sand.  In most places, the sand is loose and moves with the wind.  Along the north shore of St. Paul Island, impressive dunes are formed",null,null,"PI002",120,"Pribilof Islands","Unconsolidated",119,null,null,1190]
["Qd","Eolian deposits","Holocene","Dunes (fine-grained sand).",null,null,"NG002",110,"Nushagak Bay","Unconsolidated",120,null,null,1200]
["Qd","Eolian deposits","Holocene","Dunes (fine-grained sand).",null,null,"NG007",710,"Nushagak Bay","Unconsolidated",120,null,null,1200]
["Qs","Silt deposits","Quaternary","Light- to dark-gray silt and sandy silt",null,null,"GO008",722,"Goodnews Bay","Unconsolidated",121,null,null,1210]
["Qsd","Silt deposits","Quaternary","Inferred by extrapolation from adjacent Bethel and Goodnews Bay quadrangles.  Chiefly light- to dark-gray silt and sandy silt containing abundant permafrost.  Deposits become sandier with depth and locally contain pebbles and wood fragments.  Deposits ar","Organic muck containing mammoth remains and nonmarine gastropods occur locally near top of deposits",null,"KB003",3121,"Kuskokwim Bay","Unconsolidated",121,null,"Q",1210]
["Qsd","Silt deposits","Quaternary","Inferred by extrapolation from adjacent Bethel and Goodnews Bay quadrangles.  Chiefly light- to dark-gray silt and sandy silt containing abundant permafrost.  Deposits become sandier with depth and locally contain pebbles and wood fragments.  Deposits ar","Organic muck containing mammoth remains and nonmarine gastropods occur locally near top of deposits",null,"BI003",3121,"Baird Inlet","Unconsolidated",121,null,null,1210]
["Qs","Silt deposits","Quaternary","Chiefly light- to dark-gray silt and sandy silt containing abundant permafrost.  Deposits become sandier with depth and locally contain pebbles and wood fragments.  Deposits are probably of nonmarine fluvial origin but may include eolian and marine membe","Organic muck containing mammoth remains and nonmarine gastropods occur locally near top of deposits",null,"BH004",3122,"Bethel","Unconsolidated",121,null,null,1210]
["Qg","Glacial Deposits","Holocene and Pleistocene","Glacial drift deposited during the last three glacial advances.  Sand, gravel, and boulders.  Includes moraines.  Also includes colluvium, talus, landslide debris, alluvium, and local silt.",null,null,"GO002",106,"Goodnews Bay","Unconsolidated",125,null,null,1250]
["Qg","Glacial Deposits","Holocene and Pleistocene","Glacial drift deposited during the last three glacial advances.  Sand, gravel, and boulders.  Includes moraines.  Also includes colluvium, talus, landslide debris, alluvium, and local silt.",null,null,"HG002",106,"Hagemeister Island","Unconsolidated",125,null,null,1250]
["Qg","Glacial Deposits","Holocene and Pleistocene","Glacial drift deposited during the last three glacial advances.  Sand, gravel, and boulders.  Includes moraines.  Also includes colluvium, tallus, landslide debris, alluvium, and local silt.",null,null,"NG002",106,"Nushagak Bay","Unconsolidated",125,null,null,1250]
["Qt","Glacial till","Pleistocene","Unconsolidated glacial till; ground lateral and end moraines",null,null,"BH002",125,"Bethel","Unconsolidated",125,null,null,1250]
["Qd","Glacial drift","Quaternary","Poorly to well-sorted silt, sand, gravel, and boulders; stipple indicates well-defined end and lateral moraines",null,null,"HG005",625,"Hagemeister Island","Unconsolidated",125,null,null,1250]
["Qg","Glacial Deposits","Holocene and Pleistocene","Glacial drift deposited during the last three glacial advances.  Sand, gravel, and boulders.  Includes moraines.  Also includes colluvium, tallus, landslide debris, alluvium, and local silt.",null,null,"NG007",703,"Nushagak Bay","Unconsolidated",125,null,null,1250]
["Qd","Glacial drift","Quaternary","Poorly to well-sorted silt, sand, gravel, and boulders; stipple indicates well-defined end and lateral moraines",null,null,"GO008",725,"Goodnews Bay","Unconsolidated",125,null,null,1250]
["Qd","Glacial drift","Quaternary","Poorly to well-sorted silt, sand, gravel, and boulders",null,null,"GO006",825,"Goodnews Bay","Unconsolidated",125,null,null,1250]
["Qd","Glacial drift","Quaternary","Chiefly unsorted and poorly sorted sand, gravel, and boulders comprising various types of ice-contact and glaciofluviatile deposits; small areas of glacial outwash, colluvium, and alluvium included with unit.",null,null,"BH004",3135,"Bethel","Unconsolidated",125,null,null,1250]
["Qm","Morainal ridges","Quaternary","Morainal ridges of all ages; however most are probably associated with Late Wisconsin events.  Topographic map interpretation enhanced by data from Warren Coonrad",null,null,"NG007",700,"Nushagak Bay","Unconsolidated",135,null,null,1350]
["Qo","Outwash deposits","Quaternary","Most probably associated with Late Wisconsin events",null,null,"NG002",140,"Nushagak Bay","Unconsolidated",140,null,null,1400]
["Qo","Outwash deposits","Quaternary","Poorly to well-sorted silt, gravel, and boulders in terraces and outwash fan-plains",null,null,"HG005",640,"Hagemeister Island","Unconsolidated",140,null,null,1400]
["Qo","Outwash deposits","Quaternary","Poorly to well-sorted silt, gravel, and boulders in terraces and outwash fan-plains",null,null,"GO008",740,"Goodnews Bay","Unconsolidated",140,null,null,1400]
["Qo","Outwash deposits","Quaternary","Most probably associated with Late Wisconsin events",null,null,"NG007",740,"Nushagak Bay","Unconsolidated",140,null,null,1400]
["Qo","Outwash deposits","Quaternary","Poorly to well-sorted sand and gravel with some silt and a few boulders, constituting terraces and outwash-fan plains.",null,null,"BH004",3140,"Bethel","Unconsolidated",140,null,null,1400]
["QTs","Semiconsolidated marine beach deposits","Pleistocene or Pliocene","Semiconsolidated marine beach deposits.  Poorly bedded, soft, pebbly siltstones cap volcanic rock sea cliffs.","shallow marine fossils of Plio-Pleistocene age",null,"HG002",112,"Hagemeister Island","Sedimentary",282,null,null,2820]
[null,"Pyroclastic deposits, St. Paul Island","Quaternary","Pyroclastic deposits, largely basaltic tuff",null,null,"PI002",310,"Pribilof Islands","Igneous",310,null,null,3100]
[null,"Pyroclastic deposits, Otter Island","Quaternary","Pyroclastic deposits",null,null,"PI002",311,"Pribilof Islands","Igneous",310,null,null,3100]
[null,"Tuff, St. George Island","Quaternary","Tuff",null,null,"PI002",312,"Pribilof Islands","Igneous",310,null,null,3100]
[null,"Pyroclastic deposits, St. George Island","Quaternary","Pyroclastic deposits, largely basaltic tuff",null,null,"PI002",313,"Pribilof Islands","Igneous",310,null,null,3100]
[null,"Pleistocene sediments, some fossiliferous, St. Paul Island","Quaternary","Pleistocene sediments, some fossiliferous.  Polymictic, but composed primarily of basaltic boulders and clasts.  Locally cross-bedded",null,null,"PI002",291,"Pribilof Islands","Unconsolidated",317,null,null,3170]
[null,"Fossiliferous sediments, St. George Island","Quaternary","Fossiliferous sediments consisting of sand and yellow tuff containing rounded basalt pebbles.  Sediemts overlie a glaciated surface of the peridotite upon which Pleistocene fossil shells have been cemented. The sediments are quite varied; however, a basa","Pelecypods and gastropods of Pleistocene age",null,"PI002",292,"Pribilof Islands","Unconsolidated",317,null,null,3170]
[null,"Sedimentary deposits, Otter Island","Quaternary","Sediments",null,null,"PI002",293,"Pribilof Islands","Igneous",317,null,null,3170]
["Qkn1","Alkalic basalt of Karon Lake","Pleistocene and Holocene","Alkalic basalt of Karon Lake; cinder cones, flows, and tephra; normally polarized rocks of Brunhes polarity epoch",null,null,"NI003",120,"Nunivak Island","Igneous",320,null,null,3200]
["Qkn1","Alkalic basalt of Karon Lake","Pleistocene and Holocene","Alkalic basalt of Karon Lake; cinder cones, flows, and tephra; normally polarized rocks of Brunhes polarity epoch",null,null,"CM003",120,"Cape Mendenhall","Igneous",320,null,null,3200]
["Qtb","Basalt of Togiak River Valley","Pleistocene","Fine- and medium-grained, columnar jointed tholeiite and alkali-olivine basalt flows on the floor of the broad Togiak River Valley.",null,"K/Ar age of 0.758 +/- 0.2 m.y.","GO002",110,"Goodnews Bay","Igneous",330,null,null,3300]
["Qtb","Basalt of Togiak River Valley","Pleistocene","Fine- and medium-grained, columnar jointed tholeiite and alkali-olivine basaltflows on the floor of the broad Togiak River Valley.",null,"K/Ar age of 0.758 +/- 0.2 m.y.","HG002",110,"Hagemeister Island","Igneous",330,null,null,3300]
["Qmn1","Tholeiitic basalt of Mekoryuk","Pleistocene and Holocene","Tholeiitic basalt of Mekoryuk; massive, columnar-jointed flows; normally polarized rocks of Brunhes polarity epoch",null,null,"NI003",130,"Nunivak Island","Igneous",330,null,null,3301]
["Qmn1","Tholeiitic basalt of Mekoryuk","Pleistocene and Holocene","Tholeiitic basalt of Mekoryuk; massive, columnar-jointed flows; normally polarized rocks of Brunhes polarity epoch",null,null,"CM003",130,"Cape Mendenhall","Igneous",330,null,null,3301]
["Qb","Basalt","Pleistocene","Unaltered olivine tholeiite basalt flows having diktytaxitic texture.  Contains olivine, subophitic clinopyroxene, plagioclase and iron oxides with sparse interstitial volcanic glass.",null,"Whole rock K/Ar age of 0.418+0.016 Ma","BH002",300,"Bethel","Igneous",330,null,null,3300]
["Qb","Quaternary basalt (Togiak basalt of Hoare and Coonrad, 1980)","Quaternary","Subaerial alkali olivine basalt flows, columnar, jointed with ropy tops; includes minor interflow tuffs and breccias. Generally nonporphyritic, dark-gray to black rock with fine microcrysts of labradorite, augite, olivine, and accessory magnetite, with d",null,"Whole-rock K-Ar determination on lower unit yields 0.78 +/- 0.2 m.y.","GO005",500,"Goodnews Bay","Igneous",330,null,null,3300]
["Qb","Quaternary basalt (Togiak basalt of Hoare and Coonrad, 1980)","Quaternary","Subaerial alkali olivine basalt flows, columnar, jointed with ropy tops; includes minor interflow tuffs and breccias. Generally nonporphyritic, dark-gray to black rock with fine microcrysts of labradorite, augite, olivine, and accessory magnetite, with d",null,"Whole-rock K-Ar determination on lower unit yields 0.78 +/- 0.2 m.y.","HG003",500,"Hagemeister Island","Igneous",330,null,null,3300]
["QTb","Basalt","Quaternary or Tertiary (early Pleistocene or late Pliocene","Highly vesicular and scoriaceous black olivine basalt flows showing little or no alteration; matrix chiefly volcanic glass.",null,null,"BH004",3350,"Bethel","Igneous",330,null,null,3300]
["Qmr1","Tholeiitic basalt of Mekoryuk","Pleistocene and Holocene","Tholeiitic basalt of Mekoryuk; massive, columnar-jointed flows; reversely polarized rocks of Matuyama polarity epoch",null,null,"NI003",131,"Nunivak Island","Igneous",350,null,null,3502]
["Qmr1","Tholeiitic basalt of Mekoryuk","Pleistocene and Holocene","Tholeiitic basalt of Mekoryuk; massive, columnar-jointed flows; reversely polarized rocks of Matuyama polarity epoch",null,null,"CM003",131,"Cape Mendenhall","Igneous",350,null,null,3502]
["Qmn2","Tholeiitic basalt of Mekoryuk","Pleistocene and Holocene","Tholeiitic basalt of Mekoryuk; massive, columnar-jointed flows; normally polarized rocks of Matuyama polarity epoch",null,null,"NI003",132,"Nunivak Island","Igneous",350,null,null,3503]
["Qmn3","Tholeiitic basalt of Mekoryuk","Pleistocene and Holocene","Tholeiitic basalt of Mekoryuk; massive, columnar-jointed flows; normally polarized rocks of Matuyama polarity epoch",null,null,"NI003",133,"Nunivak Island","Igneous",350,null,null,3503]
[null,"Basaltic flows, St. Paul Island","Quaternary","Basaltic flows and sills.  Flows range in thickness from 20 cm to 7 m or more.  Some are vesicular, some dense.  Compositionally they are basalt and olivine hylobasanite, alkalic",null,null,"PI002",330,"Pribilof Islands","Igneous",450,null,null,4500]
[null,"Basaltic flows, St. George Island","Quaternary","Basaltic flows and sills.  Flows range in thickness from 20 cm to 7 m or more.  Some are vesicular, some dense.  Compositionally they are basalt and olivine basanite, alkalic",null,null,"PI002",331,"Pribilof Islands","Igneous",450,null,null,4500]
[null,"Hylobasanitic flows, Otter Island","Quaternary","Lava flows of hylobasanite at leaat 325 feet thick, alkalic",null,null,"PI002",332,"Pribilof Islands","Igneous",450,null,null,4500]
["QTv","Mafic volcanic rocks","Quaternary/Tertiary","Basalt lava flows and cinder cones.",null,null,"BI002",5,"Baird Inlet","Igneous",450,null,null,4500]
["QTv","Mafic volcanic rocks","Quaternary/Tertiary","Basalt lava flows and cinder cones.",null,null,"NI002",5,"Nunivak Island","Igneous",450,null,null,4500]
["QTv","Mafic volcanic rocks","Quaternary/Tertiary","Basalt lava flows and cinder cones.",null,null,"CM002",5,"Cape Mendenhall","Igneous",466,null,null,4660]
["Qkr1","Alkalic basalt of Karon Lake","Pleistocene and Holocene","Alkalic basalt of Karon Lake; cinder cones, flows, and tephra; reversely polarized rocks of Matuyama (?) polarity epoch",null,null,"NI003",121,"Nunivak Island","Igneous",466,null,null,4660]
["Qkr1","Alkalic basalt of Karon Lake","Pleistocene and Holocene","Alkalic basalt of Karon Lake; cinder cones, flows, and tephra; reversely polarized rocks of Matuyama (?) polarity epoch",null,null,"CM003",121,"Cape Mendenhall","Igneous",466,null,null,4660]
["Qkn2","Alkalic basalt of Karon Lake","Pleistocene and Holocene","Alkalic basalt of Karon Lake; cinder cones, flows, and tephra; normally polarized rocks of Matuyama (?) polarity epoch",null,null,"NI003",122,"Nunivak Island","Igneous",466,null,null,4660]
["Qkn2","Alkalic basalt of Karon Lake","Pleistocene and Holocene","Alkalic basalt of Karon Lake; cinder cones, flows, and tephra; normally polarized rocks of Matuyama (?) polarity epoch",null,null,"CM003",122,"Cape Mendenhall","Igneous",466,null,null,4660]
["Ta","Alkalic basalt of Ahzwiryuk Bluff","Tertiary, Pliocene","Alkalic basalt of Ahzwiryuk Bluff; nubbly mottled flows and pyroclastic ejecta; includes both normally and reversely polarized rocks older than Gauss polarity epoch",null,null,"NI003",140,"Nunivak Island","Igneous",1023,null,null,null]
["Tbn1","Tholeittic basalt of Binakslit Bluff","Tertiary, Pliocene","Tholeittic basalt of Binakslit Bluff; massive, columnar-jointed flows; normally polarized flows of Gauss polarity epoch",null,null,"NI003",141,"Nunivak Island","Igneous",1024,null,null,null]
["Tbn1","Tholeittic basalt of Binakslit Bluff","Tertiary, Pliocene","Tholeittic basalt of Binakslit Bluff; massive, columnar-jointed flows; normally polarized flows of Gauss polarity epoch",null,null,"CM003",141,"Cape Mendenhall","Igneous",1024,null,null,null]
["Tb","Tholeittic basalt of Binakslit Bluff","Tertiary, Pliocene","Tholeittic basalt of Binakslit Bluff; massive, columnar-jointed flows; includes both normally and reversely polarized flows older than Gauss polarity epoch",null,null,"NI003",142,"Nunivak Island","Igneous",1024,null,null,null]
["Tif","Felsic intrusive rocks","Tertiary","Light-colored, fine-grained, commonly porphyritic felsic intrusive rocks.  Chiefly rhyolitic to dacitic dikes and sills",null,"K/Ar age of 13 +/- 0.5 m.y. from biotite.","GO002",160,"Goodnews Bay","Igneous",1053,null,null,null]
["Tif","Felsic intrusive rocks","Tertiary","Light-colored, fine-grained, commonly porphyritic felsic intrusive rocks.  Chiefly rhyolitic to dacitic dikes and sills",null,"K/Ar age of 13 +/- 0.5 m.y. from biotite.","HG002",160,"Hagemeister Island","Igneous",1053,null,null,null]
["Tif","Felsic intrusive rocks","Tertiary","Light-colored, fine-grained, commonly porphyritic felsic intrusive rocks.  Chiefly rhyolitic to dacitic dikes and sills",null,"K/Ar age of 13 +/- 0.5 m.y. from biotite.","NG002",160,"Nushagak Bay","Igneous",1053,null,null,null]
["Tr","Tertiary rhyolite","Tertiary","Abundant sills and dikes cutting Kus and Jln in vicinity of Nunavarchak Lake (only largest body shown). Consists of cream-colored, often iron-stained, aphanitic to porphyritic rhyolite to dacite. Phenocrysts are quartz, plagioclase, orthoclase, and acces",null,"Yields a K-Ar biotite age of 13.0 +/- 0.5 m.y.; however, its association with feeder dikes of Upper Cretaceous volcanic rocks suggest true intrusive age may be Late Cretaceous.","GO005",502,"Goodnews Bay","Igneous",1053,null,null,null]
["Tr","Tertiary rhyolite","Tertiary","Abundant sills and dikes cutting Kus and Jln in vicinity of Nunavarchak Lake (only largest body shown). Consists of cream-colored, often iron-stained, aphanitic to porphyritic rhyolite to dacite. Phenocrysts are quartz, plagioclase, orthoclase, and acces",null,"Yields a K-Ar biotite age of 13.0 +/- 0.5 m.y.; however, its association with feeder dikes of Upper Cretaceous volcanic rocks suggest true intrusive age may be Late Cretaceous.","HG003",502,"Hagemeister Island","Igneous",1053,null,null,null]
["Tr","Tertiary rhyolite","Tertiary","Abundant sills and dikes cutting Kus and Jln in vicinity of Nunavarchak Lake (only largest body shown). Consists of cream-colored, often iron-stained, aphanitic to porphyritic rhyolite to dacite. Phenocrysts are quartz, plagioclase, orthoclase, and acces",null,"Yields a K-Ar biotite age of 13.0 +/- 0.5 m.y.; however, its association with feeder dikes of Upper Cretaceous volcanic rocks suggest true intrusive age may be Late Cretaceous.","NG006",502,"Nushagak Bay","Igneous",1053,null,null,null]
["Tnr","Nukluk Volcanic Field; rhyolite","Tertiary, Eocene","Moderately altered rhyolite flows, domes, and ash-flow tuffs.  Rhyolite of the main volcanic field contains phenocrysts of sanidine, riebeckitic amphibole, and rare quartz.",null,"Ar/Ar total-fusion age of 54.7+1.6 Ma from riebeckite","BH002",1110,"Bethel","Igneous",1110,null,null,null]
["Tnba","Nukluk Volcanic Field; basalt and andesite","Tertiary, Eocene","Massive, columnar-jointed, basalt and subordinate andesite flows.  Minor latite and dacite.  Overlies Tnr in Fog River area.  Elsewhere, interbedded.",null,null,"BH002",1111,"Bethel","Igneous",1111,null,null,null]
["Tr","Rhyolite and dacite tuff","Tertiary","Chiefly rhyolite and dacite welded tuff and tuff breccia and dark rhyolite vitrophyre in the northern part of map area.  Chiefly light-colored rhyolite and dacite hypabyssal rocks in the southern part of the map area.  May be extrusive and hypabyssal cog",null,null,"ST002",101,"Saint Matthew","Igneous",1120,null,null,null]
[null,"Aplite, St. George Island","Quaternary","Aplite granite dike intruding peridotite.  Surface weathered before eruption of overlying basatic flows",null,null,"PI002",400,"Pribilof Islands","Igneous",1301,null,null,null]
["TKst","Swift Creek Volcanic Field; Rhyolite ash-flow tuff","Early Tertiary and (or) Late Cretaceous","Fresh to moderately altered, densely welded rhyolite ash-flow tuff.  Chiefly black glassy vitrophyre.",null,null,"BH002",1600,"Bethel","Igneous",1603,null,null,null]
["TKsr","Swift Creek Volcanic Field; Rhyolite","Early Tertiary and (or) Late Cretaceous","Frost-riven rubble from single rhyolite dome(?)",null,null,"BH002",1601,"Bethel","Igneous",1603,null,null,null]
["TKer","Eek Volcanic Field; Rhyolite","Paleocene and Cretaceous (?)","Pale pink to orange rhyolite domes found as small knobs or large domical hills as large as 4 km in diameter with 300 to 500 m in relief.",null,"Whole rock K/Ar age of 62.5+1.9 Ma and 59.3+1.8 Ma","BH002",1603,"Bethel","Igneous",1603,null,null,null]
["TKtb","Tulip Volcanic Field; Block and ash flow","Early Tertiary and (or) Late Cretaceous","One block and ash flow mapped in area.  Broken blocks of dacite in an ashy matrix of the same lithology.  Interpreted as a hot avalanche deposit formed during dome collapse.  Dacite contains very coarse (up to 14 mm) phenocrysts.",null,null,"BH002",1607,"Bethel","Igneous",1603,null,null,null]
["Tr","Albite rhyolite","Tertiary(?)","Light- to medium-gray, fine-grained, porphyritic albite rhyolite, commonly shows well-developed flow structures.  Forms small stock-like bodies, dikes, and sills.",null,null,"BH004",31603,"Bethel","Igneous",1603,null,null,null]
["TKtd","Tulip Volcanic Field; Dacite and Andesite flows and Dacite tuff","Early Tertiary and (or) Late Cretaceous","Dacite and subordinate andesite flows and underlying dacite pyroclastic rocks.  Flows crop out as columnar-jointed cliffs.",null,null,"BH002",1604,"Bethel","Igneous",1604,null,null,null]
["TKsa","Swift Creek Volcanic Field; Andesite flows","Early Tertiary and (or) Late Cretaceous","Columnar-jointed andesite flows capping small hills that overlie unit Ksl.",null,null,"BH002",1602,"Bethel","Igneous",1605,null,null,null]
["TKea","Eek Volcanic Field; Andesite flows and Porphyry","Paleocene and Cretaceous (?)","Small outcrops and columnar jointed andesite flows.  Subordinate altered andesite porphyry.  Minor basalt, andesite lithic tuff, and dacite.",null,"Ar/Ar total-fusion age of 59.5+12.3 Ma from plagioclase","BH002",1605,"Bethel","Igneous",1605,null,null,null]
["Tv","Volcanic rocks","middle to late Tertiary","Chiefly black, porphyritic olivine basalt; includes some andesitic flows and water-laid tuff and a small amount of obsidian and siliceous tuff.  Rocks are moderately folded and unconformable on steeply dipping rocks of Cretaceous age and older.",null,null,"BH004",31004,"Bethel","Igneous",1605,null,null,null]
["Tf","Felsic rocks","Tertiary(?)","Pink and gray, fine-grained quartz-feldspar porphyry; locally shows flow structure.  Possibly a felsic border facies of granitic rocks similar to felsic rocks associated with the Horn Mountain stock in the central Kuskokwim region (Cady, 1955).",null,null,"BH004",31625,"Bethel","Igneous",1625,null,null,null]
[null,"Peridotite, St. George Island","Quaternary?","Peridotite, forms basement of island.  Massive, originally was a dunite and now largely altered to serpentine and magnetite.  The upper surface of the peridotite is an erosion surface, shows glacial striae, appears polished, and has a brownish-black varn",null,null,"PI002",460,"Pribilof Islands","Igneous",1640,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite.",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","GO002",165,"Goodnews Bay","Igneous",1655,null,null,null]
["Kug","Upper Cretaceous granitic plutons","Late Cretaceous","Medium-grained granitic plutonic rocks, ranging from quartz monzonite to granodiorite to diorite, with accessory biotite and (or) hornblende (Hoare and Coonrad, 1978a). Intrude a variety of units across map, with narrow biotite-hornblende hornfels zones.",null,"Age based on several K-Ar determinations.","GO005",542,"Goodnews Bay","Igneous",1655,null,null,null]
["Kug","Upper Cretaceous granitic plutons","Late Cretaceous","Medium-grained granitic plutonic rocks, ranging from quartz monzonite to granodiorite to diorite, with accessory biotite and (or) hornblende (Hoare and Coonrad, 1978a). Intrude a variety of units across map, with narrow biotite-hornblende hornfels zones.",null,"Age based on several K-Ar determinations.","HG003",542,"Hagemeister Island","Igneous",1655,null,null,null]
["TKif","Fisher Dome and Marvel Creek plutons, undivided","Early Tertiary and (or) Late Cretaceous","Small intrusions of about 1 km (square).  Hornblende-biotite granite and granodiorite porphyry.  Randomly oriented euhedral brown hornblende, brown biotite, plagioclase, and resorbed quartz phenocrysts in a fine-grained aplitic matrix of quartz, plagiocl",null,null,"BH002",1655,"Bethel","Igneous",1655,null,null,null]
["Tg","Granitic rocks","Tertiary(?)","Pink, light- to dark-gray, fine- to coarse-grained granite, quartz monzonite, granodiorite, and diorite.",null,null,"BH004",31655,"Bethel","Igneous",1655,null,null,null]
["Tn","Igneous rocks of Nayorurun River area","Tertiary","Intrusive-extrusive complex consisting of dikes, sills, and related tuffs and breccias in the Nayorurun River area.",null,"K/Ar age of 60.7 +/- 1.8 m.y. from biotite","GO002",162,"Goodnews Bay","Igneous",1656,null,null,null]
["Tial","Aniak Lake pluton","Tertiary, Paleocene","Coarse-grained, porphyritic to seriate leucocratic biotite granite pluton 10 km (square) in area.  Speckled texture with randomly oriented feldspar phenocrysts.  Porphyritic rhyolite dikes common in the uppermost part of pluton and in surrounding biotite",null,"Ar/Ar total-fusion age of 60.8+1.8 Ma from biotite","BH002",1320,"Bethel","Igneous",1656,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite.  Subdivision of granite from original Hoare and Coonrad (1978) unit.",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","GO006",6165,"Goodnews Bay","Igneous",1656,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","NG002",165,"Nushagak Bay","Igneous",1657,null,null,null]
["Kug","Upper Cretaceous granitic plutons","Late Cretaceous","Medium-grained granitic plutonic rocks, ranging from quartz monzonite to granodiorite to diorite, with accessory biotite and (or) hornblende (Hoare and Coonrad, 1978a). Intrude a variety of units across map, with narrow biotite-hornblende hornfels zones.",null,"Age based on several K-Ar determinations.","NG006",542,"Nushagak Bay","Igneous",1657,null,null,null]
["Kug","Upper Cretaceous granitic plutons","Late Cretaceous","Medium-grained granitic plutonic rocks, ranging from quartz monzonite to granodiorite to diorite, with accessory biotite and (or) hornblende (Hoare and Coonrad, 1978a). Intrude a variety of units across map, with narrow biotite-hornblende hornfels zones.",null,"Age based on several K-Ar determinations.","GO006",6542,"Goodnews Bay","Igneous",1657,null,null,null]
["TKik","Quartz monzonite of Kipchuk River","Early Tertiary and (or) Late Cretaceous","Small (< 1 km (square)) quartz monzodiorite intrusion in Kkcd of Kuskokwim Group causing contact metamorphism of Kkcd.  Medium-grained, intergranular-textured biotite-augite quartz monzodiorite and quartz diorite.",null,null,"BH002",1656,"Bethel","Igneous",1658,null,null,null]
["Kick","Crooked Mountain pluton","Late Cretaceous","Large composite pluton with thin gabbro and diorite margin that partially rims and is intruded by massive core of biotite-hornblende granodiorite and granite.  Dominantly augite-biotite-hornblende and (augite-) hornblende-biotite granodiorite, quartz mon",null,"Ar/Ar total-fusion age of 69.8+2.1 Ma from biotite","BH002",2460,"Bethel","Igneous",1658,null,null,null]
["Kicc","Canyon Creek pluton","Late Cretaceous","Small (~1 km (square)), medium- to coarse-grained, intergranular to hypidiomorphic granular augite-biotite quartz diorite to hornblende-biotite granodiorite.",null,"Ar/Ar total-fusion age of 70.3+2.1 Ma from biotite","BH002",2461,"Bethel","Igneous",1658,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite.  Subdivision of quartz monzonite from original Hoare and Coonrad (1978) unit.",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","GO006",6166,"Goodnews Bay","Igneous",1658,null,null,null]
["Tg","Granodiorite","Tertiary","Fine-grained hornblende granodiorite",null,"K/Ar age of 62.2 +/- 2 Ma (recalc) from hornblende","ST002",102,"Saint Matthew","Igneous",1660,null,null,null]
["Ticp","Cripple Mountain pluton","Paleocene","Elliptical, erosionally recessive pluton, 40 km (square).  Coarse-grained, hypidiomorphic-granular hornblende-biotite granodiorite and granite, with lesser quartz monzodiorite and quartz monzonite.  Aplite dikes near pluton margin.",null,"Ar/Ar total-fusion age of 62.2+1.9 Ma from biotite","BH002",1350,"Bethel",null,1660,null,null,null]
["TKin","North Fork pluton","Early Tertiary and (or) Late Cretaceous","Two phases:  Main Felsic Phase is seriate to hypidiomorphic granular (augite-) hornblende-biotite quartz monzodiorite, granodiorite, and minor biotite granite.  Aplite dikes are common.  Mafic Phase is a coarse-grained cumulus-textured augite quartz gabb",null,"Ar/Ar total-fusion age of 64.3+1.9 Ma from biotite in Felsic Phase.","BH002",1660,"Bethel","Igneous",1660,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite.  Subdivision of tonalite-monzonite from original Hoare and Coonrad (1978) unit.",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","GO006",6167,"Goodnews Bay","Igneous",1660,null,null,null]
["TKie","Eek River pluton and related plutonic rocks","Early Tertiary and (or) Late Cretaceous","Sill 50 to 500 m thick crops out in discontinuous exposures over 10 km length cutting and contact-metamorphosing Kkcd of Kuskokwim Group north of Eek River.  Dominantly medium- to coarse-grained, porphyritic to diabasic (hornblende) augite diorite, quart",null,null,"BH002",1665,"Bethel","Igneous",1665,null,null,null]
["TKig","Gemuk Mountain pluton","Early Tertiary and (or) Late Cretaceous","Elongate, north-trending, erosionally resistant, mafic to intermediate quartz gabbro to mafic granodiorite pluton, 25 km (square).  Cuts and contact-metamorphoses units Kkv of Kuskokwim Group and Kvs of Togiak Terrane.",null,null,"BH002",1666,"Bethel","Igneous",1665,null,null,null]
["TKip","Mt. Plummer pluton","Early Tertiary and (or) Late Cretaceous","Medium- to coarse-grained, erosionally resistant, hypidiomorphic granular augite-biotite mafic granodiorite, quartz monzodiorite, and quartz diorite pluton.  Intrudes and contact metamorphoses Kkmf, Kksh, and Kkcd of Kuskokwim group.",null,"K/Ar ages of 65.5+2.0 Ma and 66.6+2.0 Ma from biotite","BH002",1667,"Bethel","Igneous",1665,null,null,null]
["Kihd","Hornblende diorite stocks and dikes","Late Cretaceous","Small, extensively altered, hornblende diorite stocks and dikes containing relict euhedral plagioclase.",null,"Ar/Ar total-fusion age of 68.0+2.0 Ma from hornblende","BH002",2490,"Bethel","Igneous",1665,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite.  Subdivision of quartz diorite and diorite from original Hoare and Coonrad (1978) unit.",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","GO006",6168,"Goodnews Bay","Igneous",1665,null,null,null]
["Tim","Mafic intrusive rocks","Tertiary","Dark-colored dikes and sills consisting of diabase, basalt, dioritic and gabbroic mafic intrusive rocks.",null,"K/Ar age of 64.6 +/- 2 m.y. from biotite","GO002",161,"Goodnews Bay","Igneous",1670,null,null,null]
["Tim","Mafic intrusive rocks","Tertiary","Dark-colored dikes and sills consisting of diabase, basalt, dioritic and gabbroic mafic intrusive rocks",null,"K/Ar age of 64.6 +/- 2 m.y. from biotite","HG002",161,"Hagemeister Island","Igneous",1670,null,null,null]
["TKg","Gabbro","Tertiary and Cretaceous","Medium- to coarse-grained pyroxene gabbro dike (?)",null,null,"ST002",202,"Saint Matthew","Igneous",1670,null,null,null]
["Tm","Mafic rocks","Tertiary(?)","Gabbro, diabase, basalt, and biotite lamphrophyre in stocks, sills, and dikes.",null,null,"BH004",31670,"Bethel","Igneous",1670,null,null,null]
["Ks","Sedimentary rocks of Summit Island","Late Cretaceous (Maestrichtian (?))","Sedimentary rocks of Summit Island.  A sequence of intertonguing nonmarine conglomerate, sandstone, shale, and carbonaceous mudstone containing abundant plant detritus and a few coal seams.","Palynomorphs indicate Late Cretaceous",null,"GO002",120,"Goodnews Bay","Sedimentary",1960,null,null,null]
["Ks","Sedimentary rocks of Summit Island","Late Cretaceous (Maestrichtian (?))","Sedimentary rocks of Summit Island.  A sequence of intertonguing nonmarine conglomerate, sandstone, shale, and carbonaceous mudstone containing abundant plant detritus and a few coal seams.","Palynomorphs indicate Late Cretaceous",null,"HG002",120,"Hagemeister Island","Sedimentary",1960,null,null,null]
["Ks","Sedimentary rocks of Summit Island","Late Cretaceous (Maestrichtian (?))","Sedimentary rocks of Summit Island.  A sequence of intertonguing nonmarine conglomerate, sandstone, shale, and carbonaceous mudstone containing abundant plant detritus and a few coal seams.","Palynomorphs indicate Late Cretaceous",null,"NG002",120,"Nushagak Bay","Sedimentary",1960,null,null,null]
["Kus","Upper Cretaceous nonmarine clastic rocks (Summit Island Formation of Hoare and others, 1983)","Late Cretaceous","Nonmarine clastic rocks, moderately to well indurated, including (in order of abundance) black carbonaceous shale, fine to coarse sandstone, conglomerate, and thin coal seams. probable depositional contact on deformed older rocks not exposed. Divisible i","Fossils pollen suggest a Late Cretaceous, possibly Maestrichtian, age.",null,"GO005",506,"Goodnews Bay","Sedimentary",1960,null,null,null]
["Kus","Upper Cretaceous nonmarine clastic rocks (Summit Island Formation of Hoare and others, 1983)","Late Cretaceous","Nonmarine clastic rocks, moderately to well indurated, including (in order of abundance) black carbonaceous shale, fine to coarse sandstone, conglomerate, and thin coal seams. probable depositional contact on deformed older rocks not exposed. Divisible i","Fossils pollen suggest a Late Cretaceous, possibly Maestrichtian, age.",null,"HG003",506,"Hagemeister Island","Sedimentary",1960,null,null,null]
["Kus","Upper Cretaceous nonmarine clastic rocks (Summit Island Formation of Hoare and others, 1983)","Late Cretaceous","Nonmarine clastic rocks, moderately to well indurated, including (in order of abundance) black carbonaceous shale, fine to coarse sandstone, conglomerate, and thin coal seams. probable depositional contact on deformed older rocks not exposed. Divisible i","Fossils pollen suggest a Late Cretaceous, possibly Maestrichtian, age.",null,"NG006",506,"Nushagak Bay","Sedimentary",1960,null,null,null]
["Kk","Kuskokwim Group","Cretaceous","Kuskokwim Group.  Marine sedimentary sequence consisting of graywacke, sandstone, conglomerate, siltstone, and shale.","Early Cretaceous (Albian) age assigned from fossils found north of the map area.",null,"GO002",121,"Goodnews Bay","Sedimentary",1970,null,null,null]
["Kkcf","Kuskokwim Group; Chert-clast provenance rocks; Outer-fan turbidite facies","Late Cretaceous (Turonian)","Thin-bedded, fine-grained, quartzose sandstone and slate with lesser thin- and thick-bedded medium-grained sandstone.","Age considered Turonian (Late Cretaceous) based on three megafossil collections",null,"BH002",1970,"Bethel","Sedimentary",1970,null,null,null]
["Kkmf","Kuskokwim Group; Mixed provenance rocks; Outer-fan turbidite facies","Late Cretaceous (Turonian)","Shale-rich sequence with lesser thin- to thick-bedded, medium-grained sandstone sections.","Age considered Turonian (Late Cretaceous) based on two megafossil occurences",null,"BH002",1972,"Bethel","Sedimentary",1970,null,null,null]
["Kkmc","Kuskokwim Group; Mixed provenance rocks; Inner-fan-channel facies","Late Cretaceous (Turonian)","Mixed shale-rich and sandstone-rich sections, with coarse sandstone and pebbly sandstone in thick-bedded, amalgamated sequences with minor interbedded shale.","Recovered fossils are nondiagnostic Cretaceous forms",null,"BH002",1973,"Bethel","Sedimentary",1970,null,null,null]
["Kkv","Kuskokwim Group; Volcanic provenance rocks","Late Cretaceous (Turonian)","Interbedded shale, siltstone, sandstone, and conglomerate composed of rounded clasts of volcanic, volcaniclastic, and plutonic rocks.","Age considered Turonian (Late Cretaceous) based on megafossil occurences",null,"BH002",1974,"Bethel","Sedimentary",1970,null,null,null]
["Kksh","Kuskokwim Group; Shale and siltstone","Late Cretaceous (Early Turonian and (or) Late Cenomanian)","Dark-gray to black, finely laminated shale, siltstone and thin-bedded, very fine grained sandstone.","Age constrained by megafossil occurances of late Cenomanian and (or) early Turonian age low in section and by overlying units of Turonian age",null,"BH002",1975,"Bethel","Sedimentary",1970,null,null,null]
["Kks","Kuskokwim Group, sedimentary rocks","middle Late (Cenomaniam and Coniacian) to late Early Cretaceous (Albian)","Chiefly consist of interbedded graywacke, siltstone, with lesser amounts of pebble grit and conglomerate and a small amount of coal.  Well-indurated, commonly light- to dark-gray and weather brown.  Vary from volcanic wacke to quartz-chert-feldspar-rich","Fossils collected from basal zone are considered late Early Cretaceous (Albian) age and fossils from the upper zone considered early and middle Late Cretaceous (Cenomanian and Coniacian)",null,"BH004",31970,"Bethel","Sedimentary",1970,null,null,null]
["KCgg","Gemuk Group, graywacke, siltstone, and conglomerate","Early Cretaceous to Mississippian(?)","Graywacke and conglomerate, massive, fine- to coarse-grained hard, dark-gray; massive and thin-bedded, light- to dark-gray and green lithic-feldspathic graywacke; massive varicolored argillite; banded slaty siltstone; minor amounts of limestone, calcareo","Fossils of early Cretaceous (Valanginian) and Late Jurassic age collected at widely scattered localities.",null,"BH004",32830,"Bethel","Sedimentary",1970,null,null,null]
["Kkcd","Kuskokwim Group; Chert-clast provenance rocks; Deltaic facies","Late Cretaceous (Turonian)","Thick bedded quartzose sandstone, pebbly sandstone, and subordinate siltstone and shale.  Re-assigned polygon from Hoare and Coonrad (1978) to subdivide Kuskokwim to match Box and others (1993)","Age considered Turonian (Late Cretaceous) based on megafossil occurences",null,"GO006",321,"Goodnews Bay","Sedimentary",1985,null,null,null]
["Kkcd","Kuskokwim Group; Chert-clast provenance rocks; Deltaic facies","Late Cretaceous (Turonian)","Thick bedded quartzose sandstone, pebbly sandstone, and subordinate siltstone and shale.","Age considered Turonian (Late Cretaceous) based on megafossil occurences",null,"BH002",1971,"Bethel","Sedimentary",1985,null,null,null]
["Kkbc","Kuskokwim Group; Basal Conglomerate","Late Cretaceous (Cenomanian(?))","Pebble to boulder conglomerate, coarse sandstone, and minor interbedded medium-grained sandstone, siltstone, and shale.",null,null,"BH002",1976,"Bethel","Sedimentary",1985,null,null,null]
["Kks","Kuskokwim Group, sedimentary rocks, conglomerate facies","middle Late (Cenomaniam and Coniacian) to late Early Cretaceous (Albian)","Chiefly consists of conglomerate facies of interbedded graywacke and siltstone, with lesser amounts of pebble grit conglomerate and and a small amount of coal.  Well-indurated, commonly light- to dark-gray and weather brown.  Varies from volcanic wacke t","Fossils collected from basal zone are considered late Early Cretaceous (Albian) age and fossils from the upper zone considered early and middle Late Cretaceous (Cenomaniam and Coniacian)",null,"BH004",31970,"Bethel","Sedimentary",1985,null,null,null]
["Ks","Graywacke-siltstone sequence","Late Cretaceous(?)","Volcanic graywacke, siltstone, and minor amounts of pebble conglomerate and coal; probably littoral marine.",null,null,"BI002",9,"Baird Inlet","Sedimentary",2021,null,null,null]
["Ks","Graywacke-siltstone sequence","Late Cretaceous(?)","Volcanic graywacke, siltstone, and minor amounts of pebble conglomerate and coal; probably littoral marine.",null,null,"NI002",9,"Nunivak Island","Sedimentary",2021,null,null,null]
["Ks?","Graywacke-siltstone sequence","Late Cretaceous(?)","Volcanic graywacke, siltstone, and minor amounts of pebble conglomerate and coal; probably littoral marine.",null,null,"NI002",10,"Nunivak Island","Sedimentary",2021,null,"Q",null]
["Ks","Sedimentary rocks","Cretaceous","Sedimentary rocks",null,null,"NI003",150,"Nunivak Island","Sedimentary",2021,null,null,null]
["Kcg","Graywacke and conglomerate","Early Cretaceous","Marine sedimentary unit consisting of hard graywacke, shaly and blocky siltstone, and local conglomerate.  Rocks commonly calcareous.","Buchia of Early Cretaceous (Valanginian age)",null,"GO002",125,"Goodnews Bay","Sedimentary",2102,null,null,null]
["Kts","Turbidite sandstone, conglomerate, and phyllite, Goodnews terrane","Early Cretaceous","Sandstone, sandy conglomerate, pebbly mudstone, siltstone, and shale with phyllitic fabric.  Reassigned polygon from Hoare and Coonrad (1978) to match unit from Box and others (1993) to north.","Pelecypod fossil collection of Valanginian, and of Late Jurassic and (or) Early Cretaceous, age",null,"GO006",325,"Goodnews Bay","Sedimentary",2102,null,null,null]
["Kts","Turbidite sandstone, conglomerate, and phyllite, Goodnews terrane","Early Cretaceous","Sandstone, sandy conglomerate, pebbly mudstone, siltstone, and shale with phyllitic fabric.","Pelecypod fossil collection of Valanginian, and of Late Jurassic and (or) Early Cretaceous, age",null,"BH002",2116,"Bethel","Sedimentary",2102,null,null,null]
["Kv","Volcanic graywacke and argillite","Cretaceous","Thinly interbedded fine-grained graywacke and siliceous argillite thermally altered by granodiorite (Tg)",null,null,"ST002",1301,"Saint Matthew","Sedimentary",2105,null,"HFS",null]
["Kb","Graywacke of Buchia Ridge","Early Cretaceous","Marine sedimentary rocks of graywacke, siltstone, and conglomerate.  Conglomerate, near the top of Buchia Ridge, contains local Buchia shell coquinas.","Buchia and other \"Fossils\" show that it is Early Cretaceous in age (Valanginian and Hauterivian ages)",null,"GO002",122,"Goodnews Bay","Sedimentary",2125,null,null,null]
["Klb","Lower Cretaceous graywacke of Buchia Ridge","Early Cretaceous","Lithic sandstone, conglomerate, and shale at least 2-5 km thick (Hoare and Coonrad, 1983). Clastic rocks composed mostly of slaty volcaniclastic rock fragments, similar to Jurassic rocks to the southeast (Jln, Jmm). No paleocurrent data available. Divisi","Klb1 preserves abundant Valanginian fauna; Klb2 yields rare Hauterivian ammonites.",null,"GO005",508,"Goodnews Bay","Sedimentary",2125,null,null,null]
["Klg","Limy grit and limestone","Early Cretaceous","Limy grit and limestone.  Chiefly small, green, fine-grained angular rock fragments and minor round quartz pebbles cemented by gray bioclastic limestone consisting of tiny shell fragments.  Coeval with the conglomeratic rocks of Buchia Ridge (Kb).","Buchia of Early Cretaceous (Valanginian age)",null,"GO002",123,"Goodnews Bay","Sedimentary",2150,null,null,null]
["Kts","Tuff and sedimentary rocks","Early Cretaceous","Thick, varied assemblage of andesitic, commonly laumontitized, tuffs, sedimentary rocks, and a few flows.","Buchia of Early Cretaceous (Valanginian age)  Radiolaria of Early Cretaceous age",null,"GO002",124,"Goodnews Bay","Sedimentary",2180,null,null,null]
["Kts","Tuff and sedimentary rocks","Early Cretaceous","Thick, varied assemblage of andesitic, commonly laumontitized, tuffs, sedimentary rocks, and a few flows.","Buchia of Early Cretaceous (Valanginian age)  Radiolaria of Early Cretaceous age",null,"HG002",124,"Hagemeister Island","Sedimentary",2180,null,null,null]
["Kvs","Togiak Terrane; Marine volcaniclastic sandstone, conglomerate, shale, and interbedded tuff","Early Cretaceous","Thin- to thick-bedded, green tuffaceous sandstone, siltstone, argillite, conglomerate, tuff, and tuffaceous chert.","Early Cretaceous pelecypods and radiolarians",null,"BH002",2180,"Bethel","Sedimentary",2180,null,null,null]
["KCgg","Gemuk Group, graywacke, siltstone, and conglomerate","Early Cretaceous to Mississippian(?)","Graywacke and conglomerate, massive, fine- to coarse-grained hard, dark-gray; massive and thin-bedded, light- to dark-gray and green lithic-feldspathic graywacke; massive varicolored argillite; banded slaty siltstone; minor amounts of limestone, calcareo","Fossils of early Cretaceous (Valanginian) and Late Jurassic age collected at widely scattered localities.",null,"BH004",32830,"Bethel","Sedimentary",2180,null,null,null]
["KCgg","Gemuk Group, graywacke, siltstone, and conglomerate","Early Cretaceous to Late Jurassic","Graywacke and conglomerate, massive, fine- to coarse-grained hard, dark-gray; massive and thin-bedded, light- to dark-gray and green lithic-feldspathic graywacke; massive varicolored argillite; banded slaty siltstone; minor amounts of limestone, calcareo","Fossils of early Cretaceous (Valanginian) and Late Jurassic age collected at widely scattered localities.",null,"BH004",32831,"Bethel","Sedimentary",2180,null,null,null]
["Ktr","Tulip Volcanic Field; Rhyolite domes and flows","Late Cretaceous","Rhyolite domes and flows found as small knobs or hills.  Moderately to severely altered.",null,null,"BH002",2210,"Bethel","Igneous",2210,null,null,null]
["Kvkr","Kipchuk Volcanic Field; Rhyolite domes and flows","Late Cretaceous","Moderately to severely altered, white to orange, platy rhyolite domes and flows, and minor rhyolite breccia.  Lithologically similar to Ktr.",null,null,"BH002",2265,"Bethel","Igneous",2210,null,"ALT",null]
["Tv","Volcanic rocks and volcanogenic deposits","Early Tertiary","Mostly andesitic and trachytic tuffs, breccias, and flows.  Lesser basaltic andesite and diabase and fine- to medium-grained volcanogenic sediments",null,null,"HG002",115,"Hagemeister Island","Igneous",2260,null,null,null]
["Tv","Volcanic rocks and volcanogenic deposits","Early Tertiary","Mostly andesitic and trachytic tuffs, breccias, and flows.  Lesser basaltic andesite and diabase and fine- to medium-grained volcanogenic sediments",null,null,"NG002",115,"Nushagak Bay","Igneous",2260,null,null,null]
["TKm","Mafic flows and volcaniclastic deposits","Early Tertiary to Late Cretaceous","Flat-lying to gently dipping mafic flows of andesite and basalt, and volcaniclastic deposits of andesitic and basaltic tuff and conglomerate",null,"K/Ar age of 78.7 +/- 2 and 66.4+/- 2 m.y. from whole rock samples of basalt","ST002",201,"Saint Matthew","Sedimentary",2260,null,null,null]
["Kuv","Upper Cretaceous volcanic rocks","Late Cretaceous","Moderately to steeply dipping, fresh to weakly altered porphyritic andesite flows and interbedded sandy to bouldery volcaniclastic rocks. Phenocrysts are plagioclase, clinopyroxene, orthopyroxene, pseudomorphic talc after olivine, and accessory magnetite",null,"Four whole-rock K-Ar determinations yield Late Cretaceous ages.","GO005",504,"Goodnews Bay","Igneous",2260,null,null,null]
["Kuv","Upper Cretaceous volcanic rocks","Late Cretaceous","Moderately to steeply dipping, fresh to weakly altered porphyritic andesite flows and interbedded sandy to bouldery volcaniclastic rocks. Phenocrysts are plagioclase, clinopyroxene, orthopyroxene, pseudomorphic talc after olivine, and accessory magnetite",null,"Four whole-rock K-Ar determinations yield Late Cretaceous ages.","HG003",504,"Hagemeister Island","Igneous",2260,null,null,null]
["Kuv","Upper Cretaceous volcanic rocks","Late Cretaceous","Moderately to steeply dipping, fresh to weakly altered porphyritic andesite flows and interbedded sandy to bouldery volcaniclastic rocks. Phenocrysts are plagioclase, clinopyroxene, orthopyroxene, pseudomorphic talc after olivine, and accessory magnetite",null,"Four whole-rock K-Ar determinations yield Late Cretaceous ages.","NG006",504,"Nushagak Bay","Igneous",2260,null,null,null]
["Kvk6","Kipchuk Volcanic Field; Andesite and Basalt flows","Late Cretaceous (Maastrichtian)","Porphyritic plagioclase-pyroxene-olivine andesite flows and flow breccias, minor interbedded flows of olivine basalt, and black andesite tuff.",null,"Ar/Ar total-fusion age of 69.5+2.1 Ma from biotite","BH002",2271,"Bethel","Igneous",2260,null,null,null]
["Kvk3","Kipchuk Volcanic Field; Andesite flows","Late Cretaceous","Porphyritic, propylitically altered, one- and two-pyroxene andesite lava flows.  Minor olivine basalt flows, dacite flows, and andesite tuff.",null,null,"BH002",2274,"Bethel","Igneous",2260,null,null,null]
["Kvk1","Kipchuk Volcanic Field; Basal Andesite flows","Late Cretaceous","Light-gray to tan, sugary textured, fine-grained andesite flows with well-developed flow banding and irregular platy fracture.",null,null,"BH002",2276,"Bethel","Igneous",2260,null,null,null]
["Ksl","Swift Creek Volcanic Field; Lithic air-fall tuff","Late Cretaceous (Campanian)","Moderately altered, andesitic lithic air-fall tuffs, tuff breccias, and altered andesite flows.  Varies from coarse-grained lithic tuff breccia with clasts as large as 2 m in diameter to ash beds containing lithic fragments less than 0.6 cm in diameter.",null,"Whole rock Ar /Ar total-fusion age of 74.3+2.2 Ma","BH002",2270,"Bethel","Igneous",2261,null,null,null]
["Kvk5","Kipchuk Volcanic Field; Fine-grained tuff, crystal-vitric tuff, and tuffaceous sandstone","Late Cretaceous (Maestrichtian)","Lacustrine, fluvial, and air-fall tuff.  Very fine- to fine-grained tuffs that are finely laminated.  Air-fall tuff is fine- to medium-grained with well developed bedding.",null,null,"BH002",2272,"Bethel","Igneous",2261,null,null,null]
["Kvk4","Kipchuk Volcanic Field; Upper black Andesite lithic tuff","Late Cretaceous (Maastrichtian)","Black, densely welded andesite tuff exposed in low hills and ridges.",null,"Whole rock K/Ar ages of 69.0+2.1 Ma and 71.4+2.1 Ma","BH002",2273,"Bethel","Igneous",2261,null,null,null]
["Kvk2","Kipchuk Volcanic Field; Lower black Andesite lithic tuff","Late Cretaceous","Massive, dark, fine-grained tuff having black opaque vitroclastic groundmass and abundant lithic fragments of volcanic rocks and lesser sandstone and shale.",null,null,"BH002",2275,"Bethel","Igneous",2261,null,null,null]
["Ki","Intermediate and silicic pyroclastic deposits","Late Cretaceous","Intermediate and silicic pyroclastic deposits including: dacite, andesite, and rhyolite nonwelded tuff breccia and crystal tuff, dacite and rhyolite welded tuff, massive dacite breccia (lahar?), fine ash-fall tuff, volcanic conglomerate, and andesite and","Pollen assemblages from carbonaceous tuffs","K/Ar age of 74.1 +/- 2 and 74.4+/- 2 m.y. from biotite and hornblende","ST002",302,"Saint Matthew","Igneous",2265,null,null,null]
["Ki","Intermediate and silicic pyroclastic deposits","Late Cretaceous","Intermediate and silicic pyroclastic deposits including: dacite, andesite, and rhyolite nonwelded tuff breccia and crystal tuff, dacite and rhyolite welded tuff, massive dacite breccia (lahar?), fine ash-fall tuff, volcanic conglomerate, and andesite and","Pollen assemblages from carbonaceous tuffs","K/Ar age of 74.1 +/- 2 and 74.4+/- 2 m.y. from biotite and hornblende","ST002",1302,"Saint Matthew","Igneous",2265,null,"HFS",null]
["Ksp","Serpentinite","Late Cretaceous","Small, pervasively slickensided bodies of serpentinite, serpentinite-matrix melange, and silica-carbonate altered serpentinite.",null,null,"BH002",2510,"Bethel","Igneous",2510,null,null,null]
["s","Serpentine","Tertiary(?)","Fibrous pale-green and massive black serpentine forming a small intrusive body north of mouth of Crooked Creek.",null,null,"BH004",32510,"Bethel","Igneous",2510,null,null,null]
["Kinc","Nyac, Bonanza Creek, and Columbia Creek plutons, undivided","Early Cretaceous","Rock is pale-pink weathering light-gray, coarse-grained porphyritic to seriate hornblende-biotite and biotite-hornblende granite, quartz monzonite, and lesser granodiorite and quartz-monzodiorite.  Nyac (~200 km) is crudely concentrically zoned from horn",null,"Nyac: K/Ar age of 101.1+3.0 Ma from hornblende; 108.5+3.3 Maÿand 120.0+3.6 Ma from biotite; and U/Pb age of 104 to 129 Ma from zircon.  Bonanza Creek: Ar/Ar total-fusion age of 110+3.3 Ma from biotite.  Columbia Creek: K/Ar age of 115.0+3.5 Ma from bioti","BH002",2530,"Bethel","Igneous",2530,null,null,null]
["KJc","Togiak Terrane; Argillite and tuffaceous chert","Early Cretaceous and (or) Late Jurassic","Thin-bedded green to brown argillite with occasional 1- to 4-cm thick tuffaceous chert, siltstone, and fine-grained tuff interbeds.","Late Jurassic and (or) Early Cretaceous age from poorly preserved radiolarians",null,"BH002",2810,"Bethel","Sedimentary",2832,null,null,null]
["KJba","Basaltic and Andesitic lava flows, Nyac terrane","Early Cretaceous and (or) Late Jurassic","Basaltic and andesitic lava flows.",null,null,"BH002",2871,"Bethel","Sedimentary",2870,null,null,null]
["KJvs","Volcanic and sedimentary rocks","Early Cretaceous to Middle Jurassic","Thick marine unit consisting of volcanic and sedimentary rocks.  Volcanic rocks range in composition from mafic pillow basalts to more abundant andesitic and trachytic flows, tuffs, and breccias.  Interbedded with the volcanic rocks are tuffaceous siltst","Radiolaria of Late Jurassic to Early Cretaceous age, and fragmentary ammonites of Jurassic age.",null,"GO002",127,"Goodnews Bay","Sedimentary",2872,null,null,null]
["KJvs","Volcanic and sedimentary rocks","Early Cretaceous to Middle Jurassic","Thick marine unit consisting of volcanic and sedimentary rocks.  Volcanic rocks range in composition from mafic pillow basalts to more abundant andesitic and trachytic flows, tuffs, and breccias.  Interbedded with the volcanic rocks are tuffaceous siltst","Radiolaria of Late Jurassic to Early Cretaceous age, and fragmentary ammonites of Jurassic age.",null,"HG002",127,"Hagemeister Island","Sedimentary",2872,null,null,null]
["KJvs","Volcanic and sedimentary rocks","Early Cretaceous to Middle Jurassic","Thick marine unit consisting of volcanic and sedimentary rocks.  Volcanic rocks range in composition from mafic pillow basalts to more abundant andesitic and trachytic flows, tuffs, and breccias.  Interbedded with the volcanic rocks are tuffaceous siltst","Radiolaria of Late Jurassic to Early Cretaceous age, and fragmentary ammonites of Jurassic age.",null,"BH003",127,"Bethel","Sedimentary",2872,null,null,null]
["TJih","Hypabyssal felsic intrusive rocks","Early Tertiary (?), Cretaceous, and Jurassic","Highly altered rhyolite and dacite porphyries.",null,null,"BH002",2885,"Bethel","Igneous",2885,null,null,null]
["KJb","Togiak Terrane; Pillow basalt","Early Cretaceous and (or) Late Jurassic","Very altered pillow basalt sequence.   Interbedded with argillite and thin-bedded chert of KJc.","Radiolarian fauna in interbedded KJc",null,"BH002",2890,"Bethel","Sedimentary",2890,null,null,null]
["TJis","Slate Creek pluton","Early Tertiary (?), Cretaceous, and Jurassic","Erosionally neutral, medium-grained hypidiomorphic-granular, mafic hornblende tonalite and granodiorite pluton, less than 2 km (square).",null,null,"BH002",2905,"Bethel","Igneous",2900,null,null,null]
["Jvs","Togiak Terrane; Marine volcaniclastic sandstone, conglomerate, and argillite","Jurassic","Turbidite-facies volcaniclastic strata, locally as coarse as fine-grained pebble conglomerate",null,null,"BH002",3121,"Bethel","Sedimentary",3005,null,null,null]
["KCgg","Gemuk Group, graywacke, siltstone, and conglomerate","Early Cretaceous to Late Jurassic","Graywacke and conglomerate, massive, fine- to coarse-grained hard, dark-gray; massive and thin-bedded, light- to dark-gray and green lithic-feldspathic graywacke; massive varicolored argillite; banded slaty siltstone; minor amounts of limestone, calcareo","Fossils of early Cretaceous (Valanginian) and Late Jurassic age collected at widely scattered localities.",null,"BH004",32830,"Bethel","Sedimentary",3005,null,null,null]
["KCgg","Gemuk Group, graywacke, siltstone, and conglomerate","Early Cretaceous to Late Jurassic","Graywacke and conglomerate, massive, fine- to coarse-grained hard, dark-gray; massive and thin-bedded, light- to dark-gray and green lithic-feldspathic graywacke; massive varicolored argillite; banded slaty siltstone; minor amounts of limestone, calcareo","Fossils of early Cretaceous (Valanginian) and Late Jurassic age collected at widely scattered localities.",null,"BH004",32832,"Bethel","Sedimentary",3005,null,null,null]
["Jvc","Volcaniclastic conglomerate, sandstone, and shale, Nyac terrnae","Late and Middle Jurassic","Epiclastic sequence of tuffaceous marine sandstone, shale, and conglomerate with minor interbedded basaltic and andesitic lava flows","Marine pelecypods of Bajocian age (Middle Jurassic);  Marine pelecypods of Tithonian age (Late Jurassic)",null,"BH002",3120,"Bethel","Sedimentary",3120,null,null,null]
["Ja","Togiak Terrane; Marine arkosic sandstone and argillite","Jurassic","Turbidite-facies arkosic sandstone and shale",null,null,"BH002",3130,"Bethel","Sedimentary",3130,null,null,null]
["Jk","Graywacke of Kulukak Bay","Middle to early Late Jurassic","A thick marine sedimentary unit referred to as \"Weary graywacke\" by Hoare and others, 1975.  Consists of very hard graywacke and siltstone with local conglomerate.","Buchia, Inoceramus, belemnites, and rare ammonite fragments ranging from Middle to early Late Jurassic age.",null,"GO002",130,"Goodnews Bay","Sedimentary",3150,null,null,null]
["Jk","Graywacke of Kulukak Bay","Middle to early Late Jurassic","A thick marine sedimentary unit referred to as \"Weary graywacke\" by Hoare and others, 1975.  Consists of very hard graywacke and siltstone with local conglomerate.","Buchia, Inoceramus, belemnites, and rare ammonite fragments ranging from Middle to early Late Jurassic age.",null,"HG002",130,"Hagemeister Island","Sedimentary",3150,null,null,null]
["Jk","Graywacke of Kulukak Bay","Middle to early Late Jurassic","A thick marine sedimentary unit referred to as \"Weary graywacke\" by Hoare and others, 1975.  Consists of very hard graywacke and siltstone with local conglomerate.","Buchia, Inoceramus, belemnites, and rare ammonite fragments ranging from Middle to early Late Jurassic age.",null,"NG002",130,"Nushagak Bay","Sedimentary",3150,null,null,null]
["Jk","Graywacke of Kulukak Bay","Middle to early Late Jurassic","A thick marine sedimentary unit referred to as \"Weary graywacke\" by Hoare and others, 1975.  Consists of very hard graywacke and siltstone with local conglomerate.  Locally hornfelsed","Buchia, Inoceramus, belemnites, and rare ammonite fragments ranging from Middle to early Late Jurassic age.",null,"NG002",20130,"Nushagak Bay","Sedimentary",3150,null,"HFS",null]
["Jmm","Middle and Upper Jurassic turbidites of Metervik Bay","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"GO005",510,"Goodnews Bay","Sedimentary",3151,null,null,null]
["Jmm","Middle and Upper Jurassic turbidites of Metervik Bay","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"HG003",510,"Hagemeister Island","Sedimentary",3151,null,null,null]
["Jmm","Middle and Upper Jurassic turbidites of Metervik Bay","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",510,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm1","Middle and Upper Jurassic turbidites of Metervik Bay, conglomeratic inner fan facies (Unit 1)","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",511,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm2","Middle and Upper Jurassic turbidites of Metervik Bay, well-bedded outer (or mid?) fan lobe facies (Unit 2)","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",512,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm3","Middle and Upper Jurassic turbidites of Metervik Bay, massive mid fan channel facies (Unit 3)","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",513,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm4a","Middle and Upper Jurassic turbidites of Metervik Bay, conglomeratic inner fan facies (Unit 4a, channel margin)","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",514,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm4b","Middle and Upper Jurassic turbidites of Metervik Bay, conglomeratic inner fan facies (Unit 4b, channel)","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",515,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm4c","Middle and Upper Jurassic turbidites of Metervik Bay, conglomeratic inner fan facies (Unit 4c, channel margin)","Late and Middle Jurassic","Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mutti, 1973): (from bottom to top) a conglomeratic inner fan facies unit; a we","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"NG006",516,"Nushagak Bay","Sedimentary",3151,null,null,null]
["Jmm","Middle and Upper Jurassic turbidites of Metervik Bay","Late and Middle Jurassic","Unit added by extension of polygon from Box (1985).  Description from Box:  Coherently deformed volcaniclastic turbidites southeast of Right Hand Fault. Reconstructed 6 km section, divided into four turbidite facies units (using criteria of Walker and Mu","Rare fossils range from Bajocian (base of third unit) to Oxfordian (in upper unit).",null,"GO006",3151,"Goodnews Bay","Sedimentary",3151,null,null,null]
["Jmt","Middle Jurassic volcaniclastic turbidites of Togiak Bay","Middle Jurassic","Tightly folded volcaniclastic turbidites at least 1.7 km thick. Sandstones and conglomerates composed entirely of volcanic and hypabyssal igneous clasts. A few tool marks and interbedded slump folds suggest ENE-directed paleocurrents. Middle Jurassic age","Middle Jurassic age constrained by occurrence of Bajocian pelecypods northeast of map area in Togiak River valley (Hoare and Coonrad, 1978a).","Intruded by Aeolus Mtn. gabbro body with 174 +/- 8 m.y. K-Ar amphibole age.","GO005",512,"Goodnews Bay","Sedimentary",3152,null,null,null]
["Jmt","Middle Jurassic volcaniclastic turbidites of Togiak Bay","Middle Jurassic","Tightly folded volcaniclastic turbidites at least 1.7 km thick. Sandstones and conglomerates composed entirely of volcanic and hypabyssal igneous clasts. A few tool marks and interbedded slump folds suggest ENE-directed paleocurrents. Middle Jurassic age","Middle Jurassic age constrained by occurrence of Bajocian pelecypods northeast of map area in Togiak River valley (Hoare and Coonrad, 1978a).","Intruded by Aeolus Mtn. gabbro body with 174 +/- 8 m.y. K-Ar amphibole age.","HG003",512,"Hagemeister Island","Sedimentary",3152,null,null,null]
["Jln","Lower Jurassic? dismembered volcaniclastic turbidites","Early Jurassic (?)","Pervasively deformed and dismembered tuffaceous sandstone-shale sequence, predominately argillaceous. Sedimentary structures variably preserved and indicate deposition from turbidity currents and other mass flow processes. Original thickness uncertain. S","Poorly preserved radiolaria from SF1 have been identified as post-Triassic Mesozoic forms. Clasts of slate similar to SF2 occur stratigraphically below Bajocian fossil occurrence in adjacent Middle Jurassic turbidites (Jmm). Deposition and deformation of",null,"GO005",518,"Goodnews Bay","Sedimentary",3230,null,null,null]
["Jln","Lower Jurassic? dismembered volcaniclastic turbidites","Early Jurassic (?)","Pervasively deformed and dismembered tuffaceous sandstone-shale sequence, predominately argillaceous. Sedimentary structures variably preserved and indicate deposition from turbidity currents and other mass flow processes. Original thickness uncertain. S","Poorly preserved radiolaria from SF1 have been identified as post-Triassic Mesozoic forms. Clasts of slate similar to SF2 occur stratigraphically below Bajocian fossil occurrence in adjacent Middle Jurassic turbidites (Jmm). Deposition and deformation of",null,"HG003",518,"Hagemeister Island","Sedimentary",3230,null,null,null]
["Jln","Lower Jurassic? dismembered volcaniclastic turbidites","Early Jurassic (?)","Pervasively deformed and dismembered tuffaceous sandstone-shale sequence, predominately argillaceous. Sedimentary structures variably preserved and indicate deposition from turbidity currents and other mass flow processes. Original thickness uncertain. S","Poorly preserved radiolaria from SF1 have been identified as post-Triassic Mesozoic forms. Clasts of slate similar to SF2 occur stratigraphically below Bajocian fossil occurrence in adjacent Middle Jurassic turbidites (Jmm). Deposition and deformation of",null,"NG006",518,"Nushagak Bay","Sedimentary",3230,null,null,null]
["Jk","Graywacke of Kulukak Bay, subdivided","Middle to early Late Jurassic","Subdivsion of unit into Box's (1985) volcaniclastic turbidites.  A thick marine sedimentary unit referred to as \"Weary graywacke\" by Hoare and others, 1975.  Consists of very hard graywacke and siltstone with local conglomerate.","Buchia, Inoceramus, belemnites, and rare ammonite fragments ranging from Middle to early Late Jurassic age.",null,"GO006",6130,"Goodnews Bay","Sedimentary",3230,null,null,null]
["Jlvs","Volcanic and sedimentary rocks","Early Jurassic","Marine unit of mafic flows, some pillow structure, volcanic breccias, and massive fine- to medium-grained volcanogenic sedimentary rocks.  Fractures commonly coated with laumontite","Weyla pelecypods of Early Jurassic age.",null,"HG002",132,"Hagemeister Island","Sedimentary",3254,null,"HFS",null]
["Jlv","Lower Jurassic interbedded volcanic and sedimentary rocks","Early Jurassic","Basaltic to dacitic volcanic and volcaniclastic rocks. Volcanic rocks (locally pillowed) typically plagioclase +/- clinopyroxene +/- hornblende porphyries. Interbedded with pyroclastic and epiclastic rocks derived from similar volcanic rocks. Grades from","Upper unit of abundantly fossiliferous, well bedded sandstones and shales",null,"HG003",516,"Hagemeister Island","Igneous",3254,null,null,null]
["TJvb","Upper Triassic-Lower Jurassic coarse volcaniclastic rocks","Early Jurassic-Late Triassic","Dense green tuffs, tuff breccias, pillow breccias, minor pillow basalt, and associated epiclastic rocks. Breccia clasts are aphanitic or plagioclase-clinopyroxene porphyries, often vesicular, mostly angular. Interbedded hyaloclastites and crystal tuffs.",null,null,"GO005",522,"Goodnews Bay","Igneous",3255,null,null,null]
["TrJvb","Upper Triassic-Lower Jurassic coarse volcaniclastic rocks","Early Jurassic-Late Triassic","Dense green tuffs, tuff breccias, pillow breccias, minor pillow basalt, and associated epiclastic rocks. Breccia clasts are aphanitic or plagioclase-clinopyroxene porphyries, often vesicular, mostly angular. Interbedded hyaloclastites and crystal tuffs.",null,null,"HG003",522,"Hagemeister Island","Igneous",3255,null,null,null]
["TrJvb","Upper Triassic-Lower Jurassic coarse volcaniclastic rocks","Early Jurassic-Late Triassic","Unit as described by Box (1985), shown as hornfels and unit Jlvs by Hoare and Coonrad (1978).  Dense green tuffs, tuff breccias, pillow breccias, minor pillow basalt, and associated epiclastic rocks. Breccia clasts are aphanitic or plagioclase-clinopyrox",null,null,"HG002",1522,"Hagemeister Island","Igneous",3255,null,"HFS",null]
["KJvs","Volcanic and sedimentary rocks","Early Cretaceous to Middle Jurassic","Thick marine unit consisting of volcanic and sedimentary rocks.  Volcanic rocks range in composition from mafic pillow basalts to more abundant andesitic and trachytic flows, tuffs, and breccias.  Interbedded with the volcanic rocks are tuffaceous siltst","Radiolaria of Late Jurassic to Early Cretaceous age, and fragmentary ammonites of Jurassic age.",null,"GO006",6127,"Goodnews Bay","Sedimentary",3255,null,null,null]
["JTrp","Togiak Terrane; Phyllite and chert","Early Jurassic and Late Triassic (?)","Gray, green, and black phyllite, fine-grained tuff, and tuffaceous chert.","Single radiolarian collection of Early Jurassic (?) age",null,"BH002",3260,"Bethel","Metamorphic",3260,null,null,null]
["Jct","Jurassic laminated tuffs and associated rocks","Jurassic","Mixed unit characterized by banded to finely laminated crystal lithic tuffs with interbedded green, white, and black tuffaceous cherts. Minor interbedded sections of massive, coarse-grained lithic tuff and (or) pillow basalt (Jpb). Highly deformed, often","Several cherts have yielded radiolaria of Jurassic age, one of which is identified as Tithonian (latest Jurassic).",null,"GO005",520,"Goodnews Bay","Igneous",3310,null,null,null]
["Jct (Jpb)","Jurassic laminated tuffs and associated rocks","Jurassic","Mixed unit characterized by banded to finely laminated crystal lithic tuffs with interbedded green, white, and black tuffaceous cherts. Minor interbedded sections of massive, coarse-grained lithic tuff and (or) pillow basalt (Jpb). Highly deformed, often","Several cherts have yielded radiolaria of Jurassic age, one of which is identified as Tithonian (latest Jurassic).",null,"HG003",520,"Hagemeister Island","Igneous",3310,null,null,null]
["Jpb","Jurassic laminated tuffs and associated rocks","Jurassic","Pillow basalt. Highly deformed, often with slaty or spaced cleavage, which is also folded. Partially altered to prennite-pumpellyite facies mineral assemblage. Several cherts have yielded radiolaria of Jurassic age, one of which is identified as Tithonia","Several cherts have yielded radiolaria of Jurassic age, one of which is identified as Tithonian (latest Jurassic).",null,"GO005",521,"Goodnews Bay","Igneous",3310,null,null,null]
["KJvs","Volcanic and sedimentary rocks, subdivided","Early Cretaceous to Middle Jurassic","Thick marine unit consisting of volcanic and sedimentary rocks.  Volcanic rocks range in composition from mafic pillow basalts to more abundant andesitic and trachytic flows, tuffs, and breccias.  Interbedded with the volcanic rocks are tuffaceous siltst","Radiolaria of Late Jurassic to Early Cretaceous age, and fragmentary ammonites of Jurassic age.",null,"GO006",6128,"Goodnews Bay","Sedimentary",3310,null,null,null]
["Jt","Trondhjemite","Jurassic and Jurassic (?)","Light-gray, medium-grained intrusive trondhjemite consisting of abundant quartz, plagioclase, and minor chlorite.",null,null,"GO002",169,"Goodnews Bay","Igneous",3380,null,null,null]
["Jg","Gabbroic rocks","Jurassic and Jurassic (?)","Medium- to coarse-grained, locally pegmatitic intrusive gabbroic rocks consisting of hornblende, clinopyroxene, and calcic plagioclase",null,"K/Ar age range of 159.3 to 186.9 m.y. from hornblende","GO002",167,"Goodnews Bay","Igneous",3406,null,null,null]
["Jg","Gabbroic rocks","Jurassic and Jurassic (?)","Medium- to coarse-grained, locally pegmatitic intrusive gabbroic rocks consisting of hornblende, clinopyroxene, and calcic plagioclase",null,"K/Ar age range of 159.3 to 186.9 m.y. from hornblende","HG002",167,"Hagemeister Island","Igneous",3406,null,null,null]
["Jmg","Middle Jurassic gabbroic plutons","Middle Jurassic","Medium- to coarse-grained (locally pegmatitic) hornblende gabbro to diorite bodies, slightly altered (i.e., sericitized plagioclase, hornblende partially replaced by actinolite and chlorite, prehnite-quartz veinlets). Intrusive into a variety of units wi",null,"K-Ar amphibole ages range from 186 to 159 (minimum) m.y., or Middle Jurassic.","GO005",546,"Goodnews Bay","Igneous",3406,null,null,null]
["Jmg","Middle Jurassic gabbroic plutons","Middle Jurassic","Medium- to coarse-grained (locally pegmatitic) hornblende gabbro to diorite bodies, slightly altered (i.e., sericitized plagioclase, hornblende partially replaced by actinolite and chlorite, prehnite-quartz veinlets). Intrusive into a variety of units wi",null,"K-Ar amphibole ages range from 186 to 159 (minimum) m.y., or Middle Jurassic.","HG003",546,"Hagemeister Island","Igneous",3406,null,null,null]
["Jvs","Volcanic and sedimentary rocks","Middle to early Late Jurassic","Volcanic and sedimentary rocks consisting of andesitic, trachytic, and basaltic flows and breccias with interbedded fine- to coarse-grained sedimentary rocks","Fossils in related rocks, north of map area, are assigned a Middle Jurassic age.",null,"BH003",131,"Bethel","Sedimentary",3450,null,null,null]
["Jab","Andesitic and Basaltic lava flows and marine epiclastic rocks, Nyac terrane","Middle Jurassic","Andesitic and basaltic lava flows, flow breccias, and tuffaceous marine sedimentary rocks","Marine pelecypods of Bajocian age (Middle Jurassic)",null,"BH002",3450,"Bethel","Sedimentary",3450,null,null,null]
["Kkv","Kuskokwim Group, volcanic rocks","Jurassic","Massive andesitic and basaltic flows; minor amounts of trachyte, trachyandesite, and dacite; some interbedded tuffaceous sedimentary rocks; and locally several hundred feet of volcanic breccia at or near base.  These rocks from a belt of low rolling hill","Originally called Cretaceous on map; note revised to Jurassic and removed from Kuskokwim.",null,"BH004",32261,"Bethel","Igneous",3450,null,null,null]
["Kkv","Kuskokwim Group, volcanic breccia","Jurassic","Several hundred feet of volcanic breccia at or near base of massive andesitic and basaltic flows; minor amounts of trachyte, trachyandesite, and dacite; some interbedded tuffaceous sedimentary rocks.  These rocks from a belt of low rolling hills on the w","Originally called Cretaceous on map; note revised to Jurassic and removes from Kuskokwim.",null,"BH004",32261,"Bethel","Igneous",3450,null,null,null]
["Jmv","Middle Jurassic interbedded volcanic and sedimentary rocks","Middle Jurassic","Basaltic and andesitic volcanic and volcaniclastic rocks, extensively altered to prehnite-pumpellyite facies assemblage. Volcanic rocks more common in lower third of exposed section, characterized by plagioclase + clinopyroxene +/- hornblende porphyries.","Locally fossiliferous with Middle Jurassic fauna.",null,"GO005",514,"Goodnews Bay","Sedimentary",3451,null,null,null]
["Jmv","Middle Jurassic interbedded volcanic and sedimentary rocks","Middle Jurassic","Basaltic and andesitic volcanic and volcaniclastic rocks, extensively altered to prehnite-pumpellyite facies assemblage. Volcanic rocks more common in lower third of exposed section, characterized by plagioclase + clinopyroxene +/- hornblende porphyries.","Locally fossiliferous with Middle Jurassic fauna.",null,"HG003",514,"Hagemeister Island","Sedimentary",3451,null,null,null]
["Jum","Ultramafic rocks","Jurassic and Jurassic (?)","Serpentinite, serpentinized dunite and websterite ultramafic rocks.",null,"K/Ar age range of 176.4 to 186.9 m.y. from hornblende","GO002",168,"Goodnews Bay","Igneous",3495,null,null,null]
["Jum","Ultramafic rocks","Jurassic and Jurassic (?)","Serpentinite, serpentinized dunite and websterite ultramafic rocks.",null,"K/Ar age range of 176.4 to 186.9 m.y. from hornblende","HG002",168,"Hagemeister Island","Igneous",3495,null,null,null]
["Jmu","Middle Jurassic ultramafic plutons","Middle Jurassic","Occur only at Red and Susie Mtns. at west end of map area. Medium-grained dunite, wehrlite, and clinopyroxenite, partially (less than 25 percent) replaced by serpentine minerals. Around margins cut by numerous coarsely pegmatitic hornblendite dikes. Nort",null,"Hornblendite dikes yield Middle Jurassic K-Ar amphibole ages.","GO005",548,"Goodnews Bay","Igneous",3495,null,null,null]
["Jmu","Middle Jurassic ultramafic plutons","Middle Jurassic","Occur only at Red and Susie Mtns. at west end of map area. Medium-grained dunite, wehrlite, and clinopyroxenite, partially (less than 25 percent) replaced by serpentine minerals. Around margins cut by numerous coarsely pegmatitic hornblendite dikes. Nort",null,"Hornblendite dikes yield Middle Jurassic K-Ar amphibole ages.","HG003",548,"Hagemeister Island","Igneous",3495,null,null,null]
["TKg","Granitic rocks","Tertiary and Cretaceous","Fine-, medium-, and coarse-grained, light- to dark-gray, rarely pink plutonic granitic rocks.  Chiefly quartz monzonite, granodiorite, and quartz diorite",null,"K/Ar age range of 62.5 to 72.5 m.y. from biotite and hornblende","HG002",165,"Hagemeister Island","Igneous",3510,null,null,null]
["Jmf","Middle Jurassic granodiorite pluton","Middle Jurassic","Medium-grained biotite-hornblende granodiorite of Hagemeister Island; slightly altered (i.e. sericitized plagioclase, chlorite partially replacing biotite and hornblende). Intrusive into Lower Jurassic rocks (Jlv) with narrow contact metamorphic zone of",null,"Yielded K-Ar hornblende age of 183 +/- 7 m.y.","HG003",544,"Hagemeister Island","Igneous",3510,null,null,null]
["Pzmg","Metagabbro and greenstone","Paleozoic (?)","Massive, fine- to coarse-grained, locally pegmatitic, greenish metagabbro and greenstone.  Probable dismembered altered ophiolite complex consisting of mafic flows, dikes, volcaniclastic rocks, and gabbro.",null,null,"HG002",147,"Hagemeister Island","Metamorphic",3890,null,null,null]
["Trub","Upper Triassic (?) pillow basalts","Upper Triassic","Pillow basalts, aphanitic to porphyritic, with interbedded pillow breccia, hyaloclastite, and interpillow and interbedded red and white radiolarian chert. Porphyries consist of plagioclase + clinopyroxene phenocrysts with intergranular to subophitic grou","Considered Upper Triassic based on radiolarian ages of associated bedded chert.",null,"GO005",524,"Goodnews Bay","Igneous",3891,null,null,null]
["Trub","Upper Triassic (?) pillow basalts","Upper Triassic","Pillow basalts, aphanitic to porphyritic, with interbedded pillow breccia, hyaloclastite, and interpillow and interbedded red and white radiolarian chert. Porphyries consist of plagioclase + clinopyroxene phenocrysts with intergranular to subophitic grou","Considered Upper Triassic based on radiolarian ages of associated bedded chert.",null,"HG003",524,"Hagemeister Island","Igneous",3891,null,null,null]
["Jt","Trondhjemite","Jurassic and Jurassic (?)","Light-gray, medium-grained intrusive trondhjemite consisting of abundant quartz, plagioclase, and minor chlorite.",null,null,"HG002",169,"Hagemeister Island","Igneous",3892,null,null,null]
["Trut","Upper Triassic (?) trondhjemite","Late Triassic(?)","Altered and irregularly cataclastized trondhjemitic plutonic rocks composed of plagioclase and quartz with minor seams of chlorite, sericite, and clinozoisite (lawsonite locally: Hoare and Coonrad, 1978b). Shown on map only south of Security Cove but sma",null,null,"HG003",554,"Hagemeister Island","Igneous",3892,null,null,null]
["Trud","Upper Triassic (?) diabasic intrusive rocks","Late Triassic(?)","Subophitic, holocrystalline plagioclase-clinopyroxene diabase (grain size to 1.5 mm). Occurs as 0.3 to 1.0-m-wide sills and dikes with basalt and chert screens west of Matogak River mouth, as thick sills intruding chert at Pyrite Point, as dikes cutting",null,"K-Ar amphibole age of hornfels is 187 +/- 10 m.y.","HG003",550,"Hagemeister Island","Igneous",3893,null,null,null]
["Trud","Upper Triassic (?) diabasic intrusive rocks","Late Triassic(?)","Originally mapped as MzPz by Hoare abd Coonrad (1978), unit is shown as described by Box (1985) with hornfels of Hoare and Coonrad (1978) added.  Subophitic, holocrystalline plagioclase-clinopyroxene diabase (grain size to 1.5 mm). Occurs as 0.3 to 1.0-m",null,"K-Ar amphibole age of hornfels is 187 +/- 10 m.y.","HG002",1550,"Hagemeister Island","Igneous",3893,null,"HFS",null]
["Trug","Upper Triassic (?) pyroxene gabbro","Late Triassic(?)","Altered clinopyroxene gabbro, locally up to 5 percent orthopyroxene. Augitic pyroxene (diallage) often kinked and fractured, occasionally rimmed or replaced by pale-green actinolitic amphibole. Plagioclase partially to completely replaced by fine aggrega",null,null,"HG003",552,"Hagemeister Island","Igneous",3894,null,null,null]
["su","Serpentinized ultramafic rocks",null,"Thoroughly serpentinized ultramafic rocks. Protoliths were predominately harzburgite (5-25 percent bastite pseudomorphs after orthopyroxene) with subordinate dunite and rare clinopyroxenite. Locally near Cape Newenham preserves a lineated tectonite fabri",null,null,"GO005",556,"Goodnews Bay","Metamorphic",3895,null,null,null]
["su","Serpentinized ultramafic rocks",null,"Thoroughly serpentinized ultramafic rocks. Protoliths were predominately harzburgite (5-25 percent bastite pseudomorphs after orthopyroxene) with subordinate dunite and rare clinopyroxenite. Locally near Cape Newenham preserves a lineated tectonite fabri",null,null,"HG003",556,"Hagemeister Island","Metamorphic",3895,null,null,null]
["Pzcs","Calcareous schist","Paleozoic","Schistose calcareous siltstone, limestone, and greenish tuffaceous rocks.",null,null,"GO002",150,"Goodnews Bay","Metamorphic",3950,null,null,null]
["Pzcs","Calcareous schist","Paleozoic","Schistose calcareous siltstone, limestone, and greenish tuffaceous rocks.",null,null,"HG002",150,"Hagemeister Island","Metamorphic",3950,null,null,null]
["JTrmc","Upper Triassic-Lower Jurassic calcareous schists","Early Jurassic-Late Triassic","Partially to completely recrystallized calcareous phyllites and schists. Protoliths include calcareous sandstones and shales, limestone conglomerates, limestone, volcanic conglomerates and mafic volcanic rocks. Clastics locally preserve turbidite feature",null,null,"GO005",540,"Goodnews Bay","Metamorphic",3950,null,null,null]
["JTrmc","Upper Triassic-Lower Jurassic calcareous schists","Early Jurassic-Late Triassic","Partially to completely recrystallized calcareous phyllites and schists. Protoliths include calcareous sandstones and shales, limestone conglomerates, limestone, volcanic conglomerates and mafic volcanic rocks. Clastics locally preserve turbidite feature",null,null,"HG003",540,"Hagemeister Island","Metamorphic",3950,null,null,null]
["JTrmb","Upper Triassic-Lower Jurassic (?) metabasaltic schists","Early Jurassic (?)-Late Triassic","Partially to completely recrystallized schistose rocks with mafic igneous protoliths, including pillow basalts, angular volcanic breccia, pebbly mudstone, fine tuffaceous sedimentary rocks, diabase, gabbro, and rare chert. Greenschist to transitional gre",null,"Two mica separates yield Late Jurassic K-Ar ages, probably resulting from Late Jurassic thermal event.","GO005",536,"Goodnews Bay","Metamorphic",3990,null,null,null]
["JTrmb","Upper Triassic-Lower Jurassic (?) metabasaltic schists","Early Jurassic (?)-Late Triassic","Partially to completely recrystallized schistose rocks with mafic igneous protoliths, including pillow basalts, angular volcanic breccia, pebbly mudstone, fine tuffaceous sedimentary rocks, diabase, gabbro, and rare chert. Greenschist to transitional gre",null,"Two mica separates yield Late Jurassic K-Ar ages, probably resulting from Late Jurassic thermal event.","HG003",536,"Hagemeister Island","Metamorphic",3990,null,null,null]
["JTrmb","Upper Triassic-Lower Jurassic (?) metabasaltic schists","Early Jurassic (?)-Late Triassic","Originally shown as part of unit KJvs by Hoare and Coonrad (1978), unit shown as described by Box (1985) with hornfels from Hoare and Coonrad (1978) added.  Partially to completely recrystallized schistose rocks with mafic igneous protoliths, including p",null,"Two mica separates yield Late Jurassic K-Ar ages, probably resulting from Late Jurassic thermal event.","HG002",1536,"Hagemeister Island","Metamorphic",3990,null,"HFS",null]
["JPvss","Permian-Jurassic (?) volcaniclastic sandstone and conglomerate","Jurassic (?)-Permian","Unit distinguished only near Goodnews Bay. Characterized by round cobble conglomerate, entirely composed of plagioclase phyric volcanic clasts, alternating with turbiditic sandstone-shale sequences. Distribution suggests it unconformably overlies Permian",null,"Middle Jurassic K-Ar amphibole ages","GO005",532,"Goodnews Bay","Sedimentary",3991,null,null,null]
["JPvss","Permian-Jurassic (?) volcaniclastic sandstone and conglomerate","Jurassic (?)-Permian","Unit distinguished only near Goodnews Bay. Characterized by round cobble conglomerate, entirely composed of plagioclase phyric volcanic clasts, alternating with turbiditic sandstone-shale sequences. Distribution suggests it unconformably overlies Permian",null,"Middle Jurassic K-Ar amphibole ages","HG003",532,"Hagemeister Island","Sedimentary",3991,null,null,null]
["JTrmvss","Upper Triassic-Lower Jurassic volcaniclastic schists","Early Jurassic (?)-Late Triassic","Partially recrystallized schistose rocks with sandstone, shale, and conglomerate protoliths derived from feldspar-rich volcanic source. Rounded conglomerate clasts mostly plagioclase +/- pyroxene +/- hornblende amygdaloidal porphyritic volcanic rocks, bu",null,"Single K-Ar determination yields a Late Triassic amphibole age.","GO005",538,"Goodnews Bay","Metamorphic",3991,null,null,null]
["JTrmvss","Upper Triassic-Lower Jurassic volcaniclastic schists","Early Jurassic (?)-Late Triassic","Partially recrystallized schistose rocks with sandstone, shale, and conglomerate protoliths derived from feldspar-rich volcanic source. Rounded conglomerate clasts mostly plagioclase +/- pyroxene +/- hornblende amygdaloidal porphyritic volcanic rocks, bu",null,"Single K-Ar determination yields a Late Triassic amphibole age.","HG003",538,"Hagemeister Island","Metamorphic",3991,null,null,null]
["Trvs","Volcanic and sedimentary rocks","Triassic","Marine unit consisting of chert, tuffaceous cherty rocks, argillite, siltstone, volcanic wacke, conglomerate, limestone, and mafic flows and breccias.","Pelecypods of Late Triassic age",null,"GO002",135,"Goodnews Bay","Sedimentary",4035,null,null,null]
["Trvs","Volcanic and sedimentary rocks","Triassic","Marine unit consisting of chert, tuffaceous cherty rocks, argillite, siltstone, volcanic wacke, conglomerate, limestone, and mafic flows and breccias.","Pelecypods of Late Triassic age",null,"BH003",135,"Bethel","Sedimentary",4035,null,null,null]
["Trb","Togiak Terrane; Pillow basalt and minor interbedded chert","Late Triassic","Massive pillow basalt and basaltic breccia interbedded with thin-bedded tuffaceous chert and shale",null,null,"BH002",4215,"Bethel","Igneous",4215,null,null,null]
["MzPz","Mesozoic and Paleozoic rocks, undivided","Early Cretaceous to Early(?) Ordovician","Thick, widespread, marine unit consisting of volcanic and sedimentary rocks ranging in age from Early (?) Ordovician to Early Cretaceous.  Unit consists of thin-bedded to massive tuffaceous cherts and siltstones, argillite, graywacke, pebble-cobble congl","Limestones commonly contain Permian fossils",null,"GO002",145,"Goodnews Bay","Sedimentary",4710,null,null,null]
["MzPz","Mesozoic and Paleozoic rocks, undivided","Early Cretaceous to Early(?) Ordovician","Thick, widespread, marine unit consisting of volcanic and sedimentary rocks ranging in age from Early (?) Ordovician to Early Cretaceous.  Unit consists of thin-bedded to massive tuffaceous cherts and siltstones, argillite, graywacke, pebble-cobble congl","Limestones commonly contain Permian fossils",null,"HG002",145,"Hagemeister Island","Sedimentary",4710,null,null,null]
["KCg","Gemuk Group","Early Cretaceous to Mississippian(?)","Chiefly massive and thin-bedded, fine-grained siliceous rocks, some volcanic rocks, calcareous siltstone, and limestone.  In the Bethel quadrangle, most probably of Jurassic, Triassic, and Permian age.",null,null,"BH004",34710,"Bethel","Sedimentary",4710,null,null,null]
["TJik","Little Kasigluk River pluton","Early Tertiary (?), Cretaceous, and Jurassic","Small masses (less than 6 km (square)) of medium-grained, hypidiomorphic granular hornblende diorite and gabbro",null,null,"BH002",3405,"Bethel","Igneous",4880,null,null,null]
["MzPz","Mesozoic and Paleozoic rocks, undivided","Early Cretaceous to Early(?) Ordovician","Thick, widespread, marine unit consisting of volcanic and sedimentary rocks ranging in age from Early (?) Ordovician to Early Cretaceous.  Unit consists of thin-bedded to massive tuffaceous cherts and siltstones, argillite, graywacke, pebble-cobble congl","Limestones commonly contain Permian fossils",null,"GO002",146,"Goodnews Bay","Sedimentary",4950,null,null,null]
["TrPzm","Tikchik Terrane; Melange","Triassic and Paleozoic","Structurally complex assemblage of intercalated chert, limestone, basalt, and greywacke","Fossils recovered from limestone are Permian and Late Triassic age.  Radiolarian fossils from chert are Paleozoic (?), pre-Late Devonian, Devonian (?), and Triassic ages.",null,"BH002",5091,"Bethel","Sedimentary",4950,null,null,null]
["KCgc","Gemuk Group, chert, siltstone, graywacke and limestone","Mississippian(?)","Massive and thin-bedded chert interbedded with siltstone and graywacke (generally calcareous), thin-bedded limestone and minor amount of mafic volcanic rocks, all of Mississippian(?) age.  Chert is black, white and gray.  No green chert, which is charact",null,null,"BH004",34713,"Bethel","Tectonite",4950,null,null,null]
["MzPzc","Chert and argillite, Goodnews terrane","Mesozoic and (or) Paleozoic","White, gray-green, and blue-green recrystallized chert in 2- to 5-cm thick beds interbedded with black to dark-green phyllite or slate beds of similar thickness","Recrystallized radiolarians (Phanerozoic)",null,"BH002",5026,"Bethel","Metamorphic",5026,null,null,null]
["MzPzv","Goodnews Terrane; Volcaniclastic sandstone and argillite","Mesozoic and (or) Paleozoic","Turbiditic, thin-bedded, medium- to fine-grained, volcaniclastic sandstone and dark-green to black argillite having weak to nonexistant slaty cleavage",null,null,"BH002",5045,"Bethel","Sedimentary",5045,null,null,null]
["MzPzs","Arkosic sandstone and slate, Goodnews terrane","Mesozoic and (or) Paleozoic","Strongly cleaved, medium-grained, generally thin-bedded, arkosic sandstone and slate",null,null,"BH002",5050,"Bethel","Sedimentary",5050,null,null,null]
["TrDs","Tikchik Terrane; Marine sandstone, shale, limestone, and conglomerate","Middle (?) Triassic to Late Devonian","Well-bedded, cleaved sandstone, shale, thin limestone interbeds, and cobble conglomerate","Conodont collection of Middle (?) Triassic and Late Devonian to Early Mississippian ages",null,"BH002",5060,"Bethel","Sedimentary",5060,null,null,null]
["MzPza","Goodnews Terrane; Argillaceous melange with blocks of limestone, basalt, and chert","Mesozoic and (or) Paleozoic","Argillaceous melange of black to green, weakly to intensely fracture foliated argillite with discontinuous phacoids of recrystallized radiolarian chert and limey sandstone","Permian pelecypods and Permian conodonts",null,"BH002",5090,"Bethel","Sedimentary",5090,null,null,null]
["MzPza","Goodnews Terrane; Argillaceous melange with blocks of limestone, basalt, and chert","Mesozoic and (or) Paleozoic","Show by extension from Box and others, 1993.  Argillaceous melange of black to green, weakly to intensely fracture foliated argillite with discontinuous phacoids of recrystallized radiolarian chert and limey sandstone","Permian pelecypods and Permian conodonts",null,"GO006",5090,"Goodnews Bay","Sedimentary",5090,null,null,null]
["MzPzp","Goodnews Terrane; Chloritic Phyllite","Mesozoic and (or) Paleozoic","Relatively homogeneous unit of finely foliated and crenulated phyllite",null,null,"BH002",5217,"Bethel","Metamorphic",5217,null,null,null]
["MzPzm","Goodnews Terrane; Metachert and Phyllitic Metachert","Mesozoic and (or) Paleozoic","Finely crystalline, thin-bedded quartzites (metachert) and finely interlayered quartzite and black phyllite","Recrystallized radiolarians (Phanerozoic)",null,"BH002",5225,"Bethel","Metamorphic",5225,null,null,null]
["MzPzb","Metabasalt and minor metachert, Goodnews terrane","Mesozoic and (or) Paleozoic","Weakly to strongly foliated metabasalt having variable recrystallization to greenschist-facies assemblage of albite-epidote-chlorite-actinolite.  Interbedded sequences of thin-bedded, white to green metachert having white mica-rich laminae.  Mid-ocean ri",null,"Metamorphic cooling constrained to Late Jurassic or Early Cretaceous time based on K/Ar age of 146.0+15.0 Ma from actinolite","BH002",5240,"Bethel","Metamorphic",5239,null,null,null]
["DOs","Schist and metachert","Devonian(?) to Ordovician(?)","Massively bedded green amphibole and chlorite schist interbedded with metachert; overlain by crystalline limestone, phyllite, and minor amounts of chlorite, graphite, and quartz-sericite schists.",null,null,"BH004",35240,"Bethel","Metamorphic",5239,null,null,null]
["Pl","Limestone","Permian","Thin, widespread, fine-grained, crystalline limestone.  Fetid odor.  Generally tuffaceous, locally cherty.",null,null,"GO002",140,"Goodnews Bay","Sedimentary",5730,null,null,null]
["Pl","Limestone","Permian","Thin, widespread, fine-grained, crystalline limestone.  Fetid odor.  Generally tuffaceous, locally cherty.",null,null,"HG002",140,"Hagemeister Island","Sedimentary",5730,null,null,null]
["Pl","Limestone","Permian","Thin, widespread, fine-grained, crystalline limestone.  Fetid odor.  Generally tuffaceous, locally cherty.",null,null,"BH004",140,"Bethel","Sedimentary",5730,null,null,null]
["Pl","Permian limestone","Permian","Massive recrystallized gray limestone with fetid odor of H2S upon breaking. Weak fracture cleavage masks bedding. Occurs as large blocks along low-angle fault between schistose rocks to northwest and mafic igneous rocks southeast of Kinegnak River. Age g","Age given by shell fragments of Atomodesma sp.",null,"GO005",528,"Goodnews Bay","Sedimentary",5730,null,null,null]
["Pl","Permian limestone","Permian","Massive recrystallized gray limestone with fetid odor of H2S upon breaking. Weak fracture cleavage masks bedding. Occurs as large blocks along low-angle fault between schistose rocks to northwest and mafic igneous rocks southeast of Kinegnak River. Age g","Age given by shell fragments of Atomodesma sp.",null,"HG003",528,"Hagemeister Island","Sedimentary",5730,null,null,null]
["KCgl","Limestone and calcareous siltstone and sandstone","Permian","Massive and thin-bedded, partly recrystallized, cream-colored limestone, estimated 500 to 1,000 feet thick near Chaekuktuli Lake; near Chikuminuk Lake, consists of interbedded gray silty limestone and calcareous siltstone and sandstone.","Invertebrate fossils reported by Mertie (1938)",null,"BH004",35730,"Bethel","Sedimentary",5730,null,null,null]
["KCgl","Gemuk Group, limestone and calcareous siltstone and sandstone","Permian","Conprises a belt of calcareous rocks of Permian age stratigraphically underneath but grading upward into the volcanic sequence.  Near Lake Chaekuktuli, the rocks are massive and thin-bedded, partly recrystalized, cream-colored limestone, estimated to be",null,null,"BH004",34712,"Bethel","Sedimentary",5730,null,null,null]
["Pvs","Permian volcaniclastic rocks","Permian","Volcaniclastic sedimentary rocks, ranging from coarsely bedded volcanic breccias to finely bedded calcareous tuffaceous rocks. Limestone cobble conglomerate locally north of Goodnews Bay. Red to black laminated argillite with radiolarian ghosts locally n","Red to black laminated argillite with radiolarian ghosts locally north and east of Goodnews Bay. Age constrained by several occurrences of fragmentary Atomodesma sp.",null,"GO005",526,"Goodnews Bay","Sedimentary",5746,null,null,null]
["Pvs","Permian volcaniclastic rocks","Permian","Volcaniclastic sedimentary rocks, ranging from coarsely bedded volcanic breccias to finely bedded calcareous tuffaceous rocks. Limestone cobble conglomerate locally north of Goodnews Bay. Red to black laminated argillite with radiolarian ghosts locally n","Red to black laminated argillite with radiolarian ghosts locally north and east of Goodnews Bay. Age constrained by several occurrences of fragmentary Atomodesma sp. Prehnite-pumpellyite facies.",null,"GO006",626,"Goodnews Bay","Sedimentary",5746,null,null,null]
["Pv","Volcanic rocks","Permian","Unit consists of basalt flows, breccias, and a few sandy tuffs.  Basalts are mostly amygdaloidal and mildly altered.  Unit includes columnar-jointed flows and pillow basalts interbedded with pillow breccias.  Volcanic rocks grade downward into fossilifer",null,null,"GO002",137,"Goodnews Bay","Igneous",5810,null,null,null]
["Pb","Permian (?) pillow basalt","Permian (?)","Pillow basalts, associated breccias and diabasic intrusive. Interbedded with Pvs unit. Prehnite pumpellyite facies.",null,null,"GO005",530,"Goodnews Bay","Igneous",5810,null,null,null]
["Pb","Permian (?) pillow basalt","Permian (?)","Pillow basalts, associated breccias and diabasic intrusive. Interbedded with Pvs unit. Prehnite pumpellyite facies.  Revision of Hoare and Coonrad (1978) based on Box (1985).  Also, volcanic rocks separated from unit MzPz of Hare and Coonrad (1978).  Tha",null,null,"GO006",630,"Goodnews Bay","Igneous",5810,null,null,null]
["KCgv","Gemuk Group, volcanic rocks","Triassic(?) and Permian","Predominantly altered dark-green to almost black mafic volcanic rocks of Permian age having abundant amygdules.  Volcanic breccia, calcareous tuff, and pillow lava make up basal part of section.  Pillow lavas also occur elsewhere in section.  Thin-bedded","Fossils of Permian age in limestone southeast of quardangle below unit and of questionable Triassic age in the Eek Mountains to south of quadrangle",null,"BH004",35810,"Bethel","Igneous",5810,null,null,null]
["KCgv","Gemuk Group, volcanic rocks","Permian(?)","Predominantly  altered mafic volcanic rocks of Permian age; dark-green to almost black with abundant amygdules, few identifiable phenocrysts.  Volcanic breccia, calcareous tuffs, and pillow lava constitute basal beds.  Lavas with well-formed pillow struc",null,null,"BH004",34711,"Bethel","Sedimentary",5810,null,null,null]
["MDv","Tikchik Terrane; Massive volcanic and volcaniclastic rocks","Early Mississippian and (or) Late Devonian","Weakly to moderately foliated and flattened pillowed and massive basalt, andesite, dacite, and rhyolite flows and breccia with greenschist-facies metamorphic-mineral assemblages","Mississippian fossils",null,"BH002",6412,"Bethel","Igneous",6412,null,null,null]
["MDm","Marble and metabasaltic dikes, Goodnews terrane","Early Mississippian and (or) Late Devonian","Light-gray to white calcitic and dolomitic marble cut by premetamorphic basaltic dikes.  Rare metamorphic blue amphiboles (magnesioriebeckite) in metabasalt dikes indicate relatively high pressure, low temperature metamorphism","Age constrained by conodonts of latest Devonian to earliest Mississippian age",null,"BH002",6380,"Bethel","Metamorphic",6580,null,null,null]
["DOs","Schist and metachert -- limestone","Devonian(?) to Ordovician(?)","Limestone mapped speparately in massively bedded green amphibole and chlorite schist interbedded with metachert; overlain by crystalline limestone, phyllite, and minor amounts of chlorite, graphite, and quartz-sericite schists.",null,null,"BH004",35240,"Bethel","Metamorphic",6580,null,null,null]
["DOl","Limestone","Devonian to Ordovician","Thin-bedded to massive, fine-grained, highly fractured limestone.  Local interbedded tuffs and mafic volcanic rocks.  Locally recrystallized to marble.","Sparse fossils of Early to Middle Devonian age and Early (?) Ordovician age.",null,"GO002",142,"Goodnews Bay","Sedimentary",6995,null,null,null]
["Dl","Devonian limestone","Devonian","Poorly exposed white limestone at southwest end of larger belt of fossiliferous Devonian shallow marine limestone (Hoare and Coonrad, 1978a).","fossiliferous Devonian shallow marine limestone.",null,"GO005",534,"Goodnews Bay","Sedimentary",6995,null,null,null]
["DOl","Limestone","Devonian to Ordovician","Thin-bedded to massive, fine-grained, highly fractured limestone.  Local interbedded tuffs and mafic volcanic rocks.  Locally recrystallized to marble.","Sparse fossils of Early to Middle Devonian age and Early (?) Ordovician age.",null,"GO006",6995,"Goodnews Bay","Sedimentary",6995,null,null,null]
["pCl","Marbleized limestone","Precambrian","White, gray, and brownish, locally garnetiferous marbleized limestones",null,null,"GO002",155,"Goodnews Bay","Metamorphic",8610,null,null,null]
["pCk","Metamorphic rocks of Kanektok River region","Precambrian","Gneiss and schist in the Kanektok River region.  Sedimentary, volcanic, and plutonic rocks metamorphosed in the upper greenschist and lower amphibolite facies.  Consists of medium- to coarse-grained, massive, and well-foliated biotite-hornblende gneisses",null,"K/Ar ages as old as 2,000 m.y. from biotite and hornblende","GO002",152,"Goodnews Bay","Metamorphic",9420,null,null,null]
["Xo","Amphibolite-facies orthogneiss and amphibolite with minor intercalated pelititc schist, Kilbuck terrane","Early Proterozoic","Strongly lineated and foliated, muscovite, biotite-muscovite, or amphibole orthogneiss with granite to tonalite to diorite protoliths.  More extensively exposed in Goodnews Bay quadrangle, where it also includes amphibolite and minor pelitic schist",null,"Two U/Pb age of igneous protolith of 2.06 Ga from zircon.  Nd/Sm isotopic systematics indicate that the rocks formed at 2 Ga.  Amphibolite-facies metamorphism U-Pb age of 1.78 Ga from sphene.  Cretaceous overprinting of most K/Ar ages suggest thermal/dyn","BH002",9420,"Bethel","Metamorphic",9420,null,null,null]
["pCm","Metamorphic complex","preCambrian","Coarse-grained pink gneiss and medium- to coarse-grained light- to dark-gray schist constituting a sequence of highly sedimentary, volcanic, possibly some intrusive rocks",null,null,"BH004",39420,"Bethel","Metamorphic",9420,null,null,null]