{"text_format":"dbase-jsonl-2026-09-30","columns":[{"name":"ROCK_UNIT","type":"character","width":5},{"name":"UNIT_NAME","type":"character","width":77},{"name":"AGE","type":"character","width":47},{"name":"DESCRIPTIO","type":"character","width":254},{"name":"FOSSIL","type":"character","width":254},{"name":"RADIOMETRI","type":"character","width":254},{"name":"SOURCE_COD","type":"character","width":5},{"name":"CLASS_CODE","type":"number","width":4,"decimals":0},{"name":"QUADRANGLE","type":"character","width":15},{"name":"ROCK_CLASS","type":"character","width":14},{"name":"NSACLASS","type":"number","width":4,"decimals":0},{"name":"LABEL","type":"character","width":1},{"name":"NSAMOD","type":"character","width":1},{"name":"QCLASS","type":"number","width":4,"decimals":0}],"n_rows":164,"rows_kept":164,"cut":false,"deleted_skipped":0,"read_ended":"whole","bounds":"16MiB/16384/4096/first_that_fit","version":"dbase_level_three","encoding_class":"enc_absent","reader":"statdb_count/9"}
["Qs?","Surficial deposits","Quaternary","Undivided surficial deposits",null,null,"KD002",100,"Kodiak","Unconsolidated",100,null,null,null]
["Qs","Surficial deposits","Quaternary","Consist of glacial and stream deposits inland and beach sediments along coast",null,null,"KD004",400,"Kodiak","Unconsolidated",100,null,null,null]
["Qs?","Surficial deposits","Quaternary","Undivided surficial deposits",null,null,"KR005",500,"Karluk","Unconsolidated",100,null,null,null]
["Qs?","Surficial deposits","Quaternary","Undivided surficial deposits",null,null,"TI002",100,"Trinity Islands","Unconsolidated",100,null,null,null]
["Qs?","Surficial deposits","Quaternary","Undivided surficial deposits",null,null,"KG002",100,"Kaguyak","Unconsolidated",100,null,null,null]
["Qs","Surficial deposits","Holocene and Pleistocene","Unconsolidated, porrly to well-sorted, poorly to moderately well-stratified doeposits; consists predominatly of alluvial, colluvial, glacial, marine, lacustrine, eolian, and swamp deposits.  Also, locally includes reworked volcanic debris as well as bloc",null,null,"KR002",100,"Karluk","Unconsolidated",100,null,null,null]
["Qs","Surficial deposits, undivided","Quaternary","Surficial deposits, undivided",null,null,"AF002",100,"Afognak","Unconsolidated",100,null,null,null]
[null,"Alluvium and marine terrace deposits","Quaternary","Alluvium and marine terrace deposits",null,null,"TI004",400,"Trinity Islands","Unconsolidated",100,null,null,null]
[null,"Surficial deposits","Quaternary","Consist of glacial and stream deposits inland and beach sediments along coast",null,null,"KR006",600,"Karluk","Unconsolidated",100,null,null,null]
[null,"Surficial deposits","Quaternary","Consists of glacial and stream deposits inland and beach sediments along coast",null,null,"AF004",100,"Afognak","Unconsolidated",100,null,null,null]
["Qmg","Present stream gravel, sand, and silt","Quaternary, Pleistocene and Recent","Low terrace gravel; alluvial fans; beach deposits.  Glacial morainal material",null,null,"AF010",1000,"Afognak","Unconsolidated",100,null,null,1000]
["Qmg","Present stream gravel, sand, and silt","Quaternary, Pleistocene and Recent","Low terrace gravel; alluvial fans; beach deposits.  Glacial morainal material",null,null,"KD007",1000,"Kodiak","Unconsolidated",100,null,null,1000]
["Qmg","Present stream gravel, sand, and silt","Quaternary, Pleistocene and Recent","Low terrace gravel; alluvial fans; beach deposits.  Glacial morainal material",null,null,"KR009",1000,"Karluk","Unconsolidated",100,null,null,1000]
["Qmg","Present stream gravel, sand, and silt","Quaternary, Pleistocene and Recent","Low terrace gravel; alluvial fans; beach deposits.  Glacial morainal material",null,null,"KG007",1000,"Kaguyak","Unconsolidated",100,null,null,1000]
[null,"Surficial deposits","Quaternary","Consists of glacial and stream deposits inland and beach sediments along coast",null,null,"AF005",100,"Afognak","Unconsolidated",100,null,null,null]
["Qs?","Surficial deposits","Quaternary","Undivided surficial deposits",null,null,"KD004",100,"Kodiak","Unconsolidated",100,null,null,null]
["Qa","Alluvial deposits","Holocene and Pleistocene","Ranges from coarse, subangular rock fragments to fine sand and silt in grainsize; locally includes considerable amounts of pumice near volcanic centers.",null,null,"AF006",105,"Afognak","Unconsolidated",105,null,null,null]
["Qaf","Alluvial fan and landslide deposits","Holocene and Pleistocene","Locally mapped; grainsize in this unit ranges from coarse, subangular rock fragments to fine sand and silt.  Alluvial fans either typically have a well-developed cone shape, or multiple cones coalescing into aprons.  Landslide deposits have poorly develo",null,null,"AF006",106,"Afognak","Unconsolidated",106,null,null,null]
["Qls","Landslide deposits","Quaternary","Lanslide deposits",null,null,"KR003",108,"Karluk","Unconsolidated",108,null,null,null]
["Qls","Landslide deposits","Quaternary","Landslide deposits ranging from nonsorted, nonstratifed, coarse angular rubble forming lobes, to large discrete blocks that resemble undisturbed bedrock",null,null,"AF002",108,"Afognak","Unconsolidated",108,null,null,null]
["ls","Landslide deposits","Quaternary","Landslide deposits ranging from nonsorted, nonstratifed, coarse angular rubble forming lobste masses at base of moderately steep to steep slopes.  Where derived from bedrock, deposits are chiefly coarse angular blocks; where derived from glacial deposits",null,null,"AF006",108,"Afognak","Unconsolidated",108,null,null,null]
["Qb","Marine beach and estuarine deposits","Holocene and Pleistocene","Marine beach and estuarine deposits.  Moderately well stratified and sorted sand and gravel on beaches; mud and silt in estuaries",null,null,"KR003",115,"Karluk","Unconsolidated",115,null,null,null]
["be","Marine beach deposits","Holocene and Pleistocene","Moderately well stratified and sorted sand and gravel on beaches",null,null,"AF006",115,"Afognak","Unconsolidated",115,null,null,null]
["Qmt","Marine terrace deposits","Holocene and Pleistocene","Marine terrace deposits.  Stratified and moderately well sorted sand and gravel deposits that form nearly level plains that end locally at prominent wave-cut scarps.  Terraces occur at 15 to 18 m elevation along Bristol Bay and between 40 and 45 m elevat",null,null,"KR003",117,"Karluk","Unconsolidated",117,null,null,null]
["mt","Marine terrace deposits","Holocene and Pleistocene","Marine terrace deposits.  Stratified and moderately well sorted sand and gravel deposits that form nearly level plains that end locally at prominent wave-cut scarps.  Terraces occur at 15 to 18 m elevation along Bristol Bay and between 40 and 45 m elevat",null,null,"AF006",117,"Afognak","Unconsolidated",117,null,null,null]
["rg","Rock glacier deposits","Quaternary","Rock glacier deposits",null,null,"AF006",127,"Afognak","Unconsolidated",127,null,null,null]
["Qad","Drift, Alaskan glaciation (Neoglacial)","Holocene","Drift, Alaskan glaciation (Neoglacial)",null,null,"KR003",130,"Karluk","Unconsolidated",130,null,null,null]
["nd","Drift, Neoglacial","Holocene","Drift, Neoglacial",null,null,"AF006",130,"Afognak","Unconsolidated",130,null,null,null]
["Qblu","Drift, undivided, Brooks Lake glaciation","Quaternary, Pleistocene","Drift, undivided, Brooks Lake glaciation",null,null,"KR003",135,"Karluk","Unconsolidated",135,null,null,null]
["blu","Drift, undivided, Brooks Lake glaciation","Quaternary, Pleistocene","Drift, undivided, Brooks Lake glaciation",null,null,"AF006",135,"Afognak","Unconsolidated",135,null,null,null]
["Qbln","Drift, Newhalen Stade, Brooks Lake Glaciation","Quaternary, Pleistocene","Drift, Newhalen Stade, Brooks Lake Glaciation",null,null,"KR003",137,"Karluk","Unconsolidated",137,null,null,null]
["Qblil","Drift, Iliamna Stade, Brooks Lake Glaciation","Quaternary, Pleistocene","Drift, Iliamna Stade, Brooks Lake Glaciation",null,null,"KR003",138,"Karluk","Unconsolidated",138,null,null,null]
["Qmhd","Drift, Mak Hill Glaciation","Quaternary, Pleistocene","Drift, Mak Hill Glaciation",null,null,"KR003",139,"Karluk","Unconsolidated",190,null,null,null]
["Qvi","Volcanic and shallow intrusive rocks","Holocene and Pleistocene","Basalitc andesite to dacite lava flows, volcaniclastic deposits.  Includes air-fall tuffs, volcanic domes, block and ash-flow deposits, ash-flow tuffs, volcanic-rubble flows, debris flows and hot-blast avalanche deposits",null,null,"KR002",150,"Karluk","Igneous",300,null,null,null]
["Qv","Volcanic rocks","Holocene and Pleistocene","Andesite, dacite, and leucobasalt lava flows, volcanic breccia, lahar deposits, and debris-flow deposits.  Lava flows and clasts in other volcanic deposits of unit are porphyritic, typically glassy, gray to black, and commonly vesicular.  Andesite is ove",null,null,"AF006",150,"Afognak","Igneous",300,null,null,null]
["Qv","Volcanic rocks","Holocene and Pleistocene","Andesite, dacite, and leucobasalt lava flows, volcanic breccia, lahar deposits, and debris-flow deposits.  Lava flows and clasts in other volcanic deposits of unit are porphyritic, typically glassy, gray to black, and commonly vesicular.  Andesite is ove",null,null,"KR004",150,"Karluk","Igneous",300,null,null,null]
["Qap","Ash-flow and ash-fall deposits","Holocene","Nonsorted, variably indurated deposits of ash, vitrophyre blocks, and (or) pumiceous lapilli.  Mapped in Valley of Ten Thousand Smokes and  at Kaguyak Crater",null,null,"AF006",161,"Afognak","Igneous",311,null,null,null]
["Qad","Domes","Holocene","Dacitic or rhyolitic vitrophyres having plagioclase, pyroxene, and (or) hornblende phenocrysts in a brown to grayish-brown glassy groundmass.",null,null,"AF002",181,"Afognak","Igneous",401,null,null,null]
["cvd","Domes","Holocene and Pleistocene","Dacite at Snowy Mountain, Mount Cerberus,  Falling Mountain, and at Kaguyak Crater and rhyolite at Novarupta",null,null,"AF006",681,"Afognak","Igneous",401,null,null,null]
["QTv","Volcanic rocks","Quaternary and Pliocene?","Andesite and basalt lava flows, sills, and plugs.  These primarily extrusive rocks typically cap ridges and include massive lava flows, agglomerate, and lahar deposits.",null,null,"AF002",190,"Afognak","Igneous",450,null,null,null]
["Ttg","Tugidak Formation","Tertiary, Pliocene","Consists of 1,500 m of of interbedded sandstone and siltstone characterized by randomly distributed pebbles and cobbles.  A single 1 m thick cobble conglomerate bed reported 350 m above base of unit","Richly fossiliferous, marine fossils of Pliocene age.",null,"TI003",212,"Trinity Islands","Sedimentary",550,null,null,null]
["Tp","Pliocene marine sedimentary rocks","Tertiary, Pliocene","Consists of 1,500 m of of interbedded sandstone and siltstone characterized by randomly distributed pebbles and cobbles.  A single 1 m thick cobble conglomerate bed reported 350 m above base of unit","Richly fossiliferous, marine fossils of Pliocene age.",null,"TI002",212,"Trinity Islands","Sedimentary",550,null,null,null]
[null,"Mainly Tertiary sandstone and shale","Tertiary","Mainly Tertiary sandstone and shale",null,null,"TI006",null,"Trinity Islands","Sedimentary",500,null,null,null]
[null,"Albatross sedimentary sequence","Tertiary, Pliocene or late Miocene","Diamictite, sandstone, and siltstone.  Conglomerate horizons contain clasts of granite, chert, melange, and slate.  Also contain distinctive calcareous shale clasts unlike any nearby exposed units","Calcareous shale clasts contain a late early Miocene fauna; enclosing unit is correlate with the Yakataga Formation",null,"TI004",401,"Trinity Islands","Sedimentary",565,null,null,null]
["Tnc","Narrow Cape Formation","Tertiary, Miocene","Formation is 700m thick, the lower 2/3 consisting of sandstone and a few conglomerate beds.  The upper third consists of siltstone.",null,null,"KD003",223,"Kodiak","Sedimentary",580,null,null,null]
["Tms","Miocene sedimentary rocks","Tertiary, Miocene","Formation is 700m thick, the lower 2/3 consisting of sandstone and a few conglomerate beds.  The upper third consists of siltstone.",null,null,"KD002",223,"Kodiak","Sedimentary",580,null,null,null]
["Tms","Miocene sedimentary rocks","Tertiary, Miocene","Formation is 700m thick, the lower 2/3 consisting of sandstone and a few conglomerate beds.  The upper third consists of siltstone.",null,null,"TI002",223,"Trinity Islands","Sedimentary",580,null,null,null]
["Tnc","Narrow Cape Formation","Tertiary, Miocene","Formation is 700m thick, the lower 2/3 consisting of sandstone and a few conglomerate beds.  The upper third consists of siltstone.",null,null,"TI003",223,"Trinity Islands","Sedimentary",580,null,null,null]
["Tnc","Narrow Cape Formation","Tertiary, Late Miocene","Narrow Cape Formation",null,null,"KD006",61,"Kodiak","Sedimentary",580,null,null,null]
["Tms","Marine sandstones of Narrow Point",null,"Marine sandstones of Narrow Point, mildly folded and moderately indurated",null,null,"KD007",null,"Kodiak","Sedimentary",580,null,null,null]
[null,"Siltstone of Trinity Islands","Tertiary, earliest Miocene or late Oligocene","Siltstone deposited in cool-temperature climactic conditions at outer neritic water depths.  Originally included is the Narrow Cape Formation, is now considered a distinctive, older unit.","Molluscan fauna and benthic foraminifers",null,"TI004",402,"Trinity Islands","Sedimentary",581,null,null,null]
["Tts","Siltstone of Trinity Island and Sitkinak Formation","Tertiary, Oligocene and Early Miocene","Siltstone of Trinity Island and Sitkinak Formation",null,null,"KD006",62,"Kodiak","Sedimentary",581,null,null,null]
["Th","Hemlock Conglomerate","late Oligocene","Composed primarily of fluvial sandstone and conglomerate that contain interbeds of siltstone, shale, and coal.  Chert, quartz, and granitic and metasedimentary rocks form most of clasts in conglomerate; volcanic rocks are small but significant proportion","Megaflora fossils of broadleaf deciduous plants and evergreen needles suggest late Oligocene age (J.A. Wolfe, written commun., 1988, in Detterman and others, 1996)",null,"KR004",231,"Karluk","Sedimentary",650,null,null,null]
["Th","Hemlock Conglomerate","late Oligocene","Composed primarily of fluvial sandstone and conglomerate that contain interbeds of siltstone, shale, and coal.  Chert, quartz, and granitic and metasedimentary rocks form most of clasts in conglomerate; volcanic rocks are small but significant proportion","Megaflora fossils of broadleaf deciduous plants and evergreen needles suggest late Oligocene age (J.A. Wolfe, written commun., 1988, in Detterman and others, 1996)",null,"AF002",231,"Afognak","Sedimentary",650,null,null,null]
["Tsk","Sitkinak Formation","Tertiary, Oligocene","Conglomerate and cross-bedded sandstone and siltstone containing coal fragments.",null,null,"KD003",233,"Kodiak","Sedimentary",660,null,null,null]
["To","Oligocene continental sedimentary rocks","Tertiary, Oligocene","Conglomerate and cross-bedded sandstone and siltstone containing coal fragments.",null,null,"KD002",233,"Kodiak","Sedimentary",660,null,null,null]
["To","Oligocene continental sedimentary rocks","Tertiary, Oligocene","Conglomerate and cross-bedded sandstone and siltstone containing coal fragments.",null,null,"TI002",233,"Trinity Islands","Sedimentary",660,null,null,null]
["Tsk","Sitkinak Formation","Tertiary, Oligocene","Conglomerate and cross-bedded sandstone and siltstone containing coal fragments.",null,null,"TI003",233,"Trinity Islands","Sedimentary",660,null,null,null]
["To","Oligocene continental sedimentary rocks","Tertiary, Oligocene","Conglomerate and cross-bedded sandstone and siltstone containing coal fragments.",null,null,"KG002",233,"Kaguyak","Sedimentary",660,null,null,null]
["Tsk","Sitkinak Formation","Tertiary, Oligocene","Conglomerate and cross-bedded sandstone and siltstone containing coal fragments.",null,null,"KG003",233,"Kaguyak","Sedimentary",660,null,null,null]
[null,"Sitkinak Formation","Tertiary, Oligocene","Conglomerate and sandstone alternating with fine-grained sandstone, siltstone, coal, and carbonaceous shale.  Primarily of terrestrial origin; deposited as channelized braided stream gravels interebedded with interchannel, lagoonal, and interdistributary",null,null,"TI004",403,"Trinity Islands","Sedimentary",660,null,null,null]
["Tss","Fresh-water sandstone, shale, and conglomerate, locally containing coly seams",null,"Fresh-water sandstone, shale, and conglomerate, locally containing coly seams.  Generally steeply dipping and well indurated; locally highly contorted.  (Includes Sitkinak and Sitkalidak Formations)",null,null,"KD007",null,"Kodiak","Sedimentary",640,null,null,null]
["Tss","Fresh-water sandstone, shale, and conglomerate, locally containing coly seams",null,"Fresh-water sandstone, shale, and conglomerate, locally containing coly seams.  Generally steeply dipping and well indurated; locally highly contorted.  (Includes Sitkinak and Sitkalidak Formations)",null,null,"KG007",null,"Kaguyak","Sedimentary",640,null,null,null]
["Tsi","Sitkalidak Formation","Tertiary, Oligocene to Eocene","Uniform sandstone and siltstone graded beds about 3,000 m thick  Rare conglomerate beds.",null,null,"KD003",241,"Kodiak","Sedimentary",740,null,null,null]
["Teo","Eo-Oligocene marine sedimentary rocks","Tertiary, Oligocene to Eocene","Uniform sandstone and siltstone graded beds about 3,000 m thick  Rare conglomerate beds.",null,null,"KD002",241,"Kodiak","Sedimentary",740,null,null,null]
["Teo","Eo-Oligocene marine sedimentary rocks","Tertiary, Oligocene to Eocene","Uniform sandstone and siltstone graded beds about 3,000 m thick  Rare conglomerate beds.",null,null,"TI002",241,"Trinity Islands","Sedimentary",740,null,null,null]
["Tsi","Sitkalidak Formation","Tertiary, Oligocene to Eocene","Uniform sandstone and siltstone graded beds about 3,000 m thick  Rare conglomerate beds.",null,null,"TI003",241,"Trinity Islands","Sedimentary",740,null,null,null]
["Teo","Eo-Oligocene marine sedimentary rocks","Tertiary, Oligocene to Eocene","Uniform sandstone and siltstone graded beds about 3,000 m thick  Rare conglomerate beds.",null,null,"KG002",241,"Kaguyak","Sedimentary",740,null,null,null]
["Tsi","Sitkalidak Formation","Tertiary, Oligocene to Eocene","Uniform sandstone and siltstone graded beds about 3,000 m thick  Rare conglomerate beds.",null,null,"KG003",241,"Kaguyak","Sedimentary",740,null,null,null]
[null,"Sitkalidak Formation, slope-basin deposits","Tertiary, Eocene","Less deformed interbedded sandstone and siltstone, mudstone and conglomerate, representative of deep-sea fan deposition.",null,null,"TI004",404,"Trinity Islands","Sedimentary",740,null,null,null]
[null,"Sitkalidak Formation, offscraped deposits","Tertiary, Eocene","More deformed interbedded sandstone and siltstone, mudstone and conglomerate, representative of deep-sea fan deposition.",null,null,"TI004",405,"Trinity Islands","Sedimentary",740,null,null,null]
[null,"Sitkalidak Formation, offscraped deposits","Tertiary, Eocene","More deformed interbedded sandstone and siltstone, mudstone and conglomerate, representative of deep-sea fan deposition.",null,null,"KG004",405,"Kaguyak","Sedimentary",740,null,null,null]
["Ts","Sitkalidak Formation, undivided","Tertiary, Eocene to Early Oligocene","Sitkalidak Formation, undivided",null,null,"KD006",63,"Kodiak","Sedimentary",740,null,null,null]
["Tsl","Sitkalidak Formation, less deformed","Tertiary, Eocene to Early Oligocene","Sitkalidak Formation, less deformed",null,null,"KD006",64,"Kodiak","Sedimentary",740,null,null,null]
["Tsm","Sitkalidak Formation, more deformed","Tertiary, Eocene to Early Oligocene","Sitkalidak Formation, more deformed",null,null,"KD006",65,"Kodiak","Sedimentary",740,null,null,null]
["Ts","Sitkalidak Formation, undivided","Tertiary, Eocene to Early Oligocene","Sitkalidak Formation, undivided",null,null,"TI005",63,"Trinity Islands","Sedimentary",740,null,null,null]
["Tc","Copper Lake Formation","early Eocene and Paleocene?","Consists of thick pebble-cobble conglomerate in its uppermost and lowermost parts and contains sandstone and siltstone in its middle part.  In measured section, conglomerate intervals are massive and have clasts that are mixture of volcanic, granitic, an","Age of Copper Lake is not well constrained; sparse megaflora in type section in Iliamna area and abundant megaflora in map area are restricted to sandstone and siltstone intervals that are present in middle part of unit (Detterman and others, 1996).",null,"AF002",250,"Afognak","Sedimentary",850,null,null,null]
["Tgc","Ghost Rocks Formation, coherent","Tertiary, early Paleocene","Ghost Rocks Formation, coherent",null,null,"KD006",69,"Kodiak","Sedimentary",960,null,null,null]
["Tgc","Ghost Rocks Formation, coherent","Tertiary, early Paleocene","Ghost Rocks Formation, coherent",null,null,"KG006",69,"Kaguyak","Sedimentary",960,null,null,null]
["Tgs","Ghost Rocks Formation, sandstone-rich unit, undivided","Tertiary, early Paleocene","Massive sandstone beds and lesser amounts of argillite and medium- to thin-bedded sandstone.  Sandstone beds show Bouma sequences indicative of deposition be turbidity currents.  Locally, channelized conglomerate units up to 100-m-thick occur on the Aliu",null,null,"KD006",67,"Kodiak","Sedimentary",961,null,null,null]
["Tgs","Ghost Rocks Formation, sandstone-rich unit, undivided","Tertiary, early Paleocene","Massive sandstone beds and lesser amounts of argillite and medium- to thin-bedded sandstone.  Sandstone beds show Bouma sequences indicative of deposition be turbidity currents.  Locally, channelized conglomerate units up to 100-m-thick occur on the Aliu",null,null,"KG006",67,"Kaguyak","Sedimentary",961,null,null,null]
["Tgs","Ghost Rocks Formation, sandstone-rich unit, undivided","Tertiary, early Paleocene","Consists of thick sections of argillite and local massive sandstone and chert-rich pebble conglomerate.  Tuff beds.  Limestone containing pelagic forams locally occurs at depositional contacts with pillow basalt.  Unit typically occurs to southeast of sa","Pelagic forams yielding early Tertiary and Late Cretaceous ages (3 collections)",null,"TI005",67,"Trinity Islands","Sedimentary",961,null,null,null]
["Tga","Ghost Rocks Formation, argillite-rich unit, undivided","Tertiary, early Paleocene","Consists of thick sections of argillite and local massive sandstone and chert-rich pebble conglomerate.  Tuff beds.  Limestone containing pelagic forams locally occurs at depositional contacts with pillow basalt.  Unit typically occurs to southeast of sa","Pelagic forams yielding early Tertiary and Late Cretaceous ages (3 collections)",null,"KD006",68,"Kodiak","Sedimentary",962,null,null,null]
["Tga","Ghost Rocks Formation, argillite-rich unit, undivided","Tertiary, early Paleocene","Massive sandstone beds and lesser amounts of argillite and medium- to thin-bedded sandstone.  Sandstone beds show Bouma sequences indicative of deposition be turbidity currents.  Locally, channelized conglomerate units up to 100-m-thick occur on the Aliu",null,null,"TI005",68,"Trinity Islands","Sedimentary",962,null,null,null]
["Tga","Ghost Rocks Formation, argillite-rich unit, undivided","Tertiary, early Paleocene","Consists of thick sections of argillite and local massive sandstone and chert-rich pebble conglomerate.  Tuff beds.  Limestone containing pelagic forams locally occurs at depositional contacts with pillow basalt.  Unit typically occurs to southeast of sa","Pelagic forams yielding early Tertiary and Late Cretaceous ages (3 collections)",null,"KG006",68,"Kaguyak","Sedimentary",962,null,null,null]
["Tab","Volcanic rocks of Barrier Range","late Tertiary","Breccia, lava flows, sills, and local pyroclastic and epiclastic tuff, southeast of active part of Aleutian Arc",null,null,"AF002",311,"Afognak","Igneous",1051,null,null,null]
["Tgva","Ghost Rocks Formation, andesitic volcanic and hypabyssal rocks","Tertiary, early Paleocene","Ghost Rocks Formation, andesitic volcanic and hypabyssal rocks",null,null,"KD006",602,"Kodiak","Igneous",1150,null,null,null]
["Tgvb","Ghost Rocks Formation, basaltic volcanic and hypabyssal rocks","Tertiary, early Paleocene","Tholeiitic basalt occurring within both sandstone- and argillite-rich units of the Formation.  Rocks are typically altered by shearing and low-grade metamorphism, yet \"* * * these lavas cannot have been derived from a single source and in many respect ex",null,null,"KD006",603,"Kodiak","Igneous",1151,null,null,null]
["TKg","Granular intrusive rocks","Latest Cretaceous or Early Tertiary","Granular intrusive rocks, mainly quartz diorite, with some diorite, and minor amounts of gabbro",null,null,"KD007",null,"Kodiak","Igneous",1200,null,"Q",null]
["TKg","Granular intrusive rocks","Latest Cretaceous or Early Tertiary","Granular intrusive rocks, mainly quartz diorite, with some diorite, and minor amounts of gabbro",null,null,"AF010",1002,"Afognak","Igneous",1200,null,"Q",null]
["TKg","Granular intrusive rocks","Latest Cretaceous or Early Tertiary","Granular intrusive rocks, mainly quartz diorite, with some diorite, and minor amounts of gabbro",null,null,"KR009",null,"Karluk","Igneous",1200,null,"Q",null]
["Tqd","Quartz diorite","Pliocene and (or) Miocene","Fine- to medium-grained, equigranular, quartz diorite, quartz monzodiorite, granodiorite and quartz monzonite.  Intrusive bodies are typically located along Pacific coast and include, but are not limited to, large plutons at Agripina Bay, Mount Becharof,",null,"Potassium-argon ages range from 2.3 to 3.2 Ma (Wilson and  others, 1981; F.H. Wilson and Nora Shew, unpub. data, 1990; Wilson and Shew, 1992)","KR002",362,"Karluk","Igneous",1250,null,null,null]
["Ti","Intrusive rocks","Pliocene and late Miocene","Medium- to coarse-grained, equigranular, granodiorite to quartz diorite plutons and stocks containing hornblende, biotite, and pyroxene as mafic minerals and typically are surrounded by well-developed hornfels zones and sporadic hydrothermal alteration i",null,"Potassium-argon ages range from 9.43 +/- 0.26 to 3.21 +/- 0.14 Ma (Wilson and  others, 1981; F.H. Wilson and Nora Shew, unpub. data, 1990; Wilson and Shew, 1992)","AF002",362,"Afognak","Igneous",1250,null,null,null]
["Ti","Granitic plutonic rocks","Tertiary, Eocene or younger","Small altered granitic plutons that intrude the Ghost Rocks Formation between Portage and Kaingnak Bays and north of Ugak Bay on the southeast coast of Kodiak Island.  Examination of a few thin-sections of these plutons show them to be distinctive from t",null,null,"KD005",500,"Kodiak","Igneous",1300,null,null,null]
["Tqm","Biotite quartz monzonite","Tertiary, Paleocene?","Kodiak batholith",null,null,"KD002",391,"Kodiak","Igneous",1320,null,null,null]
["Tqm","Biotite quartz monzonite","Tertiary, Paleocene?","Kodiak batholith",null,null,"KR005",391,"Karluk","Igneous",1320,null,null,null]
["Tqm","Biotite quartz monzonite","Tertiary, Paleocene?","Kodiak batholith",null,null,"TI002",391,"Trinity Islands","Igneous",1320,null,null,null]
["Tqm","Biotite quartz monzonite","Tertiary, Paleocene?","Kodiak batholith",null,"Mobil Oil dates of approximately 62 Ma cited in Byrne (1981, Ph.D.)","KG002",391,"Kaguyak","Igneous",1320,null,null,null]
["Tgd","Granodiorite","Tertiary, Paleocene","Granodiorite",null,null,"KD006",66,"Kodiak","Igneous",1320,null,null,null]
["Tg","Granitic rocks","early Tertiary","Inferred granitic rocks based on aeromagnetic evidence and unconfirmed reports.",null,null,"AF005",801,"Afognak","Igneous",1320,null,"Q",null]
["Tgh","Ghost Rocks Formation","Tertiary, Paleocene to Eocene","Consists of zeolite-bearing tuffaceous sandstone, basalt, claystone, sandstone, tuff, and graded beds (wildflysch)",null,null,"KD003",261,"Kodiak","Tectonite",1780,null,null,null]
["Tpe","Paleocene volcanic and sedimentary rocks","Tertiary, Paleocene to Eocene","Consists of zeolite-bearing tuffaceous sandstone, basalt, claystone, sandstone, tuff, and graded beds (wildflysch)",null,null,"KD002",261,"Kodiak","Tectonite",1780,null,null,null]
["Tpe","Paleocene volcanic and sedimentary rocks","Tertiary, Paleocene to Eocene","Consists of zeolite-bearing tuffaceous sandstone, basalt, claystone, sandstone, tuff, and graded beds (wildflysch)",null,null,"TI002",261,"Trinity Islands","Tectonite",1780,null,null,null]
["Tgh","Ghost Rocks Formation","Tertiary, Paleocene to Eocene","Consists of zeolite-bearing tuffaceous sandstone, basalt, claystone, sandstone, tuff, and graded beds (wildflysch)",null,null,"TI003",261,"Trinity Islands","Tectonite",1780,null,null,null]
["Tpe","Paleocene volcanic and sedimentary rocks","Tertiary, Paleocene to Eocene","Consists of zeolite-bearing tuffaceous sandstone, basalt, claystone, sandstone, tuff, and graded beds (wildflysch)",null,null,"KG002",261,"Kaguyak","Tectonite",1780,null,null,null]
["Tgm","Ghost Rocks Formation, melange","Tertiary, early Paleocene","Ghost Rocks Formation, melange",null,null,"KD006",601,"Kodiak","Tectonite",1780,null,null,null]
["Tgh","Ghost Rocks Formation","Tertiary, Paleocene to Eocene","Consists of zeolite-bearing tuffaceous sandstone, basalt, claystone, sandstone, tuff, and graded beds (wildflysch)",null,null,"KG003",261,"Kaguyak","Tectonite",1780,null,null,null]
["Kk","Kodiak Formation","Late Cretaceous","Consists of graded bed sequences an average 1-m-thick of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"KD003",417,"Kodiak","Sedimentary",1917,null,null,null]
["Kkd","Kodiak Formation","Late Cretaceous","Consists of average 1 m thick graded bed sequences of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"KD002",417,"Kodiak","Sedimentary",1917,null,null,null]
["Kk","Kodiak Formation","Late Cretaceous, Maestrichtian","Medium- to thickly bedded arkosic wacke and shale having occaisional beds of pebbly conglomerate.  Flute casts and complete Bouma sequences indicate deposition by turbidity currents below wave base.  Strike NE and dips steeply NW, generally deformed in t","Inoceramus kusiroensis",null,"KD004",492,"Kodiak","Sedimentary",1917,null,null,null]
["Kkd","Kodiak Formation","Late Cretaceous","Consists of average 1 m thick graded bed sequences of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"KR005",417,"Karluk","Sedimentary",1917,null,null,null]
["Kkd","Kodiak Formation","Late Cretaceous","Consists of average 1 m thick graded bed sequences of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"TI002",417,"Trinity Islands","Sedimentary",1917,null,null,null]
["Kk","Kodiak Formation","Late Cretaceous","Consists of graded bed sequences an average 1-m-thick of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"TI003",417,"Trinity Islands","Sedimentary",1917,null,null,null]
["Kkd","Kodiak Formation","Late Cretaceous","Consists of average 1 m thick graded bed sequences of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"KG002",417,"Kaguyak","Sedimentary",1917,null,null,null]
["Kk","Kodiak Formation","Late Cretaceous","Consists of graded bed sequences an average 1-m-thick of thick medium-grained sandstone grading to thin slate","Inoceramus of Late Cretaceous age",null,"KG003",417,"Kaguyak","Sedimentary",1917,null,null,null]
["Kk","Kodiak Formation","Late Cretaceous","Kodiak Formation",null,null,"KD006",604,"Kodiak","Sedimentary",1917,null,null,null]
["Kk","Kodiak Formation","Late Cretaceous, Maestrichtian","Medium to thickly bedded arkosic wacke and shale with occaisional beds of pebbly conglomerate.  Flute casts and complete Bouma sequences",null,null,"AF004",417,"Afognak","Sedimentary",1917,null,"Q",null]
["Ksg","Mainly Upper Cretaceous rocks","Late Cretaceous","Slate, argillite, graywacke, and conglomerate, thoroughly indurated, and generally highly metamorphosed.",null,null,"AF010",417,"Afognak","Metamorphic",1917,null,"Q",null]
["Ksg","Mainly Upper Cretaceous rocks","Late Cretaceous","Slate, argillite, graywacke, and conglomerate, thoroughly indurated, and generally highly metamorphosed.",null,null,"KD007",417,"Kodiak","Metamorphic",1917,null,"Q",null]
["Ksg","Mainly Upper Cretaceous rocks","Late Cretaceous","Slate, argillite, graywacke, and conglomerate, thoroughly indurated, and generally highly metamorphosed.",null,null,"KG007",417,"Kaguyak","Metamorphic",1917,null,"Q",null]
["Ksg","Mainly Upper Cretaceous rocks","Late Cretaceous","Slate, argillite, graywacke, and conglomerate, thoroughly indurated, and generally highly metamorphosed.",null,null,"KR009",417,"Karluk","Metamorphic",1917,null,"Q",null]
["Kk","Kaguyak Formation","Late Cretaceous; Maestrichtian and Campanian","Measured thickness is more than 1,200 m of dark-gray to pale-brown, typically thin bedded shale, siltstone, and fine grained sandstone.  Proportion of sandstone in unit increases up-section.  Load and flute casts are common; in upper part of unit, graywa","In general, fossils are sparse; however, in lower part of unit they are locally abundant.  Ammonites are most common and may range in size to as much as 1-m-across.  Fossils allow age assignment of latest Campanian and early Maestrichtian for Kaguyak.",null,"AF002",415,"Afognak","Sedimentary",1955,null,null,null]
["Kc","Cape Current terrane of Connelly (1978)","Late Cretaceous","Informal unit consisting principally of medium- to thick-bedded arkosic and lithic sandstone containing occaisional sections of vesicular pillow lava and pillow breccia.  Slightly metamorphosed and moderately deformed.  Contains two bodies of red pelagic","Coccoliths of indeterminate age and Late Cretaceous foraminifera in limestone",null,"AF004",420,"Afognak","Sedimentary",2130,null,null,null]
["Khe","Herendeen Formation","Early Cretaceous; Barremian and Hauterivian","Originally described as limestone, rocks of formation are actually an unusually uniform calc-arenaceous sandstone.  Rocks are thin bedded, medium grained, and dusky yellow to pale yellowish brown on freshly broken surfaces and weather to conspicuous ligh","Inoceramus fragments form major component of formation, although complete specimens have only been found in the Mount Katmai area.  A belemnite similar to Acroteuthis sp. A (Jones and Detterman, 1966) was found in rocks of formation just east of Staniuko",null,"AF008",441,"Afognak","Sedimentary",2150,null,null,null]
["Ku","Uyak Complex","Cretaceous","Lithologically chaotic assemblage of deep-sea rock types.  Includes: argilite and gray chert containing minor tuff; massive arkosic sandstone; pillowed and massive greenstone; bedded radiolarian chert; minor limestone; and tuffaceous argillite.",null,null,"KD004",450,"Kodiak","Tectonite",2190,null,null,null]
["Kuf","Uyak Formation","Triassic","Principally black shale and local schistose tuff.  A few shale and sandstone graded beds occur.  Middle third of Formation contains many beds of pillow basalt and red chert and the upper characterized by thick layers of light-gray chert.  Thin limestone","Triassic marine fossils in lower limestone lense",null,"KR007",457,"Karluk","Tectonite",2190,null,null,null]
["Ku","Uyak Complex","Cretaceous","Lithologically chaotic assemblage of deep-sea rock types.  Includes argillite and gray chert, massive arkosic sandstone, pillowed and massive greenstone, rhythmically bedded radiolarian chert, minor limestone, and tuffaceous argillite.",null,null,"KR006",450,"Karluk","Tectonite",2190,null,null,null]
["Ku","Uyak Complex","Cretaceous","Lithologically chaotic assemblage of deep-sea rock types.  Includes: argilite and gray chert containing minor tuff; massive arkosic sandstone; pillowed and massive greenstone; bedded radiolarian chert; minor limestone; and tuffaceous argillite.",null,null,"AF004",450,"Afognak","Tectonite",2190,null,null,null]
["sgs","Mainly Triassic and Jurassic rocks possibly some Paleozoic or older rocks","Mesozoic and Paleozoic?","A structurally complex group of rocks of great lithologic diversity.  Includes ellipsoidal lava with associated slate, thin-bedded chert and slate, calcareous slate, graywacke, and limestone, and their metamorphic equivalents, represented by greenstone s",null,null,"AF010",1001,"Afognak","Tectonite",2190,null,null,null]
["sgs","Mainly Triassic and Jurassic rocks possibly some Paleozoic or older rocks","Mesozoic and Paleozoic?","A structurally complex group of rocks of great lithologic diversity.  Includes ellipsoidal lava with associated slate, thin-bedded chert and slate, calcareous slate, graywacke, and limestone, and their metamorphic equivalents, represented by greenstone s",null,null,"KD007",null,"Kodiak","Tectonite",2190,null,null,null]
["sgs","Mainly Triassic and Jurassic rocks possibly some Paleozoic or older rocks","Mesozoic and Paleozoic?","A structurally complex group of rocks of great lithologic diversity.  Includes ellipsoidal lava with associated slate, thin-bedded chert and slate, calcareous slate, graywacke, and limestone, and their metamorphic equivalents, represented by greenstone s",null,null,"KR009",null,"Karluk","Tectonite",2190,null,null,null]
["KJm","McHugh Complex","Cretaceous","Weakly metamorphosed siltstone, graywacke, arkose and conglomeratic sandstone; greenstone (mostly basaltic), chert and argillite",null,null,"AF011",1450,"Afognak","Tectonite",2190,null,null,null]
["Kuu","Uyak Complex- Gabbroic and ultramafic rocks","Cretaceous","Lithologically chaotic assemblage of deep-sea rock types.  Gabbroic and ultramafic rock, including layered gabbro, clinopyroxenite, dunite, and plagioclase peridotite.",null,null,"KD004",470,"Kodiak","Tectonite",2197,null,null,null]
["Kuu","Uyak Complex - gabbroic and ultramafic rocks","Cretaceous","Lithologically chaotic assemblage of deep-sea rock types.  Gabbroic and ultramafic rock, including layered gabbro, clinopyroxenite, dunite, and plagioclase peridotite.",null,null,"KR006",470,"Karluk","Tectonite",2197,null,null,null]
["Kuu","Uyak Complex- Gabbroic and ultramafic rocks","Cretaceous","Lithologically chaotic assemblage of deep-sea rock types.  Gabbroic and ultramafic rock, including layered gabbro, clinopyroxenite, dunite, and plagioclase peridotite.",null,null,"AF004",470,"Afognak","Tectonite",2197,null,null,null]
["Jn","Naknek Formation","Late Jurassic; Tithonian to Oxfordian","Originally named Naknek Series by Spurr (1900, p. 169-171, 179, 181) for exposures at Naknek Lake.  Detterman and others (1996; see also, Detterman and Hartsock, 1966; Martin and Katz, 1912) have subdivided unit into five members on Alaska Peninsula.","Megafossils, particularly pelecypod Buchia (Detterman and Reed, 1980, p. B38; J.W. Miller, written communs., 1982-88), are common, and fauna, which also includes ammonites, indicate age range of Oxfordian to late Tithonian (Late Jurassic).",null,"AF008",510,"Afognak","Sedimentary",3010,null,null,null]
["Jns","Naknek Formation -- Sandstone member","Late Jurassic; late Oxfordian to Kimmeridgian","Upper part consists of up to 759 m of mainly thin-bedded fine-grained, olive-brown sandstone.  Lower part mainly massive to thick bedded medium- to coarse-grained arkosic sandstone","Buchia fossils are  in upper of unit, sparse ammonites.",null,"KR002",512,"Karluk","Sedimentary",3012,null,null,null]
["Jnn","Naknek Formation -- Northeast Creek Sandstone Member","Late Jurassic; Oxfordian","Type section consists of 624 m of fine- to coarse-grained, light-brownish-gray arkosic sandstone and minor amounts of olive-gray to dark-gray, thin-bedded siltstone in lower part of section.  Sandstone is typically thick bedded and crossbedded and contai","Fossils are uncommon in unit although carbonaceous debris is common locally.",null,"AF008",512,"Afognak","Sedimentary",3012,null,null,null]
["Jnn","Naknek Formation -- Northeast Creek Sandstone member","Late Jurassic; Oxfordian","Type section consists of 624 m of fine- to coarse-grained, light-brownish-gray arkosic sandstone and minor amounts of olive-gray to dark-gray, thin-bedded siltstone in lower part of section.  Sandstone is typically thick bedded and crossbedded and contai","Fossils are uncommon in unit although carbonaceous debris is common locally.",null,"KR004",512,"Karluk","Sedimentary",3012,null,null,null]
["Jnst","Naknek Formation -- Siltstone member","Late Jurassic; Oxfordian","Medium- to dark-olive-gray, slightly calcareous to siliceous and micaceous siltstone with nodules, concretions, and thin, lenticular limestone beds","Main fossils present are Buchia Concentrica and a few ammonites.",null,"KR002",513,"Karluk","Sedimentary",3013,null,null,null]
["Jns","Naknek Formation -- Snug Harbor Siltstone Member","Late Jurassic; Kimmeridgian and Oxfordian","Reference section consists of more than 638 m of dark-yellowish-brown and dark-gray, thin-bedded siltstone and minor amounts of thin- to medium-bedded olive-gray sandstone.  Limestone nodules are locally abundant, and limestone beds are present in some s","It is lowest abundantly fossiliferous member of Naknek; main fossils present are of genus Buchia.",null,"KR004",516,"Karluk","Sedimentary",3013,null,null,null]
["Jns","Naknek Formation -- Snug Harbor Siltstone Member","Late Jurassic; Kimmeridgian and Oxfordian","Reference section consists of more than 638 m of dark-yellowish-brown and dark-gray, thin-bedded siltstone and minor amounts of thin- to medium-bedded olive-gray sandstone.  Limestone nodules are locally abundant, and limestone beds are present in some s","It is lowest abundantly fossiliferous member of Naknek; main fossils present are of genus Buchia.",null,"AF008",513,"Afognak","Sedimentary",3013,null,null,null]
["Jni","Naknek Formation -- Indecision Creek Sandstone Member","Late Jurassic; Tithonian and Kimmeridgian","Consists of medium-gray, fine- to medium-grained arkosic sandstone and siltstone.  It is thin bedded to massive; where bedded, it is locally crossbedded.  Fresh biotite and hornblende are minor, but important, components of sandstone, as they are interpr","Indecision Creek Sandstone Member is abundantly fossiliferous; however, fossils are restricted almost exclusively to pelecypods of genus Buchia.",null,"KR004",514,"Karluk","Sedimentary",3014,null,null,null]
["Jni","Naknek Formation -- Indecision Creek Sandstone Member","Late Jurassic; Tithonian and Kimmeridgian","Consists of medium-gray, fine- to medium-grained arkosic sandstone and siltstone.  It is thin bedded to massive; where bedded, it is locally crossbedded.  Fresh biotite and hornblende are minor, but important, components of sandstone, as they are interpr","Indecision Creek Sandstone Member is abundantly fossiliferous; however, fossils are restricted almost exclusively to pelecypods of genus Buchia.",null,"AF008",514,"Afognak","Sedimentary",3014,null,null,null]
["Jnc","Naknek Formation -- Conglomerate member","Late Jurassic","Limited to northern half of Alaska Peninsula, consists of massive to thick-bedded conglomerate and interbedded, crossbedded, clean quartzose sandstone.  Clasts as large as 2 m.  Clast composition is mainly granitic rocks, and up to 20 percent metamorphic",null,null,"KR002",511,"Karluk","Sedimentary",3016,null,null,null]
["Jnc","Naknek Formation -- Chisik Conglomerate member","Late Jurassic (Oxfordian)","Limited to northern half of Alaska Peninsula, unit is composed of 614 m of massive to thick-bedded conglomerate and interbedded, crossbedded, clean quartzose sandstone.  Clasts range in size from maximum of 120 cm at bottom to 15 cm at top.  Clast compos",null,null,"KR004",511,"Karluk","Sedimentary",3016,null,null,null]
["Jss","Shelikof Formation -- Sandstone member","Middle Jurassic; Callovian","Massive to thick-bedded, medium to coarse-grained, dark-green to gray volcanogenic sandstone containing abundant magnetite grains  (Note, owing to rapid lateral facies changes, informal subdivisions of Capps (1923) have been found impractical for mapping","Megafauna are locally abundant in Shelikof, although, in general, formation is unfossiliferous.  Vast majority of fossils collected from formation are ammonites of Callovian age; however, a few specimens suggest a Bathonian(?) age for some rocks (Allaway",null,"KR002",520,"Karluk","Sedimentary",3020,null,null,null]
["Jk","Kialagvik Formation","Middle and Early Jurassic; Bajocian to Toarcian","Olive-gray to green, medium-bedded, fine- to medium-grained graywacke, mudstone, siltstone, and shale; local lenses of volcanic pebble conglomerate.","Shallow-water deposits of Kialagvik Formation are abundantly fossiliferous; most megafauna indicate age of early and middle Bajocian, although overall age range of fossils collected from unit is late Toarcian to Callovian (Imlay, 1984; see also, Detterma",null,"KR002",530,"Karluk","Sedimentary",3190,null,null,null]
["Jt","Talkeetna Formation","Early Jurassic","Lower part composed of dark-gray tuffaceous limestone, tuff, and dark siliceous shale.  Upper part thin to massive tuffaceous gray sandstone with minor siltstone and shale interbeds.","Age of unit, Early Jurassic (Hettangian and early Sinemurian), is based on abundant megafauna; however, this megafauna is present in great abundance in only a few horizons and may represent mass kills as a result of volcanic eruptions (Detterman and othe",null,"KR002",540,"Karluk","Sedimentary",3250,null,null,null]
["Js","Schist of Kodiak Island","Jurassic","Thinly layered and complexly folded quartz-mica schist, greenschist, crossite-epidote schist, and epidote amphibolite.",null,null,"AF004",572,"Afognak","Metamorphic",3610,null,null,null]
["Js","Schist of Kodiak Island","Jurassic","Thinly layered and complexly folded quartz-mica schist, greenschist, crossite-epidote schist, and epidote amphibolite.",null,null,"KR006",572,"Karluk","Metamorphic",3610,null,null,null]
["Trls","Limestone","Late Triassic; Norian","Medium- to thick-bedded dark-gray limestone and thin to shaly bedded light tan limestone; locally contains massive chert-pebble and limestone-cobble conglomerate.  Interbedded with basalt flows, volcanic rubble flows and agglomerate.","Locally abundant pelecypods and ammonites yield Norian age","A 46-m-thick columnar-jointed basalt flow or sill from upper part of section has yielded a potassium-argon age of 197? +/- 12 Ma (Wilson and Shew, 1992); however, it remains to be determined whether basalt is sill from overlying Early Jurassic Talkeetna","KR002",602,"Karluk","Sedimentary",4020,null,null,null]
["Trk","Kamishak Formation","Late Triassic; Norian","Detterman and Reed (1980) divided unit into three members, in descending order, Ursus Member, middle member, and Bruin Limestone Member.  On Alaska Peninsula (see inset A, pl. 1), Triassic limestone strata was assigned to Bruin(?) Limestone Member of Kam","Fossils that have been found yield Norian age (Detterman and Reed, 1980; C.D. Blome, U.S. Geological Survey, oral commun., 1981).","A 46-m-thick columnar-jointed basalt flow or sill from upper part of section has yielded a potassium-argon age of 197? +/- 12 Ma (Wilson and Shew, 1992); however, it remains to be determined whether basalt is sill from overlying Early Jurassic Talkeetna","KR004",601,"Karluk","Sedimentary",4020,null,null,null]
["Trss","Shuyak Formation, sedimentary member","Late Triassic","Volcaniclastic sequence consisting of thin- to medium-bedded lithic sandstone containing lesser conglomerate, argillite, and siliceous tuff intruded by mafic dikes and sills (unit Trm of Connelly, 1978).",null,null,"AF004",610,"Afognak","Sedimentary",4150,null,null,null]
["Trss","Shuyak Formation, sedimentary member","Late Triassic","Volcaniclastic sequence consisting of thin- to medium-bedded lithic sandstone containing lesser conglomerate, argillite, and siliceous tuff intruded by mafic dikes and sills (unit Trm of Connelly, 1978).",null,null,"KR006",610,"Karluk","Sedimentary",4150,null,null,null]
["Trv","Volcanic rocks","Late Triassic","Columnar-jointed basalt flows, volcanic breccia, and agglomerate.  Chemical data (Hill, 1979; Wilson and Shew, 1992) indicate these rocks are of tholeiitic affinity.  Interbedded with Late Triassic Kamishak Formation (Trk)",null,"Potassium-argon age determination on flow unit was 197 +/- 12 Ma (Wilson and Shew, 1992); age is thought to be minimum age, as it is younger than stratigraphic position suggests.","KR002",625,"Karluk","Igneous",4230,null,null,null]
["Trm","Mafic dikes, sills, and plugs","Triassic?","Diabasic bodies intruding Shuyak Formation",null,null,"AF004",651,"Afognak","Igneous",4240,null,null,null]
["Trsv","Shuyak Formation, volcanic member","Late Triassic","Vesicular pillowed greenstone, locally containing beds of pillow breccia agglomerate, tuff, and argillite.  Greenstone is tholeiitic in composition.",null,null,"AF004",640,"Afognak","Igneous",4250,null,null,null]
["Ja","Afognak Pluton","Jurassic","Hornblende diorite and hornblende quartz diorite",null,"K-Ar ages on hornblende of 192.7, and 188.4 Ma; U-Pb age of about 210 Ma","KD004",630,"Kodiak","Igneous",4310,null,null,null]
["Ja","Afognak Pluton","Jurassic","Hornblende diorite and hornblende quartz diorite",null,"K-Ar ages on hornblende of 192.7, and 188.4 Ma; U-Pb age of about 210 Ma","KR006",630,"Karluk","Igneous",4310,null,null,null]
["Ja","Afognak Pluton","Jurassic","Hornblende diorite and hornblende quartz diorite",null,"K-Ar ages on hornblende of 192.7, and 188.4 Ma; U-Pb age of about 210 Ma","AF004",630,"Afognak","Igneous",4310,null,null,null]
["Pls","Limestone","middle Permian","Consists of 40 m of massive, light-gray, crystalline limestone containing thin interbeds of chert, located on a small islet (100 by 200 m) at entrance to Puale Bay.  No contacts are exposed, although highly contorted beds dip about 40ø northwest, which p","Hanson (1957) reported age of late middle Permian (early Guadalupian) for these rocks on the basis of poorly preserved and silicified coral, brachiopod, and foraminifer fossils.",null,"KR002",701,"Karluk","Sedimentary",5730,null,null,null]
["Pls","Limestone","Permian; early Guadalupian","Consists of 40 m of thin- to thick-bedded, medium-grained, crystalline tan to gray limestone containing thin interbeds of chert, located on a small islet (100 by 200 m) at entrance to Puale Bay.  No contacts are exposed, although highly contorted beds di","Hanson (1957) reported age of late mid-Permian (early Guadalupian) for these rocks on the basis of poorly preserved and silicified coral, brachiopod, and foraminifer fossils.",null,"KR004",701,"Karluk","Sedimentary",5730,null,null,null]
["Pv","Volcanic rocks","Permian?","Massive, dark-green to black volcanic breccia, agglomerate, and andesitic flows (Hanson, 1957; Hill, 1979).  These rocks are only exposed on offshore islets east of Puale Bay and were not examined during this study (see inset A, pl. 1).  Well-developed j",null,null,"KR004",750,"Karluk","Igneous",5810,null,null,null]