Digital data for the geology of the Prince William Sound and Kenai Peninsula region, Alaska

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Frequently-anticipated questions:

What does this data set describe?
    Title:
    Digital data for the geology of the Prince William Sound and Kenai Peninsula region, Alaska
    Abstract:
    The Prince William Sound and Kenai Peninsula region includes a significant part of one of the world's largest accretionary complexes and a small part of the classic magmatic arc geology of the Alaska Peninsula. Physiographically, the map area ranges from the high glaciated mountains of the Alaska-Aleutian Range and the Chugach Mountains to the coastal lowlands of Cook Inlet and the Copper River delta. Structurally, the map area is cut by a number of major faults and postulated faults. Most important of these are the Border Ranges, Contact, and Bruin Bay fault systems.

    This map has been compiled from existing mapping, without generalizations, and new or revised data has been added where available.

    This data set is a portion of a statewide geology database, which is being compiled by the U.S. Geological Survey's National Surveys and Analysis (NSA) project, whose goal is to compile geologic, geochemical, geophysical, and other data.

  1. How should this data set be cited?

    Wilson, Frederic H., Hults, Chad P., Shew, Nora, and Labay, Keith A., 2008, Digital data for the geology of the Prince William Sound and Kenai Peninsula region, Alaska: U.S. Geological Survey Open-File Report OFR 2008-1002.

    Online Links:

    This is part of the following larger work.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -153.0
    East_Bounding_Coordinate: -144.0
    North_Bounding_Coordinate: 61.0
    South_Bounding_Coordinate: 59.0

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 2008
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set.

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 5
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -153.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000
      False_Northing: 0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.000256
      Ordinates (y-coordinates) are specified to the nearest 0.000256
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.9787.

  7. How does the data set describe geographic features?

    polygons
    Characteristics of the polygon features in the geology coverages are coded in the polygon attribute table. The table <cov>.pat includes the following items: CLASS, QCLASS (not used), LITH2 (not used), SOURCE, NSACLASS, NSAMOD, LABEL, MIN_AGE, and MAX_AGE. (Source: this data set)

    NSACLASS
    NSACLASS is a positive integer value (4 5 B) item in the polygon attribute table. Values range discontinuously from 100 to 5220. NSACLASS is a numeric code for the geologic unit. This data set represents a generalized map, thus it is possible that a geologic unit is made of multiple NSACLASS values. Each NSACLASS matches with geologic unit labels in LABEL and has a minimum (MIN_AGE) and maximum (MAX_AGE) range, given in million of years (my). Supplemental attribute tables included with this data set contain additional descriptive information of each geologic unit. A user may use items SOURCE and CLASS to retrieve information about the original units from which these generalized units were formed. NOTE: Because of the limitations of common GIS fonts, the letters "Tr" and "Mz" are substituted for the standard symbols for "Triassic" and "Mesozoic". (Source: this data set)

    ValueDefinition
    100Qs - Unconsolidated surficial deposits, undivided (Quaternary)
    101ice
    102water
    103Qtf - Modern tidal flat and estuarine deposits (Quaternary, Holocene)
    105Qat - Alluvial and terrace deposits (Quaternary)
    106Qat - Alluvial and terrace deposits (Quaternary)
    107Qls - Landslide and colluvial deposits (Quaternary)
    108Qls - Landslide and colluvial deposits (Quaternary)
    109Qat - Alluvial and terrace deposits (Quaternary)
    110Qat - Alluvial and terrace deposits (Quaternary)
    111Qat - Alluvial and terrace deposits (Quaternary)
    112Qsl - Lacustrine, swamp, and fine silt deposits (Quaternary)
    113Qsl - Lacustrine, swamp, and fine silt deposits (Quaternary)
    114Qat - Alluvial and terrace deposits (Quaternary)
    115Qb - Beach deposits (Quaternary)
    116Qes - Estuarine deposits (Quaternary)
    117Qes - Estuarine deposits (Quaternary)
    119Qd - Eolian deposits (Quaternary)
    120Qd - Eolian deposits (Quaternary)
    123Qgl - Glaciolacustrine deposits (Quaternary)
    124Qgl - Glaciolacustrine deposits (Quaternary)
    125Qm - Glacial deposits (Quaternary)
    126Qm - Glacial deposits (Quaternary)
    127Qm - Glacial deposits (Quaternary)
    128Qls - Landslide and colluvial deposits (Quaternary)
    130Qag - Drift of Neoglacial age (Holocene)
    131Qao - Outwash of the Neoglacial age (Holocene)
    135Qgn - Glacial deposits of the Naptowne and Brooks Lake Glaciations (Pleistocene)
    136Qgn - Glacial deposits of the Naptowne and Brooks Lake Glaciations (Pleistocene)
    137Qgn - Glacial deposits of the Naptowne and Brooks Lake Glaciations (Pleistocene)
    138Qgn - Glacial deposits of the Naptowne and Brooks Lake Glaciations (Pleistocene)
    139Qgn - Glacial deposits of the Naptowne and Brooks Lake Glaciations (Pleistocene)
    140Qgno - Outwash and valley train deposits (Pleistocene)
    170Qdl - Deltaic deposits (Quaternary)
    190Qog - Older glacial deposits (Pleistocene)
    194Qog - Older glacial deposits (Pleistocene)
    195Qogo - Outwash associated with older glacial deposits (Pleistocene)
    200Qch - Moraine of the Caribou Hills Glaciation (Pleistocene)
    201Qch - Moraine of the Caribou Hills Glaciation (Pleistocene)
    295Qs - Unconsolidated surficial deposits, undivided (Quaternary)
    300Qv - Volcanic rocks, undivided (Quaternary)
    305Qv - Volcanic rocks, undivided (Quaternary)
    311Qv - Volcanic rocks, undivided (Quaternary)
    312Qdf - Debris-flow deposits (Holocene)
    313Qdf - Debris-flow deposits (Holocene)
    314Qdf - Debris-flow deposits (Holocene)
    402Qad - Andesite and dacite domes (Pleistocene)
    540Ts - Kenai Group, Sterling Formation (Pliocene and Miocene)
    545Tb - Kenai Group, Beluga Formation (Miocene)
    560Tkn - Kenai Group (Tertiary, Pliocene to Oligocene)
    565QTy - Yakataga Formation (Quaternary, Pleistocene to Tertiary, Miocene)
    600Tty - Kenai Group, Tyonek Formation (Miocene and Oligocene)
    630Th - Kenai Group, Hemlock Conglomerate, undivided (Oligocene)
    675Tr - Redwood Formation (Tertiary, Pliocene to Oligocene?)
    680Tps - Poul Creek Formation, Sedimentary rocks (Tertiary, early Miocene to late Eocene)
    810Tt - Tokun Formation (Tertiary, Eocene)
    820Tsw - Stillwater Formation (Tertiary, Eocene)
    855Twf - West Foreland Formation (Tertiary, Eocene and Paleocene)
    860Tkt - Kulthieth Formation (Tertiary, Eocene)
    950Tos - Orca Group, Sedimentary rocks, undivided (Tertiary, early middle Eocene to late Paleocene)
    951Tovs - Volcanic and sedimentary rocks (Tertiary, Eocene)
    952Toc - Orca Group, Conglomerate (Tertiary, early middle Eocene to late Paleocene)
    1000Tvu - Lava flows (middle? to late? Tertiary)
    1053Tdc - Dacite of Cape Saint Elias (Tertiary, Pliocene or Miocene)
    1080Tpv - Poul Creek Formation, Volcanic rocks (Tertiary, early Miocene to late Eocene)
    1090Tm - Mafic plugs (Tertiary, Oligocene?)
    1135Tov - Volcanic rocks, undivided (Tertiary, Eocene)
    1136Top - Pillow basalt (Tertiary, Eocene)
    1137Tod - Sheeted basalt dikes (Tertiary, Eocene)
    1270Tg - Granitic rocks (Tertiary, Oligocene? and latest Eocene)
    1273Tg - Granitic rocks (Tertiary, Oligocene? and latest Eocene)
    1294Tgd - Gabbro and diorite (Tertiary, Oligocene and older)
    1300Tgg - Granite and granodiorite (Tertiary, Eocene)
    1301TKd - Dikes (early Tertiary to Early Cretaceous)
    1320Tgh - Granitic rocks of Harding Icefield region (Tertiary, Eocene and Paleocene)
    1374Togb - Gabbro (Tertiary, Eocene)
    1375Tou - Ultramafic rocks (Tertiary, Eocene)
    1380Tmu - Mafic and ultramafic plutonic rocks (Tertiary, Eocene and Paleocene?)
    1660TKgd - Granodiorite (Tertiary and (or) Cretaceous)
    1961Ksm - Saddle Mountain section of Magoon and others (1980) (Upper Cretaceous, Maastrichtian)
    2190KMm - McHugh Complex (Cretaceous to Mississippian)
    2198KJms - McHugh Complex, graywacke and conglomerate (Early Cretaceous to Early Jurassic, Pliensbachian)
    2199KTrmc - McHugh Complex, basalt and chert (Early Cretaceous, Albian to Middle Triassic, Ladinian)
    2430Kqd - Quartz diorite (Cretaceous)
    2700Kvs - Valdez Group, Metasedimentary rocks, undivided (Upper Cretaceous)
    2702Kvvs - Valdez Group, Interbedded metavolcanic and metasedimentary rocks (Upper Cretaceous)
    2705Kvv - Valdez Group, Metavolcanic rocks, undivided (Upper Cretaceous)
    2706Kvt - Valdez Group, Aquagene tuff (Upper Cretaceous)
    2708Kvm - Valdez Group, Melange of Iceworm Peak of Kusky and others (1997) (Upper Cretaceous)
    2710Kvgs - Valdez Group, Schist (Upper Cretaceous)
    2715Kvgg - Valdez Group, Gneiss (Upper Cretaceous)
    2900KJg - Quartz monzodiorite (Cretaceous and (or) Jurassic)
    3012Jnn - Naknek Formation, Northeast Creek Sandstone Member (Upper Jurassic, Oxfordian)
    3013Jnst - Naknek Formation, Snug Harbor Siltstone Member (Upper Jurassic, Kimmeridgian and Oxfordian)
    3014Jnp - Naknek Formation, Pomeroy Arkose Member (Upper Jurassic, Kimmeridgian and Oxfordian?)
    3016Jnc - Naknek Formation, Chisik Conglomerate Member (Upper Jurassic)
    3020Jcp - Chinitna Formation, Paveloff Siltstone Member (Middle Jurassic, Callovian)
    3030Jct - Chinitna Formation, Tonnie Siltstone Member (Middle Jurassic, Callovian)
    3181Jtb - Tuxedni Group, Bowser Formation (Middle Jurassic, Callovian and Bathonian)
    3182Jtt - Tuxedni Group, Twist Creek Siltstone (Middle Jurassic, Bajocian)
    3183Jtc - Tuxedni Group, Cynthia Falls Sandstone (Middle Jurassic, Bajocian?)
    3184Jtf - Tuxedni Group, Fitz Creek Siltstone (Middle Jurassic, middle Bajocian)
    3185Jtg - Tuxedni Group, Gaikema Sandstone (Middle Jurassic, lower middle Bajocian)
    3186Jtrg - Tuxedi Group, Red Glacier Formation (Middle Jurassic, lower Bajocian to lower middle Bajocian)
    3250Jtk - Talkeetna Formation, undivided (Lower Jurassic)
    3251Jtkh - Talkeetna Formation, Horn Mountain Tuff Member (Lower Jurassic)
    3252Jtkp - Talkeetna Formation, Portage Creek Agglomerate Member (Lower Jurassic)
    3253Jtkm - Talkeetna Formation, Marsh Creek Breccia Member (Lower Jurassic)
    3265Jp - Pogibshi formation of Kelley (1980), undivided (Lower Jurassic, Sinemurian to Hettangian and older?)
    3380Jtr - Alaska-Aleutian Range batholith, Trondhjemite (Late Jurassic)
    3402Jg - Alaska-Aleutian Range batholith, Quartz diorite, tonalite, and diorite (Jurassic)
    3403Jg - Alaska-Aleutian Range batholith, Quartz diorite, tonalite, and diorite (Jurassic)
    3404Jg - Alaska-Aleutian Range batholith, Quartz diorite, tonalite, and diorite (Jurassic)
    3420Jg - Alaska-Aleutian Range batholith, Quartz diorite, tonalite, and diorite (Jurassic)
    3610Jsch - Seldovia metamorphic complex (Early Jurassic)
    4019Trpg - Port Graham formation of Kelley (1980) (Upper Triassic, Norian)
    4310Trdt - Quartz diorite and tonalite (Late Triassic)
    4880Mzg - Gabbro (Mesozoic)
    4890Mzu - Ultramafic plutonic rocks (Mesozoic)
    5220JPk - Kakhonak Complex (Jurassic, Triassic, and Permian(?) or older(?))

    NSAMOD
    NSAMOD is a character (8 10 C) item in the polygon attribute table. (Source: this data set)

    HFS - contact metamorphism, hornfels Q - queried unit

    SOURCE
    SOURCE is a character (6 8 C) item found in both the polygon and arc attribute tables. The values are abbreviated codes representing the original source reference for the polygon or arc feature. The format for SOURCE is XX###, where XX is a two letter code for the 1:250,000 scale quadrangle and ### is a three digit number (with leading zeros). All source codes with '001' are unspecified sources for water and ice features, often paper topographic maps, and DRG or DLG files. (Source: this data set)

    ValueDefinition
    BS002Nelson, S.W., Dumoulin, J.A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645B, scale 1:250,000.
    BS004Tysdal, R.G., and Case, J.E., 1979, Geologic map of the Seward and Blying Sound quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-1150, scale 1:250,000.
    BS005Bradley, D.C., and Miller, M.L., 2006, Field guide to south-central Alaska's accretionary complex Anchorage to Seward: Alaska Geological Society, 32 p.
    CV002Nelson, S.W., Dumoulin, J.A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645B, scale 1:250,000.
    CV003Winkler, G.R., and Plafker, George, 1993, Geologic map of the Cordova and Middleton Island quadrangles, southern Alaska: U.S. Geological Survey Miscellaneous Investigations Map I-1984, scale 1:250,000.
    CV004Richter, D.H., Preller, C.C., Labay, K.A., and Shew, N.B., 2005, Geology of Wrangell-Saint Elias National Park and Preserve, southcentral Alaska: U.S. Geological Survey Scientific Investigations Series Map SIM-2877, scale 1:350,000.
    CV005Pavlis, T.L., and Sisson, V.B., 2002, Geologic map of the Bremner River area, written communication.
    CV006Pavlis, T.L., and Sisson, V.B., 2002, Geologic map of the Van Cleve Glacier area, written communication.
    CV007Wilson, F.H., and Hults, C.P., 2007, edits.
    KN002Magoon, L.B., Adkison, W.L., and Egbert, R.M., 1976, Map showing geology, wildcat wells, Tertiary plant localities, K-Ar age dates, and petroleum operations, Cook Inlet area, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-1019, scale 1:250,000, 3 sheets.
    KN003Bradley, D.C., and Wilson, F.H., 2000, Reconnaissance bedrock geology of the southeastern part of the Kenai quadrangle, Alaska, in Kelley, K.D., and Gough, L.P., eds., Geologic Studies in Alaska: U.S. Geological Survey Professional Paper 1615, p. 59-64.
    KN005Detterman, R.L., and Hartsock, J.K., 1966, Geology of the Iniskin-Tuxedni region, Alaska: U.S. Geological Survey Professional Paper 512, 78 p., 6 plates, map, scale 1:63,360.
    KN006Riehle, J.R., and Emmel, K.S., 1980, Photointerpretation map of the surficial geology, Polly Creek to MacArthur River, Cook Inlet, Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 64, 2 sheets, scale 1:63,360.
    KN008Wilson, F.H., Blodgett, R.B., Blome, C.D., Mohadjer, Solmaz, Preller, C.C., Klimasauskas, E.P., Gamble, B.M., and Coonrad, W.L., in prep, Reconnaissance bedrock geologic map for the northern Alaska Peninsula area, southwestern Alaska; including the Dillingham, Iliamna, Lake Clark, Taylor Mountains, and the western part of the Kenai and Seldovia 1:250,000 scale quadrangles: U.S. Geological Survey Scientific Investigations Map SIM-2942, pamphlet 111 ms. p., 2 sheets, scale 1:350,000.
    KN009Reed, B.L., Lanphere, M.A., and Miller, T.P., 1992, Double Glacier volcano, a 'new' Quaternary volcano in the eastern Aleutian volcanic arc: Bulletin of Volcanology, v. 54, p. 631-637.
    KN011Waythomas, C.F., and Miller, T.P., 1999, Preliminary volcano-hazard assessment for Illiamna volcano: U.S. Geological Survey Open-File Report 99-373, 31 p.. 1 plate.
    KN012Reed, B.L., Miesch, A.T., and Lanphere, M.A., 1983, Plutonic rocks of Jurassic age in the Alaska-Aleutian Range batholith: Chemical variations and polarity: Geological Society of America Bulletin: v. 94, p. 1232-1240.
    KN013Karlstrom, T.N.V., 1964, Quaternary geology of the Kenai Lowland and glacial history of the Cook Inlet region, Alaska: U.S. Geological Survey Professional Paper 443, 69 p., 7 plates, various scales.
    KN015Wilson, F.H., and Hults, C.P., 2007, Edits to resolve matching with Seldovia, Seward, and Blying Sound quadrangle maps
    MI003Winkler, G.R., and Plafker, George, 1993, Geologic map of the Cordova and Middleton Island quadrangles, southern Alaska: U.S. Geological Survey Miscellaneous Investigations Map I-1984, scale 1:250,000.
    SR002Nelson, S.W., Dumoulin, J.A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645B, scale 1:250,000.
    SR004Tysdal, R.G., and Case, J.E., 1979, Geologic map of the Seward and Blying Sound quadrangles, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-1150, scale 1:250,000.
    SR005Nelson, S.W., Miller, M.L., Haeussler, P.J., Snee, L.W., Phillips, P.J., Huber, Carol, 1999, Preliminary geologic map of the Chugach National Forest Special Study Area, Alaska: U.S. Geological Survey Open-File Report 99-362, scale 1:63,360.
    SR006Wilson, F.H., and Hults, C.P., 2007, edits
    SR007Bradley, D.C., and Miller, M.L., 2006, Field guide to south-central Alaska's accretionary complex Anchorage to Seward: Alaska Geological Society, 32. p.
    SR008Bol, A.J., and Gibbons, Helen, 1992, Tectonic implications of out-of-sequence faults in the accretionary prism, Prince William Sound, Alaska: Tectonics, v. 11, n.6, p. 1288-1300.
    SV002Bradley, D.C., Kusky, T.M., Haeussler, P.J., Karl, S.M., and Donley, D.T., 1999, Geology of the Seldovia quadrangle: U.S. Geological Survey Open-File Report 99-18, scale 1:250,000.
    SV004Detterman, R.L., and Hartsock, J.K., 1966, Geology of the Iniskin-Tuxedni region, Alaska: U.S. Geological Survey Professional Paper 512, 78 p., 6 plates, map, scale 1:63,360.
    SV007Karlstrom, T.N.V., 1964, Quaternary geology of the Kenai Lowland and glacial history of the Cook Inlet region, Alaska: U.S. Geological Survey Professional Paper 443, 69 p., 7 plates, various scales.
    SV008Bradley, D.C., oral communication, June 7, 2007.
    SV009Wilson, F.H., and Hults, C.P., 2007, Edits to resolve matching with Kenai and Blying Sound quadrangle maps.
    SV010Magoon. L.B., Adkison, W.L., and Egbert, R.M., 1976, Map showing geology, wildcat wells, Tertiary plant localities, K-Ar age dates, and petroleum operations, Cook Inlet area, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-1019, scale 1:250,000, 3 sheets.

    arcs
    Characteristics of the arc features in the geology, lineation, dike, and fold coverages are coded in the arc attribute table. Table <cov>.aat includes the following items: ARC-CODE, ARC-PARA1, ARC-PARA2 (not used), and SOURCE. For explanation of SOURCE, see attribute definitions for polygons. (Source: this data set)

    ARC-CODE
    ARC-CODE is a positive integer value (3 3 I) item in the arc attribute table. Values range discontinuously from 0 to 99. Values match one-for-one with geologic features (such as stratigraphic contact, fault, etc.) Some ARC-CODE values have additional modifiers in item ARC-PARA1. (Source: this data set)

    ValueDefinition
    1Stratigraphic or intrusive contact, location certain
    2Stratigraphic or intrusive contact, location approximate
    3Stratigraphic or intrusive contact, location inferred, queried
    4Normal fault, location certain; if ARC-PARA1 = 1, then upthrown side is on right from origin
    5Normal fault, location approximate, if ARC-PARA1 = 1, then upthrown side is on right from origin
    6Normal fault, location inferred or queried, if ARC-PARA1 = 1, then upthrown side is on right from origin
    7Shoreline or riverbank
    8Internal contact or phase change; no symbol drawn
    10Thrust fault, location certain; teeth on right from origin
    11Thrust fault, location approximate, teeth on right from origin
    15Ice contact
    19Moraine limit; tics on right from origin; ARC-PARA1 used to designate Naptowne glaciations on Kenai Peninsula
    21Syncline, location certain, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    22Syncline, location approximate, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    24Anticline, location certain, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    25Anticline, location approximate, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    24Anticline, location certain, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip.
    30Fault, sense of displacement uncertain; location certain
    31Fault, sense of displacement uncertain; location approximate
    32Fault, sense of displacement uncertain; location inferred
    41Syncline, overturned, location certain, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    44Anticline, overturned, location certain, digitized in direction of plunge; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    50Dikes and sills
    51Concealed contact
    52Concealed normal fault; if ARC-PARA1 = 1, then upthrown side is on right from origin
    53Concealed thrust fault
    57Concealed right lateral fault
    60Concealed fault, sense of displacement uncertain
    69Fissure
    81Syncline, inverted, location certain; ARC-PARA1 equals angle of plunge, 0 is no plunge, 1 is plunge of unknown dip
    87Right lateral fault, location certain
    88Right lateral fault, location approximate
    91Left lateral fault, location approximate
    93Lineament
    99Bounding line of coverage

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    This data set was prepared by Frederic H. Wilson (USGS), Chad Hults (USGS), Keith Labay (USGS), D. Thomas Donley (USGS), Lana Cohen (contractor), Karen Preston (USFS), Michelle Victor (contractor), and Nora Shew (USGS).

  3. To whom should users address questions about the data?

    U.S. Geological Survey
    c/o Frederic H. Wilson
    Geologist
    4200 University Drive
    Anchorage, Alaska 99508-4667
    U.S.A.

    907-786-7448 (voice)
    fwilson@usgs.gov

Why was the data set created?
This data set represents part of a systematic effort to release geologic map data for the United States in a uniform manner. Geologic data in this series has been compiled from a wide variety of sources, published and unpublished, ranging from state and regional geologic maps to large- scale field mapping.

How was the data set created?
  1. Where did the data come from?

  2. What changes have been made?

    Date: 2008 (change 1 of 1)
    Line work for the geology compilation was hand digitized from material of various media and scale. The arcs and polygons were attributed. The spatial databases are provided in UTM projection and geographic coordinates. The native ARC/Info coverages have been exported to an interchange file format, and also converted to shape files.

    Person responsible for change:

    U.S. Geological Survey
    c/o Frederic H. Wilson
    Geologist
    4200 University Drive
    Anchorage, Alaska 99508-4667
    U.S.A.

    907-786-7448 (voice)
    fwilson@usgs.gov

How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?

    There were many types of source materials, of varying scale, used to compile this data set. Sources include previously published maps, unpublished mapping, and air photo interpretation. The dates of the mapping range from the present to 1960's. Vector features were mostly digitized on a large digitizing tablet. Vector and polygon attributes were assigned based on the original source. The digital data has been checked, and the geologic map has been technically reviewed and edited.

  2. How accurate are the geographic locations?

    This data is presented for use at a nominal scale of 1:350,000, although some sources were from 1:250,000 scale mapping.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    The complete data set consists of 15 different GIS coverages, six geology coverages, three lineation coverages, five fold coverage, and a dike coverage. There is also an associated relational database of geologic units. Each coverage has the extent of a 1:250,000 scale quadrangle. A graphic representation of the database and a report with complete geologic unit descriptions is provided in .pdf format.

  5. How consistent are the relationships among the observations, including topology?

    Each geology coverage is a network coverage containing attributed arcs and polygons. Each polygon has a coded attribute designating the mapped geologic unit. Faults, stratigraphic contacts, and other linear features are represented as arcs. When a fault is also a stratigraphic contact, only a single arc is present. Dangling arcs may be present (faults, dike, etc.)

How can someone get a copy of the data set?
Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:
None. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data.

  1. Who distributes the data set? (Distributor 1 of 1)

    U.S. Geological Survey
    MS902 Box 25286 Denver Federal Center
    Lakewood, CO 80225
    U.S.A.

    1-888-ASK-USGS (voice)

  2. What's the catalog number I need to order this data set?

    Open-File Report 2008-1002

  3. What legal disclaimers am I supposed to read?

    This world-wide web publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.

  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 24-Jan-2008

Metadata author:
U.S. Geological Survey
c/o Nora Shew
4200 University Drive
Anchorage, AK 99508-4667
U.S.A.

907-786-7445 (voice)
nshew@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.4.30 on Thu Jan 24 11:13:36 2008