Bedrock geologic map of the northern Alaska Peninsula area, southwest Alaska

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
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  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Wilson, Frederic H., Blodgett, Robert B., Blome, Charles D., Mohadjer, Solmaz, Preller, Cindi C., Klimasauskas, Edward P., Gamble, Bruce M., and Coonrad, Warren L., 2017, Bedrock geologic map of the northern Alaska Peninsula area, southwest Alaska: U.S. Geological Survey Scientific Investigations Map SIM 2942.

   Online Links:

   • https://doi.org/10.3133/sim2942

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -159.0
   East_Bounding_Coordinate: -151.333
   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: 2017Currentness_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. It contains the following vector data types (SDTS terminology):
      • G-polygon (26347)
   2. What coordinate system is used to represent geographic features?
      The map projection used is NAD 1983 Alaska Albers (ESRI Full Name: NAD_1983_Alaska_Albers).
      

      Projection parameters:

      Standard_Parallel: 55.0
      Standard_Parallel: 65.0
      Longitude_of_Central_Meridian: -154.0
      Latitude_of_Projection_Origin: 50.0
      False_Easting: 0.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      
7. How does the data set describe geographic features?

   NAPgeol_poly

   Characteristics of the geologic unit are coded in the polygon attribute table. The table includes the following items: CLASS, QCLASS, SOURCE, NSACLASS, NSASUB, NSAMOD, SOURCECLASS, SYMBOL, LABEL, LABEL2, UNITNAME, and AGE_RANGE. (Source: This data set)

   CLASS

   Unique numeric code assigned to a geologic unit from an original source map. Number is unique only within a given quadrangle and specific to SOURCE. (Source: this data set)

   Formal codeset
   Codeset Name:	napunits (provided as geodatabase table, Filemaker database, CSV, and DBF files) This table excludes class values for bedrock unknown (class = 99), glaciers (class = 101), and water (class = 102).
   Codeset Source:	this data set

   QCLASS

   Subdivision of attribute NSACLASS providing more detailed Quaternary classification. Field QCLASS is a key field for linking to field QCLASS in table napqkey. (Source: this data set)

   Formal codeset
   Codeset Name:	napunits (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   SOURCE

   Unique code assigned to each source; uses the 2-letter quadrangle code and a three digit number. By default, 001 is reserved for the topographic map or other source of hydrologic spatial data for each quadrangle. Field SOURCE is a key field and links to SOURCE in table naprefs. (Source: this data set)

   Formal codeset
   Codeset Name:	naprefs (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   NSACLASS

   Regional numeric code assigned to similar geologic units. Field NSACLASS is a key field and links to field NSACLASS in tables nsaage, nsakey, nsalith, naprefs, and napdescrip. NSACLASS is also a 1:many relationship with NSACLASS in table napunits. (Source: this data set)

   Formal codeset
   Codeset Name:	nsakey (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   NSASUB

   Same coding as NSACLASS, but used to define the bedrock unit beneath surficial deposits. Not universally populated. (Source: this data set)

   Formal codeset
   Codeset Name:	nsakey (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   NSAMOD

   Indicates if a geologic unit is altered, contact metamorphosed, or has a queried unit assignment. Some maps show contact metamorphosed areas as separate units; these units are assigned a NSACLASS for the appropriate protolith and have 'HFS' selected as NSAMOD value. If only a few polygons of a geologic unit are altered or contact metamorphosed, then the NSAMOD value is set for those polygons only. When NSAMOD has the value 'Q'or 'HFS, Q' the geologic unit is 'queried' and the symbol '?' is appended to the value in LABEL and LABEL2. (Source: this data set)

   Value	Definition
   {Null Value / Empty Field Entry}	Unit is not altered, contact metamorphosed, or queried.
   ALT	Hydrothermally altered, nonspecific
   ALT-SER	Sericitic alteration
   HFS	Contact metamorphism, nonspecific
   HFS, Q	Contact metamorphism, nonspecific, and queried
   Q	Queried (?) geologic unit

   SOURCECLASS

   Concatenated field that uniquely identifies a given source map (SOURCE) and geologic unit (CLASS). Field SOURCECLASS is a key field that links to field SOURCE_CLASS in table napunits. (Source: this data set)

   Formal codeset
   Codeset Name:	napunits (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   SYMBOL

   Number defining symbol color in WPGCMYKG.style for ArcGIS to use when displaying the polygons. (Source: this data set)

   Range of values
   Minimum:	0
   Maximum:	992

   LABEL

   Same as LABEL2 but uses special characters in FGDCGeoAge font to display the symbols for geologic time periods. (Source: this data set) } represents Mesozoic; ^ Triassic; | Paleozoic; * Pennsylvanian; _ Cambrian; = preCambrian; and < Proterozoic. LABEL correlates with Attribute_Label LABEL2.

   LABEL2

   Geologic unit label used in the Description of Map Units. Label is in standard text font and does not use special characters. Px is used for Proterozoic and IP for Pennsylvanian. (Source: this data set)

   Value	Definition
   Qs	Surficial deposits, undivided (Quaternary)
   bu	Bedrock unknown (Unknown)
   Kk	Kuskokwim Group, undivided (Cretaceous, Campanian(?) to Albian(?))
   Kkn	Kuskokwim Group, nearshore facies (Cretaceous)
   Kkv	Kuskokwim Group(?), volcanogenic rocks (Cretaceous(?))
   KJvs	Volcanic and sedimentary rocks (Lower Cretaceous to Middle Jurassic)
   KJv	Olivine basalt and fragmental volcanic rocks (Cretaceous or Jurassic)
   Jkw	Graywacke of Kulukak Bay (Middle to Upper Jurassic)
   Mzm	Melange (Mesozoic(?))
   KTrag	Argillite and graywacke (Lower Cretaceous to Upper Triassic)
   KTragi	Argillite and graywacke, cut by dike swarms (Lower Cretaceous to Upper Triassic)
   Jms	Sedimentary rocks (Lower Jurassic)
   JTrp	Phyllite and chert (Lower Jurassic and Upper Triassic(?))
   Trcg	Chert and limestone (Upper Triassic)
   Trv	Volcanic rocks (Upper Triassic)
   TrPzrc	Rainbow chert (Triassic(?) to Paleozoic(?))
   Pv	Volcanic rocks (Permian(?))
   Pls	Limestone (Permian)
   Pcs	Clastic rocks (Permian(?))
   MDv	Greenstone and schist (Mississippian(?) and (or) Devonian(?))
   Pzc	Black chert (lower Paleozoic(?))
   Jssc	Chert, sandstone, and siltstone (Lower Jurassic)
   Trlc	Limestone, silty limestone, and chert (Upper Triassic, Norian)
   DZn	Farewell terrane, Nixon Fork subterrane of Decker and others (1994), undivided (Devonian(?) to Proterozoic)
   Sab	Algal boundstone (Upper Silurian, Pridoki and Ludlow)
   Sls	Lime mudstone (Upper Silurian, Wenlock to late Llandover)
   Olss	Tcherskidium-bearing limestone (Upper Ordovician, Ashgillian)
   Os	Shale (Ordovician)
   Oab	Algal boundstone and lime mudstone (Lower Ordovician)
   Ols	Lime mudstone (Lower Ordovician)
   Cls	Limestone (Middle Cambrian)
   Cs	Clastic and carbonate rocks (Lower Cambrian)
   Zs	Dolostone, limestone, orthoquartzite, and minor chert (Neoproterozoic(?))
   Ts	Sedimentary rocks (Tertiary, Pliocene or Miocene)
   Ttyh	Kenai Group, Tyonek Formation and Hemlock Conglomerate undivided (Tertiary, Miocene and Oligocene)
   Twf	West Foreland Formation (Tertiary, early Eocene and late Paleocene)
   Tcl	Copper Lake Formation, undivided (Tertiary, Eocene and Paleocene(?))
   Ksm	Saddle Mountain section of Magoon and others (1980) (Upper Cretaceous, Maastrichtian)
   Kkg	Kaguyak Formation (Upper Cretaceous, Maastrichtian and Campanian)
   KJkr	Koksetna River sequence of Wallace and others (1989) (Lower Cretaceous, Valanginian to Upper Jurassic, Kimmeridgian)
   Jn	Naknek Formation (Upper Jurassic, Tithonian to Oxfordian)
   Jnp	Pomeroy Arkose Member (Upper Jurassic, Kimmeridgian and Oxfordian(?))
   Jni	Indecision Creek Sandstone Member (Upper Jurassic, Kimmeridgian and Oxfordian(?))
   Jnst	Snug Harbor Siltstone Member (Upper Jurassic, Kimmeridgian and Oxfordian)
   Jnn	Northeast Creek Sandstone Member (Upper Jurassic, Oxfordian)
   Jnc	Chisik Conglomerate Member (Upper Jurassic)
   Jcp	Chinitna Formation, Paveloff Siltstone Member (Middle Jurassic, Callovian)
   Jct	Chinitna Formation, Tonnie Siltstone Member (Middle Jurassic, Callovian)
   Jtb	Tuxedni Group, Bowser Formation (Middle Jurassic, Callovian and Bathonian)
   Jtt	Tuxedni Group, Twist Creek Siltstone (Middle Jurassic, Bajocian)
   Jtc	Tuxedni Group, Cynthia Falls Sandstone (Middle Jurassic, Bajocian(?))
   Jtf	Tuxedni Group, Fitz Creek Siltstone (Middle Jurassic, middle Bajocian)
   Jtg	Tuxedni Group, Gaikema Sandstone (Middle Jurassic, lower middle Bajocian)
   Jtrg	Tuxedni Group, Red Glacier Formation (Middle Jurassic, lower middle Bajocian to lower Bajocian)
   Jtk	Talkeetna Formation, undivided (Lower Jurassic)
   Jtkh	Talkeetna Formation, Horn Mountain Tuff Member (Lower Jurassic)
   Jtkp	Talkeetna Formation, Portage Creek Agglomerate Member (Lower Jurassic)
   Jtkm	Talkeetna Formation, Marsh Creek Breccia Member (Lower Jurassic)
   Trk	Kamishak Formation, undivided (Upper Triassic, Norian)
   Trku	Kamishak Formation, Ursus Member (Upper Triassic, Norian)
   Trkm	Kamishak Formation, middle Member (Upper Triassic, Norian)
   Trkb	Kamishak Formation, Bruin Limestone Member (Upper Triassic, Norian)
   Trsh	Gray shale and gray volcaniclastic sandstone (Triassic)
   JPk	Kakhonak and Tlikakila Complexes (Jurassic, Triassic, and Permian(?) or older(?))
   Qv	Volcanic rocks, undivided (Quaternary)
   Qhv	Volcanic rocks (Quaternary, Holocene)
   Qdf	Debris-flow deposits (Quaternary, Holocene)
   Qmf	Volcanic rubble and mudflows (Quaternary, Holocene)
   Qamp	Andesite and dacite domes (Quaternary)
   QTv	Volcanic rocks, undivided (Quaternary, Pleistocene or Tertiary, Pliocene)
   Ti	Intrusive rocks, undivided (Tertiary)
   Tig	Granite and aplite (Oligocene(?) and younger)
   Tpgr	Peralkaline granite (Tertiary)
   Tign	Gabbronorite (Tertiary)
   Togd	Granodiorite and quartz monzodiorite (Oligocene and late Eocene)
   Teg	Granite (late Eocene)
   Tipg	Older granite (Paleocene)
   Tigd	Granodiorite (Paleocene)
   KJg	Mafic granitic rocks (Cretaceous and (or) Jurassic)
   Jtr	Trondhjemite (Late Jurassic)
   Jla	Lamprophyre and basalt dikes (Jurassic)
   Jqm	Granodiorite and quartz monzonite (Jurassic)
   Jqd	Quartz diorite, tonalite, and diorite (Jurassic)
   Jmu	Mafic and ultramafic plutonic rocks (Early Jurassic)
   Trc	Cottonwood Bay Greenstone and Chilikradrotna Greenstone (Triassic)
   MzPzb	Metamorphosed mafic volcanic and sedimentary rocks (Mesozoic and (or) Paleozoic)
   Tvu	Volcanic rocks, undivided (Tertiary)
   Tb	Basaltic volcanic rocks (late Tertiary)
   Tpg	Gibraltar Lake Tuff (Tertiary, Pliocene(?) to Oligocene(?))
   Tvr	Felsic volcanic rocks (Tertiary)
   Tmv	Volcanic rocks, undivided (Tertiary, Oligocene and Eocene)
   Tmf	Tuffaceous felsic volcanic rocks (Tertiary, Oligocene and Eocene)
   Tmba	Basalt and andesite (Tertiary, Oligocene and Eocene)
   Tvig	Ignimbrite (Tertiary, Paleocene)
   TKv	Volcanic breccia and flows, undivided (Tertiary and (or) Cretaceous)
   TKr	Rhyolite and dacite flows, tuff, dikes, and sills (Tertiary and (or) Cretaceous)
   TKb	Basalt flows (Tertiary and (or) Cretaceous)
   TKg	Granitic rocks, undivided (Tertiary and (or) Cretaceous)
   TKgr	Granite and alaskite (Tertiary and (or) Cretaceous)
   TKgs	Syenitic rocks (Tertiary and (or) Cretaceous)
   TKqm	Quartz monzonite and quartz monzodiorite (Tertiary and (or) Cretaceous)
   TKgd	Granodiorite (Tertiary and (or) Cretaceous)
   TKqd	Monzodiorite and quartz diorite (Tertiary and (or) Cretaceous)
   Mzmi	Mafic igneous rocks (Mesozoic(?))
   Kg	Plutonic rocks, undivided (Cretaceous)
   Kqms	Quartz monzonite and syenite (Late Cretaceous)
   Klgd	Granodiorite (Late Cretaceous)
   Kgr	Granite (Cretaceous)
   Kgd	Granodiorite (Cretaceous)
   Kqd	Quartz diorite, tonalite, and diorite (Cretaceous)

   UNITNAME

   Unit name as used in the Description of Map Units (Source: this data set) See Enumerated_Domain_Value_Definition for LABEL2.

   AGE_RANGE

   Age range of the map unit in the Description of Map Units. (Source: this data set) See Enumerated_Domain_Value_Definition for LABEL2.

   NAPgeol_arc

   Characteristics of linear features, which include various types of faults, stratigraphic contacts, and other line types. Lineations and dikes are stored in separate feature classes, but contain similar attributes. Items in NAPgeol_arc include the following items: ARC_CODE, ARC_PARA1, ARC_PARA2, SOURCE, LINEID, LINE_TYPE. (Source: this data set)

   ARC_CODE

   ARC_CODE is a positive integer value in the arc attribute table. Values range discontinuously from 0 to 99. Values match one-for-one with LINE_TYPE. (Source: this data set)

   Value	Definition
   1	Stratigraphic contact or intrusive contact, location certain
   2	Stratigraphic contact or intrusive contact, location approximate
   3	Stratigraphic contact or intrusive contact, location inferred, queried
   4	Normal fault, location certain; if arc-para1 = 1, then upthrown side is on right-hand side
   5	Normal fault, location approximate; if arc-para1 = 1, then upthrown side is on right-hand side
   6	Normal fault, location inferred, queried; if arc-para1 = 1, then upthrown side is on right-hand side
   7	Shoreline or riverbank; arc-para1 = 1 designates single-sided stream or high tide shoreline, typically used in areas of braiding
   9	Boundary of altered zone or hornfels
   10	Thrust fault, location certain, teeth on right from origin
   11	Thrust fault, location approximate, teeth on right from origin
   12	Thrust fault, location inferred, queried, teeth on right from origin
   13	Moraine or till margin (scour) on bedrock
   14	Caldera or crater rim
   15	Ice contact (glacier limit)
   18	Internal contact
   19	Moraine limit having tics on right from origin
   30	Fault, sense of displacement uncertain, location certain
   31	Fault, sense of displacement uncertain, location approximate
   32	Fault, sense of displacement uncertain, location inferred
   34	Terrace, erosional, or wave-cut scarp, water on right from origin
   35	High-angle reverse fault, location certain, teeth on right from origin
   36	High-angle reverse fault, location approximate, teeth on right from origin
   51	Concealed contact
   52	Concealed normal fault; if arc-para1 = 1, then upthrown side is on right-hand side
   53	Concealed thrust fault, teeth on right from origin
   54	Concealed high-angle reverse fault, teeth on right from origin
   57	Concealed right-lateral fault
   60	Concealed fault of uncertain displacement
   88	Right lateral fault, location approximate
   97	Scratch lines, used where polygons were not closed on source map or limit of mapping
   99	Bounding line (neatline) of coverage

   ARC_PARA1

   Used as a modifier for ARC_CODE (Source: this data set) See ARC_CODE attribute definitions for ARC_PARA1 definition

   ARC_PARA2

   ARC-PARA2 is generally not used, however this data set uses ARC-PARA2 to aid with producing the map. (Source: this data set)

   Value	Definition
   -99	Signifies that the stratigraphic contact should not be drawn when the same unit is present on both sides.

   SOURCE

   Unique code assigned to each source; uses the 2-letter quadrangle code and a three digit number. By default, 001 is reserved for the topographic map or other source of hydrologic spatial data for each quadrangle. Field SOURCE is a key field for linking to field SOURCE in table naprefs. (Source: this data set)

   Formal codeset
   Codeset Name:	naprefs (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   LINEID

   LINEID provides additional attributes for some faults and glacial moraines. For faults, LINEID identifies the fault system the feature belongs to. For moraines, LINEID identifies the moraine or glacial limit. LINEID is an 8 character alpha-numeric code following this naming convention. The first letter is 'f' if the feature is a fault, or 'm' if a moraine. The second and third characters are alpha abbreviations for the fault system, region, or glaciation. These abbreviations are defined below. The final 4 numbers in LINEID are identifiers which further subdivide the line's description. Field LINEID is a key field for linking to field LINEID in table LINEID. (Source: this data set)

   Value	Definition
   fDE	Denali fault system
   fTK	Talkeetna suture zone
   fWR	Wrangellia region
   fYK	Yukon-Kuskokwim region

   LINE_TYPE

   Descriptive name for ARC_CODE (Source: this data set) Brief description of ARC_CODE

   NAPgeol_dike

   Line features representing dikes and sills (Source: this data set)

   ARC_CODE

   Dikes and sills (Source: this data set)

   Value	Definition
   50	Dikes and sills

   SOURCE

   Unique code assigned to each source; uses the 2-letter quadrangle code and a three digit number. Same as attribute SOURCE in NAPgeol_arc and NAPgeol_poly. (Source: this data set)

   Formal codeset
   Codeset Name:	naprefs (available as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   CLASS

   Unique numeric code assigned to a geologic unit from the original source map. Number is unique only within a given quadrangle and specific to SOURCE. Not universally populated. (Source: this data set)

   Formal codeset
   Codeset Name:	napunits (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   NSACLASS

   Regional numeric code assigned to similar units. Not universally populated. (Source: this data set)

   Formal codeset
   Codeset Name:	nsakey (provided as a geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   LINE_TYPE

   Descriptive name for ARC_CODE (Source: this data set) Dikes and sills

   NAPgeol_lineament

   Line features representing lineaments (Source: this data set)

   ARC_CODE

   Lineaments (Source: this data set)

   Value	Definition
   93	Lineaments

   SOURCE

   Unique code assigned to each source; uses the 2-letter quadrangle code and a three digit number. Same as attribute SOURCE in NAPgeol_arc and NAPgeol_poly. (Source: this data set)

   Formal codeset
   Codeset Name:	naprefs (provided as geodatabase table, Filemaker database, CSV, and DBF files)
   Codeset Source:	this data set

   LINE_TYPE

   Descriptive name for ARC_CODE (Source: this data set) Lineament

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Wilson, Frederic H.
   • Blodgett, Robert B.
   • Blome, Charles D.
   • Mohadjer, Solmaz
   • Preller, Cindi C.
   • Klimasauskas, Edward P.
   • Gamble, Bruce M.
   • Coonrad, Warren L.
2. Who also contributed to the data set?

   This data set was prepared by Frederic H. Wilson (USGS), Solmaz Mohadjer (contractor), Keith A. Labay (USGS), Chad Hults (USGS), and Nora Shew (USGS)

3. To whom should users address questions about the data?
   U.S. Geological Survey, Alaska Science Center

   Attn: Frederic H. Wilson

   Research Geologist

   4210 University Drive

   Anchorage, Alaska
   

   US

   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. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: Unknown (process 1 of 2)

   Linework for the geology compilation was hand digitized from material of various media and scale. The arcs and polygons were attributed and topology was checked.

   Date: 2016 (process 2 of 2)

   The geology data from the individual quadrangles was combined to create the map feature classes in NAP_geol.gdb

3. What similar or related data should the user be aware of?

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, air photo interpretation, and limited new field mapping. The dates of the mapping range from the present to the 1930'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- and 1:63,360 scale mapping.
3. How accurate are the heights or depths?
   not applicable
4. Where are the gaps in the data? What is missing?
   The data set NAP_geol.gdb consists of arc and polygon features depicting the geology of the northern Alaska Peninsula. The geologic units are described in the Description of Map Units (DMU) found in the accompanying pamphlet. There is also an associated relational database of geologic units.
5. How consistent are the relationships among the observations, including topology?
   The geologic data consists of attributed arcs and polygons. Each polygon has a coded attribute designating the mapped geologic unit. Faults, stratigraphic contacts, dikes, lineations 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 (fault, dike, lineation, 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. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations. 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

   MS 902 Box 25286 Denver Federal Center

   Lakewood, CO
   

   USA

   1-888-ASK-USGS (voice)
2. What's the catalog number I need to order this data set? SIM 2942
3. What legal disclaimers am I supposed to read?

   This data set was modified from a more detailed data set. This version was created to simplify the production of a map product and is not intended for distribution.

   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 of any agency thereof.

4. How can I download or order the data?

Who wrote the metadata?

Dates:

Last modified: 26-Jan-2017

Metadata author:

U.S. Geological Survey

Attn: Keith Labay

4200 University Drive

Anchorage, Alaska

U.S.A.

907-786-7410 (voice)

klabay@usgs.gov

Metadata standard:

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