USGS - science for a changing world

Mineral Resources On-Line Spatial Data

Mineral Resources > Online Spatial Data > Geology > by state

Preliminary Integrated Geologic Map Databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island, Vermont

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:


What does this data set describe?

Title:
Preliminary Integrated Geologic Map Databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island, Vermont
Abstract:
These metadata are specifically for the State of Rhode Island, one state in the national compilation of state geologic map databases. The digital geologic state map data was prepared by the Rhode Island Geological Survey in 1994. Subsequent editing of the spatial data by the USGS was limited to fitting a standardized state boundary to the data, standardizing the arc coding, reprojecting the data, and minor edits of arc or polygon attributes to conform with the paper map. This open-file report is one of several that present the preliminary results of the USGS Mineral Resources Program activity to compile a national-scale geologic map database to support national and regional level projects, including mineral resource and geoenvironmental assessments. The only comprehensive sources of regional- and national-scale geologic maps are state geologic maps with scales ranging from 1:100,000 to 1:1,000,000. Digital versions of these state maps form the core of what is presented here. Because no adequate geologic map exists for the state of Alaska, it is being compiled in regional blocks that also form part of this national database. It is expected that this series will completed by approximately the end of 2007. These maps and databases are being released in blocks of states or, in the case of Alaska, as compiled blocks of 1:250,000-scale quadrangles as chapters in this series. For Alaska, formal maps as well as databases are being published here, whereas for the conterminous U.S. only state databases and preview graphics are presented, because published maps for most states already exist. For Alaska these regional compilations will form the base for compiling a new geologic map of the state. As documented in CONUSdocumentationNENJ.pdf, standards for the conterminous U.S. are somewhat different than those for Alaska and Hawaii.
Supplemental_Information:
This database consists of up to five major Arc/Info GIS datasets for each state; - one: geologic map with formations, - two: faults (where present), - three: dikes (where present), - four: miscellaneous line features (where present), - five: miscellaneous point features (where present).
  1. How might this data set be cited?
    Nicholson, Suzanne W., Dicken, Connie L., Horton, John D., Foose, Michael P., Mueller, Julia A.L., and Hon, Rudi, 2006, Preliminary Integrated Geologic Map Databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island, Vermont: U.S. Geological Survey Open-File Report 2006-1272, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.907675
    East_Bounding_Coordinate: -71.099608
    North_Bounding_Coordinate: 42.018398
    South_Bounding_Coordinate: 41.063767
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2006Currentness_Reference: publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: map
  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?
      The map projection used is Lambert Conformal Conic.
      Projection parameters:
      Standard_Parallel: 33
      Standard_Parallel: 45
      Longitude_of_Central_Meridian: -100.0
      Latitude_of_Projection_Origin: 0
      False_Easting: 0.00000
      False_Northing: 0.00000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.01
      Ordinates (y-coordinates) are specified to the nearest 0.01
      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 1/294.98.
  7. How does the data set describe geographic features?
    RI_geol.pat
    Polygon attribute table for the Rhode Island geologic coverage. (Source: ESRI)
    ORIG_LABEL
    unmodified map unit symbol from source cover.

    type: character width: 12 output width: 12 (Source: Doug Stoeser (USGS))
    ValueDefinition
    ChHoppin Formation
    Cpc+OCcjPirate Cove Formation
    DsaScituate Igneous Suite - alkali-feldspar granite
    DsdScituate Igneous Suite - diorite/gabbro
    DsfgScituate Igneous Suite - fine-grained granite
    DsgScituate Igneous Suite - granite
    DsgdScituate Igneous Suite - granodiorite
    DsmScituate Igneous Suite - monzonite/monzodiorite
    DsrScituate Igneous Suite - rhyolite
    DsvScituate Igneous Suite - volcaniclastic rock
    DZccumberlandite
    DZgdgabbro/diorite
    Jmmonchiquite
    KrRaritan Formation
    MDcaalkali-feldspar granite of Cumberland
    OCcdiConanicut Group - Dutch Island Harbor Formation
    OCcepConanicut Group - East Passage Formation
    OCcj+OCcfbConanicut Group - Fort Burnside Formation
    OCcjConanicut Group - Jamestown Formation
    OCcuConanicut Group - undifferentiated rock
    OCmnminette
    PnbdNarragansett Bay Group - Dighton Conglomerate
    PnbpoNarragansett Bay Group - Pondville Conglomerate
    PnbpuNarragansett Bay Group - Purgatory Conglomerate
    PnbrNarragansett Bay Group - Rhode Island Formation
    PnbsNarragansett Bay Group - Sachuest Arkose
    PnbwNarragansett Bay Group - Wamsutta Formation
    PZmcOther metasedimentary rocks - metaclastic rock, undivided
    PngfNarragansett Pier Plutonic Suite - fine-grained granite
    PngNarragansett Pier Plutonic Suite - granite
    PnlgNarragansett Pier Plutonic Suite - leucocratic granite
    PnpgNarragansett Pier Plutonic Suite - porphyritic granite
    Tddiabase
    Tvqvein quartz
    waterWater
    ZbmBlackstone Group - greenstone, amphibolite, serpentinite
    ZbqBlackstone Group - quartzite
    ZbsBlackstone Group - epidote and biotite schist
    ZbuBlackstone Group - undifferentiated rock
    ZdgDedham Granite
    ZeaggEsmond Igneous Suite - augen granite gneiss
    ZefgEsmond Igneous Suite - fine-grained granite
    ZefvEsmond Igneous Suite - felsic volcaniclastic rock
    ZegEsmond Igneous Suite - granite
    ZegdEsmond Igneous Suite - granodiorite
    ZeggEsmond Igneous Suite - granite gneiss
    ZemEsmond Igneous Suite - mafic/intermediate rock
    ZhaHarmony Group - Absalona Formation
    ZhnHarmony Group - Nipsachuck Formation
    ZhwHarmony Group - Woonasquatucket Formation
    Zmsmica schist
    ZnfaNewport Group - Fort Adams Formation
    ZnnnNewport Group - Newport Neck Formation
    ZnpnNewport Group - Price Neck Formation
    ZpPlainfield Formation
    ZsagSterling Igneous Suite - alaskite gneiss
    ZsegGranites of southeastern Rhode Island - granite
    ZsepgGranites of southeastern Rhode Island - porphyritic granite
    ZsggSterling Igneous Suite - granite gneiss
    ZsmgSterling Igneous Suite - mafic/intermediate gneiss
    ZwmWaterford Group - Mamacoke Formation
    ZwrWaterford Group - Rope Ferry Gneiss
    SGMC_LABEL
    orig_label + ;n where n= province number (n=0 if no province number)

    type: character width: 16 output width: 16 (Source: Doug Stoeser (USGS))
    ValueDefinition
    CAh;0Hoppin Formation
    CApc;0Pirate Cove Formation
    Dsa;0Scituate Igneous Suite - alkali-feldspar granite
    Dsd;0Scituate Igneous Suite - diorite/gabbro
    Dsfg;0Scituate Igneous Suite - fine-grained granite
    Dsg;0Scituate Igneous Suite - granite
    Dsgd;0Scituate Igneous Suite - granodiorite
    Dsm;0Scituate Igneous Suite - monzonite/monzodiorite
    Dsr;0Scituate Igneous Suite - rhyolite
    Dsv;0Scituate Igneous Suite - volcaniclastic rock
    DZc;0cumberlandite
    DZgd;0gabbro/diorite
    Jm;0monchiquite
    Kr;0Raritan Formation
    MDca;0alkali-feldspar granite of Cumberland
    OCAcdi;0Conanicut Group - Dutch Island Harbor Formation
    OCAcep;0Conanicut Group - East Passage Formation
    OCAcfb;0Conanicut Group - Fort Burnside Formation
    OCAcj;0Conanicut Group - Jamestown Formation
    OCAcu;0Conanicut Group - undifferentiated rock
    OCAmn;0minette
    PAnbd;0Narragansett Bay Group - Dighton Conglomerate
    PAnbpo;0Narragansett Bay Group - Pondville Conglomerate
    PAnbpu;0Narragansett Bay Group - Purgatory Conglomerate
    PAnbr;0Narragansett Bay Group - Rhode Island Formation
    PAnbs;0Narragansett Bay Group - Sachuest Arkose
    PAnbw;0Narragansett Bay Group - Wamsutta Formation
    PAZmc;0Other metasedimentary rocks - metaclastic rock, undivided
    Pnfg;0Narragansett Pier Plutonic Suite - fine-grained granite
    Png;0Narragansett Pier Plutonic Suite - granite
    Pnlg;0Narragansett Pier Plutonic Suite - leucocratic granite
    Pnpg;0Narragansett Pier Plutonic Suite - porphyritic granite
    TRd;0diabase
    TRvq;0vein quartz
    water;0Water
    Zbm;0Blackstone Group - greenstone, amphibolite, serpentinite
    Zbq;0Blackstone Group - quartzite
    Zbs;0Blackstone Group - epidote and biotite schist
    Zbu;0Blackstone Group - undifferentiated rock
    Zdg;0Dedham Granite
    Zeag;0Esmond Igneous Suite - augen granite gneiss
    Zefg;0Esmond Igneous Suite - fine-grained granite
    Zefv;0Esmond Igneous Suite - felsic volcaniclastic rock
    Zeg;0Esmond Igneous Suite - granite
    Zegd;0Esmond Igneous Suite - granodiorite
    Zegg;0Esmond Igneous Suite - granite gneiss
    Zem;0Esmond Igneous Suite - mafic/intermediate rock
    Zha;0Harmony Group - Absalona Formation
    Zhn;0Harmony Group - Nipsachuck Formation
    Zhw;0Harmony Group - Woonasquatucket Formation
    Zms;0mica schist
    Znfa;0Newport Group - Fort Adams Formation
    Znnn;0Newport Group - Newport Neck Formation
    Znpn;0Newport Group - Price Neck Formation
    Zp;0Plainfield Formation
    Zsag;0Sterling Igneous Suite - alaskite gneiss
    Zseg;0Granites of southeastern Rhode Island - granite
    Zsepg;0Granites of southeastern Rhode Island - porphyritic granite
    Zsgg;0Sterling Igneous Suite - granite gneiss
    Zsmg;0Sterling Igneous Suite - mafic/intermediate gneiss
    Zwm;0Waterford Group - Mamacoke Formation
    Zwr;0Waterford Group - Rope Ferry Gneiss
    unit_link
    composite map label = ST + sgmc_label This creates a unique identifier for every unit in the CONUS (continental United States) covers.

    type: character width: 18 output width: 18 (Source: Doug Stoeser (USGS))
    ValueDefinition
    RICAh;0Hoppin Formation
    RICApc;0Pirate Cove Formation
    RIDsa;0Scituate Igneous Suite - alkali-feldspar granite
    RIDsd;0Scituate Igneous Suite - diorite/gabbro
    RIDsfg;0Scituate Igneous Suite - fine-grained granite
    RIDsg;0Scituate Igneous Suite - granite
    RIDsgd;0Scituate Igneous Suite - granodiorite
    RIDsm;0Scituate Igneous Suite - monzonite/monzodiorite
    RIDsr;0Scituate Igneous Suite - rhyolite
    RIDsv;0Scituate Igneous Suite - volcaniclastic rock
    RIDZc;0cumberlandite
    RIDZgd;0gabbro/diorite
    RIJm;0monchiquite
    RIKr;0Raritan Formation
    RIMDca;0alkali-feldspar granite of Cumberland
    RIOCAcdi;0Conanicut Group - Dutch Island Harbor Formation
    RIOCAcep;0Conanicut Group - East Passage Formation
    RIOCAcfb;0Conanicut Group - Fort Burnside Formation
    RIOCAcj;0Conanicut Group - Jamestown Formation
    RIOCAcu;0Conanicut Group - undifferentiated rock
    RIOCAmn;0minette
    RIPAnbd;0Narragansett Bay Group - Dighton Conglomerate
    RIPAnbpo;0Narragansett Bay Group - Pondville Conglomerate
    RIPAnbpu;0Narragansett Bay Group - Purgatory Conglomerate
    RIPAnbr;0Narragansett Bay Group - Rhode Island Formation
    RIPAnbs;0Narragansett Bay Group - Sachuest Arkose
    RIPAnbw;0Narragansett Bay Group - Wamsutta Formation
    RIPAZmc;0Other metasedimentary rocks - metaclastic rock, undivided
    RIPnfg;0Narragansett Pier Plutonic Suite - fine-grained granite
    RIPng;0Narragansett Pier Plutonic Suite - granite
    RIPnlg;0Narragansett Pier Plutonic Suite - leucocratic granite
    RIPnpg;0Narragansett Pier Plutonic Suite - porphyritic granite
    RITRd;0diabase
    RITRvq;0vein quartz
    RIwater;0Water
    RIZbm;0Blackstone Group - greenstone, amphibolite, serpentinite
    RIZbq;0Blackstone Group - quartzite
    RIZbs;0Blackstone Group - epidote and biotite schist
    RIZbu;0Blackstone Group - undifferentiated rock
    RIZdg;0Dedham Granite
    RIZeag;0Esmond Igneous Suite - augen granite gneiss
    RIZefg;0Esmond Igneous Suite - fine-grained granite
    RIZefv;0Esmond Igneous Suite - felsic volcaniclastic rock
    RIZeg;0Esmond Igneous Suite - granite
    RIZegd;0Esmond Igneous Suite - granodiorite
    RIZegg;0Esmond Igneous Suite - granite gneiss
    RIZem;0Esmond Igneous Suite - mafic/intermediate rock
    RIZha;0Harmony Group - Absalona Formation
    RIZhn;0Harmony Group - Nipsachuck Formation
    RIZhw;0Harmony Group - Woonasquatucket Formation
    RIZms;0mica schist
    RIZnfa;0Newport Group - Fort Adams Formation
    RIZnnn;0Newport Group - Newport Neck Formation
    RIZnpn;0Newport Group - Price Neck Formation
    RIZp;0Plainfield Formation
    RIZsag;0Sterling Igneous Suite - alaskite gneiss
    RIZseg;0Granites of southeastern Rhode Island - granite
    RIZsepg;0Granites of southeastern Rhode Island - porphyritic granite
    RIZsgg;0Sterling Igneous Suite - granite gneiss
    RIZsmg;0Sterling Igneous Suite - mafic/intermediate gneiss
    RIZwm;0Waterford Group - Mamacoke Formation
    RIZwr;0Waterford Group - Rope Ferry Gneiss
    source
    An alphanumeric code (e.g. US001) that designates the source material used.

    type: character width: 6 output width: 8 (Source: Doug Stoeser (USGS))
    ValueDefinition
    RI001Hermes, O.D., Gromet, L.P., Murray, D.P., Hamidzada, N.A., 1994, Geologic Map of Rhode Island, Rhode Island Geographic Information System, http://www.edc.uri.edu/rigis-spf/Statewide/state.html#geology, scale 1:100,000.
    US001Johnson, Bruce R. and Leveritch, Beth, 1998, 1:100,000 Scale State Boundaries of the Conterminous United States: U.S. Geological Survey, unpublished (see metadata file: st100kmeta.txt, CONUSdocumentationNENJ.pdf)
    unit_age
    The geologic age from the source map used.

    type: character width: 60 output width: 60 (Source: Doug Stoeser (USGS))
    ValueDefinition
    Cambrian 
    Cambro-Ordovician 
    Cambro-Ordovician? to Carboniferous? 
    Cretaceous 
    Devonian 
    Devonian? or Mississippian? 
    Holocene 
    Jurassic 
    Late Proterozoic 
    Late Proterozoic? or older? 
    Late Proterozoic? to Devonian? 
    Pennsylvanian 
    Pennsylvanian? or Late Proterozoic? 
    Permian 
    Triassic? 
    unknown 
    rocktype1
    The predominant lithology found in the formation.

    type: character width: 40 output width: 40 (Source: Johnson Lith Class 6.1a)
    ValueDefinition
    alkali-granite (alaskite) 
    arenite 
    ash-flow tuff 
    augen gneiss 
    biotite gneiss 
    clay or mud 
    conglomerate 
    diabase 
    felsic gneiss 
    gneiss 
    granite 
    granitic gneiss 
    granodiorite 
    greenstone 
    lamprophyre 
    mafic gneiss 
    marble 
    meta-conglomerate 
    mica schist 
    migmatite 
    olistostrome 
    phyllite 
    plutonic rock (phaneritic) 
    quartz diorite 
    quartz monzonite 
    quartzite 
    rhyolite 
    sandstone 
    siltstone 
    tonalite 
    troctolite 
    tuff 
    unknown 
    water 
    rocktype2
    The second most predominant lithology in the formation.

    type: character width: 40 output width: 40 (Source: Johnson Lith Class 6.1)
    ValueDefinition
    amphibolite 
    arenite 
    argillite 
    augen gneiss 
    diorite 
    gneiss 
    granitic gneiss 
    granodiorite 
    ignimbrite 
    metasedimentary rock 
    mica schist 
    monzonite 
    pegmatite 
    phyllite 
    quartz diorite 
    quartzite 
    sand 
    sandstone 
    schist 
    shale 
    siltstone 
    slate 
    RI_geol.aat
    Arc attribute table for Rhode Island geologic coverage. (Source: ESRI)
    arc-code
    Unique identifier for the line feature

    type: integer width: 3 output width: 3 (Source: AAT data dictionary)
    ValueDefinition
    1contact, location certain
    3contact, location inferred, queried
    4normal fault, location certain, digitized with upthrown side on the right (code of 1 added to ARC-PARA1 where U/D is designated in source)
    6normal fault, location inferred, queried, digitized with upthrown side on the right (code of 1 added to ARC-PARA1 where U/D is designated in source)
    7shoreline or riverbank
    10thrust fault, location certain, teeth on right from origin (angle of thrusting added to ARC-PARA1 where designated in source)
    12thrust fault, location inferred, queried, teeth on right from origin (angle of thrusting added to ARC-PARA1 where designated in source)
    30fault, sense of displacement unknown or undefined, location certain.
    32fault, sense of displacement unknown or undefined, location inferred or queried.
    94shear zone, certain
    99bounding line (neatline) of coverage
    113strike slip fault, motion unknown, location certain.
    115strike slip fault, motion unknown, location inferred.
    124state boundary
    arc-para1
    Used for "decorated" lines where additional information is needed.

    type: integer width: 3 output width: 3 (Source: AAT data dictionary)
    ValueDefinition
    0no additional information
    1U/D designated in source.
    arc-para2
    "Scratch" field used mostly in Alaska.

    type: integer width: 3 output width: 3 (Source: AAT data dictionary)
    ValueDefinition
    0no additional information
    1Narragansett Basin border fault
    2probable fault
    source
    An alphanumeric code (e.g. US001) that designates the source material used.

    type: character width: 6 output width: 8 (Source: Doug Stoeser (USGS))
    ValueDefinition
    RI001Hermes, O.D., Gromet, L.P., Murray, D.P., Hamidzada, N.A., 1994, Geologic Map of Rhode Island, Rhode Island Geographic Information System, http://www.edc.uri.edu/rigis-spf/Statewide/state.html#geology, scale 1:100,000.
    RI101C.L. Dicken flipped arcs.
    US001Johnson, Bruce R. and Leveritch, Beth, 1998, 1:100,000 Scale State Boundaries of the Conterminous United States: U.S. Geological Survey, unpublished (see metadata file: st100kmeta.txt, CONUSdocumentationNENJ.pdf)
    Entity_and_Attribute_Overview:
    Coding for polygon attributes:

    NAME: FEATURE: orig_label unmodified map unit symbols from source cover sgmc_label orig_label modified for standard geologic age symbols and an integer code added for province unit_link sgmc_label and a state code identifier source reference to source of data unit_age geologic age rocktype1 predominant lithology rocktype2 second most predominant lithology

    Coding for arc attributes:

    NAME: FEATURE: arc-code unique integer identifier arc-para1 used where additional information is needed arc-para2 scratch field source reference to source of data

    Coding for point attributes:

    NAME: FEATURE: point_feature name of feature on map source reference to source of data

    Coding for dikes (special arcs) attributes:

    NAME: FEATURE: orig_label unmodified map unit symbols from source cover sgmc_label orig_label modified for standard geologic age symbols and an integer code added for province arc-code unique integer identifier dike_lith general lithology dike_age geologic age source reference to source of data

    Entity_and_Attribute_Detail_Citation: ESRI

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?
    State Geologic Map Compilation (SGMC) activity of the National Surveys and Analysis projects of the US Geological Survey Mineral Resources Program.

  3. To whom should users address questions about the data?
    Suzanne W. Nicholson
    U.S. Geological Survey
    12201 Sunrise Valley Dr. MS954
    Reston, VA
    USA

    703-648-6344 (voice)
    swnich@usgs.gov

Why was the data set created?

A primary goal of this work is to develop geologic map datasets with standardized structure and attribution. The database design and standards are documented in CONUSdocumentationNENJ.pdf of this series. The intent is that contiguous databases can be merged seamlessly and without any additional effort. In addition to a common database structure, the conterminous U.S. state databases (the contiguous 48 states) have been fitted to a set of standard state boundaries so that, when states are merged, they match without slivers or overlap. No attempt has been made to reconcile differences in mapping across state boundaries.

How was the data set created?

  1. From what previous works were the data drawn?
    rigeol (source 1 of 3)
    Hermes, O.D, Gromet, L.P., Murray, D.P., and Hamidzada, N.A., 1994, Geologic Map of Rhode Island: Rhode Island Geographic Information System, Providence, Rhode Island.

    Online Links:

    Type_of_Source_Media: vector
    Source_Scale_Denominator: 100000
    Source_Contribution: provided geology for state map
    state boundaries (source 2 of 3)
    Johnson, Bruce R., 1:100,000 Scale State Boundaries of the Conterminous United States.

    Other_Citation_Details:
    Arc/INFO coverage developed by Bruce Johnson. Derived from USGS 100,000-scale DLG boundary layer quadrangles.
    Type_of_Source_Media: online
    Source_Scale_Denominator: 100000
    Source_Contribution: provided linework of the conterminous state boundaries
    lithclass (source 3 of 3)
    Johnson, Bruce R., Geologic Map Unit Classification, ver. 6.1.

    Other_Citation_Details:
    Document has been modified and is included in Appedices of the publication.
    Type_of_Source_Media: digital data
    Source_Scale_Denominator: none
    Source_Contribution:
    Source of lithologic codes and specific rock names found in ROCKTYPE1 and ROCKTYPE2.
  2. How were the data generated, processed, and modified?
    Date: 2003 (process 1 of 10)
    The purpose of this standardization is to allow all SGMC covers to be seamlessly joined without any additional effort to form regional or national level digital maps. Note that for Alaska, the state is being compiled as blocks of 1:250k quadrangles that will ultimately be used to compile a new state map. Douglas Stoeser (USGS) and Ric Wilson (USGS) are co-coordinators for the overall SGMC effort, with Stoeser coordinating work on the mainland states and Wilson coordinating work for Alaska and Hawaii.
    Date: 2006 (process 2 of 10)
    C.L. Dicken obtained the digital geologic map of Rhode Island from Rhode Island Geographic Information System, http://www.edc.uri.edu/rigis-spf/Statewide/state.html#geology. The coverage was re-projected into the following:

    projection: Lambert Conformal Conic units: meters datum: NAD27 standard parallel 1: 33 0 0.000 standard parallel 2: 45 0 0.000 central meridian: -100 0 0.000 reference latitude: 0 0 0.000 false easting: 0.00000 false northing: 0.00000

    (Note: Attributes associated with the generation of the coverages were not deleted. PAT - shape, area, perimeter, coverage#, and coverage-id AAT - shape, fnode#, tnode#, lnode#, rnode#, length, coverage#, and coverage-id)

    All attributes were deleted except unit_label. The values from unit_label where then calculated into a new field called orig_label.
    Date: 2006 (process 3 of 10)
    The relevant state outline (arcs) was removed from the coverage and replaced with the arcs from the 1:100,000 Scale State Boundaries of the Conterminous United States.

    This allows for a seamless fit of each state to a standard state boundary base.
    Date: 2006 (process 4 of 10)
    The following attributes were exported from Filemaker as a .dbf: orig_label, map_symbol2, unit_link, reference_id, unit_age, rocktype1, and rocktype2.

    orig_label reflects the original map symbol used on the source map

    map_symbol2 reflects map-symbol1 with the addition of a province number

    unit_link is an auto generated field based on map-symbol2 and the state abbreviation (e.g. RI001) that produces a unique identifier for each map unit

    reference_id was populated with an alphanumeric code (e.g. US001) that designates the source used for the linework and other references used to describe the age or lithologies of the unit.

    unit_age was populated with general age assignment

    rocktype1 records dominant lithology (does not imply minimum percentage of abundance), using standardized data dictionary

    rocktype2 records second most dominant lithology, using standardized data dictionary

    The attributes were then converted using the following structure:

    item name: orig_label width: 12 output: 12 type: c

    item name: sgmc_label width: 16 output: 16 type: c

    item name: unit_link width: 18 output: 18 type: c

    item name: source width: 6 output: 8 type: c

    item name: unit_age width: 60 output: 60 type: c

    item name: rocktype1 width: 40 output: 40 type: c

    item name: rocktype2 width: 40 output: 40 type: c
    Date: 2006 (process 5 of 10)
    Once the .dbf was in the correct format with standardized column widths and data structure, it was converted into a lookup table (.lut) in Arc/Info. Then a joinitem was performed to join the look-up table to the polygon attribute table. orig_label was used as the merge item.
    Date: 2006 (process 6 of 10)
    Next, in preparing the uniform .aat file, the following items were added to the table:

    item name: arc-code width: 3 output: 3 type: i

    item name: arc-para1 width: 3 output: 3 type: i

    item name: arc-para2 width: 3 output: 3 type: i

    item name: source width: 6 output: 8 type: c

    Date: 2006 (process 7 of 10)
    Arc-code was populated using the paper map source to tag the lines using the AAT line type data dictionary (see CONUSdocumentationNENJ.pdf in this series).

    Arc-para1 was populated when additional information was available such as identifying the upthrown side of a fault or direction of thrusting on a fault. (see CONUSdocumentationNENJ.pdf)

    Arc-para2 is a scratch field that is used mostly in Alaska.

    Source was populated with an alphanumeric code (e.g. US001) that designates the source used for the linework.

    Date: 2006 (process 8 of 10)
    Once the .aat and the .pat were populated with the correct attributes, the coverage was exported as an .e00 file (RIgeol_lcc.e00).

    Then it was unprojected into geographic coordinates and exported again (RIgeol_dd.e00).
    Date: 2006 (process 9 of 10)
    Faults were extracted from the coverage and created a separate fault coverage (RIfaults_lcc) and then exported (RIfaults_lcc.e00).
    Date: 2006 (process 10 of 10)
    Finally, the geology lines, geology polygons and faults were converted into shapefiles; in both geographic coordinates and in Lambert Conformal Conic projection.
  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?
    The values of the attributes ROCKTYPE1 and ROCKTYPE2 were assigned based on the information in the legends of the source maps (most of which are paper). The definitions of these values are described in the draft document Geologic Map Classification version 6.1 (Johnson and others); available at the following website: http://geology.usgs.gov/dm
  2. How accurate are the geographic locations?
    Accuracy of Rhode Island state boundary and those arcs intersecting it: The accuracy of the state boundary arcs is based on the 1:100,000 scale original data used to produce this boundary. (Johnson, Bruce R. and Leveritch, Beth, 1998, 1:100,000 Scale State Boundaries of the Conterminous United States: U.S. Geological Survey, unpublished (see metadata file: st100kmeta.txt, CONUSdocumentationNENJ.pdf))

    Those internal arcs intersecting the state boundary were extended or shortened as needed to complete polygons, possibly creating a small amount of error.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Bodies of water are classified as water, and the geologic units underlying them are not included in this coverage.
  5. How consistent are the relationships among the observations, including topology?
    All internal polygons were checked for closure with vendor software and on hard copy plots. Overshoots and undershoots have been deleted or corrected as appropriate.

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:
This database is not meant to be used or displayed at any scale other than 1:500,000.

Any hardcopies utilizing these data sets shall clearly indicate their source. If the licensee has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. Licensee specifically agrees not to misrepresent these data sets, nor to imply that changes they made were approved by the U.S. Geological Survey.

  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Information Services Reston-ESIC
    U.S. Geological Survey
    507 National Center
    Reston, Virginia
    USA

    1-888-ASK-USGS or 1-703-648-5953 (voice)
    http://www.usgs.gov/contact/
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the USGS. Although these data have been used by the USGS and have been successfully imported into data base programs, no warranty, expressed or implied, is made by the USGS as to how successfully or accurately the data can be imported into any specific application software running on any specific hardware platform. The fact of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith. This data base GIS is not meant to be used or displayed at any scale other than 1:500,000.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 30-Jan-2006
Metadata author:
U.S. Geological Survey
Attn: Connie L. Dicken
12201 Sunrise Valley Dr. MS954
Reston, VA
USA

703-648-6482 (voice)
cdicken@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://mrdata.usgs.gov/geology/state/metadata/ri.faq.html>

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Peter Schweitzer
Page Last Modified: Monday, 03-Jul-2017 15:29:16 MDT

Generated by mp version 2.9.40 on Mon Jul 3 15:29:16 2017