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Geologic Map of the Hogback Mountain Quadrangle, Lewis and Clark and Meagher Counties, Montana

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What does this data set describe?

Title:
Geologic Map of the Hogback Mountain Quadrangle, Lewis and Clark and Meagher Counties, Montana
Abstract:
The geologic map of the Hogback Mountain quadrangle, scale 1:24,000, was made as part of the Montana Investigations Project to provide new information on the stratigraphy, structure, and geologic history of an area in the geologically complex southern part of the Montana disturbed belt. In the Hogback Mountain area, rocks ranging in age from Middle Proterozoic through Cretaceous are strongly folded within and under thrust plates of equivalent rocks. Continental rocks of successive thrust plates have been telescoped eastward over a buttress of the stable continent. Erosional remnants of Oligocene andesitic basalt lie on highest surfaces eroded across the strongly deformed older rocks; younger erosion has dissected the terrain deeply, producing Late Tertiary and Quaternary deposits of alluvium, colluvium, and local landslide debris in the valleys and canyons.
Different stratigraphic successions are exposed at different structural levels across the quadrangle. In the northeastern part of the quadrangle at the lowest structural level, rocks of the Upper Mississippian Big Snowy Group, including the Kibbey Formation and the undivided Otter and Heath Formations, the overlying Pennsylvanian Amsden and undivided Quadrant and Phosphoria Formations, the Ellis Group, and the Kootenai Formation, are folded and broken by thrust faults. The next higher structural level, the Avalanche Butte thrust plate, exposes strongly folded and, in places, attenuated strata of Cambrian (Flathead Sandstone, Wolsey Shale, Meagher Limestone, and undivided Pilgrim Formation and Park Shale), Devonian (Maywood Formation, Jefferson Formation, and most of the Three Forks Formation), and Mississippian (uppermost part of the Three Forks Formation and Lodgepole and Mission Canyon Limestones) ages. The overlying Hogback Mountain thrust plate contains strongly folded rocks ranging in age from the Middle Proterozoic Greyson Formation to the Upper and Lower Mississippian Mission Canyon Limestone and Cretaceous diorite sills. The highest structural level, the Moors Mountain thrust plate, contains the Middle Proterozoic Greyson and Newland Formations and discontinuous Upper Proterozoic diabase sills.
Rocks are complexly folded and faulted across the quadrangle. At the lowest level in the northeastern part of the quadrangle, Upper Mississippian and younger strata are folded along northwest-trending axes and broken by thrust faults that at outcrop level displace the same rocks. The central core of the quadrangle is formed by the Avalanche Butte thrust plate, which contains recumbently folded and thrust faulted Paleozoic rocks. A succession of four tight recumbent folds within the plate have axial traces that trend northwest and north-northwest, and that are both arched and downfolded along east- and northeast-trending axes. Carbonate rocks of the Mission Canyon and Lodgepole Limestones in the upper part of the Avalanche Butte thrust plate exposed in the canyon of Trout Creek are folded and attenuated in stacked east-directed recumbent folds that developed as a succession of folded duplex thrust slices. The exposed remnant of the next higher structural level, the Hogback Mountain thrust plate, contains northeast- and east-trending folds that are inverted on the upper overturned limb of a younger northwest-trending recumbent fold. The Hogback Mountain thrust fault is itself folded and, in its northernmost exposures, is overturned to dip west beneath the overlying Moors Mountain thrust plate. During post-middle Tertiary deformation, the Hogback Mountain thrust fault moved as a normal fault, down on the east. The structurally highest Moors Mountain thrust plate rests on the Avalanche Butte thrust plate in the southwestern part of the quadrangle and across both the Avalanche Butte and Hogback Mountain thrust plates along the northwest edge of the quadrangle. In the central eastern part of the map area, the edge of a large klippen of the Moors Mountain thrust plate rests on a major inverted syncline of the underlying Hogback Mountain thrust plate. At the base of both the contiguous thrust plate and its klippen, the bounding Moors Mountain thrust fault ramps steeply upward from south to north across a structural culmination in underlying thrust plates.
In the southwest corner of the quadrangle, strata of the Greyson Formation are faulted down on the west along a normal fault that, in the Nelson quadrangle adjacent on the west, is listric down to the west with the Moors Mountain thrust fault. Movement on the normal fault is younger than middle Oligocene.
Supplemental_Information:
Map political location: Lewis and Clark and Meagher Counties, Montana
Map scale: 1:24,000
Geology mapped in 1976 and 1977
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ARC/INFO format, this metadata file may include some ARC/INFO-specific terminology.
GEOSPATIAL FILES INCLUDED IN THIS DATA SET:
hogpoly: polygon coverage containing geologic unit contacts, faults, dikes, and labels
hogline: arc coverage containing cross sections, anticlines, synclines
hogpoint: point coverage containing strike and dip attitudes of bedding and foliation, and other point-data map entities
  1. How might this data set be cited?
    Reynolds, Mitchell W., 2003, Geologic Map of the Hogback Mountain Quadrangle, Lewis and Clark and Meagher Counties, Montana: U.S. Geological Survey Geologic Investigations Series I-2773, U.S. Geological Survey, Denver, Colorado.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -111.750
    East_Bounding_Coordinate: -111.625
    North_Bounding_Coordinate: 46.875
    South_Bounding_Coordinate: 46.750
  3. What does it look like?
    http://pubs.usgs.gov/imap/i-2773/i-2773.gif (GIF)
    Reduced-size image of the map sheet, 250x210 pixels, 25k bytes.
    http://pubs.usgs.gov/imap/i-2773/i-2773.pdf (PDF)
    Printable representation of map layout, 2.7 MB.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2003Currentness_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. It contains the following vector data types (SDTS terminology):
      • Point
      • String
      • GT-polygon composed of chains
    2. What coordinate system is used to represent geographic features?
      The map projection used is Polyconic.
      Projection parameters:
      Longitude_of_Central_Meridian: -111.625
      Latitude_of_Projection_Origin: 46.75
      False_Easting: 0.00000
      False_Northing: 0.00000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 10
      Ordinates (y-coordinates) are specified to the nearest 10
      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?
    Entity_and_Attribute_Overview:
    ---------------------------------------------------------------
    COVERAGE NAME: hogpoly.pat
    ---------------------------------------------------------------
    COLUMN  ITEM NAME    WIDTH  OUTPUT  TYPE  N.DEC  ALTERNATE NAME   INDEXED?
    1    AREA                8      18     F      5                        -
    9    PERIMETER           8      18     F      5                        -
    17   HOGBACKPOLY#        4       5     B      -                        -
    21   HOGBACKPOLY-ID      4       5     B      -                        -
    25   LABEL              10      10     C      -                        -
    35   SHADESYM            4       4     I      -                        -
    39   DESCRIPTION       100     100     C      -   DESC                 -
    139  PATTERN            10      10     I      -                        -
    ------------------------------------
    USER-DEFINED ITEMS IN HOGPOLY.PAT:
    ------------------------------------
    ITEM NAME: LABEL
    DATABASE ITEM STRUCTURE: 10,10,C,0
    DESCRIPTION  text description of feature type
    ITEM VALUES FOR 'LABEL':
    Cf
    Cm
    Cpp
    Cw
    DCu
    Dj
    Dm
    Jme
    Khd
    Kk
    MDt
    Mbk
    Mbu
    Ml
    Mm
    OGb
    PPpq
    Pa
    QTg
    Qa
    Ql
    Qog
    Yg
    Yn
    ITEM NAME: SHADESYM
    DATABASE ITEM STRUCTURE: 4,4,I,0
    DESCRIPTION  shade symbol value from shadeset color524.shd to fill polygons
    ITEM VALUES FOR 'SHADESYM':
    0
    4
    30
    52
    55
    60
    71
    100
    102
    143
    164
    233
    261
    263
    264
    274
    300
    304
    346
    410
    453
    511
    530
    533
    611
    ITEM NAME: DESCRIPTION
    DATABASE ITEM STRUCTURE: 100,100,C,0
    DESCRIPTION  text description of feature type
    ITEM VALUES FOR 'DESCRIPTION':
    Flathead Sandstone (Middle Cambrian)
    Meagher Limestone (Middle Cambrian)
    Pilgrim Formation and Park Shale, undivided (Upper and Middle Cambrian)
    Wolsey Shale (Middle Cambrian)
    Devonian and Cambrian rocks undivided
    Jefferson Formation (Upper Devonian)
    Maywood Formation (Upper and Middle Upper Devonian)
    Morrison Formation and Ellis Group undivided (Jurassic)
    Hornblende diorite (Upper Cretaceous)
    Kootenai Formation (Lower Cretaceous)
    Big Snowy Group, Kibbey Formation (Upper Mississippian)
    Big Snowy Group, Health and Otter Formations, undivided (Upper Mississippian)
    Three Forks Formation (Lower Mississippian and Upper Devonian)
    Lodgepole Limestone (Lower Mississippian)
    Mission Canyon Limestone (Upper and Lower Mississippian)
    Basalt (Oligocene)
    Amsden Formation  (Pennsylvanian)
    Phosphoria and Quadrant Formations, undivided (Permian and Pennsylvanian)
    Alluvium (Holocene)
    Landslide deposits (Holocene and Pleistocene)
    Old gravel (Holocene and Pleistocene)
    Older gravel (Pleistocene and Pliocene)
    Greyson Formation (Belt Supergroup, Middle Proterozoic)
    Newland Formation (Belt Supergroup, Middle Proterozoic)
    Diorite sills (Upper Proterozoic)
    ITEM NAME: PATTERN
    DATABASE ITEM STRUCTURE: 10,10,I,0
    DESCRIPTION  Indicates cross hatch sections
    ITEM VALUES FOR 'PATTERN':
    0
    101
    *******************************************************************************
    ---------------------------------------------------------------
    COVERAGE NAME: hogpoly.aat
    ---------------------------------------------------------------
    COLUMN  ITEM NAME    WIDTH  OUTPUT  TYPE  N.DEC  ALTERNATE NAME   INDEXED?
    1   FNODE#               4       5     B      -                        -
    5   TNODE#               4       5     B      -                        -
    9   LPOLY#               4       5     B      -                        -
    13  RPOLY#               4       5     B      -                        -
    17  LENGTH               8      18     F      5                        -
    25  HOGBACKPOLY#         4       5     B      -                        -
    29  HOGBACKPOLY-ID       4       5     B      -                        -
    33  LINECODE             4       4     I      -                        -
    37  DESCRIPTION         80      80     C      -    DESC                -
    ------------------------------------
    USER-DEFINED ITEMS IN HOGPOLY.AAT:
    ------------------------------------
    ITEM NAME: LINECODE
    DATABASE ITEM STRUCTURE: 4,4,I,0
    DESCRIPTION  set lineset values for line coding
    ITEM VALUES FOR 'LINECODE':
    1
    2
    3
    4
    15
    20
    22
    24
    26
    35
    51
    176
    183
    184
    216
    217
    218
    220
    221
    222
    223
    227
    321
    328
    330
    ITEM NAME: DESCRIPTION
    DATABASE ITEM STRUCTURE: 80,80,C,0
    DESCRIPTION  text description of linear feature type
    ITEM VALUES FOR 'DESCRIPTION':
    contact - approximately located
    contact - certain
    contact - concealed
    contact - inferred
    dike - OGb
    dike Khd - approximately located
    dike Khd - certain
    dike Zd - approximately located
    dike Zd - certain
    fault - approximately located
    fault - certain
    fault - inferred
    fault displacement unknown - concealed
    neatline
    normal fault - concealed
    normal fault - inferred
    overturn thrust fault - approximately located
    overturn thrust fault - certain
    thrust fault - approximate location queried
    thrust fault - approximately located
    thrust fault - certain
    thrust fault - concealed
    thrust fault - inferred
    thrust fault - inferred, queried
    ******************************************************************************
    ---------------------------------------------------------------
    COVERAGE NAME: hogline
    ---------------------------------------------------------------
    COLUMN  ITEM NAME    WIDTH  OUTPUT  TYPE  N.DEC  ALTERNATE NAME   INDEXED?
    1    FNODE#              4       5     B      -                        -
    5    TNODE#              4       5     B      -                        -
    9    LPOLY#              4       5     B      -                        -
    13   RPOLY#              4       5     B      -                        -
    17   LENGTH              8      18     F      5                        -
    25   HOGBACKLINE#        4       5     B      -                        -
    29   HOGBACKLINE-ID      4       5     B      -                        -
    33   LINECODE            3       3     I      -                        -
    36   DESCRIPTION        80      80     C      -    DESC                -
    116  LINESET            30      30     C      -                        -
    ------------------------------------
    USER-DEFINED ITEMS IN HOGLINE.AAT:
    ------------------------------------
    ITEM NAME: LINECODE
    DATABASE ITEM STRUCTURE: 3,3,I,0
    DESCRIPTION  set lineset values for line coding in hogline
    ITEM VALUES FOR 'LINECODE':
    1
    60
    61
    62
    80
    81
    92
    93
    94
    112
    113
    114
    121
    332
    ITEM NAME: DESCRIPTION
    DATABASE ITEM STRUCTURE: 80,80,C,0
    DESCRIPTION  text description of linear feature type
    ITEM VALUES FOR 'DESCRIPTION':
    anticline - approximately located
    anticline - certain
    anticline - inferred
    inverted anticline - approximately located
    inverted syncline - approximately located
    line of cross-section A
    line of cross-section B
    line of cross-section C
    line of cross-section D
    overturned anticline - approximately located
    overturned anticline - certain
    overturned syncline, approximately located
    overturned syncline, certain
    overturned syncline, concealed
    overturned syncline, inferred
    syncline - Approximately located
    syncline - certain
    syncline - concealed
    syncline - inferred
    ITEM NAME: LINESET
    DATABASE ITEM STRUCTURE: 30,30,C,0
    DESCRIPTION  identifies linesets used for linear symbolset
    ITEM VALUES FOR 'LINESET':
    geol_sfo.lin
    plotter
    ********************************************************************************
    ---------------------------------------------------------------
    COVERAGE NAME: hogpoint
    ---------------------------------------------------------------
    COLUMN  ITEM NAME    WIDTH  OUTPUT  TYPE  N.DEC  ALTERNATE NAME   INDEXED?
    1    AREA                8      18     F      5                        -
    9    PERIMETER           8      18     F      5                        -
    17   HOGBACKPT#          4       5     B      -                        -
    21   HOGBACKPT-ID        4       5     B      -                        -
    25   SYMBOL              3       3     I      -                        -
    28   ROTATION            3       3     I      -    AZIMUTH             -
    31   INCLINATION         3       3     I      -    DIP                 -
    34   DESCRIPTION        80      80     C      -    DESC                -
    118  SYMSET             10      10     C      -                        -
    ------------------------------------
    USER-DEFINED ITEMS IN HOGPOINT.PAT:
    ------------------------------------
    ITEM NAME: SYMBOL
    DATABASE ITEM STRUCTURE: 3,3,I,0
    DESCRIPTION  value used to identify symbol from markerset
    ITEM VALUES FOR 'SYMBOL':
    1
    2
    3
    6
    7
    15
    101
    109
    114
    133
    742
    743
    746
    747
    ITEM NAME: ROTATION
    DATABASE ITEM STRUCTURE: 3,3,I,0
    DESCRIPTION  compass orientation of feature, in degrees
    ITEM VALUES FOR 'ROTATION':
    0
    4
    7
    13
    20
    30
    35
    37
    57
    58
    60
    65
    67
    70
    73
    80
    82
    83
    85
    88
    90
    92
    94
    95
    98
    100
    102
    103
    105
    107
    108
    110
    112
    113
    114
    115
    116
    117
    118
    120
    125
    127
    128
    130
    132
    133
    135
    137
    140
    142
    143
    145
    147
    148
    150
    153
    155
    157
    160
    162
    163
    165
    166
    168
    170
    173
    175
    177
    180
    185
    195
    205
    210
    213
    215
    220
    225
    230
    235
    236
    240
    247
    248
    255
    257
    258
    260
    262
    270
    273
    274
    275
    279
    283
    287
    290
    293
    294
    297
    300
    303
    305
    310
    312
    313
    315
    318
    327
    330
    335
    338
    342
    345
    348
    350
    ITEM NAME: INCLINATION
    DATABASE ITEM STRUCTURE: 3,3,I,0
    DESCRIPTION  inclination from horizontal of feature, in degrees
    ITEM VALUES FOR 'INCLINATION':
    0
    5
    7
    8
    10
    12
    13
    15
    17
    18
    20
    22
    23
    24
    25
    26
    27
    28
    30
    31
    32
    33
    34
    35
    36
    37
    38
    40
    42
    43
    45
    46
    47
    48
    50
    52
    53
    55
    57
    60
    64
    65
    66
    67
    68
    70
    74
    75
    76
    77
    80
    83
    85
    90
    ITEM NAME: DESCRIPTION
    DATABASE ITEM STRUCTURE: 80,80,C,0
    DESCRIPTION  text description of each symbol
    ITEM VALUES FOR 'DESCRIPTION':
    Dip of fault surface
    Dry oil well
    bedding overturned > 180 degrees - strike and dip
    Zd outcrop too small to show at map scale
    horizontal bedding
    inclined bedding - strike and dip
    inclined cleavage - strike and dip
    overturned bedding - strike and dip
    prospect
    quartz vein
    spring
    vertical bedding
    ITEM NAME: SYMSET
    DATABASE ITEM STRUCTURE: 10,10,C,0
    DESCRIPTION  defines markersets used
    ITEM VALUES FOR 'SYMSET':
    GEOSCAMP2
    MUNICIPAL
    OILGAS
    USGS
    
    Entity_and_Attribute_Detail_Citation: http://pubs.usgs.gov/imap/i-2773/i-2773_508.pdf

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?
    Radiometric dating of samples from adjacent areas applicable to this quadrangle was performed by Harald H. Mehnert, U.S. Geological Survey. Technical reviews by Karl K. Kellogg and David A. Lindsey, U.S. Geological Survey, helped improve the quality of the geologic map, illustrations, and text. Sharon A. Smith graciously and painstakingly translated the map data into digital files. Carlos Vulgamott made preliminary digital copy of the map and cross sections.
  3. To whom should users address questions about the data?
    Mitchell W. Reynolds
    U.S. Geological Survey
    P.O. Box 25046 Federal Center, MS 913
    Denver, CO
    USA

    303-236-8007 (voice)
    303-236-5349 (FAX)
    mwreynol@usgs.gov

Why was the data set created?

The geologic map of the Hogback Mountain quadrangle provides new geologic information for public use and for use by governmental agencies for land-use planning, including assessment of natural resources, natural hazards, and recreational potential, and for land-use management. The map provides an interpretation of the complex geology and terrain to recreationalists using the Gates of the Mountains Wilderness. The map provides data for scientific interpretation of the geology of part of the south end of the Montana disturbed belt.

How was the data set created?

  1. From what previous works were the data drawn?
    Billingsley and Locke (1939) (source 1 of 9)
    Billingsley, P.R., and Locke, Augustus, 1939, Structure of ore deposits in the continental framework: American Institute of Mining and Metallurgical Engineers, New York.

    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Folk (1962) (source 2 of 9)
    Folk, R.L., 1962, Spectral subdivision of limestone types: American Association of Petroleum Geologists Memoir 1, American Association of Petroleum Geologists, Tulsa, Oklahoma.

    Other_Citation_Details: p. 62-84
    This is part of the following larger work.

    Ham, W. E., (ed.), 1962, Classification of carbonate rocks--A symposium: American Association of Petroleum Geologists Memoir 1, American Association of Petroleum Geologists, Tulsa, Oklahoma.

    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Harrison and Reynolds (1976) (source 3 of 9)
    Harrison, J.E., and Reynolds, M.W., 1976, Western U.S. continental margin--A stable platform dominated by vertical tectonics in the late Precambrian: Geological Society of America Abstracts with Programs 8 (6), Geological Society of America, Boulder, Colorado.

    Other_Citation_Details: p. 905
    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Hobbs and others (1965) (source 4 of 9)
    Hobbs, S.W., Griggs, A.B., Wallace, R.E., and Campbell, A.B., 1965, Geology of the Coeur d'Alene District, Shoshone County, Idaho: U.S. Geological Survey Professional Paper 478, U.S. Geological Survey, Denver, Colorado.

    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Reynolds (1977) (source 5 of 9)
    Reynolds, M.W., 1977, Character and significance of deformation at the east end of the Lewis and Clark line, Montana: Geological Society of America Abstracts with Programs 9 (6), Geological Society of America, Boulder, Colorado.

    Other_Citation_Details: pp. 758-759
    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Reynolds (1979) (source 6 of 9)
    Reynolds, M.W., 1979, Character and extent of basin-range faulting, western Montana and east-central Idaho: Rocky Mountain Association of Geologists, Denver, Colorado.

    Other_Citation_Details: p. 185-193
    This is part of the following larger work.

    Newman, G.W. (ed.), and Goode, H.D. (ed.), 1979, RMAG and UGA 1979 Basin and Range Symposium: Rocky Mountain Association of Geologists, Denver, Colorado.

    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Reynolds and Close(1984) (source 7 of 9)
    Reynolds, M.W., and Close, T.J., 1984, Gates of the Mountains Wilderness and additions, Montana: U.S. Geological Survey Professional Paper 1300, v. 2, U.S. Geological Survey, Denver, Colorado.

    Other_Citation_Details: p. 705-708
    This is part of the following larger work.

    Marsh, S.P. (ed.), Kropschot, S.J. (ed.), and Dickinson, R.G. (ed.), 1984, Wilderness Mineral Potential: U.S. Geological Survey Professional Paper 1300, v. 2, U.S. Geological Survey, Denver, Colorado.

    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
    Reynolds and Hays(2003) (source 8 of 9)
    Reynolds, M.W., and Hays, W.H., 2003, Geologic map of the Nelson quadrangle, Lewis and Clark County, Montana: U.S. Geological Survey Geologic Investigations Series I-2774, U.S. Geological Survey, Denver, Colorado.

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000
    Source_Contribution: preliminary geologic information
    Reynolds and Kleinkopf(1977) (source 9 of 9)
    Reynolds, M.W., and Kleinkopf, M.D., 1977, The Lewis and Clark line, Montana-Idaho--A major intraplate tectonic boundary: Geological Society of America Abstracts with Programs 9 (7), Geological Society of America, Boulder, Colorado.

    Other_Citation_Details: p. 1140-1141
    Type_of_Source_Media: paper
    Source_Contribution: preliminary geologic information
  2. How were the data generated, processed, and modified?
    Date: 2001 (process 1 of 7)
    Polygons, lines, and points representing geologic features and data points were digitized from scale-stable compilation materials using ARC/INFO software.
    Date: 2001 (process 2 of 7)
    Draft check plots of the geologic map and explanation were created and submitted for peer review. Geologists reviewed the plots for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. Revisions were made to geospatial database as needed.
    Date: 2001 (process 3 of 7)
    First draft of metadata created by Sharon Smith using FGDCMETA.AML ver. 1.32 01/11/99
    Date: 2001 (process 4 of 7)
    Geospatial database files and metadata were quality checked for completeness and consistency.
    Date: 2001 (process 5 of 7)
    Database files, metadata, and check plots were edited by the USGS Central Publications Group, and revisions made to the geospatial database as needed.
    Date: 2001 (process 6 of 7)
    Final preparation of the geospatial database for distribution, and preparation of map information for publication.
    Date: 03-Dec-2002 (process 7 of 7)
    Creation of original metadata record Person who carried out this activity:
    U.S. Geological Survey
    Attn: Theodore R. Brandt, Sharon Smith
    Box 25046, Federal Center, MS-913
    Denver, CO
    USA

    303-236-1901, 303-236-4610 (voice)
    tbrandt@usgs.gov, ssmith@usgs.gov
  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?
    Geologic data were entered in the field directly on the Hogback Mountain topographic base map at a scale of 1:24,000. Location of control and data points was made by instrument resection and by inspection where topographic contours were distinct. Elevations were checked in the field using an altimeter calibrated at base stations and at surveyed elevations from the topographic base map. Data were transferred from field sheets to a scale-stable mylar base map, and separate scale-stable registered overlays were constructed for polygons, lines, symbols, and tags. Color check test plots were compared carefully to the original geologic map, and corrections were made as needed. The map has been thoroughly reviewed for conformity with U.S. Geological Survey stratigraphic nomenclature and editorial standards.
  2. How accurate are the geographic locations?
    Lines and data points were located in the field by instrument resection and by inspection from the topographic base map where topographic contours are distinct. Elevations were checked in the field using an altimeter calibrated at base stations and at surveyed elevations from the topographic base map. Thus line and points on original field maps generally were located with a vertical position accuracy of less than one contour interval and a horizontal position accuracy of about 15 m. Lines and points were digitized from the scale-stable geologic base map using a digitizer tablet with a resolution of 0.001 inch. Information is added in accordance to U.S. National Map Accuracy Standards, Revised June 17, 1947. 95 percent of points plotted on mylar matched the source map within 1/50 inch.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    No features that could be accurately represented at the compilation scale of 1:24,000 were eliminated or generalized. The smallest area represented is about 113 square meters. All geospatial database elements are attributed.
  5. How consistent are the relationships among the observations, including topology?
    Map elements were visually checked for overshoots, undershoots, duplicate features, polygon closure, and other errors by the author and by the GIS technicians who created/edited the digital database. Automated (ARC/INFO) routines were also used to check the databases for polygon label errors, line or point attribution errors, sliver polygons, dangling arcs, intersection errors, and projection information. Check plots of the map were reviewed by at least two other geologists for consistency with basic geologic principles and general conformity to USGS mapping standards.

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. However, citation of publication reference and acknowledgment of the U.S. Geological Survey would be appreciated in all products that use or are derived from these data. These data should not be used at scales larger than 1:24,000.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Central Publications Group
    Denver, CO
    USA

    1-888-ASK-USGS (voice)
  2. What's the catalog number I need to order this data set? USGS Geologic Investigations Series Map I-2773
  3. What legal disclaimers am I supposed to read?
    Although these data have been subjected to rigorous review and are substantially complete, they are released on the condition that neither the U.S. Geological Survey nor the Unites States Government may be held liable for any damages resulting from their authorized or unauthorized use.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 13-Jun-2016
Metadata author:
Peter N Schweitzer
USGS Midwest Area
Collection manager, USGS Geoscience Data Clearinghouse, http://geo-nsdi.er.usgs.gov/
Mail Stop 954
12201 Sunrise Valley Dr
Reston, VA
USA

703-648-6533 (voice)
703-648-6252 (FAX)
pschweitzer@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://geo-nsdi.er.usgs.gov/metadata/map-i/2773/metadata.faq.html>

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URL: https://geo-nsdi.er.usgs.gov/metadata/map-i/2773/metadata.faq.html
Page Contact Information: Peter Schweitzer
Page Last Modified: Monday, 14-Aug-2017 12:01:00 EDT

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