Geologic Map of the Devore 7.5' quadrangle, San Bernardino County, California

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Title:
Geologic Map of the Devore 7.5' quadrangle, San Bernardino County, California
Abstract:
This data set maps and describes the geology of the Devore 7.5' quadrangle, San Bernardino County, California. Created using Environmental Systems Research Institute's ARC/INFO software, the data base consists of the following items: (1) a map coverage containing geologic contacts and units, (2) attribute tables for geologic units (polygons), contacts (arcs), and site-specific data (points). In addition, the data set includes the following graphic and text products: (1) A PostScript graphic plot-file containing the geologic map, topography, cultural data, a Correlation of Map Units (CMU) diagram, a Description of Map Units (DMU), an index map, a regional geologic and structure map, and a key for point and line symbols; (2) PDF files of this Readme (including the metadata file as an appendix), Description of Map Units (DMU), and the graphic produced by the PostScript plot file.
The Devore quadrangle straddles part of the boundary between two major physiographic provinces of California, the Transverse Ranges Province to the north and the Peninsular Ranges Province to the south. The north half of the quadrangle includes the eastern San Gabriel Mountains and a small part of the western San Bernardino Mountains, both within the east-central part of the Transverse Ranges Province. South of the Cucamonga and San Andreas Fault zones, the extensive alluviated area in the south half of the quadrangle lies within the upper Santa Ana River Valley, and represents the northernmost part of the Peninsular Ranges Province.
There are numerous active faults within the quadrangle, including right-lateral strike-slip faults of the San Andreas Fault system, which dominate the younger structural elements, and separate the San Gabriel from the San Bernardino Mountains. The active San Jacinto Fault zone projects toward the quadrangle from the southeast, but its location is poorly constrained not only within the quadrangle, but for at least several kilometers to the southeast. As a result, the interrelation between it, the Glen Helen Fault, and the probable easternmost part of the San Gabriel Fault is intrepretive. Thrust faults of the Cucamonga Fault zone along the south margin of the San Gabriel Mountains, represent the rejuvinated eastern end of a major old fault zone that bounds the south side of the western and central Transverse Ranges (Morton and Matti, 1993). Rejuvenation of this old fault zone, including the Cucamonga Fault zone, is apparently in response to compression in the eastern San Gabriel Mountains resulting from initiation of right-lateral slip on the San Jacinto Fault zone in the Peninsular Ranges.The structural grain within the San Gabriel Mountains, as defined by basement rocks, is generally east striking. Within the Devore quadrangle, these basement rocks include a Paleozoic (?) schist, quartzite, and marble metasedimentary sequence, which occurs as discontinuous lenses and septa within Cretaceous granitic rocks. Most of the granitic rocks are of tonalitic composition, and much of them are mylonitic. South of the granitic rocks is a complex assemblage of Proterozoic (?) metamorphic rocks, at least part of which is metasedimentary. The assemblage was metamorphosed to upper amphibolite and lower granulite grade, and subsequently remetamorphosed to a lower metamorphic grade. It is also intensely deformed by mylonitization which is characterized by an east striking, north dipping foliation, and by a pronounced lineation that plunges shallowly east and west.
East of Lytle Creek and west of the San Andreas Fault zone, the predominant basement lithology is Mesozoic Pelona Schist, which consists mostly of greenschist grade metabasalt and metagraywacke. Intruding the Pelona Schist, between Lytle Creek and Cajon Canyon, is the granodiorite of Telegraph Peak of Oligocene age (May and Walker, 1989). East of the San Andreas Fault in the San Bernardino Mountains, basement rocks consist of amphibolite grade gneiss and schist intermixed with concordant and discordant tonalitic rock and pegmatite. Tertiary conglomerate and sandstone occur in the Cucamonga Fault zone and in a zone 200 to 700 m wide between strands of the San Andreas Fault zone and localized thrust faults northeast of the San Andreas. Most of the conglomerate and sandstone within the Cucamonga Fault zone is overturned forming the north limb of an overturned syncline. Clasts in the conglomerate are not derived from any of the basement rocks in the eastern San Gabriel Mountains. Clasts in the conglomerate and sandstone northeast of the San Andreas Fault zone do not appear to be locally derived either. The south half of the quadrangle is dominated by the large symmetrical alluvial-fan emanating from the canyon of Lytle Creek, and by the complex braided stream sediments of Lytle Creek and Cajon Wash.
The San Andreas Fault is restricted to a relatively narrow zone marked by a pronounced scarp that is especially well exposed near the east margin of the quadrangle. Two poorly exposed, closely spaced, north-dipping thrust faults northeast of the San Andreas Fault have dips that appear to range from 55ƒ to near horizontal. The shallower dips probably are the result of rotation of initially steeper fault surfaces by downhill surface creep. Between the San Andreas and Glen Helen Fault zones, there are several faults that have north facing scarps, the largest of which are the east striking Peters Fault and the northwest striking Tokay Hill Fault. The Tokay Hill Fault is at least in part a reverse fault. Scarps along both faults are youthful appearing.
The Glen Helen Fault zone along the west side of Cajon Creek, is well defined by a pronounced scarp from the area north of Interstate 15, south through Glen Helen Regional Park; an elongate sag pond is located within the park.
The large fault zone along Meyers Canyon, between Penstock and Lower Lytle Ridges, is probably the eastward extension of the San Gabriel Fault zone that is deformed into a northwest orientation due to compression in the eastern San Gabriel Mountains (Morton and Matti, 1993). At the south end of Sycamore Flat, this fault zone consists of three discreet faults distributed over a width of 300 m. About 2.5 km northwest of Sycamore Flats, it consists of a 300 m wide shear zone. At the north end of Penstock Ridge, the fault zone has bifurcated into four strands, which at the northwest corner of the quadrangle are distributed over a width of about one kilometer. From the northern part of Sycamore Flat, for a distance of nearly 5 km northwestward, a northeast dipping reverse fault is located along the east side of the probable San Gabriel Fault zone. This youthful reverse fault has locally placed the Oligocene granodiorite of Telegraph Peak over detritus derived from the granodiorite.
The Lytle Creek Fault, which is commonly considered the western splay of the San Jacinto Fault zone, is located on the west side of Lytle Creek. Lateral displacement on the Lytle Creek Fault has offset parts of the old Lytle Creek channel; this offset gravel-filled channel is best seen at Texas Hill, near the mouth of Lytle Creek, where the gravel was hydraulic mined for gold in the 1890s.
The Cucamonga Fault zone consists of a one kilometer wide zone of northward dip- ping thrust faults. Most splays of this fault zone dip north 25ƒ to 35ƒ.
The geologic map database contains original U.S. Geological Survey data generated by detailed field observation and by interpretation of aerial photographs. This digital Open-File map supercedes an older analog Open-File map of the quadrangle, and includes extensive new data on the Quaternary deposits, and revises some fault and bedrock distribution within the San Gabriel Mountains. The digital map was compiled on a base-stable cronoflex copy of the Devore 7.5í topographic base and then scribed. This scribe guide was used to make a 0.007 mil blackline clear-film, from which lines and point were hand digitized. Lines, points, and polygons were subsequently edited at the USGS using standard ARC/INFO commands. Digitizing and editing artifacts significant enough to display at a scale of 1:24,000 were corrected. Within the database, geologic contacts are represented as lines (arcs), geologic units as polygons, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum.
  1. How might this data set be cited?
    Morton, Douglas M., and Matti, Jonathan C., 2001, Geologic Map of the Devore 7.5' quadrangle, San Bernardino County, California: U.S. Geological Survey Open-File Report 01-173, U.S. Geological Survey, Menlo Park, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -117.50009251
    East_Bounding_Coordinate: -117.37490753
    North_Bounding_Coordinate: 34.24999997
    South_Bounding_Coordinate: 34.12498409
  3. What does it look like?
    http://geo-nsdi.er.usgs.gov/metadata/open-file/01-173/browse.png (PNG)
    Non-navigable image of the geologic map, topographic base, Correlation of Map Units, Description of Map Units and key to point and line symbols.
    http://pubs.usgs.gov/of/2001/0173/pdf/of01-173_map.pdf (PDF)
    Navigable portable document file (.pdf) image of the geologic map, topographic base, Correlation of Map Units, Description of Map Units and key to point and line symbols.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 01-Apr-1974
    Ending_Date: 01-Aug-1981
    Currentness_Reference:
    New data and previously published data
  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):
      • Point (1517)
      • String (3724)
      • GT-polygon composed of chains (1518)
    2. What coordinate system is used to represent geographic features?
      The map projection used is Polyconic.
      Projection parameters:
      Longitude_of_Central_Meridian: -117.4375
      Latitude_of_Projection_Origin: 34.1250
      False_Easting: 0.00000
      False_Northing: 0.00000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.0027668476104
      Ordinates (y-coordinates) are specified to the nearest 0.0027668476104
      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:
    Version 1.0 of the Devore 7.5' quadrangle comprises three ARC/INFO coverages, of which two contain geologic data and one contains cartographic features: devre_geo (geology), devre_str (structural point data), and devre_ldr (annotation leaders). Line and point identities are recorded in the .aat and .pat tables using a system of identity codes. Two INFO tables, lines.rel and points.rel provide a full description of each of the geologic line and point codes in the database. A full source citation is provided in the Entity_and Attribute_Detail_Citation section of this metadata document.
    Geologic data represented by line entities and the polygons they delineate are contained in the coverage DEVRE_GEO. For display purposes, the geology coverage contains two annotation subclasses: anno.geo contains unit labels, and anno.fault contains formal, fault names.
    Geological point data includes site-specific information describing the types and the orientation of bedding, foliation, and lineations. One annotation subclass is included in the geologic points coverage, DEVRE_STR: anno.dip displays the respective dip and plunge values associated with individual point data.
    Entity_and_Attribute_Detail_Citation:
    A complete description of the polygon, line, and point data coding schemes is available in U.S. Geological Survey Open-File Reports OFR 97-859, OFR 97-860, and OFR 97-861 (full source citations follow):
    Matti, J.C., Miller, F.K., Powell, R.E., Kennedy, S.A., Bunyapanasarn, T.P., Koukladas, Catherine, Hauser, R.M., and Cossette, P.M., 1997b, Geologic-point attributes for digital geologic-map databases produced by the Southern California Areal Mapping Project (SCAMP), Version 1.0: U.S.Geological Survey Open-File Report 97-859
    Matti, J.C., Miller, F.K., Powell, R.E., Kennedy, S.A., and Cossette, P.M., 1997c, Geologic-polygon attributes for digital geologic-map databases produced by the Southern California Areal Mapping Project (SCAMP), Version 1.0: U.S.Geological Survey Open-File Report 97-860
    Matti, J.C., Powell, R.E., Miller, F.K., Kennedy, S.A., Ruppert, K.R., Morton, G.L., and Cossette, P.M., 1997a, Geologic-line attributes for digital geologic-map databases produced by the Southern California Areal Mapping Project (SCAMP), Version 1.0: U.S.Geological Survey Open-File Report 97-861
    devre_geo.pat
    Geologic units (LABL) and their corresponding names (NAME) identified in the Devore 7.5'quadrangle
    SHDPS
    polygon color (as integer value) from shadeset scamp2.shd (included in the data package)
    SHDFIL
    polygon fill pattern (as integer value) from shadeset geology2.shd (included in the data package)
    LABL
    geologic map unit label, in plain text
    ValueDefinition
    KgMonzogranite and granodiorite
    KgcMylonitic leucogranite
    KgmLeucocratic muscovite monzogranite
    KmgBiotite monzogranite
    KtTonalite of San Sevaine Lookout
    Ktm1Mylonitized tonalite of San Sevaine Lookout
    MzgnGneiss east of San Andreas Fault zone
    MzpgGreenstone
    MzpsSiliceous schist
    TMztpPelona Schist and granodiorite of Telegraph Peak
    MzpwMuscovite schist
    PrgGranulitic gneiss, mylonite, and cataclasite, unretrograded
    PrmGranulitic gneiss, mylonite, and cataclasite
    PzsSchist and gneiss
    KPzgsSchist, gneiss, monzogranite, and granodiorite
    KPztsSchist, gneiss, and tonalite
    QafArtificial fill
    QcModern colluvial deposits
    QfModern alluvial-fan deposits
    Qf1Modern alluvial-fan deposits, Unit 1
    QfbModern alluvial-fan deposits, boulder gravel
    QfgModern alluvial-fan deposits, gravel
    QlsModern landslide deposits
    QoaOld alluvial-valley deposits
    Qoa1Old alluvial-valley deposits, Unit 1
    QofOld alluvial-fan deposits
    Qof1bOld alluvial-fan deposits, Unit 1, boulder gravel
    Qof2bOld alluvial-fan deposits, Unit 2, boulder gravel
    Qof3Old alluvial-fan deposits, Unit 3
    QofbOld alluvial-fan deposits, boulder gravel
    QolsOld landslide deposits
    QswModern slopewash deposits
    QtModern talus deposits
    QuarryDisturbed ground
    QvofVery old alluvial-fan deposits
    Qvof1bVery old alluvial-fan deposits, Unit 1, boulder gravel
    Qvof2Very old alluvial-fan deposits, Unit 2
    Qvof2bVery old alluvial-fan deposits, Unit 2, boulder gravel
    Qvof2gVery old alluvial-fan deposits, Unit 2, gravel
    QvofbVery old alluvial-fan deposits, boulder gravel
    QvolsaVery old landslide deposits, arenaceous
    QvowbVery old wash deposits, boulder gravel
    QwModern wash deposits
    Qw1Modern wash deposits, Unit 1
    Qw2Modern wash deposits, Unit 2
    Qw2bModern wash deposits, Unit 2, boulder gravel
    QwbModern wash deposits, boulder gravel
    Qya4Young alluvial-valley deposits, Unit 4
    Qya5Young alluvial-valley deposits, Unit 5
    QyfYoung alluvial-fan deposits
    Qyf1bYoung alluvial-fan deposits, Unit 1, boulder gravel
    Qyf2bYoung alluvial-fan deposits, Unit 2, boulder gravel
    Qyf3Young alluvial-fan deposits, Unit 3
    Qyf3bYoung alluvial-fan deposits, Unit 3, boulder gravel
    Qyf4Young alluvial-fan deposits, Unit 4
    Qyf4bYoung alluvial-fan deposits, Unit 4, boulder gravel
    Qyf4gYoung alluvial-fan deposits, Unit 4, gravel
    Qyf5Young alluvial-fan deposits, Unit 5
    Qyf5bYoung alluvial-fan deposits, Unit 5, boulder gravel
    QyfbYoung alluvial-fan deposits, boulder gravel
    QyfcYoung alluvial-fan deposits, clayey
    QyfgYoung alluvial-fan deposits, gravel
    QylsYoung landslide deposits
    QytYoung talus deposits
    QywYoung wash deposits
    TaAndesitic dikes
    TcConglomerate
    Tc1Volcanic-clast conglomerate
    Td3Olivine diabase and gabbro
    TtdHypabyssal dike
    TtpGranodiorite of Telegraph Peak
    TsArkosic sandstone
    cgm1Chloritized, cataclastic granitic rock
    fzCrushed rock in fault zones
    gnmCataclastic gneiss
    mMarble
    PLABL
    Coded geologic map unit label used to generate plot labels with relevant stratigraphic symbols. The geologic units with LABL designating Mesozoic (Mz), Paleozoic (Pz), and Proterozoic (Pr) have keystroke substitute characters, }, |, and < respectively, that call their corresponding symbols from the Geoage Font Group. Geologic map unit labels will plot on derivative map plots with appropriate stratigraphic symbols if PLABL is used as the source for unit labels. The Geoage Font Group is accessed through geofont.txt. The GeoAge Font Group and relevant information are available by anonymous FTP from: Server: onyx.wr.usgs.gov
    NAME
    Geologic name of map unit (see list under LABL attribute)
    devre_geo.aat
    Geologic features such as contacts and faults that bound rock-unit polygons (a complete description of each line type is available in the data table, lines.rel.)
    L-TAG
    Coded alpha-numerical symbol that relates arc to definition of line type in dictionary look-up table (lines.rel). For description of attributes in line classification dictionary, refer to USGS Open-File Report 97-861 (see Entity_and_Attribute_Detail_Citation)
    ValueDefinition
    C1Contact, generic, certain, location meets map accuracy standard
    C100Contact, scratch boundary, metamorphic
    C17Contact, landslide, certain, location meets map accuracy standard
    C18Contact, landslide, certain, location may not meet map accuracy standard
    C19Contact, landslide, inferred, location may not meet map accuracy standard
    C20Contact, landslide, concealed, location may not meet map accuracy standard
    C29Contact, sedimentary, certain, location meets map accuracy standard
    C30Contact, sedimentary, certain, location may not meet map accuracy standard
    C31Contact, sedimentary, inferred, location may not meet map accuracy standard
    C32Contact, sedimentary, concealed, location may not meet map accuracy standard
    C34Contact, sedimentary, questionable, location may not meet map accuracy standard
    C37Contact, sedimentary, separates terraced alluvial units, certain, location meets map accuracy standard
    C38Contact, sedimentary, certain, separates terraced alluvial units, location may not meet map accuracy standard
    C49Contact, igneous, location meets map accuracy standard
    C50Contact, igneous, location may not meet map accuracy standard
    C51Contact, igneous, inferred, location may not meet map accuracy standard
    C66Contact, metamorphic, certain, location may not meet map accuracy standard
    C67Contact, metamorphic, inferred, location may not meet map accuracy standard
    C99Contact, igneous, scratch boundary
    CL1Cartographic line, map boundary
    F1Fault, high angle, slip unspecified, location meets map accuracy standard
    F11Fault, high angle, reverse slip, location may not meet map accuracy standard
    F13Fault, high angle, slip unspecified, inferred, location may not meet map accuracy standard
    F177Fault, thrust, older over younger, certain, location meets map accuracy standard
    F178Fault, thrust, older over younger, certain, location may not meet map accuracy standard
    F180Fault, thrust, older over younger, concealed, location may not meet map accuracy standard
    F182RFault, thrust, older over younger, questionable, location may not meet map accuracy standard
    F183RFault, thrust, older over younger, questionable, concealed, location may not meet map accuracy standard
    F19Fault, high angle, slip unspecified, concealed, location may not meet map accuracy standard
    F193Fault, thrust, older over younger, scarp, certain, location meets map accuracy standard
    F2Fault, high angle, right lateral strike slip, certain, location meets map accuracy standard
    F20Fault, high angle, right lateral strike slip, concealed, location may not meet map accuracy standard
    F37Fault, high angle, slip unspecified, questionable, concealed, location may not meet map accuracy standard
    F44Fault, high angle, right lateral strike slip, questionable, concealed, location may not meet map accuracy standard
    F49Fault, high angle, slip unspecified, scarp, certain, location meets map accuracy standard
    F50Fault, high angle, right lateral strike slip, scarp, certain, location meets map accuracy standard
    F55Fault, high angle, slip unspecified, scarp, certain, location may not meet map accuracy standard
    F56Fault, high angle, right lateral strike slip, scarp, certain, location may not meet map accuracy standard
    F61RFault, high angle, slip unspecified, scarp, questionable, location may not meet map accuracy standard
    F7Fault, high angle, slip unspecified, certain, location may not meet map accuracy standard
    F8Fault, high angle, right lateral strike slip, certain, location meets map accuracy standard
    GF9Geomorphic feature, ground failure crown scarp, located well but may not meet map accuracy standard
    L-SYMB
    stores appropriate line symbol value from the lineset geoscamp2.lin
    L-NAME
    Formal name of fault
    devre_str.pat
    Geological point data includes site-specific information describing the types and the orientation of bedding, foliation, and lineations. One annotation subclass is included in the geologic points coverage, DEVRE_STR: anno.dip displays the respective dip and plunge values associated with individual point data.
    P-TAG
    Coded alpha-numerical value that relates point entity to definition of point type in dictionary INFO table, points.rel. For description of attributes in point classification dictionary, refer to USGS Open-File Report 97-859 (see Entity_and_Attribute_Detail_Citation)
    ValueDefinition
    B1Bedding, sedimentary, horizontal
    B2Bedding, sedimentary, inclined
    B4Bedding, sedimentary, vertical
    B6Bedding, sedimentary, overturned
    FC4Direction and dip of fault
    FN42Foliation, metamorphic, inclined
    FN43Foliation, metamorphic, vertical
    L10Lineation, metamorphic, horizontal
    L22Lineation, metamorphic, aligned mineral grains
    L66Lineation, unspecified
    P-SYMB
    Coded integer value that relates point to cartographic point symbol in markerset geoscamp2.mrk
    P-STRIKE
    Azimuthal strike of planar feature
    P-DIP
    Dip of planar feature
    P-DIPDIR
    Azimuthal direction of dip of planar feature
    P-PLUNGE
    Plunge of linear feature
    P-BEARING
    Azimuthal direction of plunge of linear feature
    devre_ldr.aat
    Annotation leaders
    L-SYMB
    Coded integer value (1) that relates arcs to cartographic line symbol in lineset geoscamp2.lin

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Douglas M. Morton
    • Jonathan C. Matti
  2. Who also contributed to the data set?
    Technical review by F.K. Miller led to significant improvements that eventually were reflected in aspects of the database, the plot file, and in the description of the geologic units of the Devore 7.5' quadrangle. Digital review by R.W. Graymer has allowed us to prepare a much improved product.
    Geologic mapping and digital preparation of this report were sponsored jointly by (1) the National Cooperative Geologic Mapping Program of the U.S. Geological Survey, (2) the California Division of Mines and Geology, and (3) the Southern California Areal Mapping Project (SCAMP). In our digital preparation of the data set, carried out in the SCAMP Geographic Information System laboratory at the University of California, Riverside by Gregory L. Morton and Catherine Koukladas, and in the USGS Geographic Information System laboratory of the Mineral Resources Program of the U.S. Geological Survey in Spokane, Washington by Pamela M. Cossette, we received valuable assistance from Rachel Alvarez in Riverside, California, and from Paul C. Hyndman in Spokane, Washington.
  3. To whom should users address questions about the data?
    Douglas M. Morton
    U.S. Geological Survey, Western Region, Earth Surface Processes Team
    Project geologist
    U.S. Geological Survey
    Department of Earth Science
    University of California, Riverside
    Riverside, California
    United States of America

    (909) 276-6397 (voice)
    (909) 276-6295 (FAX)
    scamp@usgs.gov

Why was the data set created?

The data set for the Devore 7.5' quadrangle was prepared under the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) as part of an ongoing effort to develop a regional geologic framework of southern California, and to utilize a Geographical Information System (GIS) format to create regional digital geologic databases. These regional databases are being developed as contributions to the National Geologic Map Database of the National Cooperative Geologic Mapping Program of the USGS.
The digital geologic map database for the Devore 7.5' quadrangle has been created as a general-purpose data set that is applicable to other land-related investigations in the earth and biological sciences. For example, it can be used for groundwater studies in the San Bernardino basin, and for mineral resource evaluation studies, animal and plant habitat studies, and soil studies in the San Bernardino National Forest. The database is not suitable for site-specific geologic evaluations.

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: 1977 (process 1 of 8)
    Field mapping and aerial photograph interpretation; iterative process (D.M. Morton, J.C. Matti).
    Date: 1989 (process 2 of 8)
    Aerial photograph interpretation and limited field checking; iterative process (J.C. Matti).
    Date: 1978 (process 3 of 8)
    Transfer of geologic linework and point data from field maps and aerial photographs to a scale-stable cartographic base of quadrangle (scribeguide) (D.M. Morton and J.C. Matti).
    Date: 1997 (process 4 of 8)
    Description of Map Units and Correlation of Map Units (D.M. Morton, J.C. Matti).
    Date: 1997 (process 5 of 8)
    The geologic map information was hand digitized from a clear-film, right-reading, 0.007 mil thickness, base-stable blackline positive (made by contact photograph from a scribeguide) of the authors-prepared geologic map at 1:24,000 scale (G. Morton, C. Koukladas).
    Date: 1997 (process 6 of 8)
    ARC/INFO database established; cleanup of digitizing artifacts; polygon, arc, and point attribute tables established using model developed for SCAMP coverages. Digitizing and editing artifacts significant enough to display at a scale of 1:24,000 were corrected (P.M. Cossette).
    Date: 14-Feb-2001 (process 7 of 8)
    First draft of metadata created by cossette using FGDCMETA.AML ver. 1.2 05/14/98 on ARC/INFO data set /pool5/b/pcossette/devore/devcovs-of/devre_geo
    Date: 12-Jun-2001 (process 8 of 8)
    Creation of original metadata record Person who carried out this activity:
    U.S. Geological Survey
    Attn: Pamela M. Cossette
    Geographer
    U.S. Geological Survey
    West 904 Riverside Avenue
    Spokane, Washington
    USA

    509-368-3123 (voice)
    509-368-3199 (FAX)
    pcossette@usgs.gov
  3. What similar or related data should the user be aware of?
    Morton, D.M., and Matti, J.C., 1991, Geologic map of the Devore 7.5' quadrangle, San Bernardino County, California: U.S. Geological Survey Open-File Report 90-695, U.S. Geological Survey, Menlo Park, California.

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    Geologic-map units in the Devore quadrangle database were described using standard field methods. Consistent with these methods, the database author has assigned standard geologic attributes to geologic lines, points, and polygons identified in the database.
    Nation-wide geologic-map accuracy standards have not been developed and adopted by the U.S. Geological Survey and other earth-science entities. Until such standards are adopted, the SCAMP project has developed internal map-accuracy standards for 1:24,000-scale geologic maps produced by the project.
    Geologic lines and points on 1:24,000 scale geologic maps are judged to meet SCAMP's internal map-accuracy standards if they are located to within +/-15 meters, relative to topographic or cultural features on the base map.
    Lines and points that meet (or may not meet) this SCAMP internal map-accuracy standard are identified both in the digital database and on derivative geologic-map plots. Within the database, line and point data that are judged to meet the SCAMP internal map-accuracy standard are denoted by the attribute code .MEE. (meets) in the appropriate data table; line and point data that may not meet the SCAMP internal map-accuracy standard are denoted by the attribute code .MNM. (may not meet).
    On any derivative geologic-map plot, line data that are judged to meet the SCAMP internal map-accuracy standard are denoted by solid lines; line data that may not meet the SCAMP internal map-accuracy standard are denoted by dashed or dotted lines. There is no cartographic device for denoting the map-accuracy for geologic-point data (eg. symbols representing bedding, foliation, lineations, etc.).
  2. How accurate are the geographic locations?
    The maximum transformation RMS error acceptable for 7.5' quadrangle transformation and data input is 0.003 (7.6 meters). Horizontal positional accuracy was checked by visual comparison of hard-copy plots with base-stable source data.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    The geologic map and digital database of the Devore 7.5' quadrangle contain new data that have been subjected to rigorous review and are a substantially complete representation of the current state of knowledge concerning the geology of the quadrangle.
  5. How consistent are the relationships among the observations, including topology?
    Polygon and chain-node topology present.
    The areal extent of the map is represented digitally by an appropriately projected (Polyconic projection), mathematically generated box. Consequently, polygons intersecting the lines that comprise the map boundary are closed by that boundary. Polygons internal to the map boundary are completely enclosed by line segments which are themselves a set of sequentially numbered coordinate pairs. Point data are represented by coordinate pairs.

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:
The Devore 7.5' geologic-map database should be used to evaluate and understand the geologic character of the Devore 7.5' quadrangle as a whole. The data should not be used for purposes of site-specific land-use planning or site-specific geologic evaluations. The database is sufficiently detailed to identify and characterize geologic materials and structures. However, it is not sufficiently detailed for site-specific determinations.
Use of this digital geologic map database should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was compiled and edited at a scale of 1:24,000 means that higher resolution information may not have been uniformly retained in the dataset. Plotting at scales larger than 1:24,000 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, although higher resolution data is incorporated in parts of the map, the resolution of the combined output will be limited by the lower resolution data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Information Services
    Box 25286 Denver Federal Center
    Denver, CO
    USA

    303-202-4700 (voice)
    303-202-4693 (FAX)
  2. What's the catalog number I need to order this data set? USGS Open-File Report 01-173
  3. What legal disclaimers am I supposed to read?
    The U.S. Geological Survey (USGS) provides these geographic data "as is." The USGS makes no guarantee or warranty concerning the accuracy of information contained in the geographic data. The USGS further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on computers at the USGS, no warranty, expressed or implied, is made by the USGS regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty.
    In no event shall the USGS have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by USGS.
    This digital, geologic map database of the San Bernardino North 7.5' quadrangle, 1:24,000 map-scale, and any derivative maps thereof, is not meant to be used or displayed at any scale larger than 1:24,000 (e.g., 1:12,000).
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: Geologic units, structural features, associated database tables in format ARCE (version 7.2.1) Size: 2.6
      Network links: http://pubs.usgs.gov/of/2001/0173/devre.tar.gz
    • Cost to order the data: none

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/open-file/01-173/metadata.faq.html>
Generated by mp version 2.9.48 on Tue Jul 03 20:05:36 2018