The Yucaipa 7.5' quadrangle is located at the southeastern margin of the San Bernardino Basin, an extensional region situated within a right-step-over zone between the San Jacinto and San Andreas Fault zones. The quadrangle is traversed by several faults of the San Andreas system, including (from oldest to youngest) the Banning Fault and the Wilson Creek, Mission Creek, Mill Creek, and San Bernardino Strands of the San Andreas Fault.
The Mill Creek Strand of the San Andreas Fault is the easternmost strand of the San Andreas in the Yucaipa quadrangle. It separates granitic and metamorphic rocks of the San Bernardino Mountains block from a thin slice of similar rocks on Yucaipa Ridge, and thus has only a small amount of strike-slip displacement.
The Wilson Creek Strand traverses Yucaipa Ridge and converges toward the Mlll Creek Strand in the Santa Ana river Canyon. The fault has juxtaposed an igneous and metamorphic complex (Wilson Creek block) and overlying nonmarine sedimentary rocks (Mill Creek Formation of Gibson, 1971) against rocks of San Bernardino Mountains-type, and thus has significant strike-slip displacement.
The Mission Creek Strand is inferred to lie beneath Quaternary surficial deposits along the southwestern base of the San Bernardino Mountains. This fault is the major strand of the San Andreas Fault zone, and has juxtaposed crystalline rocks of San Gabriel Mountains-type (including Pelona Schist overlain by the Vincent Thrust and associated upper-plate crystalline rocks) against the Wilson Creek block and the San Bernardino Mountains.
The San Bernardino Strand defines the modern trace of the San Andreas Fault. The strand forms primary fault features in all but the youngest Quaternary surficial units, and is thought to have evolved in the last 125,000 years or so based on regional fault relations.
Complications within the San Andreas Fault system over the last several hundred thousand years have created a landscape setting in which Quaternary surficial materials of the Yucaipa quadrangle have accumulated. Crustal extension throughout the San Bernardino Basin region led to uplift of the Crafton Hills block and down-dropping of the Yucaipa Valley region on faults of the Crafton Hills and Chicken Hill complex. Subsequent middle and late Quaternary streamflows deposited several generations of axial-valley and alluvial-fan sediment in the down-dropped lowlands. These deposits and the older San Timoteo beds they overlie record the history of Quaternary fault movements, and form reservoirs for ground water in the Yucaipa quadrangle.
Digital Data:
The geologic database of the Yucaipa 1:24,000-scale 7.5' quadrangle, San Bernardino and Riverside Counties, California, was prepared by the Southern California Areal Mapping Project (SCAMP), a regional geologic-mapping project sponsored jointly by the U.S. Geological Survey and the California Geological Survey. The database was created in ARC/INFO (Environmental Systems Research Institute, ESRI), and includes the following files: (1) a readme.txt file, (2) this metadata file, (3) coverages containing geologic data and station-location data, (4) associated INFO attribute data files, (5) a browse graphic (.pdf) of the geologic-map plot and map-marginal explanatory information, (6) a PostScript graphics file of the geologic-map plot with map-marginal explanatory information, and (7) .pdf text files describing the map units of the Yucaipa quadrangle (Description of Map Units) and their geologic age and correlation (Correlation of Map Units).
Geologic information contained in the Yucaipa database is general-purpose data that are applicable to land-related investigations in the earth and biological sciences. The term "general-purpose" means that all geologic-feature classes have minimal information content adequate to characterize their general geologic characteristics and to interpret their general geologic history. However, no single feature class may have enough information to definitively characterize its properties and origin. For this reason the database cannot be used for site-specific geologic evaluations, although it can be used to plan and guide investigations at the site-specific level.
(1) Quaternary surficial materials in the NW part of the quadrangle (Sec. 7, 8, 17, 18, 19, 20) and SE corner of the quadrangle (Sec. 7, 8, 11, 12, and unsurveyed) have been reinterpreted based on analysis of 1938 and 1953 Department of Agriculture (Agricultural Stabilization and Conservation Service, ASCS) aerial photography.
(2) In digital version 1.0, units in the Qa series (Qa, Qya, Qoa, and Qvoa) are identified as "axial-valley deposits". In the 1992 analog version, these units were described as "deposits of alluvial plains". These changes do not affect the geologic interpretation or information content of the map. Rather, they are merely nomenclatuaral changes that are the consequence of the U.S. Geological Survey's continued efforts to refine the classification of Quaternary surficial materials in the San Bernardino-Yucaipa region.
(3) For some faults, digital version 1.0 provides new, geologic data and interpretations.
The database is sufficiently detailed to identify and characterize many actual and potential geologic hazards represented by faults and landslides and posed by ground subsidence and earthquake-generated ground shaking. However, it is not sufficiently detailed for site-specific determinations or evaluations of these features. Faults shown do not take the place of fault-rupture hazard zones designated by the California State Geologist (see Hart, 1988).
Use of the Yucaipa geologic-map database should not violate the spatial resolution of the data. Although the digital form of the data allows the scale to be manipulated at the discretion of the user, detail and accuracy issues that are inherent to map-scale limitations similarly exist in the digital data. The fact that this database was constructed and edited at a scale of 1:24,000 means that higher-resolution data generally are not present in the dataset. Therefore, plotting at scales larger than 1:24,000 will not yield greater, real detail, although enlarged plots may reveal fine-scale (artificial) irregularities beyond the intended resolution of the database. Although higher-resolution data may be incorporated at a few places, the resolution of the entire database output is limited by the lower-resolution data.
Hart, E. W., 1988, Fault-rupture zones in California; Alquist-Priolo Special Studies Zones Act of 1972 with index to special studies zones maps: California Division of Mines and Geology Special Publication 42
Scientific Peer Review: The database and plot file benefitted from technical reviews by R.F. Yerkes, P. Stone, F.K. Miller, and D. Bedford. We thank Peter M. Sadler and Michael O. Woodbourne for discussions of the stratigraphy and structure of rocks in the Yucaipa quadrangle.
Programmatic Credit: Geologic mapping, topical studies, and digital preparation for this database were sponsored jointly by the following: (1) the U.S. Geological Survey's National Cooperative Geologic Mapping Program, the National Earthquake Hazards Program, and the Mineral Resources Program; (2) California Geological Survey; (3) San Bernardino Valley Municipal Water District provided funding support for database development; (4) U.S. Forest Service (San Bernardino National Forest). Mr. Raj Daniel of the San Bernardino National Forest facilitated funding support of this database.
ATTRIBUTE ACCURACY
The attribute-accuracy statement for the Yuciapa database incorporates four elements: (1) map-unit description and attribution, (2) geotechnical standards against which the observations are measured, (3) map-unit identification, and (4) description of linear and planar geologic structures.
Map-unit description and attribution:
Geologic-map units in the Yucaipa quadrangle database were described using standard field methods (see Process_Description 1 of 6). Consistent with these methods and consistent with the time available to assemble the data set, the database authors have assigned standard geologic attributes to geologic lines, points, and polygons identified in the database.
Geotechnical standards for geologic descriptions:
Plutonic rock classification: Plutonic rocks and their deformed equivalents are classified in accordance with the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks (1973; Streckeisen, 1976).
Sedimentary rock classifications: Sandstones are classified in accordance with the scheme suggested by Friedman and Sanders (1978, Table 7-4). For all sedimentary materials, bedding-thickness classification follows Ingram (1954) and grain-size classification follows Wentworth (1922).
Surficial-materials classification: Surficial materials are mapped and classified according to a southern California-wide classification scheme being developed by the Southern California Areal Mapping Project (SCAMP).
Terminology for slope-failure deposits (landslides and other slope-failure types) follows Varnes (1978).
Color classification: The matrix color of surficial materials and their pedogenic soils is classified according to the Munsell soil-color charts (Munsell, 1975). Bedrock colors also are classified according to the Munsell system, supplemented by the Rock-Color Chart distributed by the Geological Society of America (reprinted 1970).
Map-unit identification
Geologic-map units in the Yucaipa quadrangle represent packages of geologic materials whose overall physical properties differ sufficiently from other such units as to constitute discrete mappable entities. From localities where map units in the quadrangle first were recognized and defined, they were extended to other areas through a mapping process that includes (a) direct outcrop observation, (b) interpretation of subsurface boring logs, and (c) aerial-photographic extrapolation into areas where site observation was not conducted. The data contained in the coverage yuc_obs indicates the density of observation and data localities in the Yucaipa quadrangle, and is a measure of whether a map unit at a particular location was identified on the basis of hands-on data or extrapolation.
Map-unit boundaries (geologic contacts) and faults identified along mapping traverses typically were extended laterally by using aerial photographs and binoculars to project or interpolate the contact or fault to its next recorded occurrence along a nearby traverse. Only rarely were individual geologic contacts or fault lines walked out to determine their variability and character throughout the map area. The bounding contacts of each surficial unit and the location of fault scarps that traverse the units were plotted by using a PG-2 photogrammetric plotter that allows location accuracy equivalent to the accuracy standard for the topographic-contour base.
Description of geologic structures
Geologic structures (planar structures displayed as lines, and structures at specific points) in the Yucaipa quadrangle are described and attributed according to the scheme described by Matti and others (1997a,b). These classifications generally follow conventional schemes for classifying geologic lines and points (Reynolds and others, 1995).
ATTRIBUTE CONFIDENCE
For digital version 1.0 of the database, the coverage yuc_obs is a proxy for attribute confidence: the number of direct observations within a map unit from place to place in the quadrangle proxies for the confidence with which the unit and its attributes are believed to be accurately identified. Future releases of the Yucaipa data set will delineate a more objective, empirical basis for map-unit identification and attribute accuracy (map-unit and attribute confidence).
Friedman, G.M., and Sanders, J.E., 1978, Principles of sedimentology: New York, John Wiley & Sons, 792 p.
Ingram, R.L., 1954, Terminology for the thickness of stratification and parting units in sedimentary rocks: Geological Society of America Bulletin, v. 65, p. 937-938.
International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks, 1973, Plutonic rocks: Geotimes, v. 18, no. 10, p. 26-30.
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
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
Munsell Color, 1975, Munsell soil color charts, 1975 edition Baltimore, Maryland, Macbeth Division of Kollmorgen Corporation.
Reynolds, M.W., Queen, J.E., and Taylor, R.B., 1995, Cartographic and digital standard for geologic map information: U.S. Geological Survey Open-File Report 95-525
Streckeisen A., 1976, To each plutonic rock its proper name: Earth Science Reviews, v. 12, p. 1-33.
Varnes, D.J., 1978, Slope movement types and processes, in Schuster, R.L., and Krizek, R.J., eds., Landslides: analysis and control: Washington, D.C., Transportation Research Board, National Academy of Sciences, Special Report 176, p. 11-33.
Wentworth, C.K., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology, v. 30, p. 377-392.
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 that are themselves a set of sequentially numbered coordinate pairs. Point data are represented by coordinate pairs.
Information for geologic units, geologic contacts, and faults by necessity is generalized. Although derived from data collected at individual observation stations, the characteristics of map units, their bounding contacts, and faults have been averaged and reduced to attributes that describe each map unit and each line element as a whole. This averaging process is necessary because of the intrinsic variability that geologic units, contacts, and faults display spatially: in detail, their characteristics necessarily vary geographically, although certain core attributes persist. To account for this variability and yet still characterize the major defining attributes of geologic entities, the database authors have selected and archived certain geologic characteristics but omitted others. In such cases, details were sacrificed in the interest of defining the average character of the geologic features.
Map-unit completeness: For map-unit polygons, version 1.0 of the Yucaipa database does not exploit the full potential afforded by the data-model and attribute scheme proposed by Matti and others (1997a). The file yuc_geo.pat contains limited information about polygon themes such as geologic name and the thickness of geologic-map units, as well as information about unique attributes that distinguish a map unit within a polygon or a particular subset of polygons. Additional lithologic-attribute data are available in the INFO data table yuc_summ.rel, including age-related data and major rock type. Other than this minimal information, however, the Yucaipa database for geologic-map units (yuc_geo) lacks the comprehensive information content of the .pdf files (yuc_dmu.pdf and yuc_cmu.pdf).
Line and Point Completeness: For line and point data, the Yucaipa database exploits the attribution scheme proposed by Matti and others (1997a,b). This scheme allows geologic elements represented as lines (geologic contacts, faults, fold axes, geomorphic features) and points (bedding orientations, foliation orientations, fault dips) to be assigned a full spectrum of attributes ranging from contact and fault type to geologic age of linear and point features. Some of these attributes are embedded directly within the line and point data bases (.aat and .pat, respectively). Most line and point attributes are stored as codes in two INFO data tables (lines.rel and points.rel).
A complete description of the SCAMP polygon, line, and point data coding schemes is available in U.S. Geological Survey Open-File Reports OF-97-859, OF-97-860, and OF-97-861 (full source citations follow):
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 URL:<http://wrgis.wr.usgs.gov/wgmt/scamp/scamp.html>
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 URL:<http://wrgis.wr.usgs.gov/wgmt/scamp/scamp.html>
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 URL:<http://wrgis.wr.usgs.gov/wgmt/scamp/scamp.html>
In the Yucaipa 1:24,000 scale quadrangle, geologic lines are judged to meet the map-accuracy standard if they are located to within ˜+/-15 meters relative to topographic or cultural features on the base map. Within the database, line data that are judged to meet the map-accuracy standard are denoted in the data table lines.rel by the attribute code .MEE. (meets); line data that may not meet the map-accuracy standard are denoted by the attribute code .MNM. (may not meet). On geologic-map plots and other plots generated from the geologic database, line data that are judged to meet the map-accuracy standard are denoted by solid lines; line data that may not meet the map-accuracy standard are denoted by dashed or dotted lines.
In the database and on geologic-map plots, no cartographic device exists for denoting the map-accuracy for geologic-point data (symbols for bedding, foliation, lineations, etc.).
Three sources of positional error exist for geologic elements in the Yucaipa quadrangle database:
(1) Positional accuracy of field observations: observation stations (data localities) were located either on aerial photographs or on the topographic basemap of the Yucaipa quadrangle by referencing hypsographic and planimetric features on the basemap.
(2) Transfer of line and point data from aerial photographs to the topographic base: For bedrock geologic materials, point data, contacts, and faults were visually transferred to scale-stable copies of the topographic base map. For most surficial geologic materials, geologic contacts and fault scarps were transferred to the base map through the use of a PG-2 sterographic plotter that allows geologic elements to be located with an accuracy and precision equivalent to the standard for the topographic-contour base.
(3) Positional fidelity during digital data processing: the maximum transformation Root Mean Square (RMS) error acceptable for 7.5' quadrangle transformation and data input is 0.003 (1.8 meters). The horizontal positional accuracy of line and point entities was checked by visual comparison of hard-copy plots with base-stable source data.
The information content of digital version 1.0 of the Yucaipa quadrangle database differs in some important ways from that of the analog version (Matti and others, 1992). As described in Process_Step 4 of 6, between 1994 and 1998 one of the database authors (J.C. Matti) reinterpreted some of the Quaternary surficial materials and some fault relationships.
Geologic data for the Yucaipa quadrangle were collected in the field by the data-set authors. The field data were plotted on aerial photographs and on a 1:24,000-scale basemap (U.S. Geological Survey, Yucaipa 7.5' quadrangle, 1967, photorevised, 1980).
Bedrock map units were described, mapped, and interpreted on the basis of traverse-mapping methods. Observations were recorded along each traverse, locations for which are stored in the coverage yuc_obs. Information recorded at these stations provides the basis for the identification and characterization of each bedrock map unit.. Map-unit boundaries (geologic contacts) and faults identified along each traverse typically were extended laterally by using aerial photographs and binoculars to project or interpolate the fault or contact to its next recorded occurrence along a nearby traverse. A few sedimentary-layering attitudes were determined through binocular observation rather than from site determinations; these are identified in the data base and on the geologic-map plot.
Surficial-materials map units were described, mapped, and interpreted on the basis of aerial-photographic interpretation augmented by observations at specific stations. The bounding contacts of each surficial unit and the location of fault scarps that traverse the units were plotted by using a PG-2 photogrammetric plotter that allows location accuracy equivalent to the accuracy standard for the topographic-contour base. The coverage yuc_obs shows the position of observation stations data from which were used to determine geologic characteristics of the surficial map units.
GEOLOGIC CONTRIBUTIONS BY AUTHORS:
Jonathan C. Matti - mapped and interpreted Quaternary surficial materials; faults of the San Timoteo Canyon, Crafton Hills, Chicken Hill, Yucaipa Valley graben complex, and San Andreas zones; San Timoteo Canyon formation; crystalline rocks in the Santa Ana River Canyon and areas to the west; crystalline rocks in the southeast corner of the quadrangle - 1979, 1985-1986, 1988, 1991.
Douglas M. Morton - mapped crystalline rocks in the Crafton Hills area - 1977.
Brett F. Cox - mapped crystalline rocks in the Crafton Hills area, in the east-central margin of the quadrangle, and between the Wilson Creek and San Bernardino strands of the San Andreas fault; mapped the Warm Springs Canyon formation in Mill Creek Canyon; Quaternary materials and faults adjacent to the San Bernardino Strand between Mill Creek and Santa Ana River - 1979 to 1980.
Scott E. Carson - mapped crystalline rocks in the vicinity of Morton Peak and Santa Ana River Canyon; described Quaternary surficial Materials in Yucaipa Valley - 1979 through 1981.
Thomas J. Yetter - mapped crystalline rocks in the vicinity of Morton Peak and Santa Ana River Canyon; beds of the Mill Creek Formation in lower Mill Creek Canyon - 1979.
The 1992 geologic-map product was produced from geologic linework drafted on a 1:24,000-scale greenline chronoflex of the Yucaipa 7.5' quadrangle. Source materials were paper field sheets produced by each map author, and pencil linework generated by a PG-2 stereographic plotter on a scale-stable 1:24,000-scale chronoflex of the Yucaipa 7.5' quadrangle.
After the 1992 geologic map of the Yucaipa quadrangle was released (Matti and others, 1992), additional observation and interpretation by J.C. Matti led to revisions of that version. Changes included: (1) re-interpretation of fault-line relations for the San Bernardino Strand of the San Andreas Fault west of the mouth of Santa Ana River Canyon; (2) re-interpretation of surficial geologic materials in the vicinity of Mentone and along the drainage of Wildwood Canyon along its entire extent; and (3) reinterpretation of the south end of the Chicken Hill Fault in the vicinity of Interstate Highway 10, including the recognition of a probable fault scarp that was obliterated by construction of the Highway right-of-way.
The basemap image (yuc.tif) was prepared by scanning a scale-stable right-reading, blackline .007-mil clear-film positive of the U.S. Geological Survey, 1:24,000-scale Yucaipa 7.5' quadrangle topographic map (1967, photorevised, 1980). Scanning was done using an Anatech Eagle 4080 monochrome 800 dots-per-inch scanner at a resolution of 500 dpi. The raster scan was converted to a monochromatic image in ARC/INFO. No elements of the base layer are attributed. The base map is provided for reference only.
Geologic line and point data on scale-stable greenline chronoflex copies of the Yucaipa 7.5' quadrangle were digitized and simultaneously converted to ARC/INFO coverages through the application and utilization of the graphical user interface ALACARTE developed by the USGS (Fitzgibbon, 1991; Fitzgibbon and Wentworth, 1991; Wentworth and Fitzgibbon, 1991) running on a Data General Aviion workstation. The database subsequently was edited and tagged on a Sun SPARC20 computer system running Solaris v. 2.4 and ARC/INFO v. 7.0.4 and v. 7.1.1. Geologic point data were captured using ALACARTE and ARC/INFO v.7.0.4.
CONTRIBUTIONS BY DATABASE EDITORS:
Pamela M. Cossette - responsible for final geologic database editing, assembling the database and plot-file products, and production of metadata
Bradley Jones - responsible for significant data capture
Melinda C. Wright - responsible for geologic point-data capture and preliminary database editing
Stephen A. Kennedy - responsible for initial database editing
Fitzgibbon, T.T., 1991, ALACARTE installation and system manual (version 1.0): U.S. Geological Survey, Open-File Report 91-587B.
Fitzgibbon, T.T., and Wentworth, C.M., 1991, ALACARTE user interface - AML code and demonstration maps (version 1.0): U.S. Geological Survey, Open-File Report 91-587A.
Wentworth, C.M., and Fitzgibbon, T.T., 1991, ALACARTE user manual (version 1.0): U. S. Geological Survey Open-File Report 91-587C.
The coverage yuc_obs contains the locations of observation stations that the dataset authors used to describe geologic materials and geologic structures in the Yucaipa quadrangle. Several kinds of observation stations are included:
(1) Field observations made by the dataset authors. These are represented by the author's name (e.g., Jonathan C. Matti), and the station ID (e.g., JF, which represents J.C. Matti, notebook F);
(2) Subsurface borings obtained by the California Department of Transportation at overpassing and underpassing right-of-ways along the Interstate and State Highway systems;
(3) Subsurface borings obtained by the U.S. Geological Survey's Water Resources Division (WRD);
(4) Subsurface borings obtained by various private geotechnical-engineering firms;
(5) Soil-profile descriptions obtained by the Natural Resources and Conservation Service (Woodruff and Brock, 1980, sheet 10);
Woodruff, G.A., and Brock, W.Z., 1980, Soil survey of San Bernardino County, southwestern part, California: U.S. Department of Agriculture, Soil Conservation Service, 64 p., scale 1:24,000.
lines.rel - (provides information about geologic features displayed as lines on the map. For a complete description of attributes in lines.rel, refer to USGS Open-File Report 97-861: see Entity_and_Attribute_Detail_Citation)
points.rel - (provides information about geologic features displayed as points on the map. For a complete description of attributes in points.rel, refer to USGS Open-File Report 97-859: see Entity_and_Attribute_Detail_Citation)
1) The coverage yuc_geo contains information about geologic-map units (represented by polygons) and planar geologic features that bound or break them (e.g. geologic contacts and faults) represented by lines. The polygons have cartographic and geologic attributes contained in yuc_geo.pat; the lines have cartographic and geologic attributes contained in yuc_geo.aat. For display purposes, the geology coverage contains two annotation subclasses: geo contains unit labels, and fault contains formal fault names.
2) The coverage yuc_pts contains analyzable structural data, including information that describes the types and orientation of planar and linear geologic features such as bedding, foliation, fault-plane dip, and fold-hinge plunge. One annotation subclass is included in the geologic points coverage which displays the respective dip and plunge values associated with individual point data.
3) The coverage yuc_obs contains point data that repesent the locality of data stations associated with multiple authors and sources, all of which have contributed geologic data. The locality data represented in yuc_obs serves several purposes: (1) as a proxy for author confidence in unit identification, (2) as a means of identifying each author's contribution, and (3) as a means of identifying data from sources other than the USGS authors. One annotation subclass, obs, identifies five particular locations: four Natural Resources Conservation Service (NRCS) soil profile description localities and one USGS Water Resource Division (WRD) well-log data locality.
4) The coverage yuc_ptsorn stores point data that represent ornamentation for geologic lines (e.g. strike slip arrows, bar and ball on down-thrown block, etc.)
5) The coverage yuc_ldr contains annotation leaders that point to unit labels that are placed outside the perimeter of a particular geologic polygon. These cartographic line entities are attributed with only a single attribute, L-SYMB, and all have the same value, 1.
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
TAG serves one additional purpose: it functions as the relate item that associates each polygon with its attributes stored in the polygon-attribute data table, YUC_SUMM.REL.
TAG is defined as LABL followed by an upper-case letter, e.g., QwA, QwB, or QwC, etc. Most map units in the Yucaipa databse have only one TAG designation, TAG A; map units having polygon subsets representing characteristics sufficiently distinct from those of the overall unit include: Qw (QwA, QwB), Qf (QfA, QfB), Qya4 (Qya4A, Qya4B), Qya5 (Qya5A, Qya5B), Qvof3 (Qvof3A, Qvof3B0, Tgr (TgrA, TgrB).
Geologic-line types in yuc_geo and their corresponding definitions in lines.rel include (abbreviated from Matti and others, 1997c):
Note: To date, there is no other way to indicate to the user the cardinal direction of dip using the traditional convention (traditional geologic notation allows a quadrant designation following the dip value).
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 Yucaipa 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).