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Digital Mapping Techniques '01 -- Workshop Proceedings
U.S. Geological Survey Open-File Report 00-223

The National Park Service Digital Geologic Map Model: Transformation from Paper to Digital, Featuring Legends, Cross Sections, Map Notes and Keyword Searchability

By Steve Fryer1, Joe Gregson1, Tim Connors2, Anne Poole3, and Bruce Heise2

1National Park Service
Natural Resources Information Division
1201 Oak Ridge Drive, Suite 350
Fort Collins, CO 80525
Telephone: (970) 225-3584
Fax: (970) 225-3585
e-mail: Steve_Fryer@NPS.gov,
Joe_Gregson@NPS.gov

2National Park Service
Geologic Resources Division
12795 West Alameda Parkway
P.O. Box 25287
Denver, CO 80225
Telephone: (303) 969-2093
Fax: (303) 987-6792
e-mail: Tim_Connors@NPS.gov,
Bruce_Heise@NPS.gov

  3National Park Service
Intermountain GIS Support
Bandelier Hall West, Room 203
Albuquerque NM 87131
Telephone: (505) 346-2885 extension 260
Fax: (505) 346-2889
e-mail: Anne_Poole@NPS.gov

SUMMARY

Beginning in 1998, the National Park Service (NPS) initiated a Geologic Resources Inventory (GRI) to document and evaluate the geologic resources of about 272 National Park System units (national parks, monuments, recreational areas, historic sites, seashores, lakeshores, etc.). GRI workshops have been held for 56 parks, geologic bibliographies developed for 235 parks, digital geologic maps produced for 11 parks (numerous more in progress and nearing completion), and geologic reports produced for 11 parks in Utah.

User-friendly (i.e. main users are NPS Natural Resource Managers) GIS tools have been developed in ESRI ArcView format for the digital geologic maps. Applications including the NPS-developed ArcView Theme Manager, graphical cross section viewer and legend text display tools are integrated with a standard geology-GIS model that is in development to reproduce the components of a "paper" geologic map into a digital geologic database. The evolving geology-GIS model is based on the Washington State ArcInfo GIS data model (Harris 1998) that is being adapted for ArcView GIS and extended to include components of the North American Geologic Map Data Model (NADM), .

INTRODUCTION

Bedrock and surficial geologic maps and supporting information provide the foundation for studies of groundwater, geomorphology, soils, and environmental hazards. Geologic maps describe the underlying physical conditions of many natural systems and are an integral component of the physical science inventories stipulated by the National Park Service (NPS) in its Natural Resources Inventory and Monitoring Guideline (NPS-75) and the 1997 NPS Strategic Plan.

The NPS Geologic Resources Inventory (GRI) is a cooperative endeavor to implement a systematic, comprehensive inventory of the geologic resources in NPS units. Cooperators include the NPS Geologic Resources Division, NPS Inventory and Monitoring (I&M ) Program (Natural Resource Information Division), U.S. Geological Survey (USGS), and individual state geological surveys. The GRI for the 272 park units with significant natural resources consists of four main products:

  1. "GRBib", compilation of a bibliography of geologic literature and maps;
  2. "scoping sessions", an on-site evaluation of park geologic maps, resources, and issues;
  3. digital geologic map products with accompanying supporting information; and
  4. a summary report with basic geologic information on hazards, issues, and existing data and studies.

STATUS OF GEOLOGIC RESOURCES INVENTORIES

In the fall of 1997, the NPS Geologic Resources Division and Inventory and Monitoring Program sponsored a workshop on baseline geologic data in Denver, Colorado. Its purpose was to receive input from the NPS, USGS, state geological survey personnel, and cooperators on needed basic geologic data that the NPS Inventory and Monitoring Program could provide. At the meeting, Colorado, Utah, and North Carolina were chosen as pilot project states to maximize cooperation among the agencies and provide consistency in workshop planning. The group discussed and adopted the four main inventory phases that are reviewed briefly below.

Geologic Bibliographies

"GRBib", the bibliography of existing geologic maps and literature for 235 NPS units is available on the Internet (URL: ; LOGIN: "geobib read", PASSWORD: "anybody") and is also prepared as printable documents at NPS.gov/grd/geology/gri/products/ geobib/>. Also, geologic index maps showing the location of associated geologic maps and their scale have been prepared for these same parks. In general, after map coverage for each park is determined, map products can be evaluated, and if needed, additional mapping projects identified and initiated.

Park Workshop Meetings

GRI Park Workshops (scoping sessions) have been conducted for 56 parks in Colorado, Utah, Idaho, North Carolina, California, Texas, New Mexico, Arizona and the National Capital area to evaluate each park's geologic resources. As a result of these workshops, park teams have evaluated existing maps for digital products and identified needed geologic mapping. New geologic mapping may be initiated on a case-by-case basis after careful evaluation of needs, costs, potential cooperators, and funding sources.

GRI staff are developing geologic-GIS standards to ensure uniform data quantity and quality for digital geologic maps throughout the National Park System. The NPS is attempting to align these digital standards with those of the USGS and the National Geologic Map Data Model that is still in development. In addition to standardized data definitions and structure, NPS resource managers also need user-friendly GIS applications that allow the digital geologic map products to "look and feel" like the original published paper maps. Pilot digitization projects are providing additional information for the evolving NPS digital map standards.

Park workshops suggest several applications for park resource management that can come from an enhanced understanding of the parks' geology as gained from a digital geologic map. Examples include the use of geologic data:

Geologic Mapping and Digitizing Projects

The NPS I&M Program has cost-shared with the Utah Geological Survey new geologic field mapping for Zion National Park (NP) and Glen Canyon National Recreation Area (NRA). Additional field mapping projects have been initiated or completed for the geologic maps for Bent's Old Fort National Historic Site (NHS), Curecanti NRA, Florissant Fossil Beds National Monument (NM), Great Sand Dunes NP, Capitol Reef NP, Cedar Breaks NM, Golden Spike NHS, and Natural Bridges NM. Digitization of geologic maps has been completed for Arches NP, Bent's Old Fort NHS, Black Canyon of the Gunnison NP, Colorado NM, Curecanti NRA, Florissant Fossil Beds NM, Great Sand Dunes NP, Hovenweep NM, Mesa Verde NP, Natural Bridges NM and Rocky Mountain NP. This data is available for download at .

The NPS Geologic Resources Inventory is being actively developed with the formal cooperation of USGS and state geological surveys. However, many opportunities for project collaboration may exist that have not yet been identified, and effective communication among cooperators is a key factor for success of the inventory.

Another challenge of inventory planning is the development of digital map standards that are adaptable to diverse geological conditions but still provide quality, uniform products and firm guidance for map developers. Indeed, the diversity of geologic resources found in the National Park System will provide a continuing challenge for effective project management. The National Park Service has identified GIS and digital cartographic products as fundamental resource management tools, and the I&M Program and Geological Resources Division are developing an efficient inventory program to expedite the acquisition of digital geologic information for NPS units throughout the country. Again, the NPS is attempting to align these digital standards with those of the USGS and the National Geologic Map Data Model that is still in development.

Summary Geologic Reports

Upon completion of an inventory in a park, the available geological literature and data from the NPS, USGS, state, and academic institutions will be documented in a summary report. The content, format, and database structure of such reports are still being developed.

GIS ISSUES AND IMPLEMENTATION - MAKING GEOLOGY "USER-FRIENDLY"

One of the unresolved issues facing developers of digital geologic maps and geology-GIS models is how to include map unit descriptions, supplemental explanatory text (references and map notes), geologic cross sections, and the variety of other printed information that occur on published maps. This issue is particularly important to the National Park Service because there are few geologists employed at parks, and resource managers rarely have the GIS and geologic expertise needed to develop a useful product from digital layers of polygons, lines, points, and associated tabular data. The overarching development goal of the NPS I&M Program is to produce digital products that are immediately useful to anyone familiar with their analog counterparts. For geologic maps, this means that the map unit legend must be sorted and shaded appropriately by geologic age and that all textual, graphical, and other information from the published maps must be available interactively to the user. In short, the digital product must "look and feel" like its published source.

Since NPS resource managers use GIS as a tool in a wide array of collateral duties, the I&M Program is developing most digital products in ESRI (Environmental Systems Research Institute) ArcView GIS. ArcView interfaces effectively with other software running on the Microsoft Windows operating system. Also, integrating a variety of tools including the Windows Help software, a Microsoft Visual Basic graphics viewer program, the ArcView legend editor, and the Avenue script language has allowed query and automatic display of published map information in the GIS.

Automating Map Unit Descriptions and Other Textual Information

In most GIS applications, the spatial database structure does not facilitate the use of voluminous textual data. For example, in ArcView, the database text fields only accommodate 254 characters (320 for INFO tables) which limits the ability to include lengthy map descriptions with the spatial data. Several options are available in ArcView to overcome this limitation including concatenating database fields, independent text files, linking to other database system files, and linking to a Microsoft Windows Help file. After testing several options, NPS developers have been implementing the Windows Help system.

This process begins with an approach using the creation of the Help file table of contents (object table). The table includes a title, a listing of all source map units (sorted by geologic age), and a list of source map references and notes. Text descriptions of map units that are page sorted by geologic age are entered next. For compiled geologic maps, maps produced from more than one source map, a unit's description often consists of multiple map unit descriptions. Finally, the source map references and notes text, also one per page, were entered. Help context IDs (HELP_ID), topic names, keywords, page numbers, and linking codes were then added to the footnotes of each page. The data was then saved as a rich text format (.RTF) file, and compiled into a Windows Help file.

Once compiled, the Windows Help file can be opened and used with almost any Microsoft Windows software. The table of contents has each map unit symbol and unit name "hot-linked" to the descriptions, and each description is hot-linked to the references and notes. Using the built-in Windows Help tools, users can jump instantly to the table of contents, page through the age-sorted unit descriptions, search for keywords, or index the file and perform full-text searches of the entire file. The Black Canyon/Curecanti pilot project help file consists of more than 50 printed pages of information for more than 130 map units. Advantages of the Windows Help file are that most text formatting, such as font, size, color, etc., are preserved in the final product, many graphics and tables are also supported, and the help system can be developed somewhat independently of the digital geologic map.

In ArcView GIS, three Avenue scripts were written to function with a toolbar button to automate the Windows Help file and call unit descriptions interactively from the geologic map. The button tool is only active when the geology theme is turned on. The user selects the map unit help tool from the ArcView toolbar and clicks on the desired map unit to view the associated unit description. Using the map unit symbol (GLG_SYM, see data model in figure 1) and the corresponding help context ID (HELP_ID), the Avenue routine loads the Windows Help file and pages to the map unit description. Thus, the map unit descriptions and other text are interactively available to the user of the digital map.

Figure 1. Simplified relationships among database tables presented in data dictionary. Bold type denotes database file names for ArcInfo (top) and ArcView (below). The tabular relationships are coded with "m" for many, and "1" for one. Related field or key names are in italics. Table types are in parentheses.

Automating the Geologic Cross Sections

Geologic cross sections are integral components of many published geologic maps and provide important spatial visualization tools to assist users with understanding the mapped geology. The I&M Program has developed a simple interactive system for displaying cross sections using ArcView and a Microsoft Visual Basic (VB) graphics viewer program. The cross sections are scanned digital graphics files (JPEG format) that ArcView can load and display via system calls to the VB graphics viewer program. This allows the user to interactively select the cross section(s) to view. With projects such as the Black Canyon/Curecanti pilot, the ability to quickly view some 28 cross sections throughout the area is a powerful asset toward understanding the area's geology.

To prepare the cross sections for viewing, the graphics are first scanned at 100 dots-per-inch (DPI) and saved as a digital JPEG (.jpg extension) graphics file. The JPEG format was chosen to allow the graphics to be served and viewed over the Internet in the future. Once again, the 8.3 file naming convention is used to facilitate sharing across all platforms, and file names are based on the map series designation and the designated cross section on the map (e.g., "gq1516a.jpg" is the A-A' cross section on the USGS Geologic Quadrangle Map GQ-1516).

Although ArcView and the Avenue language provide several ways to display graphics and images, ArcView's capabilities are inadequate for efficient viewing of cross sections that could be up to 6" x 48" in size. Therefore, a simple VB graphics viewer program was developed to provide this capability. The viewer displays the graphics at 100% with the ability to scroll from one end of the section to the other.

In ArcView GIS, three Avenue scripts were written to function with a toolbar button to automate the cross sections and call graphics files interactively from the geologic map. The button tool is only active when the cross section theme (CODESEC, see data model section below) is turned on. The user selects the cross section viewer tool from the ArcView toolbar and clicks on the desired cross section line displayed on the map. Using the cross section line and the corresponding filename, the Avenue script loads the graphics viewer and displays the selected section. Thus, the cross sections are interactively available to the user of the digital map.

GIS Map Unit Legend

In ArcView, theme legends can be customized to reproduce map feature symbols and colors of published source maps. To represent map features of a particular theme, an attribute field is selected in that theme's legend editor that relates map feature type with legend symbol type and color. In the NPS geology-GIS data model (presented below), the attribute field that denotes map feature type is typically either COV_TYPE for point themes or COV_LT for line themes, where COV represents the theme/coverage abbreviation. For polygon themes (themes typically representing geologic map units of aerial extent), and also for point and line themes that represent point and line geologic map units, respectively, GLG_AGE_NO is the attribute field that relates feature type with symbol type (pattern) and color. As mentioned in the data dictionary section of the paper, the GLG_AGE_NO is a numeric attribute field also used to sort map units by geologic time.

For point symbols that indicate or represent directionality, ArcView also allows for those symbols to be aligned to their correct orientation using a second attribute or rotation field. For attitude observation points, (e.g. strike and dip of bedding, trend and plunge of inclusions ..), which is the only coverage presently in the data model that has oriented point symbols, the ATD_AV_ROT field designates the desired symbol rotation value.

When a theme legend is completed, it can be saved as an ArcView legend file (.avl extension). In the data model, a legend file is named as per the theme/coverage file name. By default in ArcView, if a legend file exists with the same file name as a theme, when that theme is added to a view the legend file is automatically loaded.

REVISED DRAFT NPS GEOLOGY-GIS DATA MODEL

As mentioned above, a standard geology-GIS data model has been developed for the National Park Service Geologic Resources Inventory (GRI). The model is based on ArcInfo and integrates with user-friendly ArcView GIS software. As per ArcView and dBase requirements, database field names have been limited to ten characters or less. In addition, although many modern operating systems allow for long file names, theme/coverage file names within the model adhere to the 8.3 file name convention. Typically, themes/coverages and associated table file names are seven characters in length. The use of only seven characters allows for an additional character to be appended to a coverage name for related look-up tables. For an NPS unit digital geologic map, the first four characters or prefix of a coverage name (CODE) are the NPS unit's alpha code. The next three characters (suffix) abbreviate the type of geologic coverage (COV). For INFO look-up tables associated with a coverage, an additional or eighth character, typically an integer, is appended to the theme/coverage name. An exception to the file naming convention presented above is arc/line map features of a polygon theme/coverage.

ArcInfo allows for both arc/line and polygon labels to exist within the same (polygon) coverage, however, ArcView does not. Thus two themes are needed to present both the arc/line and polygon attribution of an ArcInfo polygon coverage in ArcView. For an ArcView arc/line theme associated with a polygon coverage, an 'A' (arc) is appended to the seven character polygon file name. As with any digital map model, alterations and additional components, many derived from unique or uncommon map components, continue to advance and expand the model. See Fryer et. al., 2000, Gregson et. al., 1999 and Gregson, 1998 for previous published (abbreviated) versions of the geology-GIS data model. The NPS geology-GIS data model was initially based on the GIS-geology data model published by Carl Harris (1998), with contributions from the AASG/USGS Draft Digital Geologic Map DataModel, Version 4.2 (Johnson et. al., 1998).

GEOLOGIC THEMES

The NPS geology-GIS model's data themes or coverages are listed below. 
Theme       Theme Type      Theme Description
_________________________________________________________________________________________________

CODEGLG     poly/line       Map units or geologic spatial data containing both polygon data line
                            describing the map units and linear data describing the interface 
                            between those units.
CODEGLN     line            Map units or geological spatial data represented as lines due to map
                            scale limitations.                            
CODEGPT     point           Map units or geological spatial data represented as points due to map 
                            scale limitations.
CODEFLT     line            Faults.
CODEFLD     line            Linear fold axes/hingelines.
CODEATD     point           Attitude observation points.
CODEDAT     point           Age-date sample location points (fossil or radiometric age estimates).
CODEVNT     point           Volcanic vents, eruptive centers, features mapped as points.
CODEVLN     line            Linear volcanic crater, eruptive and flow features.
CODEDKE     line            Individual lithologic dikes.
CODEDKS     poly/line       Areas of lithologic dikes too numerous to map as individual line 
                            segments (e.g. dike swarms).
CODEMIN     point           Mine and mining related features.
CODESEC     line            Cross section lines.
CODEASH     poly/line       Volcanic ash map units containing both polygon data describing line
                            the map units and linear data describing the interface between those
                            units.						 																
CODEMET     line            Metamorphic grade boundaries.
CODEMOR     line            Linear glacial moraine features.
CODEJLN     line            Linear joint features.
CODELN#     line            Contour and other lines.
CODESPF     point           Geologic point data deemed sensitive by NPS Unit.
CODEUPF     point           Unique 'non-sensitive' geologic point data.
CODESUR     poly/line       Surficial geology consisting of both polygon data describing 
                            surficial mapunits and linear data describing the interface between
                            those units.
CODEMUT     point           Measured unit thickness points.

# denotes a number assigned to theme/coverage name.

Theme/Coverage Data Dictionary

At present, all of the 22 themes/coverages presented in the data model have been evaluated and adapted into a coverage data dictionary. Of note, each theme/coverage has several attribute fields that ArcInfo adds automatically to a coverage. For polygon and point coverages, AREA, PERIMETER, CODECOV# and CODECOV-ID are added to the coverages polygon attribute table (.pat). For arc/line coverages and polygon coverage arc/line attribution, FNODE#, TNODE#, LPOLY#, RPOLY#, CODECOV# and CODECOV-ID are added to the coverages arc attribute table (.aat). Two INFO look-up tables relating to map source information (CODEMAP) and additional lithology unit data (CODEGLG1) are also presented.

To limit the length of this paper, only four data model themes/coverages are presented. In addition to the themes presented, two INFO look-up tables relating to additional lithology unit data (CODEGLG1) and map source information (CODEMAP) are also presented. Figure 1 illustrates relationships among data model themes/coverages presented in this paper to INFO and dBase database tables and the Windows Help File System (CODEGLG.HLP). 

_________________________________________________________________________________________________

SPATIAL THEME (FILENAME):   Area Geologic Map Units (CODEGLG)
THEME DESCRIPTION:          Polygon and Arc/line coverage(s)
TABLE COVERAGE/FILE NAME:   CODEGLG.PAT (ArcInfo), CODEGLG.DBF (ArcView)
TABLE FORMAT:               INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:           10


FIELD NAME   TYPE-WIDTH         FIELD DEFINITION
AREA            F - 4           area of the polygon
PERIMETER       F - 4           perimeter of the polygon (in map units)
CODEGLG_        B - 4           unique internal (PAL) sequence number for each polygon, converted
                                from CODEGLG# (ArcInfo field).
CODEGLG_ID      B - 4           sequence ID-number for each polygon, converted from CODEGLG-ID
                                (ArcInfo field)
GLG_IDX         I - 6           user-defined ID-number for each polygon, 
GLG_SYM         C - 12          age-lithology unit symbol, used to relate coverage with the
                                CODEGLG1.INF look-up table
USGS_SYM        C - 12          geologic symbol from USGS geologic map(s)
GLG_AGE_NO      N - 7 .4        number to age-sort units in legend
GMAP_ID         I - 6           unique number assigned to each source map by the GRI that relates
                                map feature to series and citation information in CODEMAP.INF
                                look-up table
HELP_ID         C - 12          code (code typically GLG_SYM value) used to link to associated
                                geologic text in Help File System



SPECIAL COVERAGE GUIDELINES 


    

  1. Water Areas:  Non-intermittent areas of water, area rivers, lakes, ponds and reservoir, are to
be captured in the CODEGLG coverage/theme.  If however, the 'underlying' geologic unit or units
can be visually discerned on the source map, then these areas are not to be captured in the
CODEGLG coverage/theme. Intermittent bodies are not to be captured unless the 'underlying'
geologic unit or units can not be visually discerned on the source map.  Captured water areas are
denoted in the GLG_SYM and USGS_SYM fields (see field descriptions above) with
the text 'WATER', and a GLG_AGE_NO (see field description above) value of 99.

    

  2. Fault Zones: Areas mapped as fault zones are to be captured in the CODEGLG coverage/theme.
These areas are denoted in the GLG_SYM and USGS_SYM fields (see field
descriptions above) with the text 'FAULTZONE', and a GLG_AGE_NO (see field description above)
value of 98.



_________________________________________________________________________________________________

SPATIAL THEME (FILENAME):    Geologic Map Unit Boundaries/Contacts (CODEGLG (ArcInfo)/CODEGLGA (ArcView))
TABLE COVERAGE/FILE NAME:    CODEGLG.AAT (ArcInfo), CODEGLGA.DBF (ArcView)
TABLE FORMAT:                INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:            11

FIELD NAME       TYPE - WIDTH    FIELD DEFINITION
FNODE_           B - 4             internal number of arc segment From Node, converted from FNODE#
                                   (ArcInfofield)
TNODE_           B - 4             internal number of arc segment To Node, converted from TNODE#
                                   (ArcInfo field)
LPOLY_           B - 4             internal left polygon number of arc segment, converted from
                                   LPOLY# (ArcInfo field)
RPOLY_           B - 4             internal right polygon number of arc segment, converted from
                                   RPOLY# (ArcInfo field)
LENGTH           F - 4             length of arc segment
CODEGLG_         B - 4             unique internal sequence, converted from CODEGLG# (ArcInfo
                                   field)
CODEGLG_ID       B - 4             sequence ID-number for each polygon, converted from CODEGLG-ID
                                   (ArcInfo field)
GLGCNT_IDX       I - 6             user-defined ID-number for each arc segment 
GLGCNT_TYP       I - 2             code value for type of polygon (contact) boundary*
FLTCNT           C - 1             flags lithologic contacts that are also faults*
GMAP_ID          I - 6             unique number assigned to each source map by the GRI that
                                   relates map feature to series and citation information in
                                   CODEMAP.INF look-up table          
HELP_ID          C - 12            code used to link to associated geologic text in Help File
                                   System

*  see Field/Attribute Code Value Lists below


FIELD/ATTRIBUTE CODE VALUE LISTS:

GLGCNT_TYP (polygon boundary/geologic contact type code)
    1    known location
    2    approximate location
    3    concealed
    4    queried
    5    approximate location, queried
    6    concealed, queried
    7    inferred location
    8    inferred, queried
    9    gradational boundary
   10    quadrangle boundary
   11    extent/map boundary
   12    shoreline
   13    shoreline, approximate
   14    ice boundary
   15    ice boundary, approximate
FLTCNT   (contact a fault?)
    Y   Yes, the lithologic contact is also a fault.
    N   No, the lithologic contact is not also a fault.



SPECIAL COVERAGE GUIDELINES


    

  1. Contact Arcs in Multiple Themes:  Contact arcs that are also geologic faults or are also
linear geologic units (FLTCNT = 'Y', see FLTCNT field description above) are present in both the
geology (CODEGLG) and fault (CODEFLT) themes, or the geology (CODEGLG) and linear geologic
(CODEGLN) themes, respectively.

    

  2. Contact Arc Directionality:  Contact arcs that are also faults are captured with the
down-thrown fault block, if applicable, on the 'right side' of the arc.  The 'right' and 'left'
sides of an arc are determined from 'starting' at the arc's 'from node' (FNODE_) and moving to
the arc's 'to node' (TNODE_).  Thus, the down-thrown fault-block should be the arc segment's
RPOLY_.  For fault arcs where the down-thrown block is not or can not be determined, or is not
applicable (i.e. a fault with only lateral displacement (heave) and no vertical displacement
(throw)), directionality does not matter.  Fault arc (capture) directionality is primarily
used for graphical representation of a fault where one side of a fault has symbology that
is different than the other side of the fault (e.g. a thrust fault with 'teeth' on the
up-thrown side).



_________________________________________________________________________________________________

SPATIAL THEME (FILENAME):   Geologic Faults (CODEFLT)
THEME DESCRIPTION:          Arc/line coverage
TABLE COVERAGE/FILE NAME:   CODEFLT.AAT (ArcInfo), CODEFLT.DBF (ArcView)
TABLE FORMAT:               INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:           15

FIELD NAME       TYPE - WIDTH       FIELD DEFINITION
FNODE_              B - 4              internal number of arc segment From Node, converted from
                                       FNODE# (ArcInfo field)
TNODE_              B - 4              internal number of arc segment To Node, converted from
                                       TNODE# (ArcInfo field)
LPOLY_              B - 4              internal left polygon number of arc segment, converted from
                                       LPOLY# (ArcInfo field)
RPOLY_              B - 4              internal right polygon number of arc segment, converted
                                       from RPOLY# (ArcInfo field)
LENGTH              F - 4              length of arc segment
CODEFLT_            B - 4              unique internal sequence, converted from CODEFLT# (ArcInfo
                                       field)
CODEFLT_ID          B - 4              sequence ID-number for each polygon, converted from
                                       CODEFLT-ID (ArcInfo field)
FLT_IDX             I - 6              user-defined ID-number for each arc 
FLT_SEG_N           I - 3              number for each fault segment
FLT_SEG_T           I - 2              code value used to differentiate fault segment line types*
FLT_TYPE            I - 2              code value for type of fault offset/displacement*
FLT_LT              I - 3              fault and line segment type code value used for line
                                       representation*
FLTCNT              C - 1              flags faults that are also contacts*
FLT_NM              C - 60             fault name, if any, common to all arc segments with the
                                       same FLT_IDX
GMAP_ID             I - 6              unique number assigned to each source map by the GRI that
                                       relates map feature to series and citation information in
                                       CODEMAP.INF look-up table
HELP_ID             C - 12             code used to link to associated geologic text in Help File
                                       System
                                       
*  see Field/Attribute Code Value Lists below


FIELD/ATTRIBUTE CODE VALUE LISTS:

FLT_SEG_T (geologic fault segment line type code)
    1    known location
    2	approximate location
    3   concealed
    4   queried
    5   approximate location, queried
    6   concealed, queried
    7   inferred location
    8   inferred, queried
FLT_TYPE (fault offset/displacement type code)
    1   thrust fault
    2   reverse fault
    3   low angle normal fault
    4   normal fault
    5   right lateral strike-slip fault
    6	left lateral strike-slip fault
    7   reverse right lateral strike-slip fault
    8   reverse left lateral strike-slip fault	
    9   normal right lateral strike-slip fault
   10   normal left lateral strike-slip fault
   11   unknown offset/displacement
   12   landslide scarp
   13   detachment fault
   14   high angle fault
   15   right lateral fault, vertical displacement/offset unknown
   16   left lateral fault, vertical displacement/offset unknown
FLT_LT (line type code)
    11  thrust fault
    12  thrust fault, approximate location
    13  thrust fault, concealed
    14  thrust fault, queried
    15  thrust fault, approximate location, queried
    16  thrust fault, concealed, queried
    17  thrust fault, inferred location
    18  thrust fault, inferred, queried
21-168  as per FLT_TYPE concatenated with FLT_SEG_T
FLTCNT  (fault also a contact?)
    Y   Yes, the fault is also a contact between different map units.
    N   No, the fault is not a contact between different map units


SPECIAL COVERAGE GUIDELINES


    

  1. Fault Arcs in Multiple Themes: Fault arcs that are also geologic contacts between different
geologic units or are also linear geologic units (FLTCNT = 'Y', see FLTCNT field description
above) are present in both the fault (CODEFLT) and geology (CODEGLG) themes, or the fault
(CODEFLT) and linear geologic (CODEGLN) themes, respectively.

    

  2. Fault Arc Directionality: Fault arcs are captured with the down-thrown fault block, if
applicable, on the 'right side' of the arc.  The 'right' and 'left' sides of an arc are
determined from 'starting' at the arc's 'from node' (FNODE_) and moving to the arc's 'to node'
(TNODE_).  The down-thrown fault-block should be the arc segment's RPOLY_.  See Standard
ArcInfo Arc Attribute Fields section for FNODE_, TNODE_ and RPOLY_ definitions/descriptions.
For fault arcs where the down-thrown block is not or can not be determined, or is not
applicable (i.e. a fault with only lateral displacement (heave) and no vertical
displacement (throw)), directionality does not matter.  Fault arc (capture) directionality is
primarily used for graphical representation of a fault where one side of a fault has symbology
that is different than the other side of the fault (e.g. a thrust fault with 'teeth' on the
up-thrown side).



SPATIAL THEME (FILENAME):   Attitude Observation Points (CODEATD)
THEME DESCRIPTION:          Point Coverage
TABLE COVERAGE/FILE NAME:   CODEATD.PAT (ArcInfo), CODEATD.DBF (ArcView)
TABLE FORMAT:               INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:           10

FIELD NAME       TYPE - WIDTH        FIELD DEFINITION
AREA                F - 4               area of the point
PERIMETER           F - 4               perimeter of the point (in map units)
CODEATD_            B - 4               unique internal sequence number for each point, converted
                                        from CODEATD# (ArcInfo field).
CODEATD_ID          B - 4               sequence ID-number for each point, converted from
                                        CODEATD-ID (ArcInfo field)
ATD_IDX             I - 6               user-defined ID-number for each point
ATD_TYPE            I - 2               code value for type of attitude measurement*
ATD_ST              I - 3               azimuth of strike or trend, (0-359) degrees clockwise from
                                        the north with dip direction clockwise from strike
                                        direction (right-rule method).
                                        non-applicable strike values assigned a value of 999.
ATD_DP              I - 2               dip or plunge degrees from horizontal
ATD_AV_ROT          I - 3               ArcView symbol rotation value field, used for symbol
                                        presentation
GMAP_ID             I - 6               unique number assigned to each source map by the
                                        GRI that relates map feature to series
                                        and citation information in CODEMAP.INF look-up table
HELP_ID             C - 12              code used to link to associated geologic text in Help
                                        File System
                                        
* see Field/Attribute Code Value Lists below                                        	                                     
						
						

FIELD/ATTRIBUTE CODE VALUE LISTS:


ATD_TYPE (observation code for structural attitude point)
    1   strike and dip of beds
    2   strike and dip of overturned beds
    3   strike of vertical beds
    4   horizontal beds
    5   strike and dip of beds, tops known from sedimentary structures
    6   strike and dip of overturned beds, tops known from sedimentary structures
    7   strike and dip of beds, tops known from sedimentary structures, dot indicates top of beds
    8   strike and dip of variable bedding
    9   approximate strike and dip of beds
   10   strike of beds, dip amount unspecified
 11-87  additional attitude point features types


SPECIAL COVERAGE GUIDELINES
 

    

  1. Point Placement:  For most attitude point types, placement of a digitized point is at the
center of the pointÕs graphical symbol.  However, for many attitude points that represent fault or
fold type, directionality and/or attitude, point placement should be on the related fault or fold
arc/line.

    

  2. Feature Symbol Rotation and Strike/Trend Values:  The rotation value used to correctly orient
many attitude feature symbols in ArcView, as mentioned in the ATD_AV_ROT field description
presented above, is dependent on the type of attitude feature, the symbology used to represent
that feature in ArcView, and the default or non-rotated orientation of that symbol.  For many of
these features, a directional component or azimuth, either strike or trend, measured at the
locality is conveyed in the graphical orientation of that feature, and is therefore directly
related to a value that rotates the orientation of that featureÕs symbol.  Thus, it is possible to
determine the ATD_ST value from the ATD_AV_ROT field, and vice versa.  Formulas to calculate the
ATD_ST value from the ATD_AV_ROT value, and vice versa, are presented in an appendix file,
ATDAVROT.DOC.



SPATIAL THEME (FILENAME):    Cross Section Lines (CODESEC)
THEME DESCRIPTION:           Arc/line coverage
TABLE COVERAGE/FILE NAME:    CODESEC.AAT (ArcInfo), CODESEC.DBF (ArcView)
TABLE FORMAT:                INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:            12

FIELD NAME       TYPE - WIDTH        FIELD DEFINITION
FNODE_              B - 4			    internal number of arc segment From Node, converted from
                                        FNODE# (ArcInfo field)
TNODE_              B - 4               internal number of arc segment To Node, converted from
                                        TNODE# (ArcInfo field)
LPOLY_              B - 4               internal left polygon number of arc segment, converted
                                        from LPOLY# (ArcInfo field)
RPOLY_              B - 4               internal right polygon number of arc segment, converted
                                        from RPOLY# (ArcInfo field)
LENGTH              F - 4               length of arc segment
CODESEC_            B - 4               unique internal sequence, converted from CODESEC# (ArcInfo
                                        field)
CODESEC_ID          B - 4               sequence ID-number for each polygon, converted from
                                        CODESEC-ID (ArcInfo field)
SEC_IDX             I - 6               unique ID-number for each cross section line
SEC_ABV_O           C - 6               initial cross section abbreviation on geologic map
SEC_ABV             C - 6               cross section abbreviation on digital map
SEC_FILE            C - 60              file directory path and graphics file name of cross
                                        section .jpg file, path and filename is 'passedÕ to a
                                        graphics viewer program that displays the cross section
                                        graphic
                                        (ex. d:\blca\data\nrdata\geology\graphics\i584a.jpg),
GMAP_ID             I - 6               unique number assigned to each source map by the GRI that
                                        relates map feature to series and citation information in
                                        CODEMAP.INF look-up table
                                       
                                        

SPECIAL COVERAGE GUIDELINES

None.

_________________________________________________________________________________________________



ACCESSORY DATA FILES

Additional data on unit lithology and source map information are included in two look-up tables
that are related to map coverages through a primary or secondary key field.

TABLE COVERAGE/FILE NAME:    CODEGLG1.INF (ArcInfo), CODEGLG1.DBF (ArcView)
TABLE FORMAT:                INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:            11

FIELD NAME        TYPE - WIDTH       FIELD DEFINITION
GLG_SYM              C - 12             age-lithology unit symbol, used to relate the coverage
                                        with the CODEGLG.INF or CODEGLG1.DBF
GLG_NAME             C - 100            formal name of map unit, if any
G_REL_AGE            C - 5              relative age of geologic units
G_SSCR_TXT           C- 6               subscript from the map symbol
GLG_AGE_NO           N  - 7.4           number to age-sort map units in legend
G_AGE_TXT            C - 50             geologic time period of map unit
G_MJ_LITH            C - 3              code value for lithologic type*
G_LITH_ID            I - 10             code value used to describe lithology
G_LITH_TXT           C -100             brief text describing lithology
G_NOTE_TXT           C -254             descriptive notes about the map unit
GMAP_SRC             C -100             source map(s) with organization and map series number
                                        (i.e. USGS GQ-1402, USGS GQ-1568)

*  see Field/Attribute Code Value Lists below


FIELD/ATTRIBUTE CODE VALUE LISTS:

G_MJ_LITH (map unit major lithology code)
     EXT    extrusive igneous
     IAM    intrusive igneous and metamorphic
     INT    intrusive igneous
     MET    metamorphic
     SED    sedimentary
     VAS    volcanic and sedimentary
     UNC    unconsolidated

Example record from CODEGLG1.INF or CODEGLG1.DBF 

    GLG_SYM      =    Qvba(pc)
    GLG_NAME     =    Basaltic Andesite of Puny Creek
    G_REL_AGE    =    Q
    G_SSCR_TXT   =    vba
    G_AGE_NO     =    1.00
    G_AGE_TXT    =    Holocene
    G_MJ_LITH    =    EXT
    G_LITH_ID    =    71
    G_LITH_TXT   =    basaltic andesite flows
    G_NOTE_TXT   =    volcanic lava flows with interbedded soil horizons
    GMAP_SRC     =    I-757; GQ-1082

TABLE COVERAGE/FILE NAME:    CODEMAP.INF (ArcInfo), CODEMAP.DBF (ArcView)
TABLE FORMAT:                INFO table (ArcInfo), dBase IV (ArcView)
NUMBER OF FIELDS:            18

FIELD NAME       TYPE - WIDTH        FIELD DEFINITION
GMAP_ID             I - 6               unique number assigned to each source map by the GRI
GMAP_CODE           C - 4               unique 4-letter abbreviation code assigned to each source
                                        map by the GRI
GMAP_ABBRV          C - 150             abbreviation of map title, often includes map name and
                                        interpretation technique (e.g., Preliminary) and/or a term
                                        that indicates the type of material (e.g., Surficial,
                                        Bedrock)
GMAP_YEAR           I - 4               compilation or publication year
GMAP_AUTH           C -254              map author(s)
GMAP_ORG            C - 100             organization that created or compiled the map 
GMAP_TITLE          C - 200             complete map title
GMAP_SER            C - 40              map series or organizational identifier
                                        (e.g.,USGS GQ-1516)
GMAP_SCALE          I- 7                source map scale denominator
GMAP_PROJ           C- 100              name or description of map projection with projection
                                        datum
GMAP_REF            C - 254             complete map citation in USGS style
GMAP_DESC           C - 254             brief description of the map
GMAP_XMAX           N Ð 9.6             western limit of map in decimal degrees
GMAP_XMIN           N Ð 9.6             eastern limit of map in decimal degrees 
GMAP_YMAX           N Ð 9.6             northern limit of map in decimal degrees
GMAP_YMIN           N Ð 9.6             southern limit of map in decimal degrees 
GMAP_SRC            C -100              source map(s) with organization and map series number
                                        (i.e. USGS GQ-1402,
                                        USGS GQ-1568)

Example record for the Geologic map of Rocky Mountain National Park and Vicinity, Colorado. The
4-letter NPS alpha code for Rocky Mountain NP is ROMO.

ROMOMAP.INF or ROMOMAP.DBF
    GMAP_ID    = 144
    GMAP_CODE  = ROMO
    GMAP_ABBRV = Rocky Mountain NP
    GMAP_YEAR  = 1990
    GMAP_AUTH  = Braddock, William A., and Cole, James C.
    GMAP_ORG   = USGS
    GMAP_TITLE = Geologic map of Rocky Mountain National Park and Vicinity, Colorado
    GMAP_SER   = I-1973
    GMAP_SCALE = 50000
    GMAP_PROJ  = Geographic
    GMAP_REF   = Braddock, William A., and Cole, James C., 1990, Geologic map of Rocky Mountain
                 National Park and Vicinity, Colorado, USGS, I-1973, 1:50,000
                 scale
    GMAP_DESC  = Geologic map of Rocky Mountain National Park and Adjacent Vicinity.
    GMAP_XMAX  = -105.958333
    GMAP_XMIN  = -105.458333
    GMAP_YMAX  = 40.566666
    GMAP_YMIN  = 40.125000
    GMAP_SRC   = see published USGS non-digital (paper) map.

REFERENCES

Fryer, S.L., Gregson, Joe, Poole, Anne, Connors, Tim, and Heise, Bruce, 2000, The National Park Service Digital Geologic Map Model: Transformation from Paper to Digital, Featuring Legends, Cross Sections, Map Notes and Keyword Searchability, in D.R. Soller, ed. Digital Mapping Techniques '00 - Workshop Proceedings: U.S. Geological Survey Open-File Report 00-325, p.69-82, https://pubs.usgs.gov/openfile/of00-325/fryer.html.

Gregson, J.D., Fryer, S.L., Poole, Anne, Heise, Bruce, Connors, Tim, and Dudek, Kay, 1999, Geologic Resources Inventory for the National Park System: Status, Applications, and Geology-GIS Data Model: in D.R. Soller, Digital Mapping Techniques '99 - Workshop Proceedings, U.S. Geological Survey Open-File Report 99-386, p. 151-162, https://pubs.usgs.gov/openfile/of99-386/gregson.html.

Gregson, J.D., 1998, Geologic Resources Inventory - Geologic Resources Division, Inventory and Monitoring Program: in D.R. Soller, Digital Mapping Techniques '98 - Workshop Proceedings, U.S. Geological Survey Open-File Report 98-487, p. 109-111, https://pubs.usgs.gov/openfile/of98-487/gregson.html.

Harris, Carl F.T., 1998, Washington State's 1:100,000-Scale Geologic Map Database: An ArcInfo Data Model Example: in D.R. Soller, Digital Mapping Techniques '98 - Workshop Proceedings, U.S. Geological Survey Open-File Report 98-487, p. 27-35, https://pubs.usgs.gov/openfile/of98-487/harris.html.

Johnson, B.R., Brodaric, Boyan, and Raines, G.L., 1998, Draft Digital Geologic Map Data Model, Version 4.2: American Assoc. of State Geologists/U.S. Geological Survey Geologic Map Data Model Working Group, May 19, 1998, http://geology.usgs.gov/model/model42.pdf/.

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National Cooperative Geologic Mapping Program | Geologic Division | Open-File Reports
U.S. Department of the Interior, U.S. Geological Survey
URL: http://pubsdata.usgs.gov/pubs/of/2001/of01-223/fryer.html
Maintained by David R. Soller
Last modified: 18:24:46 Wed 07 Dec 2016
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