קקקקקקקקקקקקקקקקקקקקקקקקקקקקקקקקק APPENDIX קקקקקקקקקקקקקקקקקקקקקקקקקקקקקקקקק DIGITAL DATABASE DESCRIPTION FOR THE GEOLOGIC MAP OF LOWER HURRICANE WASH AND VICINITY, MOHAVE COUNTY, NORTHWESTERN ARIZONA Database by Scott E. Graham INTRODUCTION This appendix describes the digital geologic map database and gives instructions for obtaining the data. The report includes PostScript and PDF plot files containing images of the geologic map sheet and an explanation sheet as well as accompanying text describing the geology of the area. For those interested in a paper plot of information contained in the database or in obtaining the PostScript plot files, please see the section entitled דFor Those Who Donגt Use Digital Geologic Map Databasesה below. The digital map database, compiled from previously published and unpublished data and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in Lower Hurricane Wash. Together with the preceeding pamphlet, it provides current information on the geologic structure and stratigraphy of the area, as well as how to access the information in the digital map database. The database delineates map units that are identified by age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:31,680 or smaller. The content and character of the database, as well as three methods of obtaining the database, are described below. FOR THOSE WHO DONגT USE DIGITAL GEOLOGIC MAP DATABASES Two sets of plot files containing images of much of the information in the database are available to those who do not use an ARC/INFO compatible Geographic Information System. Each set contains an image of a geologic map sheet and the accompanying explanatory pamphlet. There is a set available in PostScript format and another in Acrobat PDF format (see sections below). Those who have computer capability can access the plot file packages in either of the two ways described below (see the section דObtaining the Digital Dataה); however, these packages do require gzip or WinZip utilities to access the plot files. Those without computer capability can obtain plots of the map files through U.S. Geological Survey Information Services. Be sure to request Map MF-2396. U.S. Geological Survey Information Services Box 25286 Denver, CO 80225 1-888-ASK-USGS e-mail:ask@usgs.gov DATABASE CONTENTS The digital database package consists of the geologic map database and supporting data including base maps, map explanation, geologic description, and references. The other two packages consist of PostScript or PDF plot files of the geologic map, explanation sheet and geologic description. Digital Database Package The digital database package is composed of geologic map database files for the Lower Hurricane Wash area. The coverages and their associated INFO directories have been converted into ARC/INFO export files. These export files are uncompressed and are easily handled and compatible with some Geographic Information Systems other than ARC/INFO. The export files included are: ARC/INFO export file Resultant Coverage Description lh-geol.e00 lh-geol/ Faults, contacts and geologic units lh-strc.e00 lh-anno.e00 lh-strc/ lh-anno/ Strike and dip information and annotation, point data and annotation; fold axes Unit labels, fault names, and fault separation values The database package also contains the following files: lhdrg.tif.gz Zipped background topographic map image lhdrg.tfw World file accompanying lhdrg.tif import.aml ASCII text file in Arc Macro Language to convert Arc export files to Arc coverages in Arc/Info mf2396.met A parseable text-only file of publication level FGDC metadata for this report mf2396.rev ASCII text file describing revisions, if any, to this publication PostScript Plot file Package The second digital data package available contains the PostScript images described below: lhmap.ps Encapsulated PostScript plottable file containing complete map composition with geology, geologic cross-sections, and correlation of units. lhgeo.ps Encapsulated PostScript plottable file containing detailed unit descriptions, geological information, sources of data, references cited and the database description. The PostScript image of the geologic map and map explanation is 44 inches high by 36 inches wide, so it requires a large plotter to produce paper copies at the intended scale. The PostScript plotfile of the geologic map was initially produced using the ־postscriptג command with compression set to zero in ARC/INFO version 8.1. The geologic description and correlation chart were created in Adobe Illustrator 9.0. PDF Plotfile Package lhmap.pdf lhgeo.pdf A PDF file containing complete map composition with geology, geologic cross-sections, and correlation of units. A PDF file containing detailed unit descriptions, geological information, sources of data, references cited and the database description. The Acrobat files were created from corresponding .ps files and are compatible with Adobe Acrobat version 4.0 and higher. To use PDF files, the user must get and install a copy of Adobe Acrobat Reader. This software is available free from the Adobe website (http://www.adobe.com/). Please follow the instructions given at the website to download and install this software. Once installed, the Acrobat Reader software contains an on-line manual and tutorial. Tar files The three data packages described above are stored in tar (UNIX tape archive) files. A tar utility is required to extract the database from the tar file. This utility is included in most UNIX systems, and can be obtained free of charge over the Internet from Internet Literacy's Common Internet File Formats Webpage (http://www.matisse.net/files/formats.html). Both tar files have been compressed, and may be uncompressed with gzip, which is available free of charge over the Internet via links from the USGS Public Domain Software page (http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/public.html). In addition, several common proprietary freeware programs such as Stuffit Expander (http://www.aladdinsys.com/expander/index.html) and shareware programs such as WinZip (http://www.winzip.com) can handle both tar file extraction and gzip uncompression. When the tar file is uncompressed and the data is extracted from the tar file, a directory is produced that contains the data in the package as described above. The specifics of the tar files are listed below: Name of Size of Directory Data package compressed compressed produced when contained tar file tar file extracted from (uncompressed) tar file ------------ --------------------- ---------------------- ---------------------------- mf2396c.tar.gz MB (MB) lhgeo Digital Database Package mf2396a.tar.gz MB (MB) lhps PostScript Plotfile Package mf2396b.tar.gz MB (MB) lhpdf PDF Plotfile Package Obtaining the Digital Data The digital data can be obtained from: http://pubs.usgs.gov/mf/2003/2396/ ACCESSING DATABASE CONTENTS ARC/INFO Export Files ARC export files are converted to their proper ARC/INFO format using the ARC command ־importג with the option proper for the format desired. To ease conversion and preserve naming convention, an AML is enclosed that will convert all the export files in the database to coverages and graphic files and will also create an associated INFO directory. From the ARC command line type: ARC: &run import.aml ARC export files can be read by other Geographic Information Systems. Refer to your documentation for proper procedure for retrieval of data. DATABASE SPECIFICS Digital Compilation Stable-base maps were scanned at the U.S. Geological Surveyגs Flagstaff Science Center using the Optronics 5040 raster scanner at a resolution of 50 microns (508 dpi). The resulting raster file was in RLE format and converted to the RLC format using the דrle2rlcה program written by Marilyn Flynn. The RLC file was subsequently converted to an ARC/INFO Grid in ARC/INFO. The linework was vectorized using gridline. A tic file was created in lat/long and projected into the base map projection (State Plane). Tics are defined in the four extreme corners of the map area in the geologic coverages corresponding with quadrangle corners both in base maps and digital maps. The tic file was used to transform the grid into STATEPLANE. Lines, points, polygons and annotation were edited using ARCEDIT. Following editing and annotation, the individual coverages were projected into STATEPLANE projection. Map Projection: Parameter Description Projection STATEPLANE Units Meters on the ground Zone 3201 Datum NAD27 Spheroid Clarke 1866 Database Fields The content of the geologic database can be described in terms of the lines, points, and areas that compose the map. Each line, point, or area in a map layer or map database (coverage) is associated with a database entry stored in a feature attribute table. Each database entry contains both a number of items generated by ARC/INFO to describe the geometry of the feature, and one or more items defined by the authors to describe the geologic information associated with that entry. Each item is defined as to the amount and type of information that can be recorded. Descriptions of the database items use the terms explained below. Parameter Description ITEM NAME Name of database field WIDTH Maximum number of characters or digits stored OUTPUT Output width TYPE B - binary integer; F- binary floating point number, I - ASCII integer, C - ASCII character string N.DEC Number of decimal places maintained for floating point numbers LINES The arcs are recorded as strings of vectors and described in the arc attribute table (AAT). They define the boundaries of the map units, faults, and map boundaries in LH-GEOL, and fold axes in LH-STRC. These distinctions and the geologic identities of the boundaries are stored in the LTYPE field according to their line type. Arc Attribute Table Definition LH-GEOL.AAT Item Name Width Output Type N. Dec Description FNODE# 4 5 B - Starting node of the arc TNODE# 4 5 B - Ending node of the arc LPOLY# 4 5 B - Polygon to the left of the arc RPOLY# 4 5 B - Polygon to the right of the arc LENGTH 4 12 F 3 Length of the arc in meters LH-GEOL# 4 5 B - Unique internal number LH-GEOL-ID 4 5 B - Unique identification number LTYPE 35 35 C - Line type PTTYPE 35 35 C - Point type for arcmarkers LH-STRC.AAT Item Name Width Output Type N. Dec Description FNODE# 4 5 B - Starting node of the arc TNODE# 4 5 B - Ending node of the arc LPOLY# 4 5 B - Polygon to the left of the arc RPOLY# 4 5 B - Polygon to the right of the arc LENGTH 4 12 F 3 Length of the arc in meters LH-GEOL# 4 5 B - Unique internal number LH-GEOL-ID 4 5 B - Unique identification number LTYPE 35 35 C - Line type PTTYPE 35 35 C - Point type for arcmarkers PLUNGE 3 3 I - For plotting arrows on plunging fold axes and basalt flow direction Line Types recorded in LTYPE field LH-GEOL.AAT contact_certain fault_normal_approx fault_normal_certain fault_normal_concealed landslide_scarp map_boundary LH-STRC.AAT anticline_certain anticline_concealed basalt_flow_direction monocline_certain monocline_concealed plunging_anticline plunging_syncline syncline_approx syncline_certain syncline_concealed xsect Arc marker types recorded in PTTYPE field LH-GEOL.AAT fault_ball_fill xx LH-STRC.AAT anticline monocline syncline xx Arcs with PTTYPE value ־xxג indicate that there is no symbol attached to the arc. Values recorded in PLUNGE field LH-STRC.AAT 0 1 32 Arcs with PLUNGE value 0 indicate no arrowhead, arcs with PLUNGE value 1 indicate a black arrowhead, and arcs with PLUNGE value 32 indicate a red arrowhead. POLYGONS Map units (polygons) are described in the polygon attribute table (PAT). This identifies the map units recorded in the PTYPE field by map label. Individual map units are described more fully in the accompanying text (lhgeo.txt, lhgeo.doc, or lhgeo.pdf) Definition of Polygon Attribute Table LH-GEOL.PAT Item Name Width Output Type N. Dec Description AREA 4 12 F 3 Area of polygon in square meters PERIMETER 4 12 F 3 Length of perimeter in meters LH-GEOL# 4 5 B - Unique internal number LH-GEOL-ID 4 5 B - Unique identification number PTYPE 5 5 C - Unit label Unit labels recorded in the ptype field LH-GEOL.PAT Pe Qa1 Qeb Qg5 Qwi TRmt Ph Qa2 Qei Qi Qwp TRmu Pkf Qa3 Qep Ql TRcp TRmv Pkh Qa4 Qf Qp TRcs Tbb Ptb Qaf Qg1 Qs TRml Tsb Pts Qb Qg2 Qt TRmlt Tsi Ptw Qc Qg3 Qv TRmm Tsp QTa Qd Qg4 Qwb TRms Plain text is substituted for conventional geologic age symbols (TR for Triassic) show on the map. POINTS Strike and dip information is recorded as coordinate data with related information. This information is described in the point attribute table (PAT). ARC/INFO coverages cannot hold both point and polygon information, thus LH-STRC has only a point attribute table, and LH-GEOL has only a polygon attribute table. Definition of Point Attribute Table LH-STRC.PAT Item Name Width Output Type N. Dec Description AREA 4 12 F 3 Area of polygon in square meters PERIMETER 4 12 F 3 Length of perimeter in meters LH-STRC# 4 5 B - Unique internal number LH-STRC-ID 4 5 B - Unique identification number PTTYPE 35 35 C - Point type DIP 3 3 I - Dip angle in degrees STRIKE 3 3 I - Strike angle in azimuth degrees The coverage LH-STRC contains strike and dip data and other pertinent structural data represented by point symbology, including collapses, sinkholes and domes. Point types recorded in the PTTYPE field approx_bedding sinkhole bedding vertical_joint collapse_structure Dome ANNOTATION The coverage LH-ANNO contains all annotation for the polygon coverage. It is defined somewhat differently from the polygon and dip coverages. The arc attribute table is of negligible importance. Arcs in this coverage are merely leaders from a unit annotation to the related polygon. LH-ANNO contains annotation with unit labels, fault separation, and monocline names. Annotation directly related to unit labeling is contained in subclass דanno.unitה and annotation including fault separation values, fault names and place names is contained in דblankה, or, not in a subclass. BASE MAP PROCEDURE The base map was prepared by mosaicing four 1:24,000 DRGs, and scanning the resultant image to generate a georeferenced TIFF (GeoTIFF) graphic. This graphic was subsequently projected into STATEPLANE, rotated and clipped into a secondary TIFF image to be used as the topographic base map for the cartographic layout. SPATIAL RESOLUTION 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. This database was created and edited at a scale of 1:31,680 which means that higher resolution data is generally not present. Plotting at scales of larger than 1:31,680 will not yield greater real detail but may reveal fine-scale irregularities below the intended resolution. ?? 3