DESCRIPTION OF THE DIGITAL DATABASE FOR GEOLOGIC MAP OF THE NORTH POLAR REGION OF MARS USGS SCIENTIFIC INVESTIGATIONS MAP 3177 INTRODUCTION This digital database for the Geologic Map of the North Polar Region of Mars includes multiple GIS features that collectively present the entire content of the geologic map, along with supporting files and metadata. Data is in shapefile and ArcGIS geodatabase format, including attribute domains, and is collated within a single feature dataset that preserves the relevant geographic information. Together with the geologic map, the GIS database provides georeferenced information on the geology, graben, unconformities, and residual ice between 75øN-90øN. All GIS data are in Stereographic North Pole projection using the Mars 2000 polar sphere geographic coordinate system (GCS_Mars_2000_Sphere_Polar). Units are in meters. GEOLOGIC CONTENT (contents of "Vector" Folder, SIM3177_geodatabase.gdb) This ArGIS geodatabase contains one feature dataset (SIM3177_feature_dataset) with the following features: SIM3177_Contacts - Line feature class, geologic unit and map boundaries including symbol types: Approximate, boundary, certain, and gradational. SIM3177_Crater_Count_Geology - Polygon feature class, geologic units with crater polygons merged into surrounding geology; used to complete crater statistics with more accurate area values. SIM3177_Craters - Point feature class, center point locations of craters used in size frequency distributions. Subset of Robbins and Hynek crater database, full dataset available at: http://webgis.wr.usgs.gov/pigwad/down/mars_crater_consortium.htm SIM3177_Geographic_Nomenclature - Annotation feature class, contains the names approved by the International Astronomical Union Working Group for Planetary System Nomenclature. SIM3177_Geology - Polygon feature class, geologic unit polygon feature class. Contains a "Type" field denoting the unit name, and a "Symbol" field denoting the unit symbol. SIM3177_Geology_Annotation - Annotation feature class, leaders and unit symbols for geologic units in the map area. SIM3177_Graben - Line feature class, denoting structural features. SIM3177_LonLat_Grid - Line feature class, denoting the longitude in 30ø wedges, and latitude in 5ø rings. SIM3177_Residual_Ice - Polygon feature class, denotes the extent of residual ice on the pole during north pole summer. Derived from MARCI image mosaic of 4 images that capture a single day on the pole. Mosaic included in map package. SIM3177_Unconformity - Line feature class, denoting breaks in the layered stratigraphy. Include both angular and parallel unconformities, although these are not distinguished from each other in the symbology or table. BASE MAP CONTENT The base map for this map is the ~230 m/pixel grayscale MOLA shaded relief derived from the MOLA digital elevation model. A secondary basemap was a mosaic of Context (CTX) images (~6 m\pixel), the subsampled mosaic (24 m\pixel) is included in this dataset. For a copy of the full resolution mosaic (~16GB), contact Corey Fortezzo at cfortezzo@usgs.gov. Supplemental information used in the identification and description of geologic units and features included: MOLA color-shaded relief (included in the data), the Thermal Emission Imaging System (THEMIS) visible range image mosaics for summer and spring (36 and 72 m/pixel for each season, included in the data), Mars Color Imager (MARCI, 1000 m\pixel, included in the data), and High Resolution Imaging Science Experiment (HiRISE, 0.25 - 0.5 m/pixel, not included). HiRISE data are available for download at: http://ode.rsl.wustl.edu/mars DIGITAL DATABASE AND METADATA PACKAGE (SIM3177_database.zip) The geologic map files, basemaps, and supportive files are included in the database package, as described below: "SIM_3177" directory -------------------------------------------- Files Description --------------------------------------------------------------------- --------------------------------------------------------------------- SIM3177_README.txt This readme file. SIM3177_metadata.txt Text-format FGDC-style metadata for the database package SIM3177_metadata.xml XML-format FGDC-style metadata for the database package SIM3177.mxd ArcGIS project for the database package "Layer_Files" directory -------------------------------------------- SIM3177_Contacts.lyr Symbology for SIM3177_Contacts feature class SIM3177_Craters.lyr Symbology for SIM3177_Craters feature class SIM3177_Geology.lyr Symbology for SIM3177_Geology feature class SIM3177_Graben.lyr Symbology for SIM3177_Graben feature class SIM3177_Residual_Ice.lyr Symbology for SIM3177_ Residual_Ice feature class SIM3177_Unconformity.lyr Symbology for SIM3177_ Unconformity feature class "Raster" directory -------------------------------------------- "CTX" directory -------------------------------------------- CTX_24m.jp2 JPEG2000 subsampled image mosaic CTX_24m.j2w Worldfile associated with JPEG2000 CTX_24m.prj Projection file associated with the JPEG2000 "MARCI" directory -------------------------------------------- MARCI.jp2 JPEG2000 image mosaic "MOLA base" directory -------------------------------------------- MOLA_DEM_75N.tif GeoTiff digital elevation model MOLA_Hillshade_75N.tif GeoTiff grayscale shaded relief derived from DEM "THEMIS" directory -------------------------------------------- Spring_36m.jp2 Spring_72m.jp2 Summer_36m.jp2 Summer_72m.jp2 "Vector" directory -------------------------------------------- "Shapefiles" directory -------------------------------------------- This directory contains GIS shapefiles exported from the ArcGIS geodatabase described above. As such, the names and descriptions for each shapefile are identical to the content of the included geodatabase. See above "GEOLOGIC CONTENT" for details. "Text_and_Figures" directory -------------------------------------------- SIM3177_Map_Text.pdf Map write-up and Description of Map Units (DOMU) SIM3177_Figure-X.pdf Figures 1-8 referred to in the SIM3177_Map_Text.pdf SIM3177_Symbols.pdf Symbology of mapped features SIM3177_COMU.pdf Correlation of map units Users of the database package may wish to download the technical and/or nontechnical pamphlet (sim3177_pamphlet.pdf) for the contained Description of Map Units. The material described above is available on the World Wide Web at http:/pubs.usgs.gov/sim/3177/. ZIP FILES The files described above are packaged within a ZIP file. Utilities to uncompress ZIP files are available for most operating systems and may be found readily with a simple web search. DIGITAL DATABASE FORMAT The digital information compiled in this report used v 10, a commercial Geographic Information System produced by Environmental Systems Research Institute, Redlands, California. OBTAINING HARD-COPY OF SIM 3177 USGS Information Services Box 25286 Denver Federal Center Denver, CO 80225-0046 (303) 202-4200 1-888-ASK-USGS Email: infoservices@usgs.gov