atlas_of_mars_geology
DESCRIPTION OF THE DIGITAL DATABASE FOR Geologic Map of Mars, Scale 1:20,000,000 USGS SCIENTIFIC INVESTIGATIONS MAP 3292
Reference: K.L. Tanaka, J.A. Skinner, Jr., J.M. Dohm, R.P. Irwin, III, E.J. Kolb, C.M. Fortezzo, Thomas Platz, G.G. Michael, and T.M. Hare, 2014, Geologic Map of Mars, Scale 1:20,000,000, U.S. Geological Survey Scientific Investigations Map SIM 3292. URL: http://pubs.usgs.gov/sim/3292
INTRODUCTION
This new global geologic map of Mars, which records the distribution of geologic units and landforms on the planet’s surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available has enabled consistent morphologic portrayal of the surface for global mapping (whereas previously used visual-range image bases were less effective, because they combined morphologic and albedo information and, locally, atmospheric haze). Also, thermal infrared image bases used for the new map tended to be less affected by atmospheric haze and thus are reliable for analysis of surface morphology and texture at even higher resolution than the topographic products.
All GIS data are in Robinson projection using the Mars 2000 geographic coordinate system (GCS_Mars_2000_Sphere, 3396190.0 radius). Units are in meters. Center Longitude = 0.0
GEOLOGIC CONTENT (contents of "ESRI_FileGeodatabase" Folder, SIM3292_geodatabase.gdb)
This ArcGIS geodatabase contains one feature dataset (SIM3292_MGM_Robinson_Mars2000_Sphere) with the following features:
SIM3292_Global_Contacts - Line feature class, contains a “ConType” field for the geologic unit and map boundaries including symbol types: Certain, Approximate, Border, and Internal.
SIM3292_Global_Geology - Polygon feature class, geologic unit polygon feature class.
Contains a “Unit” field denoting the unit name and “UnitDesc” the short unit
decription. “SphArea_km” is the geodesic area of the polygon in km^2.
SIM3292_Global_Structure - Structural layer. Contains a “Morphology” field denoting the structure type including “Origin”, “Interpretation”, and “Preservation”.
BASE MAP CONTENT To produce an up-to-date global geologic map for Mars using modern bases including the Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) digital elevation model (DEM) (463 m/pixel resolution at lower latitudes to 115 m/pixel near the poles) (Smith and others, 2001) and the Mars Odyssey (ODY) Thermal Emission Imaging System (THEMIS) daytime infrared (IR) image mosaic (100 m/pixel) (Christensen and others, 2004). See Pamphlet for more information and references.
DIGITAL DATABASE AND METADATA PACKAGE (SIM3292_database.zip)
The geologic map files, basemaps, and supportive files are included in the database package, as described below:
"SIM3292_MarsGlobalGeologicGIS_20M" directory
Files Description
SIM3292_README.txt This readme file.
SIM3292_metadata.txt Text-format FGDC-style metadata for the database package
SIM3292_metadata.xml XML-format FGDC-style metadata for the database package
SIM3292_MarsGlobalGeologicGIS_20M_ArcMap10.1.mxd ArcGIS (version 10.1) project
"Basemaps" basemap directory
MOLA_Hillshade_Robinson_128ppd.tif - MOLA shaded relief basemap Goddard and USGS.
hillshade_n_128.jpg - North Pole MOLA shaded relief basemap Goddard
hillshade_s_128.jpg - South Pole MOLA shaded relief basemap Goddard
Vector directories
"SIM3292_geodatabase.gdb" - ArcMap 10.0 versioned geodatabase
"Shapefiles" - This directory contains GIS shapefiles exported from the ArcGIS geodatabase described above using decimal degrees. As such, the names and descriptions for each shapefile are identical to the content of the included geodatabase. See above "GEOLOGIC CONTENT" for details.
Users of the database package may wish to download the PDF version of the map for the Description of Map Units.
The material described above is available on the World Wide Web at http:/pubs.usgs.gov/sim/3292
"Mars_PublishedGeologicMaps_1Mscale_greater" directory
Contains a locator map and GIS shapefiles and ArcMap project for existing Mars geologic maps above 1:1,000,000 scale.
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 3292
USGS Information Services Box 25286 Denver Federal Center Denver, CO 80225-0046
(303) 202-4200 1-888-ASK-USGS Email: infoservices@usgs.gov