Mars Viking Geologic Map I-1962 of East Mangala Valles
The east Mangala Valles area merits detailed geologic study because it contains several small channels whose ages can be determined relative to geologic units that range in age from early (Noachian) to late (Amazonian) periods of Martian history. Because small channels are of three ages and geomorphic types, their study increases our understanding of the continuity of fluvial processes in the evolutionary history of Mars. For these reasons, part of the area is a candidate site for a sample return mission to Mars.
- Mimetype
- application/zip
- Filename
- Mars-Viking-Geologic-Map-I-1962-of-East-Mangala-Valles.zip
- Publisher
- USGS Astrogeology Science Center
- Publication Date
- 1 January 2023
- Author
- Mary G. Chapman
- Originator
- USGS Astrogeology Science Center, Harold Masursky, Arthur L. Dial Jr.
- Group
- MRCTR
- Added to Astropedia
- 19 August 2013
- Modified
- 16 June 2021
General
- Purpose
Mars geologic mapping
- Geospatial Data Presentation Form
- Vector Data
- Series Id
- I-1962
- Edition
- 1
- Online Linkage
- http://astrogeology.usgs.gov/search
- Native Data Set Environment
- ESRI Arcinfo
Keywords
- System
- Mars
- Target
- Mars
- Theme
- Geology, Geographic Information System (GIS)
- Mission
- Viking
- Mission Specific
- Instrument
- VISA, VISB
- Search Terms
- Mars, Geology, Mangala Valles
Contact and Distribution
- Access Constraints
- none
- Access Instructions
- You will need GIS software to view included files.
- Use Constraints
- none
Data Status and Quality
- Currentness Reference
- Publication date
- Progress
- Complete
- Update Frequency
- None planned
- Logical Consistency Report
- These data are believed to be logically consistent, though no tests were performed.
- Completeness Report
Maps were completed on Viking-era basemaps.
- Process Date
- 9 August 2000
- Process Description
The map was compiled on a Viking 1:500, 000-scale photomosaic base (U.S. Geologic Survey, 1985). Some map units correspond or are partly equivalent to units on smaller scale maps (Mutch and Morris, 1979; Scott and Schaber, 1981; Scott and Tanaka, 1986) and the formal terminology proposed by Scott and Tanaka (1986) was followed were feasible. However, in many places interpretations and contacts have been revised to reflect information visible on high-resolution Viking images; geomorphologic details on these images were clarified by spatial filtering (Condit and Chavez, 1979). The depths of channels, thicknesses of geologic units, and heights of scarps prevalent in the area were obtained in places by using photoclinometric methods of Davis and Soberblom (1984). Geomorphology of channels and stratigraphic relationsof geologic units observed on both computer-enhanced and nonenhanced high-resolution images provide new information regarding the geologic history and hydrologic activity of the east Mangala Valles area. The relative ages of small channels and faults were established by their stratigraphic relation to geologic units that are either overlapped or transected by these features. Ages of the geologic units, in turn, were determined by stratigraphic relations and crater counts. Cumulative densities of craters whose diameters are greater than 1 km, normalized to 10^6 km^2, are listed in the unit descriptions, except as noted for the oldest unit, Noachian ridged plateau material. (The production-function slope of this unit falls off for crater diameters less than 40 km as small craters are preferentially destroyed.) Map preparation was on mylar or acetate made from USGS negatives. All features were scanned at 50 microns and then vectorized and attributed in Arc/INFO.
- Horizontal Positional Accuracy Value
- 5000
- Horizontal Positional Accuracy Report
- Accurate to Control Net
- Entity and Attribute Overview
- Geologic units and structural layers
- Entity and Attribute Detailed Description
- Please see original map sheet for unit descriptions (included with .zip file): Mars_Viking_Geologic_Map_I_1962_of_East_Mangala_Valles_Glg_Units.pdf
- Entity and Attribute Linkage
- http://astrogeology.usgs.gov/rpif
Lineage
- Source Originator
- United States Geological Survey
- Source Publication Date
- 1 January 1998
- Source Title
- Geologic Map of Science Study Area 1A, East Mangala Valles Region of Mars
- Source Online Linkage
- http://astrogeology.usgs.gov/search
- Type of Source Media
- Stable-Base Material
- Attribute Accuracy Report
- Best Effort
Geospatial Information
- Feature Name
- Mangala Valles
- Feature Target
- East Mangala Valles
- Minimum Latitude
- -7.6012
- Maximum Latitude
- -2.3993
- Minimum Longitude
- -150.1025
- Maximum Longitude
- -144.899
- Direct Spatial Reference Method
- Vector
- Object Type
- Polygon
- Quad Name
- Radius A
- 3393400
- Radius C
- 3375730
- Control Net
- Viking MDIM1.0
- Map Projection Name
- Simple Cylindrical
- Latitude Type
- Planetocentric
- Longitude Direction
- Positive East
- Longitude Domain
- -180 to 180