Geologic Map of MTM -20012 and -25012 Quadrangles, Margaritifer Terra Region of Mars

Scientific Investigations Map 3041
Prepared for the National Aeronautics and Space Administration
By: , and 



Mars Transverse Mercator (MTM) -20012 and -25012 quadrangles (lat 17.5 deg - 27.5 deg S., long 345 deg - 350 deg E.) cover a portion of Margaritifer Terra near the east end of Valles Marineris. The map area consists of a diverse assemblage of geologic surfaces including isolated knobs of rugged mountainous material, heavily cratered and dissected ancient highland material, a variety of plains materials, chaotic terrain materials, and one of the highest densities of preserved valleys and their associated deposits on the planet (Saunders, 1979; Baker, 1982; Phillips and others, 2000, 2001). The map area is centered on a degraded, partially filled, ~200-km-diameter impact structure (lat 22 deg S., long 347.5 deg E.), informally referred to as Parana basin, located between Parana Valles to the east and Loire Valles to the west. Parana Valles is a network of multidigitate, mostly east-west-oriented valleys that flowed west and discharged into Parana basin (Grant, 1987, 2000; Grant and Parker, 2002). Loire Valles, broadly comparable in length to the Grand Canyon on Earth, has a deeply incised channel within the map area that originates at the west-northwest edge of Erythraeum Chaos within Parana basin (Grant, 1987, 2000; Grant and Parker, 2002; Strom and others, 2000). Parana and Loire Valles, combined with Samara Valles to the west, form one of the most laterally extensive, well-integrated valley networks on Mars (Grant, 2000) and record a long history of modification by fluvial processes. The origin and morphology of the valley networks, therefore, provide insight into past environmental conditions, whereas their relation with other landforms helps constrain the timing and role of fluvial processes in the evolution and modification of the Margaritifer Terra region.
Publication type Report
Publication Subtype USGS Numbered Series
Title Geologic Map of MTM -20012 and -25012 Quadrangles, Margaritifer Terra Region of Mars
Series title Scientific Investigations Map
Series number 3041
ISBN 9781411323483
DOI 10.3133/sim3041
Edition Version 1.0
Year Published 2009
Language ENGLISH
Publisher U.S. Geological Survey
Contributing office(s) Astrogeology Science Center
Description Report: 12 p.; Map Sheet: 35 x 43 inches
Projection Mars Transverse Mercator (MTM)
Scale 1004000
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details