Geomorphological map of the Afekan Crater region, Titan: Terrain relationships in the equatorial and mid-latitude regions

• Published in: Icarus (New York, N.Y. 1962) Vol. 270; pp. 130 - 161
• Main Authors: Malaska, Michael J., Lopes, Rosaly M.C., Williams, David A., Neish, Catherine D., Solomonidou, Anezina, Soderblom, Jason M., Schoenfeld, Ashley M., Birch, Sam P.D., Hayes, Alex G., Le Gall, Alice, Janssen, Michael A., Farr, Thomas G., Lorenz, Ralph D., Radebaugh, Jani, Turtle, Elizabeth P.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.05.2016; Elsevier
• Subjects: Astrophysics; Cassini mission; Craters; Dunes; Earth and Planetary Astrophysics; Geological processes; Mapping; Saturn satellites; Sciences of the Universe; Synthetic aperture radar; Terrain; Titan; Titan, surface; Titan; Geological processes; Titan, surface; Titan surface
• ISSN: 0019-1035; 1090-2643
• DOI: 10.1016/j.icarus.2016.02.021

[Display omitted] •Plains units dominate the mid-latitude region near Afekan Crater on Titan.•Hummocky/mountainous, and labyrinth are the oldest terrains, dunes are the youngest.•Labyrinth, plains, and dunes units are consistent with organic materials.•Sedimentary processes have dominated the Afekan Crater region. We carried out geomorphological mapping in a mid-latitude area surrounding the Afekan Crater region on Titan. We used Cassini RADAR (Synthetic Aperture Radar mode) data as the basemap, supplemented by Cassini RADAR microwave emissivity, Imaging Science Subsystem (ISS) infrared data, Visual and Infrared Mapping Spectrometer (VIMS) spectral images, and topography derived from Synthetic Aperture Radar (SAR). Mapping was done at a spatial scale of 300m/pixel, which corresponds to a map scale of 1:800,000. We describe multiple terrain units and their spatial relations. We describe five broad classes of units that are in agreement with previous mapping efforts: crater, labyrinth, hummocky/mountainous, plains, and dune terrain classes. We subdivide these into seven crater units, four hummocky/mountainous units, six plains units, and three dunes units. Our results show that plains are the dominant class of terrain unit in Titan’s mid latitudes. Of the plains units, the undifferentiated plains are the largest by total areal extent in the mapped region, accounting for over 45% of the mapped area. We developed a stratigraphic sequence that has the hummocky/mountainous and labyrinth terrains as the oldest units. The observed properties of the hummocky/mountainous terrain are consistent with fractured water ice materials, while the labyrinth terrains are consistent with organic materials. The youngest units are the dune units and streak-like plains units, with the undifferentiated plains units being of intermediate age. The microwave emissivity of the undifferentiated plains and dune units are consistent with organic materials. Given their properties and stratigraphic placement, we conclude that the hummocky/mountainous terrains are most consistent with the presumed crustal materials of Titan. The plains materials are consistent with deposits resulting from the transport and emplacement of organic-rich materials predominantly by aeolian mechanisms. Our geomorphological mapping results are consistent with the equatorial and mid-latitudes of Titan being dominated by organic materials that have been deposited and emplaced by aeolian activity.