GSA Annual Meeting in Indianapolis, Indiana, USA - 2018

Paper No. 238-11
Presentation Time: 10:40 AM

GEOLOGIC MAP OF NEW HORIZONS' ENCOUNTER HEMISPHERE OF CHARON, VI (Invited Presentation)


ROBBINS, Stuart J.1, BEYER, Ross A.2, SPENCER, John R.1, GRUNDY, Will3, WHITE, Oliver L.4, SINGER, K.N.5, MOORE, Jeffrey6, DALLE ORE, C.M.7, MCKINNON, William B.8, LISSE, C.M.9, RUNYON, Kirby D.10, BEDDINGFIELD, Chloe B.11, SCHENK, Paul M.12, UMURHAN, Orkan13, CRUIKSHANK, D.P.7, LAUER, Tod R.14, BRAY, V.J.15, BINZEL, R.P.16, BUIE, M.W.5, BURATTI, B.J.17, CHENG, A.C.9, LINSCOTT, I.R.18, REUTER, D.C.19, SHOWALTER, M.R.20, YOUNG, L.A.5, OLKIN, C.B.5, ENNICO, K.7, WEAVER, H.A.10 and STERN, S. Alan1, (1)Southwest Research Institute, 1050 Walnut Street, Boulder, CO 80302, (2)NASA Ames Research Center, Moffett Field, CA 94035; SETI Institute, Mountain View, CA, (3)Lowell Observatory, (4)SETI Institute, 189 Bernardo Ave., Suite #200, Mountain View, CA 94035; NASA Ames Research Center, Moffett Field, CA 94035, (5)Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302, (6)NASA Ames Research Center, MS-245-3, Moffett Field, CA 95129, (7)NASA Ames Research Center, Mountain View, CA 94035, (8)Washington University, Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, One Brookings Drive, Saint Louis, MO 63130, (9)Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, (10)Planetary Exploration Group, Applied Physics Laboratory, 11101 Johns Hopkins Road, Laurel, MD 20723, (11)NASA Ames Research Center, Mountain View, CA 94035; SETI Institute, Mountain View, CA, (12)Lunar and Planetary Institute, Houston, TX 77058, (13)NASA Ames Research Center, Space Science Division, MS-245-3, Moffett Field, CA 94035, (14)National Optical Astronomy Observatory, Tucson, AZ, (15)Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, (16)Massachusetts Institute of Technology, Cambridge, MA 02139, (17)NASA Jet Propulsion Laboratory, La CaƱada Flintridge, CA, (18)Stanford University, 350 Serra Mall, David Packard #319, Stanford, CA 94305, (19)NASA Goddard Space Flight Center, Greenbelt, MD, (20)SETI Institute, 189 Bernardo Ave., Suite #200, Mountain View, CA 94035

NASA's New Horizons spacecraft revealed diverse landscapes on both Pluto and Charon during its July 2015 flyby, and we are completing geomorphologic mapping efforts to better understand the different landforms, how they may have formed, and relative timing. The work herein focuses on Charon, and images from the spacecraft have revealed a variety of features that include hundreds of tectonic manifestations and vast but diverse plains. This mapping and chronostratigraphy are currently under peer-review.

Data relevant for geomorphologic mapping come from LORRI (LOng-Range Reconnaissance Imager), MVIC (Multi-spectral Visible Imaging Camera), and LEISA (Linear Etalon Imaging Spectral Array). LORRI is panchromatic and provided images of Charon at up to 160 m/px, MVIC 4-color images are up to 620 m/px, and LEISA spectral cubes are up to 5 km/px. Additional, derived data includes crater maps, reconstructed topography from stereo and photoclinometry, and mineralogy maps.

The New Horizons team developed informal names used herein. Primarily for this abstract, the broad, heavily tectonized area to the north is "Oz Terra" and the smoother equatorial plains are "Vulcan Planum."

Tectonic Features Mapping: Initial geomorphologic mapping focused on tectonic features. Beyer et al. found the majority of tectonic features are aligned northeast-southwest; this parallels the large tectonic features that forms the southern margin of Oz Terra and may be related. Based on superposed, large impact craters, we estimate the majority of the larger tectonic features formed ~4 Ga. However, crater density maps show a deficit of craters in some areas that are possibly due to disruption by tectonic features, indicating that some tectonic activity may be significantly younger.

Vulcan Planum Mapping: Vulcan Planum is younger than Oz Terra, indicated by the spatial density of large craters and superposition relationships. In topography, it shows a "moat" at its margins, possibly indicating a frozen viscous fluid flow. The geomorphologic map has revealed only two primary types of landscape: smooth plains (Sm), and patterned ground (Pg) which resembles an elephant skin-like texture. Near its southern margin, it also shows numerous broad warps that may represent upwelling or downwelling. Vulcan Planum in general may be a large cryovolcanic flow.