Subsurface Reflectors Detected by SHARAD Reveal Stratigraphy and Buried Channels Over Central Elysium Planitia, Mars

Siting Xiong,Jan‐Peter Muller,Jacqueline D Campbell,Yu Tao,Alfiah Rizky Diana Putri,Divya M Persaud

doi:10.1029/2019ea000968

Abstract

AbstractThe Central Elysium Planitia (CEP) is one of the youngest geological units on Mars and displays evidence of volcanic and fluvial activities on the surface. The origin of the CEP material has long been debated with a range of hypotheses from purely fluvial to solely volcanic origins. This study presents a comprehensive investigation of SHAllow RADar (SHARAD) data to reveal subsurface radar reflectors over the CEP region. Distribution of the detected radar reflectors show possible connections between the CEP and outflow channels, such as Athabasca Valles and Marte Vallis. Analysis of the radar reflectors in the CEP region show six subsurface layers implying multiple depositional and erosional episodes. One detected subsurface layer is found to correspond to the upper exposed layers of one terraced crater. By measuring the depth accurately of these exposed layers in the derived HiRISE (High Resolution Imaging Scientific Experiment) and CTX (Context Camera) DTMs (Digital Terrain Models) and inverting the dielectric constant combining the layers in radargrams, an interpretation that the filling material contains water ice is favored.

Highlights

The Cerberus plains, is a broad low-lying plain in the central part of Elysium Planitia (CEP) on Mars extending from about 140°E to 185°E and from 5°S to 10°N (Cassanelli & Head, 2018; Plescia, 1990, 2003; Vaucher et al, 2009)
This study presents a comprehensive investigation of SHAllow RADar (SHARAD) data to reveal subsurface radar reflectors over the Central Elysium Planitia (CEP) region
Athabasca Valles is thought to have been carved by a high-discharge flood of water based on streamlined islands, notches on the sides of the breach hanging valleys and a low number of tributaries, while other authors have argued that this channel might be carved by fluid lava, which is supported by fissure vents (Plesica, 2000), long lava flows (Berman & Hartmann, 2002; Lanagan, 2004), and shield volcanoes (Plescia, 1990, 2003)

Summary

Introduction

The Cerberus plains, is a broad low-lying plain in the central part of Elysium Planitia (CEP) on Mars extending from about 140°E to 185°E and from 5°S to 10°N (Cassanelli & Head, 2018; Plescia, 1990, 2003; Vaucher et al, 2009). There is evidence for numerous constructional and erosional landforms, such as relic waterfalls, down-cut erosional channels, streamlined islands within the channels, notches on the sides of the breach hanging valleys, and eroded topographic obstacles (Durrant et al, 2017; Kossacki et al, 2006; Murray et al, 2005). These suggest that fluvial events carved the current landforms in the Athabasca Valles. Volcanic landforms, such as linear fissure vents (Plesica, 2000), long lava flows

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