Using Terrestrial Analogs to Distinguishing Eolian, Fluvial, and Volcanic Deposits on Mars
Abstract
A critical part of landed Mars missions is the opportunity to conduct detailed investigations of rock outcrops comparable to those done in terrestrial field geology. In doing so, the record of past processes and environments can be read and interpreted in detail. However, our ability to accurately interpret some aspects of this record on Mars is questionable. One particular challenge lies in distinguishing deposits from dilute pyroclastic density currents (DPDCs) from eolian and fluvial deposits, all of which can produce sandy cross-stratified accumulations. While bedforms in eolian and fluvial deposits are well characterized, there is an insufficient understanding of bedform kinematics and sediment transport processes in DPDCs on Earth. Here we report initial findings from fieldwork at several terrestrial DPDC deposits, and criteria that may be used to distinguish them from eolian and fluvial environments, particularly when geologic context is limited. Several prime examples of DPDC deposits are exposed in southern New Mexico at the Afton craters (Kilbourne Hole and Hunts Hole), and northern Arizona in the Hopi Buttes volcanic field (Teshim Butte, Haskie Volcano, and Triplets Maar). Fieldwork was conducted to mirror the types of data available for Mars rover missions. Preliminary results indicate several characteristics that may be used to identify DPDC deposits on Mars, including grain size and sorting, preservation of dune crests and stoss sides, supercritical angles of climb, angles of stoss and lee slopes, trends in transport direction, and components such as accretionary lapilli and volcanic bombs. Ongoing work will refine the range of bedform properties anticipated for DPDC deposits through comparison across multiple terrestrial sites, and predictions for Mars. This study recognizes the challenge in distinguishing DPDC in remote sensing data, but highlights the importance of terrestrial analogs to better understand processes and environments that may be identified on Mars.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.P31H3797E
- Keywords:
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- 5464 Remote sensing;
- PLANETARY SCIENCES: SOLID SURFACE PLANETSDE: 5470 Surface materials and properties;
- PLANETARY SCIENCES: SOLID SURFACE PLANETSDE: 5494 Instruments and techniques;
- PLANETARY SCIENCES: SOLID SURFACE PLANETSDE: 5499 General or miscellaneous;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS