Recognition and Significance of Stratal Geometries and Unconformities in Martian Layered Deposits
Abstract
The deposition and erosion of sedimentary rocks on Mars is controlled by similar water- and wind-moderated processes as those on Earth, and its stratigraphic record can be analyzed through analogous methods. We demonstrate that chronostratigraphic tools, developed for interpreting terrestrial seismic data, can be applied to images of rock outcrops on Mars. This study uses data from the High Resolution Imaging Science Experiment (HiRISE) onboard the Mars Reconnaissance Orbiter (MRO), in combination with Digital Elevation Models (DEMs) and software for chronostratigraphic analysis to quantify the spatial and temporal characteristics of Martian layered deposits. Patterns of deposition and erosion in space and time can be used to predict sedimentary facies as well as internal stratigraphic architecture and continuities of deposits within sedimentary basins. Initial application of this method focuses on the North Polar Layered Deposits (NPLDs) due to their complex stratal geometries, relative lack of surface disturbances, and inferred tie to climate variations. Chronstratigraphic analysis of the NPLD reveals multiple depositional sequences with modeled time increments that are distinct from previous studies. This technique also provides insight regarding the depositional and erosional history of the NPLD margin, through the migration of spiral troughs. Chronostratigraphic analysis indicates that migration occurs as fluctuating depositional events, which may be tied to longer-term climate variations. Application of this method to other layered deposits reveals that one particular location - Galle crater - may represent an ancient polar layered deposit, and that ice may still be present beneath the surface.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMEP13C0873E
- Keywords:
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- 5462 PLANETARY SCIENCES: SOLID SURFACE PLANETS / Polar regions;
- 5464 PLANETARY SCIENCES: SOLID SURFACE PLANETS / Remote sensing