1. A depth versus diameter scaling relationship for the best-preserved melt-bearing complex craters on Mars.
- Author
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Tornabene, Livio L., Watters, Wesley A., Osinski, Gordon R., Boyce, Joseph M., Harrison, Tanya N., Ling, Victor, and McEwen, Alfred S.
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MARTIAN craters , *GEOLOGICAL formations , *MARTIAN crust , *STRATIGRAPHIC geology , *THERMOPHYSICAL properties - Abstract
We use topographic data to show that impact craters with pitted floor deposits are among the deepest on Mars. This is consistent with the interpretation of pitted materials as primary crater-fill impactite deposits emplaced during crater formation. Our database consists of 224 pitted material craters ranging in size from ∼1 to 150 km in diameter. Our measurements are based on topographic data from the Mars Orbiter Laser Altimeter (MOLA) and the High-Resolution Stereo Camera (HRSC). We have used these craters to measure the relationship between crater diameter and the initial post-formation depth. Depth was measured as maximum rim-to-floor depth, ( d r ), but we also report the depth measured using other definitions. The database was down-selected by refining or removing elevation measurements from “problematic” craters affected by processes and conditions that influenced their d r /D, such as pre-impact slopes/topography and later overprinting craters. We report a maximum (deepest) and mean scaling relationship of d r = ( 0.347 ± 0.021 ) D 0.537 ± 0.017 and d r = ( 0.323 ± 0.017 ) D 0.538 ± 0.016 , respectively. Our results suggest that significant variations between previously-reported MOLA-based d r vs. D relationships may result from the inclusion of craters that: 1) are influenced by atypical processes ( e.g. , highly oblique impact), 2) are significantly degraded, 3) reside within high-strength regions, and 4) are transitional (partially collapsed). By taking such issues into consideration and only measuring craters with primary floor materials, we present the best estimate to date of a MOLA-based relationship of d r vs. D for the least-degraded complex craters on Mars. This can be applied to crater degradation studies and provides a useful constraint for models of complex crater formation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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