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Determining the Origin of Filled Craters Within the South Pole-Aitken Basin

Author: 
Noah Petro
Topic: 
Geology
Delivered As: 
Oral
Abstract Text: 

Across the interior of the South Pole-Atiken Basin (SPA) are a number of partially or totally filled craters [1]. Based on surface morphology, there appears to be two classes of crater fill material, a smooth fill, potentially caused by volcanic flooding, and a hummocky fill, possibly due to crater/basin ejecta [e.g., 2]. Constraining the origin of fill is critical to determining the resurfacing history of the interior of SPA, especially in determining the origin of material within the regolith [3]. In this presentation we will describe the origin of such fill material within SPA, and use this insight to define the likely resurfacing history of the basin interior.

Using the full suite of remotely sensed data from both the Lunar Reconnaissance Orbiter and Chandryaan-1, we characterize the relative roughness of various units [e.g., 4, 5, 6], the composition of the fill material [1], the rock abundance of such fill material [7], and the thickness of such material derived from high-resolution topographic data products [8]. The integration of these datasets allows us to constrain the origins of these units. Of particularly importance is to identify those craters filled by ejecta, as such material will also reveal that the surrounding regions are also likely blanketed by ejecta from the same source crater(s). A number of the remote datasets show distinctions between likely volcanic and impact-generated material. Compositionally the distinction between high- and low-Ca pyroxenes [1, 9] provides strong evidence regarding the origin of materials, but also the rock abundance map [7] clearly shows areas where there are more surface rocks near small craters, that is, a thinner regolith, versus thick regolith on ancient surfaces [10].

Identifying the origins of surficial material within SPA is key to unraveling the geologic history of the basin as well as for identifying potential sample return sites that contain ancient SPA material. Ultimately, developing a stratigraphic history for a region will be important in constraining the likely contributors the regolith at a particular site [10].

Identifying the origins of surficial material within SPA is critical for both unraveling the geologic history of the basin; as well as for identifying potential sample return sites that contain ancient SPA material. Ultimately, developing a stratigraphic history for a region will be important in constraining the likely contributors the regolith at a particular site [11].

[1] Moriarty, D. P. and C. M. Pieters, (2015) GRL, 42, 7907-7915.
[2] Fassett, C. I., et al., (2011) GRL, 38, 17201.
[3] Petro, N. E. and C. M. Pieters, (2004) Journal of Geophysical Research, 109(E6), E06004, doi:06010.01029/02003JE002182.
[4] Rosenburg, M. A., et al., (2011) Journal of Geophysical Research, 116, E02001.
[5] Kreslavsky, M. A., et al., (2013) Icarus, 226, 52-66.
[6] Clegg-Watkins, R., et al., (2016) The Distribution of Mare and Cryptomare in the South Pole-Aitken Basin: New Perspectives from Multiple Datasets, 2072.
[7] Bandfield, J. L., et al., (2011) J. Geophys. Res., 116, E00H02.
[8] Barker, M. K., et al., (2016) Icarus,
[9] Klima, R. L., et al., (2011) Journal of Geophysical Research, 116,
[10] Petro, N. E., et al., (2016) Unraveling the Geologic History of the South Pole-Aitken Basin Interior: A Case Study of the Bhabha Region Using Multiple Remote Sensing Datasets, 47, 2669.
[11] Cohen, B. A. and R. F. Coker, (2010) LPSC, 41, 2475.

Co-Authors: 
T. D. Glotch"...
SSERVI Identifier: 
NESF2016-103

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Recognizing that science and human exploration are mutually enabling, NASA created the Solar System Exploration Research Virtual Institute (SSERVI) to address basic and applied scientific questions fundamental to understanding the Moon, Near Earth Asteroids, the Martian moons Phobos and Deimos, and the near space environments of these target bodies. As a virtual institute, SSERVI funds investigators at a broad range of domestic institutions, bringing them together along with international partners via virtual technology to enable new scientific efforts."