The South Pole-Aitken basin region, Moon: GIS-based geologic investigation using Kaguya elemental information

Abstract

Using Geographic Information Systems (GIS), we performed comparative analysis among stratigraphic information and the Kaguya (SELENE) GRS data of the 2500-km-diameter South Pole-Aitken (SPA) basin and its surroundings. Results indicate that the surface rock materials (including ancient crater materials, mare basalts, and possible SPA impact melt) are average to slightly elevated in K and Th with respect to the rest of the Moon. Also, this study demonstrates that K and Th have not significantly changed since the formation of SPA. The elemental signatures of the impact basin of Fe, Ti, Si, O through time include evidence for resurfacing by ejecta materials and late-stage volcanism. The oldest surfaces of SPA are found to be oxygen-depleted during the heavy bombardment period relative to later stages of geologic development, followed by both an increase in silicon and oxygen, possibly due to ejecta sourced from outside of SPA, and subsequent modification due to mare basaltic volcanism, which increased iron and titanium within SPA. The influence of the distinct geologic history of SPA and surroundings on the mineralogic and elemental abundances is evident as shown in our investigation.

Potassium and Thorium Abundances at the South Pole‐Aitken Basin Obtained by the Kaguya Gamma‐Ray Spectrometer

“…The large impact event implies that more basaltic material is contained in the SPA crust than in the surrounding highlands, which provides important constraints on the formation and evolution of lunar magma ocean. Actually, several basaltic mare units of Imbrian and Eratosthenian age are exposed in the SPA region (e.g., Haruyama et al, ; Kim et al, ; Yingst & Head, , ). Mare deposits exposed at the SPA basin provide insights into the evolutional history of the lunar farside crust and mantle.…”

Potential Geologic Issues of Von Kármán Crater Revealed by Multisource Remote Sensing Data

“…The composition distribution is a key to better understand the formation and evolution of the SPA basin (Kim et al, 2012;Pasckert et al, 2017). Clementine UV-VIS data provide a good candidate to estimate the (FeO+TiO 2 ) abundance (FTA) in the SPA basin (Lucey et al, 2000;Gillis et al, 2004;Pasckert et al, 2017), which is also employed in this study (Figure 4).…”

“…SPA basin has a latitude of 40°S to 60°S and a longitude centred at around 180° and it is the largest and oldest crater in the Moon with a diameter of about 2 600 km (Ouyang, 2005;Jolliff, 2012). The distribution of material compositions in the SPA basin as well as the formation and evolution of the basin have always been the focus of the scientific research but still in debate (Zhang et al, 2011;Kim et al, 2012;David and Daniel, 2012;Pasckert et al, 2017). Some small-scale distribution of olivine, plagioclase, spinel and high-calcium pyroxene were also found in the SPA basin based on Clementine, Kaguya and Chandrayaan Moon Mineralogy Mapper (M 3 ) (Moriarty et al, 2013;Pieters et al, 2001;Ohtake et al, 2009;Kramer et al, 2013;Yamamoto et al, 2012).…”