A multispectral geological study of the Schrödinger impact basin

Abstract

Schrödinger basin is a well-preserved peak-ring basin located on the lunar farside, along the rim of the much larger South Pole – Aitken (SPA) basin. The relatively young age (Lower Imbrian series, or 3.8 Ga) of this basin makes it an ideal site to study the geology of peak-ring basins in general, and the geological history of SPA specifically. Impact materials still recognizable include a well-defined crater rim, wall terraces, quasi-circular peak ring, and interior and exterior melt units. A small pyroclastic deposit fills a portion of the basin floor, along with several mare patches. This study uses Clementine multispectral ultraviolet–visible (UV–VIS) data, and a limited set of higher spectral resolution Chandrayaan-1 Moon Mineralogy Mapper (M3) data, as well as radar, camera, and topography data from the Lunar Reconnaissance Orbiter to better understand Schrödinger’s geology. Sampled spectral profiles and linear unmixing models applied to the Clementine data indicate there is a heterogeneous distribution of both anorthositic and basaltic materials in the crater floor. M3 data further validates this observation, and the high spectral resolution shows that most of the mafic content is dominated by pyroxene. These results challenge the traditional assumption that Schrödinger was formed in mostly highland terrain. Our assessment brings forth a new understanding regarding the placement of Schrödinger within SPA and the role SPA impact materials played in shaping the composition of Schrödinger.

Several Geological Issues of Schrödinger Basin Exposed by CE-2 CELMS Data

“…Additionally, abundant fractures occur in the basin floor, some of which extend to a few hundred kilometers long. Shankar et al [8] verified a heterogeneous distribution of both anorthositic and basaltic materials in the basin floor. Using remote sensing data and impact crater modeling, Kramer et al [9] reevaluated the composition of materials that make up the basin wall, impact melt, and peak ring, providing a new understanding of basin-forming processes.…”

Peak-ring structure and kinematics from a multi-disciplinary study of the Schrödinger impact basin

“…Schrödinger is believed to be an early Imbrian-aged impact feature (that is, ca . 3.8 Ga378910). In addition to well-preserved impact-generated materials, the basin floor hosts two younger volcanic deposits811.…”

Potential sample sites for South Pole–Aitken basin impact melt within the Schrödinger basin

“…The modeled gabbroic norite compositions of that melt correlate with materials dominated by pyx with some plag in M 3 spectral maps (red and pink areas in highlighted region of Fig. 1c, after Kramer et al, 2013;Shankar et al, 2013). Although outcrops with this mineralogy are observed throughout Schrödinger basin, SPA impact melt should be most abundant within regions characterized by FeO-enriched signatures.…”