Geologic Map of the Poincaré Region, Moon.

The lunar South Pole-Aitken (SPA) basin, the oldest, largest, and deepest impact basin on the Moon, is a high-interest target for future lunar exploration missions due to its unique geology and insights into the formation and evolution of the Moon [1]. Existing large-scale geological maps of the SPA basin [2-6] have improved our understanding of regional and global geological units [7]. However, these large-scale maps do not provide sufficient information about the detailed geology within SPA, including superposed impact basins such as the Poincaré basin, which is critical for mission planning, landing site safety assessment, resource utilization potential, and traverse planning. This study presents a detailed 1:200,000 scale geological map of the Poincaré region (159°E to 179°W, 48° to 64°S). With a diameter of 349 km, the Poincaré basin is one of the largest multiring basins superposed on the southwestern floor of SPA [3, 8-10]. Our map aims to provide the necessary geologic context for detailed planning of future exploration missions, such as the Endurance mission [2, 7].

We utilized high-resolution images from the Lunar Reconnaissance Orbiter (LRO) Wide-Angle Camera (100 m/pixel) [11], topographic data from the LRO Lunar Orbiter Laser Altimeter (118 m/pixel) [12], and Clementine data (100 m/pixel) [13]. Our map follows the standards of the Federal Geographic Data Committee [14], following the stratigraphic scheme originally proposed by [6].

We identified 10 geologic units, categorized as terra, plains, and crater materials. Our stratigraphy is based on superposition relationships and degradation stages, with absolute model ages available from the literature [e.g., 4,6,9]. The Poincaré region has a complex history dominated by impact and volcanic processes. The southern central parts of Poincaré crater are crossed by the traverses designed for the NASA Endurance rover [2]. Hence, our geologic map can contribute to the development of this mission, the definition of its scientific objectives, and evaluating the different lithologies that could be sampled by this mission and eventually returned to Earth.

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[13] Pieters et al. (1994), Science, 266

[14] FGDC (2006), FGDC-STD013-2006