The Tacquet Formation (TF) was first identified in geologic mapping of southern Mare Serenitatis as a distinct low albedo region split by the linear Rimae Menelaus rilles. A distinct western dome, split by a linear rille and less distinct eastern dome (the Menelaus domes) are also present within the TF. Previous Earth-based radar analyses showed that the TF has a lower circular polarization ratio consistent with a pyroclastic mantle. In this study, compositional and spectroscopic parameters were derived from Moon Mineralogy Mapper (M-3) data. Lunar Reconnaissance Orbiter Camera Wide Angle Camera (LROC WAC) and SELENE Kaguya Multiband Imager (MI) multispectral data were also utilized. FeO derived from MI data for the TF and Menelaus domes was elevated at levels consistent with pyroclastic glasses. While not diagnostic of pyroclastics, TiO2 derived from LROC WAC data over the TF and Menelaus domes was also elevated relative to the background materials. Analysis of 1 and 2 mu m band parameters also show the TF and Menelaus domes as being distinct with a band center moderately longer than 1 mu m and 2 mu m band center shorter than the surroundings, characteristics consistent with pyroclastic glass and/or increased ilmenite. M-3 data thermally corrected via two different thermal correction approaches indicate a moderately deeper band in the 3 mu m region indicative of OH and/or H2O, a characteristic that is also potentially associated with pyroclastic deposits. These compositional findings are consistent with the Earth-based radar data suggesting that the TF is a pyroclastic mantle and potentially represents a previously unrecognized sub-class of pyroclastic deposits associated with lunar volcanic domes.

In a new era of lunar exploration, pyroclastic deposits have been identified as valuable targets for resource utilization and scientific inquiry. Little is understood about the geomechanical properties and the trafficability of the surface material in these areas, which is essential for successful mission planning and execution. Past incidents with rovers highlight the importance of reliable information about surface properties for future, particularly robotic, lunar mission concepts. Characteristics of 149 boulder tracks are measured in Lunar Reconnaissance Orbiter Narrow Angle Camera images and used to derive the bearing capacity of pyroclastic deposits and, for comparison, mare and highland regions from the surface down to similar to 5-m depth, as a measure of trafficability. Results are compared and complemented with bearing capacity values calculated from physical property data collected in situ during Apollo, Surveyor, and Lunokhod missions. Qualitative observations of tracks show no region-dependent differences, further suggesting similar geomechanical properties in the regions. Generally, bearing capacity increases with depth and decreases with higher slope gradients, independent of the type of region. At depths of 0.19 to 5m, pyroclastic materials have bearing capacities equal or higher than those of mare and highland material and, thus, may be equally trafficable at surface level. Calculated bearing capacities based on orbital observations are consistent with values derived using in situ data. Bearing capacity values are used to estimate wheel sinkage of rover concepts in pyroclastic deposits. This study's findings can be used in the context of traverse planning, rover design, and in situ extraction of lunar resources. Plain Language Summary Future explorers will be visiting pyroclastic deposits for research and resource extraction. However, the properties of the surface are not well known and it is unclear how well vehicles and humans are able to travel across these areas. Properties of 149 boulder tracks are measured in spacecraft imagery and are used to derive estimations for the strength of pyroclastic, mare, and highland area material from the surface down to similar to 5-m depth. Results are compared and complemented with soil strength estimates that have been derived based on in situ measurements taken during previous lunar surface missions. In all regions of interest, tracks have similar appearances, implying that the surface material has comparable properties. Generally, soil strength increases with increasing depth and decreases with higher local slope angles. At depth, pyroclastic deposits show equal or significantly higher strength in comparison to mare and highland areas and, therefore, might be equally trafficable at surface level. Calculations based on globally distributed spacecraft images agree with values derived from Apollo-era in situ data. Based on the soil strength, the sinkage of rovers in the areas of interest is estimated. Potential applications of this work include rover design and mission planning, infrastructure construction, and resource extraction.