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MESSENGER observations from Mercury orbit reveal that a large contiguous expanse of smooth plains covers much of Mercury's high northern latitudes and occupies more than 6% of the planet's surface area. These plains are smooth, embay other landforms, are distinct in color, show several flow features, and partially or completely bury impact craters, the(More)
[1] Orbital images from the MESSENGER spacecraft show that ~27% of Mercury's surface is covered by smooth plains, the majority (>65%) of which are interpreted to be volcanic in origin. Most smooth plains share the spectral characteristics of Mercury's northern smooth plains, suggesting they also share their magnesian alkali-basalt-like composition. A(More)
[1] High‐resolution compositional data from Moon Mineralogy Mapper (M 3) for the Moscoviense region on the lunar farside reveal three unusual, but distinctive, rock types along the inner basin ring. These are designated " OOS " since they are dominated by high concentrations of orthopyroxene, olivine, and Mg‐rich spinel, respectively. The OOS occur as small(More)
[1] The Orientale basin is a multiring impact structure on the western limb of the Moon that provides a clear view of the primary lunar crust exposed during basin formation. Previously, near-infrared reflectance spectra suggested that Orientale's Inner Rook Ring (IRR) is very poor in mafic minerals and may represent anorthosite excavated from the Moon's(More)
Orbital observations by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft are used to re-evaluate the nature and origin of the oldest mapped plains deposits on Mercury, the intercrater and intermediate plains units defined by Mariner 10 investigators. Despite the large areal extent of these plains, which comprise(More)
Background & Premise: The lunar highlands Mg-suite samples are predominantly comprised of coarse grained, ultramafic intrusive clasts including dunites, troctolites and norites [e.g. 1-3]. Consistent with a current lack of remotely sensed Mg-suite volcanic deposits [4], only two known lunar basaltic clasts (within samples 14305 and ALHA 81005) may be(More)
[1] Moon Mineralogy Mapper (M 3) image and spectral reflectance data are combined to analyze mare basalt units in and adjacent to the Orientale multiring impact basin. Models are assessed for the relationships between basin formation and mare basalt emplacement. Mare basalt emplacement on the western nearside limb began prior to the Orientale event as(More)
Early extrusive volcanism from mantle melting marks the transition from primary to secondary crust formation. Detection of secondary crust is often obscured by the high impact flux early in solar system history. To recognize the relationship between heavily cratered terrain and volcanic resurfacing, this study documents how volcanic resurfacing alters the(More)
Cryptomaria, lunar volcanic deposits obscured by crater and basin impact ejecta, can provide important information about the thermal and volcanic history of the Moon. The timing of cryptomare deposition has implications for the duration and flux of mare basalt volcanism. In addition, knowing the distribution of cryptomaria can provide information about(More)
Ancient lunar volcanic deposits, known as cryptomaria, have been detected by remote telescopic and orbital measurements since the 1970s. Cryptomaria are most easily identified by the presence of dark-halo impact craters and are associated with a mare basalt mineralogy, which is indicated by two pyroxene spectral absorption features near 1 μm and 2 μm in the(More)