Geology of the Smythii and Marginis region of the Moon: Using integrated remotely sensed data

Abstract

Abstract. We characterized the diverse and complex geology of the eastern limb region of the Moon using a trio of remote-sensing data sets: Clementine, Lunar Prospector, and Apollo. On the basis of Clementine-derived iron and titanium maps we classify the highlands into low-iron (3-6 wt % FeO) and high-iron (6-9 wt % FeO) units. The association of the latter with basalt deposits west of Smythii basin suggests that the highland chemical variation is the result of mixing between basalt and highland lithologies. Mare Smythii and Mare Marginis soils are compositionally similar, containing moderate iron (15-18 wt % FeO) and titanium (2.5-3.5 wt % TiO2). Smythii basin, in addition to the basalt deposits, contains an older, moderate-albedo plains unit. Our investigation reveals that the dark basin plains unit has a distinct albedo, chemistry, and surface texture and formed as a result of impact-mixing between highland and mare lithologies in approximately equal proportions. Clementine iron and maturity maps show that swirls along the northern margin of Mare Marginis have the same iron composition as the surrounding nonswirl material and indicate that the swirl material is bright because of its low agglutinate content. Gravity data for the eastern limb show high, positive Bouguer gravity anomalies for areas of thin basalt cover (e.g., Smythii basin and complex craters Joliot, Lomonosov, and Neper). We deduce that the uplift of dense mantle material is the primary (and mare basaltic fill the secondary) source for generating the concentration of mass beneath large craters and basins.

Lunar surface geochemistry: Global concentrations of Th, K, and FeO as derived from lunar prospector and Clementine data

“…The TiO 2 -sensitive FeO derivation using CSR data yields FeO concentrations that more accurately match high-Fe/ low-Ti mare-basalt-rich surfaces. The slightly higher FeO contents produced using this algorithm are important for remote sensing studies of basalts with similar high-FeO low-TiO 2 compositions (e.g., Gillis and Spudis, 2000;Blewett and Hawke, 2001). Also, the modified algorithm produces FeO concentrations for the northern farside highlands that are consistent with the feldspathic meteorite compositions (Table 7).…”

Remote sensing studies of the Lomonosov‐Fleming region of the Moon

“…The light plains units associated with cryptomare east of Mare Marginis (Figure 4a) are Balmer‐type. Early mare basalt deposits in this area were subsequently contaminated by highlands material contributed by a number of later impact events [ Hawke et al , 1985; Gillis and Spudis , 2000] As noted in a previous section, several of the small mare ponds in the L‐F region are heavily contaminated with highlands debris. These mare deposits will become cryptomare with the passage of time.…”

Integration of the Clementine UV‐VIS spectral reflectance data and the Lunar Prospector gamma‐ray spectrometer data: A global‐scale multielement analysis of the lunar surface using iron, titanium, and thorium abundances

“…Some of these areas are Mendeleev (140°E, 5°N), the Keeler‐Heaviside (165°E, 10°S), Korolev (25°E, 5°S) and Hertzsprung (230°E, 0°N) basins and the Inner Rook Montes of the Orientale basin (270°E, 20°S) [ Hawke et al , 1993; Peterson et al , 2000]. Although highly feldspathic composition has already been recognized outside the innermost ring of the Smythii basin, particularly in its eastern part [ Gillis and Spudis , 2000], it seems that the presence of significant nearly pure anorthositic materials has not been reported so far farther to the south of the basin, in the Sklodowska‐Humboldt region.…”