Artigo Revisado por pares

Lateral heterogeneity of lunar volcanic activity according to volumes of mare basalts in the farside basins

2017; Wiley; Volume: 122; Issue: 7 Linguagem: Inglês

10.1002/2016je005246

ISSN

2169-9100

Autores

Masako Taguchi, Tomokatsu Morota, Shinsuke Kato,

Tópico(s)

Space Science and Extraterrestrial Life

Resumo

Abstract Estimates for volumes of mare basalts are essential to understand the thermal conditions of the lunar mantle and its lateral heterogeneity. In this study, we estimated the thicknesses and volumes of mare basalts within five farside basins, Apollo, Ingenii, Poincare, Freundlich‐Sharonov, and Mendel‐Rydberg, using premare craters buried by mare basalts and postmare craters that penetrated/nonpenetrated mare basalts employing topographic and multiband image data obtained by SELENE (Kaguya). Furthermore, using the Gravity Recovery and Interior Laboratory crustal thickness model and the mare volumes estimated by this and previous studies, we investigated the relationship between the volumes of the mare basalts and the crustal thicknesses. The results suggest that the minimum crustal thicknesses within the basins were a dominant factor determining whether magma erupted at the surface and that the critical crustal thicknesses for magma eruption were ~10 km on the farside and >20 km on the nearside. The total areas of the regions in which magmas could erupt at the surface are ~10 times larger on the nearside than on the farside. A comparison between the mare volumes within the mare basins on the nearside and the farside shows that magma production in the farside mantle might have been ~20 times smaller than that in the nearside mantle, implying a stronger dichotomy than previously estimated. These results suggest that the mare hemispherical asymmetry should be attributed to both the difference in the crustal thickness distribution and the difference in the quantity of magma production between the nearside and farside mantles.

Referência(s)