Lithospheric Elastic Thickness Beneath the Caloris Basin: Implications for the Thermal Structure of Mercury

Abstract

The basin interior is covered by the Caloris interior plains (CIP) that have been deformed by complex tectonic features (Denevi et al., 2018), including concentric ridges and tensional grabens that exhibit both radial and tangential strikes (Byrne et al., 2018). Both the northern and southern parts of the basin floor have been significantly uplifted to heights that exceed the basin rim (Figure 1c), and the two mountain belts have a trend that is more-or-less parallel to the east-northeast to west-southwest direction (Byrne et al., 2014).

The Ancient Lithospheric Parameters of Impact Basins on the Far Side of the Moon Based on the Mantle and Mare Basalt Load Model

“…Within the circular region delineated by the red dashed lines in the basin, Figures 8b–8d illustrate that a positive load ratio corresponds to a negative transverse density anomaly. This finding is in line with previous studies (Belleguic et al., 2005; Deng, Xiao, et al., 2023; Deng, Zhong, et al., 2023; Zhong et al., 2022). Moreover, the absolute value of the density anomaly gradually increases with the increase in the load ratio, which reduces the initial positive net load from topography plus mantle plug and mare basalt.…”

“…In this study, we utilize the approach proposed by Deng, Xiao, et al. (2023) and Deng, Zhong, et al. (2023) to quantify the model uncertainties as follows: $$$\sigma (Te,f)=\frac{1}{{l}_{\max }-{l}_{\text{win}}+1}{\sum\limits _{l={l}_{\text{win}}}^{{l}_{\max }}\left[\frac{Z(l)-{Z}^{\text{model}}(l)}{\kappa z(l)}\right]}^{2}$$$ where l max represents the highest degree of fit between gravity and topography.…”

“…(2005), Deng, Xiao, et al. (2023), and Deng, Zhong, et al. (2023), a ratio f is defined to describe the relationship between the pre‐deflection topography and the lateral density variation: $$$f=-\frac{{\Delta }\rho {D}_{\text{thick}}}{{\rho }_{c}{h}_{i}}$$$ …”

“…Ding et al (2019) and Broquet and Wieczorek (2019) used the chi-square function to calculate misfits (σ) and rejected all values generated by greater than their 1-𝜎 uncertainties. In this study, we utilize the approach proposed by Deng, Xiao, et al (2023) and to quantify the model uncertainties as follows:…”

“…Where g h , g 1 , g mare , and g 2 are the gravitational acceleration at the surface geoid, sub-surface equipotential interface, the base of mare basalts and the base of D thick , respectively. With reference to the studies of Belleguic et al (2005), Deng, Xiao, et al (2023), and, a ratio f is defined to describe the relationship between the pre-deflection topography and the lateral density variation:…”