Open AccessThe structure and compensation of the lunar highland crust
Author(s) -
Wieczorek Mark A.,
Phillips Roger J.
Publication year - 1997
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97je00666
Subject(s) - geoid , crust , geology , discontinuity (linguistics) , gravity anomaly , isostasy , upper crust , geodesy , geophysics , seismology , lithosphere , tectonics , measured depth , paleontology , mathematical analysis , mathematics , oil field
A new method of interpreting geoid to topography ratios (GTRs) on a sphere is presented, in which it is shown that the GTR is equivalent to a sum of spectrally weighted degree‐dependent admittances. Using this method combined with newly obtained gravity, topography, and near‐global surface iron concentrations from the Clementine mission, the structure and compensation of the lunar highland crust have been investigated. Geoid to topography ratios were tested against single‐layer Pratt and Airy compensation models, as well as dual‐layered Airy models. Regional lateral variations in crustal density are found to play an insignificant role in crustal compensation, and the single‐layer and dual‐layered Airy models both strongly suggest that the lunar crust is vertically stratified. The depth of the intracrustal interface obtained from these models is consistent with the existence of a 20‐km seismic discontinuity beneath the Apollo 12 and 14 sites. A uniform density crust with compensation occurring at the Moho is a viable interpretation of crustal structure only when the extreme limits of the observed GTR distribution are used.