Major lunar crustal terranes: Surface expressions and crust‐mantle origins
作者:Bradley L. Jolliff, Jeffrey J. Gillis, L. A. Haskin, R. L. Korotev, M. A. Wieczorek · 发表于:Journal of Geophysical Research Atmospheres · 年份:2000 · DOI:10.1029/1999je001103 · 被引用次数:926 · 研究领域:Planetary Science and Exploration、Astro and Planetary Science、Geology and Paleoclimatology Research
In light of global remotely sensed data, the igneous crust of the Moon can no longer be viewed as a simple, globally stratified cumulus structure, composed of a flotation upper crust of anorthosite underlain by progressively more mafic rocks and a residual‐melt (KREEP) sandwich horizon near the base of the lower crust. Instead, global geochemical information derived from Clementine multispectral data and Lunar Prospector gamma‐ray data reveals at least three distinct provinces whose geochemistry and petrologic history make them geologically unique: (1) the Procellarum KREEP Terrane (PKT), (2) the Feldspathic High‐lands Terrane (FHT), and (3) the South Pole‐Aitken Terrane (SPAT). The PKT is a mafic province, coincident with the largely resurfaced area in the Procellarum‐Imbrium region whose petrogenesis relates to the early differentiation of the Moon. Here, some 40% of the Th in the Moon's crust is concentrated into a region that constitutes only about 10% of the crustal volume. This concentration of Th (average ∼5 ppm), and by implication the other heat producing elements, U and K, led to a fundamentally different thermal and igneous evolution within this region compared to other parts of the lunar crust. Lower‐crustal materials within the PKT likely interacted with underlying mantle materials to produce hybrid magmatism, leading to the magnesian suite of lunar rocks and possibly KREEP basalt. Although rare in the Apollo sample collection, widespread mare volcanic rocks havi...