Olivine composition and reflectance spectroscopy relationship revisited from advanced MGM deconvolution based on synthetic and natural samples

Abstract

The behavior of the three primary olivine absorptions near 1 μm (referred to as M1-1, M2, M1-2) is revisited by means of an advanced version of MGM analysis. The (M1-1, M2, M1-2) band center positions are used simultaneously to produce a constrained prediction across an extended range Fo#[0–90] of olivine solid solution composition. The established trend lines based on synthetic samples from the Suny and Bristol suites appear robust when implemented on natural samples, and represent an improvement over previous solutions. The methodology, based on a wavelength deconvolution along the entire visible and near-infrared range (540-2600 nm), and the trend lines derived from the current solution, perform well, even when considering the complex situation of chromite-bearing lunar olivines. Furthermore, through the use of separate and quadratic estimates to the trends, an assessment is offered to qualify the Fo# determination made on unknown samples and/or remote sensing observations.