  Olivine and pyroxene are important mineral end-members for studying the
sur-face material compositions of mafic bodies. The profiles of visible and
near-infraredspectra of olivine-orthopyroxene mixtures systematically varied
with their compositionratios. In our experiments, we combine the RELAB spectral
database with a new spec-tral data obtained from some assembled
olivine-orthopyroxene mixtures. We found thatthe commonly-used band area ratio
(BAR, Cloutis et al. 1986) does not work well onour newly obtained spectral
data. To investigate this issue, an empirical procedure basedon fitted results
by modified Gaussian model is proposed to analyze the spectral curves.Following
the new empirical procedure, the end-member abundances can be estimatedwith a
15% accuracy with some prior mineral absorption features. In addition, the
mix-ture samples configured in our experiments are also irradiated by pulsed
lasers to simulateand investigate the space weathering effects. Spectral
deconvolution results confirm thatlow-content olivine on celestial bodies are
difficult to measure and estimate. Therefore,the olivine abundance of space
weathered materials may be underestimated from remotesensing data. This study
may be used to quantify the spectral relationship of olivine-orthopyroxene
mixtures and further reveal their correlation between the spectra of ordi-nary
chondrites and silicate asteroids.
