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The wide range of TiO 2 contents within the returned samples has been used as a
chemical property for separating them into groups including high- (>9 wt%, TiO 2 ),
low- (1.5-9 wt% TiO 2 ), and very low-Ti (<1.5 wt% TiO 2 ) basalts, which generally
cannot be related to the same source regions (Papike et al. 1998 ). The observed
distribution of lunar basalt types suggests that mare volcanism was regionally
complex with no simple correlation between composition and absolute age (e.g.,
Pieters 1978 ; Hiesinger et al. 2003 , 2011 ).
Space weathering and mixing have altered the reflectance properties of the
lunar surface over time; hence it is difficult to characterize the mineralogy of
emplaced basalts from remote measurements of optically mature soils (Staid et al.
2011 ). In contrast, relatively crystalline and unweathered basaltic regolith associated
with younger impact craters still retains diagnostic absorption features that can
be interpreted based on measurements of returned lunar samples (Pieters 1977 ;
McCord et al. 1981 ). M 3 data from Chandrayaan-1 have provided both the high
spatial and spectral resolutions capable of investigating the detailed reflectance
properties of small mare craters and allowed more direct characterization of basalt
mineralogy than measurements of lunar soils that have been altered by space-
weathering and non-mare contamination (Staid et al. 2011 ). Estimation of the
relative abundance and composition of pyroxene and olivine will provide constraints
on basaltic source regions, temporal evolution, and emplacement mechanisms.
2.3
Materials and Methods
India's first lunar mission Chandrayaan-1 Moon Mineralogical Mapper data,
RELAB chemistry, and spectra were used in the present study. The Moon
Mineralogy Mapper (M 3 ) is an imaging spectrometer developed by Brown
University and the Jet Propulsion Laboratory, which sampled the lunar terrain
from visible to near-infrared spectral region (400-3,000 nm), and provides high
spatial and spectral resolution data for mineralogical study of the entire lunar
surface (Goswami and Annadurai 2009 ). Remotely obtained reflectance spectra,
combined with spectroscopic, chemical, and mineralogical data acquired in the
Reflectance Experiment Laboratory (RELAB) from the lunar returned samples, can
provide constraints on understanding and establishing compositional information
about unexplored or unsampled planetary surfaces.
2.3.1
Methods
The methodology adopted in the study is shown in Fig. 2.2 .
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