Geoscience Reference
In-Depth Information
the Mare Orientale spectra almost match with the RELAB high-Ti basaltic spectra.
The Lacus Veris spectrum is plotted in between the low- and medium-Ti RELAB
basaltic spectra. The Lacus Autumni spectra were not matched with this group of
basaltic spectra, and it indicates admixing and contamination of the maria regolith
with materials excavated or ejected from underlying and neighboring rocks in the
Lacus Autumni region.
2.5
Conclusion and Future Work
Since the RELAB basaltic samples were brought from the nearside of the moon,
there may be slight variation in the Orientale basin basalts. Apollo geochemical
ground tracks and sample collection did not cover this region; hence, the relative
end-member spectral library and chemistry such as plagioclase, ortho- and clinopy-
roxenes, and olivine and low-, medium-, and high-Ti basalts are only used. The more
precise results can be provided once we get samples from Orientale basalts.
The spectral mixtures were derived from RELAB spectra, based on lunar rock
classification, and they are considered as end-members for estimating the abundance
of the rock content in the specified area using M 3 data. If there are similar kinds of
studies for the other basaltic terrain on the lunar surface, the results can be used as
validation. However, only the global lunar mineral mapping maps using the UVVIS
multispectral Clementine data are available at present, so the current results have
been validated with RELAB chemistry.
To improve this work, it is important to compare the fraction covers with field
data in order to verify the data obtained through the images. In addition, field
spectral data is necessary for end-member selection, because a good choice of end-
members is the most important step for a good spectral unmixing. Mixed pixels may
cover a region containing different components, and therefore, traditional image
classification approach should be altered, which assigns a particular class of ground
cover to each pixel (Kanniah et al. 2001 ).
Low-Ti basalts are younger than the high-Ti basalts. But remote sensing data
based studies suggests that high-Ti basalts are younger. Finally, there is no obvious
correlation between the ages and low-Ti and high-Ti concentrations (e.g., Pieters
1978 ; Hiesinger et al. 2003 , 2011 ). Based on the TiO 2 analysis , the Mare Orientale
basalts have high-TiO 2 ( 15 %) content compared with the Lacus Veris and Lacus
Autumni (<6 %). Papike et al. ( 1976 ) has concluded that the Mare Orientale age is
older than the Lacus Veris and Lacus Autumni, which supports the result of crater
counting given by Whitten et al. ( 2011 ). In the future, if we obtain sample from the
Orientale basin, with radiometric dating and geochemical measurements, we will
get precise chronology of the Orientale basin and clarify the relation between the
TiO 2 content and ages. In mineral mapping, all basaltic terrains from the Orientale
basin are dominant with clinopyroxene followed by plagioclase.
The future work will focus on the thermal and photometrically corrected data,
which would be used to estimate the minerals and mineral mixtures using Hapke's
Search WWH ::




Custom Search