TY - JOUR
T1 - Spectral reflectance properties of carbonaceous chondrites
T2 - 6. CV chondrites
AU - Cloutis, E. A.
AU - Hudon, P.
AU - Hiroi, T.
AU - Gaffey, M. J.
AU - Mann, P.
AU - Bell, James
N1 - Funding Information:
We wish to thank the invaluable and generous assistance provided by many individuals which made this study possible. In particular we thank the US and Japanese Antarctic meteorite programs for recovering the majority of the samples included in this study. The RELAB facility at Brown University is a multi-user facility operated with support from NASA Planetary Geology and Geophysics Grant NNG06GJ31G , whose support is gratefully acknowledged. The PSF facility at the University of Winnipeg was established with generous support from the Canada Foundation for Innovation, the Manitoba Research Innovations Fund, and the Canadian Space Agency. This study was supported by an NSERC Discovery grant to EAC. The authors also wish to thank Julie Ziffer and an anonymous reviewer for their many helpful comments which helped improve the quality and readability of this paper.
PY - 2012/9
Y1 - 2012/9
N2 - Multiple reflectance spectra of 11 CV chondrites have been measured to determine spectral-compositional relationships for this meteorite class and to aid the search for CV parent bodies. The reflectance of CV chondrite spectra is variable, ranging from ∼5% to 13% at 0.56μm, and ∼5% to 15% at the 0.7μm region local reflectance maximum. Overall slopes range from slightly blue to red for powders, while slab spectra are strongly blue-sloped. With increasing average grain size and/or removal of the finest fraction, CV spectra generally become more blue-sloped. CV spectra are characterized by ubiquitous absorption features in the 1 and 2μm regions. The 1μm region is usually characterized by a band centered near 1.05-1.08μm and a band or shoulder near 1.3μm that are characteristic of Fe-rich olivine. Band depths in the 1μm region for powdered CVs and slabs range from ∼1% to 10%. The 2μm region is characterized by a region of broad absorption that extends beyond 2μm and usually includes band minima near 1.95 and 2.1μm; these features are characteristic of Fe 2+-bearing spinel. The sample suite is not comprehensive enough to firmly establish whether spectral differences exist between CV R, CV OxA, and CV OxB subclasses, or as a function of metamorphic grade. However, we believe that the mineralogic and petrologic differences that exist between these classes, and with varying petrologic subtype (CV3.0->3.7), may not be significant enough to result in measurable spectral differences that exceed spectral variations within a subgroup, within an individual meteorite, or as a function of grain size. Terrestrial weathering seems to affect CV spectra most noticeably in the visible region, resulting in more red-sloped spectra for finds as compared to falls. The search for CV parent bodies should focus on the detection of olivine and spinel absorption bands, specifically absorption features near 1.05, 1.3, 1.95, and 2.1μm, as these are the most commonly seen spectral features of CV chondrites.
AB - Multiple reflectance spectra of 11 CV chondrites have been measured to determine spectral-compositional relationships for this meteorite class and to aid the search for CV parent bodies. The reflectance of CV chondrite spectra is variable, ranging from ∼5% to 13% at 0.56μm, and ∼5% to 15% at the 0.7μm region local reflectance maximum. Overall slopes range from slightly blue to red for powders, while slab spectra are strongly blue-sloped. With increasing average grain size and/or removal of the finest fraction, CV spectra generally become more blue-sloped. CV spectra are characterized by ubiquitous absorption features in the 1 and 2μm regions. The 1μm region is usually characterized by a band centered near 1.05-1.08μm and a band or shoulder near 1.3μm that are characteristic of Fe-rich olivine. Band depths in the 1μm region for powdered CVs and slabs range from ∼1% to 10%. The 2μm region is characterized by a region of broad absorption that extends beyond 2μm and usually includes band minima near 1.95 and 2.1μm; these features are characteristic of Fe 2+-bearing spinel. The sample suite is not comprehensive enough to firmly establish whether spectral differences exist between CV R, CV OxA, and CV OxB subclasses, or as a function of metamorphic grade. However, we believe that the mineralogic and petrologic differences that exist between these classes, and with varying petrologic subtype (CV3.0->3.7), may not be significant enough to result in measurable spectral differences that exceed spectral variations within a subgroup, within an individual meteorite, or as a function of grain size. Terrestrial weathering seems to affect CV spectra most noticeably in the visible region, resulting in more red-sloped spectra for finds as compared to falls. The search for CV parent bodies should focus on the detection of olivine and spinel absorption bands, specifically absorption features near 1.05, 1.3, 1.95, and 2.1μm, as these are the most commonly seen spectral features of CV chondrites.
KW - Asteroids
KW - Meteorites
KW - Spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84865981614&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865981614&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2012.07.007
DO - 10.1016/j.icarus.2012.07.007
M3 - Article
AN - SCOPUS:84865981614
SN - 0019-1035
VL - 221
SP - 328
EP - 358
JO - Icarus
JF - Icarus
IS - 1
ER -