Date of Award

7-28-2011

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Earth System Science & Policy

First Advisor

Michael|Gaffey, Michael Hill

Abstract

This research program initiated a systematic visible-near-infrared (VNIR) spectroscopic survey to search for links between twenty-seven asteroidal bodies adjacent to the 3:1 resonance and meteorite types in the terrestrial collections. The 3:1 Kirkwood gap located at 2.5 AU is a potential major source for meteorites and near-Earth asteroids. This research program utilized observations using the NASA IRTF SpeX instrument to obtain high signal-to-noise NIR spectra (0.8–2.5 μm) of asteroids in a zone centered on the 3:1 resonance. The spectra were used to mineralogically characterize asteroids in the zone to identify their meteorite analogs (if any). The mineralogy, petrology, isotope chemistry, and cosmic ray exposure history revealed by laboratory study of the meteorites provides detailed insights into the relative and absolute timing of major processes operating and conditions present in the early inner solar system. However, the source regions of individual meteorites types are poorly constrained because their specific parent bodies – and hence their early solar system locations – have generally not yet been identified. Mineralogical characterizations of the asteroids provide a "geologic map" of conditions and processes in the early solar system.The chronological studies of the meteorite types provide a "clock" for the relative timing of those events and processes. By identifying the source asteroids of particular meteorite types, the "map" and "clock" can be combined to provide a much more sophisticated understanding of the history and evolution of the early solar system.Results of the study revealed two probable, three plausible, two possible, and two unique/not represented parent bodies have been spectroscopically identified in the chaotic region of the 3:1 Kirkwood Gap. Eleven Maria family members have been identified as plausible parent bodies. Four asteroids lacking absorption features were unable to be associated with a particular meteorite type and two asteroids need better spectra for a more rigorous mineralogical assessment. The data presented here is consistent with Farinella et al. (1993) dynamical predictions that meteoritic material can/is delivered to Earth from this particular region in the mainbelt. The 3:1 Kirkwood gap asteroids are a mineralogically diverse set of asteroids located in a region that delivers meteoroids to Earth.

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