Since the data gathered
only represents limited samples from two pallasites, it is difficult to
make broad conclusions regarding pallasite formation. However, the
implications of the data at hand are quite clear. The discrete, angular
boundaries between metal and olivine seen in Imilac samples as well as
the cracks and veins seen, seem to indicate that there was an impact at
some point in this meteorite's history. Springwater on the other hand
has less discrete, more rounded boundaries between olivine and metal,
contains accessory phosphate minerals, and more varied metal alloy
composition, indicating a longer, less interrupted thermal history.
I would like to thank
Brian McIntyre for all of his lectures and good humor. I would also
like to thank Margaret Samuels for her help throughout course lab
exercises. Finally, I would like to thank the Paleomagnetic Reserach
Group for providing the necessary meteorite samples.
References and Further Reading:
Buseck and Holdsworth. "Phosphate Minerals in Pallasite Meteorites." Mineralogical Magazine.
(1977): 41, 91-102.
Davis and Olsen. "The Origin of Phosphate Minerals in Eagle Station and
Springwater Pallasites." Lunar
and Planetary Science Conference XX
A. Desrousseaux Et al. "An Analytical Electron Microscope Investigation
of Some Pallasites." Physics
of the Earth and Planetary Interiors
(1997): 103, 101-115.
Wasson and Choi. "Main-group pallasites: Chemical composition,
relationship to IIIAB irons, and origin." Geochimica et Cosmochimica
Acta, (2003): 67, 16, 3079 –3096.