Ryan A. Zeigler, Planetary Scientist; Apollo Sample Curator
Lunar Petrology and Geochemistry
NASA / KT
Ph.D, Washington University, 2004
M.A., Washington University, 2000
B.A., State University of New York - Potsdam, 1998
The principal focus of my research is to study the geochemistry and petrography of lunar samples to better understand how the Moon formed, how it differentiated, and how impacts have subsequently altered its surface. Recently, I have concentrated my research on lunar meteorites and small glass fragments found in the Apollo soils. Lunar meteorites come from random locations on the lunar surface, and the large number of source craters for lunar meteorites (N>40) means that lunar meteorites are the most globally representative lunar sample suite we have. Thus, a better understanding of the lithologies in lunar meteorites will lead to a better understanding of how the Moon evolved. Impacts on the lunar surface are ubiquitous and each impact into the lunar surface melts, deforms, and redistributes material over an area of the Moon proportional to the size of the impact. Therefore, in order to fully understand the geology of a lunar site, we need to better understand how impacts redistribute materials over the surface of the Moon. To this end, I have studied the major- and trace-element compositions of glasses found in Apollo soils to better constrain the provenance of the glassy constituents in soil and to better understand how impacts redistribute material over the lunar surface.
Korotev R. L., Jolliff B. L., Zeigler R. A., Seddio S. M, and Haskin L. A. (2011) "Apollo 12 revisited." Geochimica et Cosmochimica Acta 75, 1540-1573.
McCubbin, Francis M.; Jolliff, Bradley L.; Nekvasil, Hanna; Carpenter, Paul K.; Zeigler, Ryan A.; Steele, Andrew; Elardo, Stephen M.; Lindsley, Donald H. "Fluorine and chlorine abundances in lunar apatite: Implications for heterogeneous distributions of magmatic volatiles in the lunar interior." Geochimica et Cosmochimica Acta, ISSN: 0016-7037, Vol: 75, Issue: 17, Date: 2011-09-01, Start page: 5073-5093
Korotev R. L., Zeigler R. A., and Floss C. (2010) "On the origin of impact glass in the Apollo 16 regolith." Geochimica et Cosmochimica Acta 74, 7362-7388.
Korotev R. L., Zeigler R. A., Jolliff B. L., Irving A. J., and Bunch T. E. (2009) "Compositional and lithological diversity among brecciated lunar meteorites of intermediate iron composition." Meteoritics & Planetary Science 44, 1287-1322.
Zeigler R. A., Korotev R. L., Jolliff B. L., L Haskin. A., and Floss C. (2006) "The geochemistry and provenance of Apollo 16 mafic glasses." Geochimica et Cosmochimica Acta 70, 6050-6067.