Dawnika is a Research Geologist with the California Volcano Observatory (CalVO). She conducts high-pressure, high-temperature experimental studies in the Magma Dynamics laboratory to complement field and petrologic studies of volcanic systems.
Dawnika works on understanding magmas, including their melt, crystal, and volatile components as they form, undergo evolution, and ultimately erupt (or not). She uses experimental petrology, coupled with microbeam analyses, FTIR, and petrographic data, to determine magmatic conditions including: temperature, pressure, oxygen fugacity, and compositions and proportions of all phases (including volatiles). She combines this information with field observations on distribution, timing, and volumes of eruptive products to connect eruptive processes to fundamental source conditions. Field-based projects include extensive mapping and sampling across the Mexican Volcanic Belt, work on Cascade arc volcanoes, Aleutian arc volcanoes, and most recently in the Clear Lake Volcanic Field and Mount Shasta region of northern California.
Education and Certifications
Ph.D. in Geology and Geophysics, 1998, University of California, Berkeley
Dissertation Title: Subduction-related volcanism: Field and experimental studies of hydrous lavas in central Mexico
B.S. with Honors in Geology, 1991, University of California, Davis.
Science and Products
Science and Products
Pre-USGS PublicationsBlatter, D.L. and Carmichael, I.S.E. (1998) Hornblende peridotite xenoliths from central Mexico reveal the highly-oxidized nature of subarc upper mantle. Geology, v. 26, pp. 1035-1038.Blatter, D.L. and Carmichael, I.S.E. (1998) Plagioclase-free andesites from Zitácuaro (Michoacán), Mexico: petrology and experimental constraints. Contributions to Mineralogy and Petrology, v. 132, pp. 121-138.Blatter, D.L, and Carmichael, I.S.E. (2001) Hydrous phase equilibria of a Mexican high-silica andesite: A candidate for a direct mantle origin? Geochimica et Cosmochimica Acta, v. 65, pp. 4041-4063.Blatter, D.L, Carmichael, I.S.E, Deino, A, and Renne, P. (2001) Neogene volcanism at the front of the central Mexican Volcanic Belt: basaltic andesites to dacites with contemporaneous shoshonites and high-TiO2 lavas. GSA Bulletin, v. 113, pp. 1324-1342.Blatter, D.L, Carmichael, I.S.E, Deino, A, and Renne, P. (2003) Reply to comment by Torres-Alvarado, I. S. and Verma, S. P. on Neogene volcanism at the front of the central Mexican Volcanic Belt: basaltic andesites to dacites with contemporaneous shoshonites and high-TiO2 lavas. GSA Bulletin, v. 115, pp. 1021-1024.Blatter, D.L, Farmer, G. L, and Carmichael, I.S.E. (2007) A N-S transect across the central Mexican Volcanic Belt at ~100°W: spatial distribution, petrologic, geochemical, and isotopic characteristics of Quaternary volcanism. Journal of Petrology, v. 48, pp. 901-950.Mukasa, S.B, Blatter, D.L, and Andronikov, A. (2007) Mantle peridotite xenoliths in andesite lava at El Peñon, central Mexican Volcanic Belt: Isotopic and trace element evidence for melting and metasomatism in the mantle wedge beneath an active arc. Earth and Planetary Science Letters, v. 260, pp. 37-55.Blatter, D.L, and Hammersley, L. (2010) Impact of the Orozco Fracture Zone on the central Mexican Volcanic Belt. Journal of Volcanology and Geothermal Research, v.197, pp. 67-84. DOI 10.1016/j.jvolgeores.2009.08.002.