Dawn Sumner

Participating Scientist

Dawn Sumner

Expertise: Astrobiology
Affiliation: University of California, Davis
B.S. (Geology) California Institute of Technology, 1989
Ph.D. in Geology, Massachusetts Institute of Technology, 1995


Dawn Sumner became interested in geology as an undergraduate at California Institute of Technology. With extensive research experience with Prof. Joe Kirschvink, she earned a Bachelorís of Science with Honors in 1989 and moved to Massachusetts Institute of Technology supported by a National Science Foundation Graduate Student Fellowship. She spent her time at MIT working with Prof. John Grotzinger (and others) on 2.5 billion year old carbonates in South Africa, as well as several side projects. Dawn finished her Ph.D. in Geology in 1995, after which she returned to California Institute of Technology as an O.K. Earl Postdoctoral Fellow. In December 1996, Dawn joined the Faculty at University of California, Davis, as an Assistant Professor of Geology. She was promoted to Associate Professor with tenure in 2002, was named a Chancellorís Fellow in 2003, and was promoted to Full Professor in 2006. In recent years, her research has expanded beyond Archean carbonates to include microbial-mineral interactions of all ages, experimental biofilms, and Martian geology.

Several specific projects relate to research at Pavilion Lake. Student Bekah Shepard and Dawn are studying how cyanobacteria organize into complex structures such as some of those found in Pavilion Lake. This research involves both experimental cyanobacterial biofilms (http://geology.ucdavis.edu/~sumner/modernmicrobes.html) and comparisons to natural mats, including those at Pavilion Lake. In addition, they are studying how microbial metabolic activity affects carbon isotopic signatures in carbonate, which can act as a geological record of microbial processes. Results from these modern studies provide a framework for interpreting ancient microbialites. Specifically, similarities between modern and 2.5 billion year old microbialites from South Africa suggest that the ancient structures record significant, but as yet unknown, microbial behaviors.

Major Science Goals at Pavilion Lake

I wish to understand the morphology of cyanobacterial mats and how microbial motility creates patterns.


Dawn Sumner's Web Site
Research Initiative on Bahamian Stromatolites