Megan Curry – 2007 Wilson Memorial Scholarship

MeganCurry07Biography and MS Research Topic: A geology graduate of the University of Akron in 2004, Megan is currently a masters student at New Mexico Tech, with an expected graduation date of May 2008. Megan began her cave science career working in traditional conduit caves in the eastern US, but has now moved on to the more exotic caves and locales of the American west. She is still undecided on what direction to take after graduation. She would like to take a break from being a graduate student for one or two years. After this break, she hopes to go back to graduate school and obtain a PhD.

Thesis Title:  Curray, M., in progress, A Geomicrobiological and Geochemical Approach to the Biogenicity of Moonmilk Formation: Spider Cave and Pahoehoe Cave, New Mexico; Thursday Morning Cave, Colorado; Cataract and Thrush Cave, Alaska.

Thesis Abstract: Many secondarily formed deposits within caves are known to be the result of primarily physiochemical processes. However, moonmilk is a unique speleothem that does not appear to be explainable via the same abiotic mechanisms, nor have the same morphologies and textures as traditional speleothems such as stalagmites and stalactites. Moonmilk is unique compared to other speleothems due to its biological content, highly variable mineralogy, and texture. Moonmilk is currently loosely defined as a microcrystalline aggregate cave deposit composed of various mineralogies and a distinguishable texture that is soft, plastic, and pasty when wet and crumbly when dry. Several explanations have been proposed concerning the origin of moonmilk. However, the body of work is sparse and the origin still unclear. A microbial role is suggested by the presence of visible pits in bedrock apparently caused by organism attachment, mineral encrustation around microbial filaments, and significant biofilm content. To explain the observed physical, chemical, and biological properties of moonmilk, we hypothesize that it is the product of a passive, microbially-mediated disaggregation of host rock and reprecipitation of carbonate from bedrock in a groundwater seepage-driven evaporative process. In order to test the relative biogenicity of moonmilk, this study will aim at distinguishing the biotic components and interactions from abiotic. The research presented in this thesis will utilize a pragmatic interdisciplinary approach encompassing geomicrobiology and geochemistry.