Elisabeth M. Hausrath

Our work helps understand chemical weathering, nutrient release, water composition and quality, the formation of soils, and biosignatures on both Earth and Mars.

I am an aqueous geochemist and astrobiologist, and the overall theme of my research program is to investigate interactions between water and minerals, and the impacts of life on those interactions. We use a combination of field work, laboratory experiments, and modeling to investigate signatures of aqueous alteration and life, the rates at which these reactions occur, and how they differ on Earth and on other planets such as Mars. Our work helps understand chemical weathering, nutrient release, the formation of soils, and biosignatures on both Earth and Mars.

In our field projects, we have examined weathering profiles that show that mineral persistence records the pH, temperature and organic acids in solutions interacting with basaltic rock (Hausrath et al., 2008a ; Hausrath et al., 2008b, Hausrath et al., 2011) and the solution pH and impact of Fe-oxidizing bacteria in solutions interacting with serpentinite rock (Baumeister et al., 2015). We also use field experiments in which we place minerals in natural environments such as arctic soils (Hausrath et al., 2008) and fumaroles (Hausrath and Tschauner, 2013) to examine changes in the surfaces with alteration.

We perform laboratory dissolution and precipitation experiments, to examine the rates at which minerals dissolve, the impacts of the dissolution on mineral surfaces, to determine the conditions that are preserved in secondary minerals, and to examine conditions that are difficult to find in natural terrestrial environments (e.g. experiments that are relevant to Mars). We have examined the dissolution of nutrient-rich phosphate minerals (Adcock et al., 2013 ; Tu et al., 2014); clay minerals found on Mars (Gainey et al., 2014), and dissolution in brines relevant to Mars (Hausrath et al., 2010; Steiner et al., 2016). Our experiments also demonstrate the environmental conditions, such as oxidation state and solution chemistry, that can be preserved in clay minerals (Gainey et al, 2017). We also include both microorganisms and the biological products of organisms such as organic acids to examine the effects of biological processes on these reactions (Hausrath et al., 2007 ; Hausrath et al., 2009; Harrold et al., 2018; Bartlett et al., 2018)

We use kinetic and thermodynamic numerical modeling to answer scientific questions that cannot be answered in a lab or field setting. We have examined weathering of basalt relevant to both Earth and Mars using reactive transport modeling (Hausrath et al., 2008), and examined the implications of dissolution of carbonate (Hausrath and Olsen, 2013), phosphate-rich rocks on Mars (Adcock et al., 2015), and leached layer formation on Mars (Hausrath et al., 2018) as well as the behavior of selenium in terrestrial environments (Devitt et al., 2014).