Introductory Chapter: Half a Lifetime in Soda Lakes

Abstract

My interest in soda lakes started more than 25 years ago from an encounter with a geologist colleague interested in astrobiology. At that time, the Mars exploration programme was underway and the chemical composition of the Mars regolith a matter for speculation. There are good reasons to believe that Mars and Earth may have experienced rather similar conditions after planet formation, with the development of extensive oceans. The chemical composition of the early oceans is a matter of debate – in particular, whether these were acid or alkaline (Kempe and Degens 1985; Kempe and Kazmierczak 1997). A consideration of weathering processes known to occur on Earth suggests that alkalinity is likely to arise as a consequence of an excess of Na⁺ over Ca²⁺ in basaltic minerals, resulting in a carbonate-rich and therefore alkaline aqueous environment (Mills and Sims 1995). In view of the possibility of life on Mars, there was, and is, interest in examining possible terrestrial analogues of the alkaline environment in order to inform any life-detection experimentation.