Prospecting for life

• Published in: Interface Focus
• Main Author: Russell, Michael J.
• Format: Text
• Language: English
• Published: The Royal Society 2019
• Subjects: Articles; Canada; Pacific; Yukon; North Atlantic
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6802130/; http://www.ncbi.nlm.nih.gov/pubmed/31641430; https://doi.org/10.1098/rsfs.2019.0050

Books with titles like ‘The Call of the Wild’ seemed to set a path for a life. Thus, I would be an explorer—a plan that did not work out so well, at least at first. On leaving school I got a job as a ‘Works Chemist Improver’, testing Ni catalysts for the hydrogenation of phenol to cyclohexanol. Taking night classes I passed enough exams to study geology at Queen Mary College, London. Armed thus I travelled to the Solomon Islands where geology is a ‘happening’! Next was Canada to visit a mine sunk into a 1.5 billion year old Pb–Zn orebody precipitated from submarine hot springs. At last I reached the Yukon to prospect for silver. Thence to Ireland researching what I also took to be ‘exhalative’ (i.e. hot spring-related) Pb–Zn orebodies. While there in 1979, the discovery of 350°C metal-bearing acidic waters issuing from submarine Black Smoker chimneys in the Pacific sent us searching for fossil examples in the Irish mines. However, the chimneys we found were more like chemical gardens than Black Smokers, a finding that made us think about the emergence of life. After all, what better for life's emergence than to have a membrane comprising Fe minerals dosed with Ni in our chimneys to mediate the ‘hydrogenation’ of CO(2)—life's job anyway. Indeed, such a membrane would keep redox and pH disequilibria at bay, just like biological membranes. At the same time, my field research among Alpine ophiolites—ocean floor mafic rocks obducted to the Alps—indicated that alkaline waters bearing H(2) and CH(4) were a result of serpentinization, a process that must have operated in all ocean floors over all time. Thus it was that we could predict the Lost City hydrothermal field 10 years before its discovery in the North Atlantic in the year 2000. Lost City comprises a number of alkaline springs at up to 90°C that produce carbonate and brucite (Mg[OH](2)) chimneys. We had surmised that Ni-enriched FeS chimneys would have precipitated at comparable alkaline springs issuing into a metal-rich carbonic ocean on the very early Earth ...