Chemical processing of phosphorus inclusions within iron meteorites and related investigations

• Main Author: Herschy, Barry
• Format: Thesis
• Language: English
• Published: University of Leeds 2013
• Subjects: Kverkfjöll; Iceland
• Online Access: https://etheses.whiterose.ac.uk/5909/; https://etheses.whiterose.ac.uk/5909/1/B_Herschy_2013_Thesis_Final.pdf

'How did life on Earth originate?' is a question that, as yet, scientists have been unable to answer. From simple building blocks, under certain conditions, a series of chemical reactions occurred leading to the formation of a living cell. Meteorites have long been considered a source of prebiotic chemicals which could have assisted in the origin of life on Earth. Iron meteorites are known to contain the mineral Schreibersite [(FeNi)3P], a good source of reduced oxidation state phosphorus (P) on the prebiotic Earth. Meteorites would be exposed, post-impact, to moisture from the atmosphere and oceans which could instigate a series of chemical reactions, giving rise to chemical precursors required for production of life. Current investigations are looking at the conditions to which Earth impacting meteorites would be exposed. Hydrothermal reactions of siderophilic P minerals such as Schreibersite were undertaken to identify and quantify any reduced P species produced and investigate reactions which could be utilised en route to life. Chapter 2 outlines the laboratory work conducted for the identification and quantification of reduced oxidation state phosphorus species (phosphine and phosphite). It investigates potential prebiotic chemistry of observed species including formation of condensed phosphorus species (pyrophosphite and isohypophosphate). Effects of temperature, pH and different metals (including magnesium [Mg], calcium [Ca] and iron [Fe]) on formation of condensed phosphorus species were investigated. Chapter 3 describes the fieldwork conducted at the Hveraldur hydrothermal field on the Kverkfjöll sub-glacial volcano. It describes the site, conditions and sampling methods. Chapter 4 covers the analysis of the experiments undertaken during the fieldwork in Iceland. It looks at products observed from corrosion of schreibersite, present in samples of Sikhote Alin meteorite and iron phosphide in natural hydrothermal �fluids and repeats prebiotic chemistry attempted in Chapter 2.