Metamorphism and putative bioalteration of basaltic glass: Coast Range Ophiolite.

摘要

Basaltic glass from the Stonyford Volcanic Complex of the Coast Range Ophiolite contains textural evidence of bioalteration. This project examines the metamorphism of the volcanic samples as well as the morphology and mineralization of microtubes found within the basaltic glass of this Jurassic seamount. Basaltic aquifers are widespread on the Earth; the pervasive nature of putative bioalteration in this setting is important for understanding the ocean crustal biosphere and the astrobiologic implications of bioalteration.;The objectives of this study are to (i) conduct a petrographic and mineralogic analysis of the volcanic samples to constrain metamorphic conditions, (ii) evaluate the textural evidence for potential biogenic alteration with a quantitative morphometric analysis of the geometry and distribution of the microtubules, and (iii) discuss the astrobiologic implications of bioalteration in relation to the search for life in basaltic aquifers on other planetary bodies.