Every Rock Has A Story - Serpentinite

Serpentinite is a low grade metamorphic rock dominated by FE /Mg – rich silicate minerals from the deep mantle portion of an oceanic plate; this specimen was thrust on to the continental margin of eastern North America in present day Vermont by the plate tectonic collision of a volcanic island arc along eastern Proto - North America during the Taconic orogeny, ~440 mya – and is currently mined as a popular building stone called Verde Antique. The parent mantle rock was altered by elevated temperature, pressure and reaction with water and carbon dioxide to form a variety of green serpentine minerals; this process of serpentinization results in the oxidation of iron and the release of free hydrogen ions initiating the formation of methane – this has been suggested as an abiotic mechanism for explaining the recent detection of methane on Mars – the hydrogen ions may also power the metabolism of bacteria and methane-producing archaea and was likely an important process for early life on Earth.