Carbon flux from hydrothermal skarn ore deposits and its potential impact to the environment

Abstract

Magmatic-hydrothermal systems transport metal, sulfur, and carbon from deep to shallow crust, providing materials to the society and potentially affecting Earth’s long-term environment. The fluxes of elements and, accordingly the environmental effects, are ultimately functions of the time-integrated amounts and durations of magmatic-hydrothermal system. In this study, we calculate the duration of prograde metamorphism induced by fluid infiltration and amount of carbon released by skarn ore deposits. This study finds that skarn ore deposits can decarbonize CO2 at an efficiency up to 1014 g/(y.km3), which is much higher than volcanism on different tectonic settings. The CO2 flux of skarn deposits increased from late Jurassic to early Cretaceous and reached a maximum value to 7.8 Mt/y at J/K boundary.Our finding provided an previously unquantified but important outgassing source in the subduction zone. This result consistent with global warming pattern based on global sedimentary records. The maximum outgassing at J/K boundary may have important impact on global warming and perhaps mass extinction.