Molecular species of impact-induced gas from carbonate mineral

Abstract

Meteorite impacts on the Earth induce the release of a huge amount of climatically active gases from the impacting body and crustal material under very high temperature and pressure condition. Here, we focused on the impact-induced degassing from carbonate minerals which is abundant on the Earth. Previous researches have assumed that impact-induced gas from carbonate is wholly CO2 [e.g. O'Keefe and Ahrens, 1989]. However, there is a prospect that the gas from carbonate contains CO which is stable under high temperature. The release of CO and its atmospheric chemical reactions may cause the increase of tropospheric ozone which has intensive greenhouse effect. Hence, when we consider the climatic effects caused by impact-induced gases from carbonate, it is very crucial problem whether the gas is CO or CO2. Now we conducted the impact-degassing experiments using a laser gun and specified the molecular species of impact-induced gas from carbonate.