报告时间：2019年1月4日14:30-15:30
报告地点：天津大学卫津路校区会议楼第八会议室
主讲嘉宾： Daniele L. Pinti 教授，加拿大Université du Québec à Montréal大学
报告摘要：
CO2 is the main gas phase in geothermal systems, which are peculiar places at the interface between the mantle and the crust. Revealing the origin of CO2 in these systems is thus important to better understand the deep cycle of C and its behavior at high temperature, in case of future CO2 storage in geothermal fields. The isotopic composition of C and O of the CO2 molecule were analyzed in four geothermal field from Mexico, belonging to different tectonic setting, from oceanic spreading to subduction. Main result of this study is that the isotopic composition of CO2 is distinct and unique for each sampled geothermal field. The C isotopic variability is controlled mainly by its sources (i.e., δ13C is ?6±2‰ in the mantle; ?20‰ in carbon organic matter-rich sediment; and 0 ± 2‰ in marine carbonates) and possibly secondary processes such as calcite precipitation. The oxygen isotopic variability is related to the degree of isotopic re-equilibration between steam (H2O) and CO2.
嘉宾简介：
Dr. Pinti graduated at the Geology department of Rome “La Sapienza” University, Italy in 1989 with a specialization in soil gas geochemistry. He obtained a PhD at the University of Paris 6 in 1993 on noble gas geochemistry and then moved at Osaka University from 1994 to 1998 where he specialized in nitrogen isotope geochemistry, applied to astrobiology. In 1999 he become associate professor at University of Paris Sud and worked for 6 years in K-Ar geochronology. Since 2014 he is professor at Université du Québec à Montréal and researcher at the Geotop research center where he is the director since 2015. He is working mainly on tracing and dating continental crustal fluids (geothermal, natural and shale gases, groundwater). He also served from 2008 to 2011 as the vice-executive editor of Geochemical Journal and since 2011 he is one of the editors of the Encyclopedia of Astrobiology.
