Léa Ostorero

From

University of Milano-Bicocca - IT

In residence at

Earth sciences institute of Orleans (ISTO) - CNRS, BRGM, OSUC / University of Orléans - FR

Host scientist

Joan Andújar Fernández

PROJECT

CALUMET (ClimAtic impact of Linzizong erUptions and their Magmas (TibET))

Volcanoes release gases through eruptions and long-lived magmatic activity. Among these gases, CO2 is a major greenhouse gas capable of driving large shifts in global temperatures over geologic timescales. Yet the link between large-scale tectonic events and associated magmatic CO2 emissions remains poorly constrained.
In particular, a key controversy concerns the main driving mechanisms and CO2 sources behind major Cenozoic climatic events, such as the Early Eocene Climatic Optimum (EECO, 52-50 Ma), when global temperatures were 9-12 °C higher than today. Pervasive early Eocene Linzizong volcanism in the Gangdese arc (southern Tibet) may have contributed significantly to the EECO, but no direct measurements of pre-eruptive CO2 contents exist. The overarching goal of the CALUMET project is thus to retrieve the CO2 content of these magmatic provinces to better understand the feedbacks between magmatism and climate. We will conduct quantitative analyses of melt inclusions, which are tiny pockets of trapped magma inside growing crystals that preserve the volatile composition of magma before eruption. This interdisciplinary project will combine the development of high-temperature and high-pressure experiments at ISTO to homogenize the crystallized melt inclusions; volatile analyses at the SIMS in Nancy; and numerical modeling to evaluate the climatic effect of magmatic CO2 emissions.