FEST: 'A story according to Lithium isotopes: what was the role of terrestrial plants in silicate weathering processes and the Earth climate evolution?'

Friday Earth Sciences Talk by Dr Xianyi Liu

Silicate weathering is a crucial process in the Earth system. By fixing atmospheric CO2 into carbonate minerals and organic carbon, it significantly influences global climate. This process has been demonstrated to act as a thermostat during past glaciation and hyperthermal events.

Despite the general consensus that plants substantially affect silicate weathering—and consequently climate—huge debates persist due to the lack of reliable proxies to monitor these processes. It remain poorly known whether plants would enhance or hinder silicate weathering.

Here we will employ Lithium isotopes to tackle this critical problem, by using two examples at different timescales. We will first look into the silicate weathering patterns in the Late Paleozoic, a pivotal era marked by extensive plant. We will then move to Iceland to investigate a more recent case: how the silicate weathering and lithium isotope would behave in the topsoil of an 60 years long afforestation project.

With the FEST, we intend to bring the departments of Earth Sciences and Physical Geography together. The aim is to present (mostly) Utrecht-based Earth Sciences in an accessible way, primarily in order to stay familiar with each other’s work across disciplines. Simultaneously, this provides an excellent platform to help (in particular MSc.) students in their orientation on possible graduation specialisations and future careers.