Tethys carbon cycle, India-Eurasia collision, and Cenozoic climate evolution

 

Since the industrial revolution, the constant increase in atmospheric CO₂ had pivotal impacts on global climate with current concentrations being the highest of the last 800 ka. In order to better understand the Earth system and the future evolution of climates, it is essential to study past hyperthermals during which global surface temperature dramatically increased above present levels. The Himalaya arose from the biggest known continental collision and has been associated with a bustling volcanism, which most likely steered the global warming (+12-14 °C) during the Early Eocene Climatic Optimum (EECO).

We here present the analytic strategy that will be implemented to quantify the carbon cycle within the Kohistan-Ladakh forearc sediments. Whilst the CO₂ input (warming) in the atmosphere related to the intensity of subduction magmatism will be quantified using the mercury isotopes, the CO₂ sink (cooling) induced by continental alteration of the exhumed units will be studied through different isotopic analyses (e.g., Hf, Nd, Sr). The stratigraphy and the reconstruction of depositional environments will be assessed through conventional field surveys and various dating methods such as, detrital zircon, nannofossils, radiolarians, and calibrated carbon isotopic curves. The overall objective is to establish the influence of the collisional Himalayan chain on global climate changes.