The Anisian Stage (Middle Triassic) marks a pivotal interval for biotic recovery following the Permian-Triassic mass extinction, yet its environmental drivers remain poorly understood. This study presents carbon isotopes, mercury (Hg) concentrations, and Hg isotope data from Anisian (mainly Pelsonian substage) marine and terrestrial sections across the Tethys. Our results reveal a widespread Hg enrichment event that is synchronous with the Pelsonian negative carbon isotope excursion (PENCIE). Hg isotopic compositions support an origin from enhanced regional volcanism, coupled with contemporaneous terrestrial input. New high-precision zircon U-Pb ages (244.200 ± 0.037 Ma and 243.451 ± 0.049 Ma), integrated with chemostratigraphic and biostratigraphic data, constrain the duration of the PENCIE to ∼0.5 Myr. This interval coincided with major biodiversification, revealing that recovery occurred alongside environmental perturbations rather than in stable conditions as traditionally thought. These global disturbances in carbon and mercury cycles, linked to volcanism and terrestrial input, likely accelerated Middle Triassic biotic recovery.
A ∼0.5 Myr perturbation of carbon and mercury cycles during the Middle Triassic biotic radiation
Gianolla, Piero;Alverà, Greta;
2026
Abstract
The Anisian Stage (Middle Triassic) marks a pivotal interval for biotic recovery following the Permian-Triassic mass extinction, yet its environmental drivers remain poorly understood. This study presents carbon isotopes, mercury (Hg) concentrations, and Hg isotope data from Anisian (mainly Pelsonian substage) marine and terrestrial sections across the Tethys. Our results reveal a widespread Hg enrichment event that is synchronous with the Pelsonian negative carbon isotope excursion (PENCIE). Hg isotopic compositions support an origin from enhanced regional volcanism, coupled with contemporaneous terrestrial input. New high-precision zircon U-Pb ages (244.200 ± 0.037 Ma and 243.451 ± 0.049 Ma), integrated with chemostratigraphic and biostratigraphic data, constrain the duration of the PENCIE to ∼0.5 Myr. This interval coincided with major biodiversification, revealing that recovery occurred alongside environmental perturbations rather than in stable conditions as traditionally thought. These global disturbances in carbon and mercury cycles, linked to volcanism and terrestrial input, likely accelerated Middle Triassic biotic recovery.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
