Filling gaps in the geological record – Early–Middle Jurassic climate and environmental dynamics

The Early–Middle Jurassic was a pivotal interval in Earth history, encompassing the expansion of calcifying plankton, the diversification of dinosaurs, and major evolutionary turnovers. This period was marked by profound changes in continental and oceanic configurations, the emplacement of large igneous provinces, and major environmental perturbations. These included the collapse of shallow-marine carbonate platforms, first- and second-order mass extinctions, episodes of eutrophication and marine anoxia, and major disruption to the global carbon cycle. Over recent decades, research has focused primarily on the causes and consequences of major Jurassic crises, such as the Triassic–Jurassic boundary, the Pliensbachian–Toarcian transition, the Toarcian Oceanic Anoxic Event and the Bajocian crisis. However, this emphasis has often overshadowed inter-crisis time intervals that shaped the broader background environmental conditions of the Early–Middle Jurassic. Although advances in modelling and geochemical proxy application have improved our understanding of the overall environmental states, atmospheric CO2 levels, and temperature, important gaps and unresolved questions remain. Studies often focus on individual events, thus limiting a comprehensive understanding of the Earth system and its long-term evolution. How far can these events be explored without losing sight of the broader context? Here, we present a new multiproxy, multi-million-year record of environmental, climatic, atmospheric CO2 proxies derived from globally distributed marine sites spanning the Toarcian–Aalenian and Bathonian–Callovian time intervals. This compilation allow us to reconstruct conditions before, during and after the major crises and discuss the triggering mechanisms, and place these events within a broader environemental and climatic framework.