Constraining 200 million years of geodynamic evolution of the North Alpine foreland at million-year resolution using clumped isotopes and U-Pb dating of diagenetic carbonates

A promising approach for the reconstruction of the geodynamic and thermal evolution of sedimentary basins is to exploit the information on temperature, pore fluid composition, and time recorded by diagenetic carbonates formed at different stages in the geological history of a basin. However, it has not yet been shown if diagenetic carbonates can provide near-continuous or even continuous records across 100 Ma timescales. Here, we constrain the geodynamic evolution of the North Alpine Foreland of Switzerland over the last 200 million years at unprecedented resolution using coupled clumped isotope thermometry and U-Pb dating of diagenetic carbonates (Δ₄₇/(U-Pb) thermochronometry). This is made possible by recent analytical progress enabling precise analysis of small carbonate cements and deep drill cores covering the entire sedimentary record over the last ∼250 Ma. For a first interval of basin subsidence in the Mesozoic, we constrain the temperature and fluid evolution during early diagenesis and burial in the Early and Middle Jurassic and report a thermal anomaly between the Middle Jurassic and Early Cretaceous with high basal heat flow which we relate to hydrothermal fluid circulation along deep-rooted basement fault systems. Our findings suggest that such basement fault systems, even if not hydrologically connected to the overlaying strata, may explain anomalously high burial temperatures in sedimentary basins. For exhumation and a second interval of basin subsidence in the Cenozoic, we constrain the time of occurrence and amount of major erosion related to the early-stage Alpine orogeny during Paleogene and document the evolution of burial temperature and pore fluids at the distal margin of the Molasse Basin between the Late Oligocene and Late Miocene. Finally, we show that the formation of the Jura fold-and-thrust belt between Middle and Late Miocene resulted in a complex arrangement with overlapping regional and site-specific effects controlling burial temperature and fluid circulation and provide new constraints on the timing and the amount of erosion of the Molasse Basin at its distal margin during the Pliocene. The presented Δ₄₇/(U-Pb) dataset represents a new benchmark in temporal and stratigraphic resolution and demonstrates the potential of diagenetic carbonates to provide near-continuous records of the geodynamic evolution of sedimentary basins across 100 Ma timescales.