Surfing the Waves of Time: Unveiling Scotian Basin Mega-Sequences through a Novel Phanerozoic Sea-Level Curve

Summary Traditionally, long-term global mean sea-level curves were derived from stratigraphic analyses, but these methods are unreliable due to local and regional influences like sediment supply, local tectonics, and dynamic topography. Recently, an alternative approach using strontium and oxygen isotopes has been developed to estimate mid-ocean ridge spreading and land ice volumes, resulting in a combined Tectono-Glacio-Eustatic (TGE) curve. Van der Meer et al. (2017 , 2022) used the strontium isotope record to quantify mid-ocean ridge spreading rates and tectonic eustasy for the Phanerozoic. Their analysis showed that plate tectonic activity was about twice as high in the mid-Mesozoic compared to the present. They further refined this approach by incorporating paleotemperature reconstructions to estimate variations in water volume locked in ice sheets. The TGE curve has been instrumental in defining four eustatically driven regressive-transgressive mega-sequences in the Scotian Basin. These sequences have helped understand key source rocks and clastic reservoirs. The Scotian Basin stratigraphy, driven primarily by eustasy, provides a valuable test of the TGE curve, demonstrating its predictive potential for other passive margins.