Long-Term Sea-Level Fluctuations Driven by Ocean Basin Dynamics

TLDR

Earth’s long‑term sea‑level history shows widespread continental flooding during the Cretaceous, followed by regression, yet Late Cretaceous sea‑level highs are debated, ranging from ~40 m to ~250 m above present, with the low estimate based on New Jersey margin stratigraphy. The study aims to model Late Cretaceous sea level by assimilating marine geophysical data into ancient ocean basin reconstructions. The model employs mantle convection to show that New Jersey subsided 105–180 m over 70 Myr as North America moved over the subducted Farallon plate, yielding a Late Cretaceous sea level estimate of 170 m above present. This mechanism reconciles New Jersey margin–based sea‑level estimates with ocean basin reconstructions.

Abstract

Earth's long-term sea-level history is characterized by widespread continental flooding in the Cretaceous period (∼145 to 65 million years ago), followed by gradual regression of inland seas. However, published estimates of the Late Cretaceous sea-level high differ by half an order of magnitude, from ∼40 to ∼250 meters above the present level. The low estimate is based on the stratigraphy of the New Jersey margin. By assimilating marine geophysical data into reconstructions of ancient ocean basins, we model a Late Cretaceous sea level that is 170 (85 to 270) meters higher than it is today. We use a mantle convection model to suggest that New Jersey subsided by 105 to 180 meters in the past 70 million years because of North America's westward passage over the subducted Farallon plate. This mechanism reconciles New Jersey margin–based sea-level estimates with ocean basin reconstructions.