Fernandes and Roberts (2020) - preprint

Abstract

There are many geoscience problems for which constraining histories of uplift or subsidence of Earth’s surface is of direct or indirect importance, for example reconstructing tectonics, mantle convection, geomorphology, sedimentary and chemical flux, biodiversity, glacio-eustasy and climate change. The least equivocal constraints on timing and amplitude of vertical motions on geological timescales come from the distribution of rock formed in shallow marine environments. However, obtaining enough observations at sufficiently large spatial and temporal scales (~100−10, 000 km, ~ 1−100 Ma) to constrain histories of regional topographic evolution remains challenging. To address this issue we adapted modern inventories of paleobiological and paleoenvironmental data to generate a new compilation of > 24, 000 spot measurements of uplift on all continents and numerous ocean islands. Uncertainties associated with paleobathymetry, post-deposition compaction and glacio-eustasy are assessed. The compilation provides self-consistent, and, in places, high-resolution (< 100 km length-scale, < 1 Ma), measurements of Cretaceous to Recent (post-deposition) net uplift across significant tracts of most continents. To illustrate how the database can be used, records from western North America and eastern South America are combined with geophysical observations (e.g., free-air gravity, shear and Pn-wave tomography) and simple isostatic calculations to determine origins of topography. We explore how lithospheric thinning and mantle thermal anomalies may generate uplift of the observed wavelengths and amplitudes. The results emphasize the importance of large inventories of paleobiological data for understanding histories of tectonic and mantle convective processes, and consequently, landscapes, climate and the environment.