How does subaerial erosion of carbonate platform distort the sedimentary record?

Carbonate platform strata have been extensively utilized to decipher geological history. However, due to the fluctuating ambient environment and the complex growth pattern of carbonate factories, preserved records are generally incomplete. For example, given the platforms are located in shallow water environment, they are prone to subaerial denudation when the sea level falls. Numerical modelling is a popular approach to examine spatial and temporal heterogeneities of carbonate platform architectures. While growth and submarine transportations that have been extensively considered, surprisingly, substantially less efforts have been invested to subaerial denudation and its effects on 3-dimentional carbonate platform architecture (e.g., the denudation rates are simplified to constant dissolution rates regardless of the varying ambient environment and local geomorphology).

Herein, we implemented a model with chemical dissolution and physical erosion, calibrated with 35Cl (a geochemical proxy used to estimate kyr-scale denudation) karst regions into CarboKitten.jl (https://mindthegap-erc.github.io/CarboKitten.jl/), a new open-source carbonate platform model. We compared the outputs of models with and without the denudation by using mathematical tool (LBP method) and assessed how the presence of denudation distorts the age-depth relationships. We find that the inclusion of denudation could increase both temporal and spatial heterogeneities, which may decrease the estimation biases on age-depth model. Our results emphasize the importance of considering subaerial denudation in reconstructing geological histories. This study provides a comprehensive framework for refining interpretations and enhancing the accuracy of paleoenvironmental reconstructions based on carbonate platform sediments.