Visualizing Sedimentary Condensation , Dilution, and Erosion using Shiny Apps

Fossil accumulations can be generated by (1) high input of organism remains or (2) by low sedimentation rates, reducing the volume of sediment between individual fossils. This creates a paradox, in which shell beds may form in environments with low biomass production. This effect of sedimentary condensation on fossil abundance is easy to understand, however, its implications are hard to grasp and visualize.

We present the shellbed condensator ( https://stratigraphicpaleobiology.shinyapps.io/shellbed_condensator/ ), a web application that allows to interactively visualize and animate the effects of sedimentary condensation and erosion on fossil abundance and proxies recorded by the sedimentary record. It is an adaptation of the seminal computer simulation by Kidwell (1985). The application is written in R Software and uses the shiny package for the construction of the web interface and the DAIME package for the sedimentological model (Hohmann, 2021). It allows creating stratigraphic expressions and age models for combinations of fossil input and sedimentation rates defined by the user.

To assess the utility of shiny apps for teaching purposes, we examine student understanding of sedimentary condensation after unsupervised studying and after unsupervised usage of the app. Due to their strong visual and interactive components, shiny apps are a powerful and versatile tool for science communication, teaching, self-study, the visualization of large datasets, and the promotion of scientific findings.