Evolution of alluvial mudrock forced by early land plants.

01 May 2018

Mudrocks are a primary archive of Earth's history from the Archean eon to recent times, and their source-to-sink production and deposition play a central role in long-term ocean chemistry and climate regulation. Using original and published stratigraphic data from all 704 of Earth's known alluvial formations from the Archean eon (3.5 billion years ago) to the Carboniferous period (0.3 billion years ago), we prove contentions of an upsurge in the proportion of mud retained on land coeval with vegetation evolution. We constrain the onset of the upsurge to the Ordovician-Silurian and show that alluvium deposited after land plant evolution contains a proportion of mudrock that is, on average, 1.4 orders of magnitude greater than the proportion contained in alluvium from the preceding 90% of Earth's history. We attribute this shift to the ways in which vegetation revolutionized mud production and sediment flux from continental interiors.