Abrupt conclusion of the late Miocene-early Pliocene biogenic bloom at 4.6-4.4\u2009Ma

B -Th Karatsolis,D De Vleeschouwer,D De Vleeschouwer,J Henderiks,B C Lougheed

doi:10.1038/s41467-021-27784-6

B -Th Karatsolis, D De Vleeschouwer + Show 3 more

Open Access

https://doi.org/10.1038/s41467-021-27784-6

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Journal: Nature Communications	Publication Date: Jan 17, 2022
Citations: 16	License type: open-access

Affiliation: Uppsala University

Abstract

The late Miocene-early Pliocene biogenic bloom was an extended time interval characterised by elevated ocean export productivity at numerous locations. As primary productivity is nutrient-limited at low-to-mid latitudes, this bloom has been attributed to an increase or a redistribution of available nutrients, potentially involving ocean-gateway or monsoon-related mechanisms. While the exact causal feedbacks remain debated, there is even less consensus on what caused the end of the biogenic bloom. Here, we compile Mio-Pliocene paleoproductivity proxy data from all major ocean basins to evaluate the timing and pacing of this termination. This systematic analysis reveals an abrupt and sustained reduction in low-latitude ocean productivity at 4.6–4.4 Ma. The decline in productivity coincided with a prolonged period of low orbital eccentricity and a shift towards lower-amplitude obliquity, an astronomical configuration linked to reduced East Asian Monsoon intensity and decreased riverine nutrient supply.

Highlights

Ocean productivity is driven by marine primary producers that rely on the availability of nutrients, which are quickly exhausted in the sun-lit surface waters if not replenished
We first vetted proxy records based on an objective scoring system that takes into account data resolution and the quality of the available geochronology (see Methods for details on the 1 to 5 scoring system)
The vetted and standardized data compilation reveals that the late Miocene to early Pliocene was a time of increased ocean productivity at the majority of the studied records (Fig. 2)

Summary

Introduction

Ocean productivity is driven by marine primary producers (e.g. diatoms and coccolithophores) that rely on the availability of nutrients, which are quickly exhausted in the sun-lit surface waters if not replenished. The vetted and standardized data compilation reveals that the late Miocene to early Pliocene was a time of increased ocean productivity at the majority of the studied records (Fig. 2).

Results

Conclusion