Late Miocene alkenone unsaturation data, age models, and regional stacks of alkenones, supplement to: Herbert, Timothy D; Lawrence, Kira T; Tzanova, Alexandrina; Peterson, Laura C; Caballero-Gill, Rocio P; Kelly, Christopher S (2016): Late Miocene global cooling and the rise of modern ecosystems. Nature Geoscience, 9(11), 843-847


During the late Miocene epoch, about seven million years ago, large areas of the continents experienced drying, enhanced seasonality, and a restructuring of terrestrial plant and animal communities. These changes are seen throughout the subtropics, but have typically been attributed to regional tectonic forcing. Here we present a set of globally distributed sea surface temperature records spanning the past 12 million years based on the alkenone unsaturation method. We find that a sustained late Miocene cooling occurred synchronously in both hemispheres, and culminated with ocean temperatures dipping to near-modern values between about 7 and 5.4 million years ago. The period of maximum cooling coincides with evidence for transient glaciations in the Northern Hemisphere and with a steepening of the pole-to-equator temperature gradient, as well. We thus infer that late Miocene aridity and terrestrial ecosystem changes occurred in a global context of increasing meridional temperature gradients. We conclude that a global forcing mechanism, such as the previously hypothesized decline in atmospheric CO2 levels between eight and six million years ago, is required to explain the late Miocene changes in temperature, climate and ecosystems.

Metadata Access
Creator Kelly, Christopher S;Peterson, Laura C;Herbert, Timothy D;Lawrence, Kira T;Tzanova, Alexandrina;Caballero-Gill, Rocio P
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2018
Rights Creative Commons Attribution 3.0 Unported (CC-BY)
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Discipline Earth System Research
Spatial Coverage (46S-69N,13E-13W)
Temporal Point 1983-01-03T11:59:59Z