Multiple tropical Andean glaciations during a period of late Pliocene warmth
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Date
2017
Authors
Roberts, Nicholas J.
Barendregt, René W.
Clague, John J.
Journal Title
Journal ISSN
Volume Title
Publisher
Nature Research
Abstract
The extent and behaviour of glaciers during the mid-Piacenzian warm period illustrate the sensitivity of the cryosphere to atmospheric CO2 concentrations above pre-industrial levels. Knowledge of glaciation during this period is restricted to globally or regionally averaged records from marine sediments and to sparse terrestrial glacial deposits in mid-to-high latitudes. Here we expand the Pliocene glacial record to the tropics by reporting recurrent large-scale glaciation in the Bolivian Andes based on stratigraphic and paleomagnetic analysis of a 95-m sequence of glacial sediments underlying the 2.74-Ma Chijini Tuff. Paleosols and polarity reversals separate eight glacial diamictons, which we link to cold periods in the benthic oxygen isotope record. The glaciations appear to coincide with the earliest glacial activity at high northern latitudes and with events in Antarctica, including the strong M2 cold peak and terminal Pliocene climate deterioration. This concordance suggests inter-hemispheric climate linkages during the late Pliocene and requires that the Central Andes were at least as high in the late Pliocene as today. Our record fills a critical gap in knowledge of Earth systems during the globally warm mid-Piacenzian and suggests a possible driver of faunal migration preceding the large-scale biotic interchange in the Americas during the earliest Pleistocene.
Description
Sherpa Romeo green journal. Open access article. Creative Commons Attribution 4.0 International License (CC by 4.0) applies
Keywords
Glaciation , Pliocene glaciations , Global warmth , Tropical Andes , Animal migration , Cryospheric science , Paleoclimate , Palaeomagnetism
Citation
Roberts, N. J., Barendregt, R. W., & Clague, J. J. (2017). Multiple tropical Andean glaciations during a period of late Pliocene warmth. Scientific Reports, 7, 41878. doi: 10.1038/srep41878