Origin of δ13C minimum events in thermocline and intermediate waters of the western South Atlantic ...

• Main Authors: Nascimento, Rodrigo Azevedo, Santos, Thiago, Venancio, Igor Martins, Chiessi, Cristiano Mazur, Ballalai, João M, Kuhnert, Henning, Govin, Aline, Portilho-Ramos, Rodrigo Costa, Lessa, Douglas Villela de Oliveira, Dias, Bruna Borba, Pinho, Tainã Marcos Lima, Crivellari, Stefano, Mulitza, Stefan, Albuquerque, Ana Luiza
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2021
• Subjects: Benthic foraminifera; Planktonic foraminifera; Stable carbon isotope δ13C; western South Atlantic; Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.1594/pangaea.936785; https://doi.pangaea.de/10.1594/PANGAEA.936785

Stable carbon isotopic (δ13C)minimum events have been widely described in marine archives recording the properties of the thermocline and intermediate waters during glacial terminations. However, the mechanisms associated with these events remain ambiguous. Here we present three high temporal resolution deep-dwelling planktonic foraminifera δ13C records from the main thermocline and one benthic δ13C record from the modern core of Antarctic Intermediate Water (AAIW). Our cores are distributed along the western South Atlantic from the equator to the subtropics, with the longest record spanning the last ~300 kyr. The results show that δ13C minimum events were pervasive features of the last three glacial terminations and Marine Isotope Stage 4/3 transition in the western South Atlantic. Two distinct mechanisms were responsible for the δ13C minima at thermocline and intermediate depth of the Atlantic, respectively. We suggest that the δ13C minimum events at the thermocline were mostly driven by the thermodynamic ...