Geochemical evidence of the 8.2 ka event and other Holocene environmental changes recorded in paleolagoon sediments, southeastern Brazil

Author(s):Show less -

Sallun, Alethea E. M. ^[1] ; Sallun Filho, William ^{[2, 1]} ; Suguio, Kenitiro ^{[2, 3]} ; Babinski, Marly ^[2] ; Gioia, Simone M. C. L. ^[2] ; Harlow, Benjamin A. ^[4] ; Duleba, Wania ^[2] ; De Oliveira, Paulo E. ^[3] ; Garcia, Maria Judite ^[3] ; Weber, Cinthia Z. ^[1] ; Christofoletti, Sergio R. ^{[1, 5]} ; Santos, Camilla da S. ^[3] ; de Medeiros, Vanda B. ^[3] ; Silva, Juliana B. ^[2] ; Santiago-Hussein, Maria Cristina ^[3] ; Fernandes, Rosana S. ^[3]

Affiliation

^[1] Secretaria Meio Ambiente Estado Sao Paulo, Inst Geol, BR-04301903 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[3] Univ Guarulhos, CEPPE, BR-07023070 Guarulhos, SP - Brazil

^[4] Washington State Univ, Stable Isotope Core Lab, Pullman, WA 99164 - USA

^[5] Secretaria Meio Ambiente Estado Sao Paulo, Inst Florestal, BR-13500970 Rio Claro, SP - Brazil

• Document type: Journal article
• Source: Quaternary Research; v. 77, n. 1, p. 31-43, JAN 2012.
• Web of Science Citations: 11

Abstract

The paleoclimatic record of Jureia Paleolagoon, coastal southeastem Brazil, includes cyclic and gradual changes with different intensities and frequencies through geological time, and it is controlled by astronomical, geophysical, and geological phenomena. These variations are not due to one single cause, but they result from the interaction of several factors, which act at different temporal and spatial scales. Here, we describe paleoenvironmental evidence regarding climatic and sea level changes from the last 9400 cal yr BP at the Jureia Paleolagoon - one of the main groups of protected South Atlantic ecosystems. Geochemical evidences were used to identify anomalies from multi-proxy analyses of a paleolagoon sediment core. The anomalies of centennial scale were correlated to climate and transgression-regression cycles from the Holocene period. Decadal scale anomalous oscillations in the Quaternary paleolagoon sediments occur between 9400 and 7500 cal yr BP, correlated with long- and short-term natural events, which generated high sedimentation rates, mainly between 8385 and 8375 cal yr BP (10 cm/yr). Our results suggest that a modem-day short-duration North Atlantic climatic event, such as the 82 ka event, could affect the environmental equilibrium in South America and intensify the South American Summer Monsoon. (C) 2011 University of Washington. Published by Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 06/04467-7 - Estação ecológica Juréia-Itatins (SP): Holocene sea-level oscillations below the present
• Grantee: Kenitiro Suguio
• Support Opportunities: Regular Research Grants