The response of a dune succession from Lençóis Maranhenses, NE Brazil, to climate changes between MIS 3 and MIS 2

André Zular, André O. Sawakuchi, Hong Wang, Carlos C.F. Guedes, Gelvam A. Hartmann, Plínio F. Jaqueto, Cristiano M. Chiessi, Francisco W. Cruz, Paulo C.F. Giannini, Vinícius K. Daros, Daniel Atencio, Ricardo I.F. Trindade

Research output: Contribution to journalArticlepeer-review

Abstract

In tropical Southern Hemisphere South America, late Quaternary marine core and speleothem records provide different proxies and accurate chronologies correlating millennial-scale intervals of increased precipitation with southward shifts of the Intertropical Convergence Zone (ITCZ). However, the climatic effect of these intervals on coastal landforms is poorly understood. Here we investigated the response of abrupt and long-lasting climate events during the Marine Isotope Stages 3 and 2 in a 13.8-m thick sand succession located in a large-scale coastal eolian system, the Lençóis Maranhenses Dunefield, NE Brazil, where winds and precipitation are anti-phased and controlled by the single action of the ITCZ. A chronology of the sediment overburden determined by optically stimulated luminescence (OSL) dating of 14 sediment samples obtained at 1-m intervals showed ages between 132.2 ± 7.0 and 12.9 ± 0.6 thousand years ago in stratigraphic order. A multi-proxy approach based on grain size, surface grain texture, heavy minerals, thermoluminescence (TL) sensitivity, inorganic geochemistry, reflectance, and magnetic parameters from 268 sediment samples collected at 5-cm intervals indicated periods of dune building and stabilization. Significant stabilization periods are synchronous with Heinrich Stadials 6, 4, 3, 2, and 1, and Greenland Stadial 4, within age model uncertainties. Heavy mineral analysis indicated a steady sand source to the dune succession, while TL sensitivity analysis of quartz grains showed the input allochthonous sediments during stadials. The preservation of peak dune activity during the Last Glacial Maximum is attributed to the enduring precipitation brought by the subsequent Heinrich Stadial 1 event.

Original languageEnglish (US)
Pages (from-to)97-111
Number of pages15
JournalQuaternary International
Volume537
DOIs
StatePublished - Jan 30 2020

Keywords

  • Coastal eolian deposits
  • Heinrich stadials
  • Last glacial maximum
  • Lençóis maranhenses dunefield
  • Multy-proxy approach
  • Optically stimulated luminescence
  • Paleoclimate

ASJC Scopus subject areas

  • Earth-Surface Processes

Fingerprint Dive into the research topics of 'The response of a dune succession from Lençóis Maranhenses, NE Brazil, to climate changes between MIS 3 and MIS 2'. Together they form a unique fingerprint.

Cite this