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

Author(s):Show less -

Zular, Andre ^[1] ; Sawakuchi, Andre O. ^[1] ; Wang, Hong ^{[2, 3, 4]} ; Guedes, Carlos C. F. ^[5] ; Hartmann, Gelvam A. ^[6] ; Jaqueto, Plinio F. ^{[7, 8]} ; Chiessi, Cristiano M. ^[9] ; Cruz, Francisco W. ^[1] ; Giannini, Paulo C. F. ^[1] ; Daros, Vinicius K. ^[10] ; Atencio, Daniel ^[1] ; Trindade, Ricardo I. F. ^[7]

Affiliation

^[1] Univ Sao Paulo, Inst Geociencias, Rua Lago 562, BR-05508080 Sao Paulo, SP - Brazil

^[2] Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian, Shaanxi - Peoples R China

^[3] Beijing Normal Univ, Interdisciplinary Res Ctr Earth Sci Frontier, Beijing - Peoples R China

^[4] Univ Illinois, Prairie Res Inst, Illinois State Geol Survey, Champaign, IL - USA

^[5] Univ Fed Parana, Dept Geol, Curitiba, Parana - Brazil

^[6] Univ Estadual Campinas, Inst Geociencias, Campinas, SP - Brazil

^[7] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Sao Paulo, SP - Brazil

^[8] Univ Minnesota, Inst Rock Magnetism, Dept Earth & Environm Sci, Minneapolis, MN - USA

^[9] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, Sao Paulo, SP - Brazil

^[10] Univ Sao Paulo, Inst Matemat & Estat, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: QUATERNARY INTERNATIONAL; v. 537, p. 97-111, JAN 30 2020.
• Web of Science Citations: 0

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 Lencois 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. (AU)

• FAPESP's process: 09/53988-8 - Acquisition of a luminescence dating system and a precision microsampler for the study of environmental changes in the Quaternary period
• Grantee: Paulo César Fonseca Giannini
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 09/54232-4 - Morphodynamics and chronology of quaternary aeolian depositional systems in Brazil
• Grantee: Paulo César Fonseca Giannini
• Support Opportunities: Regular Research Grants