Luminescence of quartz and feldspar fingerprints provenance and correlates with the source area denudation in the Amazon River basin

Author(s):Show less -

Sawakuchi, A. O. ^[1] ; Jain, M. ^[2] ; Mineli, T. D. ^[1] ; Nogueira, L. ^[1] ; Bertassoli, Jr., D. J. ^[1] ; Haeggi, C. ^[3] ; Sawakuchi, H. O. ^{[4, 5]} ; Pupim, F. N. ^[6] ; Grohmann, C. H. ^[7] ; Chiessi, C. M. ^[8] ; Zabel, M. ^[3] ; Mulitza, S. ^[3] ; Mazoca, C. E. M. ^[1] ; Cunha, D. F. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Geosci, Rua Lago 562, Sao Paulo, SP - Brazil

^[2] Tech Univ Denmark, Ctr Nucl Technol, DTU Riso Campus, DK-4000 Roskilde - Denmark

^[3] Univ Bremen, Ctr Marine Environm Sci, MARUM, Leobener Str 8, D-28359 Bremen - Germany

^[4] Univ Sao Paulo, Ctr Nucl Energy Agr, Environm Anal & Geoproc Lab, Av Centendrio 303, Piracicaba, SP - Brazil

^[5] Umea Univ, Dept Ecol & Environm Sci, KBC Huset, Linnaeus Vag 6, S-90187 Umea - Sweden

^[6] Univ Fed Sao Paulo, Dept Environm Sci, Rua Sao Nicolau 210, Diadema, SP - Brazil

^[7] Univ Sao Paulo, Inst Energy & Environm, Av Prof Luciano Gualberto 1289, Sao Paulo, SP - Brazil

^[8] Univ Sao Paulo, Sch Arts Sci & Humanities, Av Arlindo Bettio 1000, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Earth and Planetary Science Letters; v. 492, p. 152-162, JUN 15 2018.
• Web of Science Citations: 7

Abstract

The Amazon region hosts the world's largest watershed spanning from high elevation Andean terrains to lowland cratonic shield areas in tropical South America. This study explores variations in optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL) signals in suspended silt and riverbed sands retrieved from major Amazon rivers. These rivers drain Pre-Cambrian to Cenozoic source rocks in areas with contrasting denudation rates. In contrast to the previous studies, we do not observe an increase in the OSL sensitivity of quartz with transport distance; for example, Tapajos and Xingu Rivers show more sensitive quartz than Solimbes and Madeira Rivers, even though the latter have a significantly larger catchment area and longer sediment transport distance. Interestingly, high sensitivity quartz is observed in rivers draining relatively stable Central Brazil and Guiana shield areas (denudation rate xi = 0.04 mm yr(-1)), while low sensitivity quartz occurs in less stable Andean terrains (xi = 0.24 mm yr(-1)). An apparent linear correlation between quartz OSL sensitivity and denudation rate suggests that OSL sensitivity may be used as a proxy for erosion rates in the Amazon basin. Furthermore, luminescence sensitivity measured in sand or silt arises from the same mineral components (quartz and feldspar) and clearly discriminates between Andean and shield sediments, avoiding the grain size bias in provenance analysis. These results have implications for using luminescence sensitivity as a proxy for Andean and shield contributions in the stratigraphic record, providing a new tool to reconstruct past drainage configurations within the Amazon basin. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 12/50260-6 - Structure and evolution of the Amazonian biota and its environment: an integrative approach
• Grantee: Lúcia Garcez Lohmann
• Support type: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 16/09293-9 - Terrestrial cosmogenic nuclides analysis to reconstruct changes in the Amazonian fluvial system in the late Cenozoic (<5 ma)
• Grantee: Fabiano Do Nascimento Pupim
• Support type: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/23334-4 - Coupling Optically Stimulated Luminescence (OSL) and Terrestrial Cosmogenic Nuclides (TCN) analysis to reconstruct changes in the Amazonian fluvial system in the Late Cenozoic (<5 Ma)
• Grantee: Fabiano Do Nascimento Pupim
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 11/06609-1 - Provenance, transport and storage of sediments in Amazon rivers
• Grantee: André Oliveira Sawakuchi
• Support type: Regular Research Grants