A continuous multi-millennial record of surficial bivalve mollusk shells from the Sao Paulo Bight, Brazilian shelf

Author(s)

Dexter, Troy A. ^[1] ; Kaufman, Darrell S. ^[2] ; Krause, Jr., Richard A. ^[3] ; Wood, Susan L. Barbour ^[4] ; Simoes, Marcello G. ^[5] ; Huntley, John Warren ^[6] ; Yanes, Yurena ^[7] ; Romanek, Christopher S. ^[8] ; Kowalewski, Michal ^[1]

Affiliation

^[1] Univ Florida, Florida Museum Nat Hist, Gainesville, FL 32611 - USA

^[2] No Arizona Univ, Sch Earth Sci & Environm Sustainabil, Flagstaff, AZ 86011 - USA

^[3] Johannes Gutenberg Univ Mainz, Inst Geosci, D-55128 Mainz - Germany

^[4] Rubicon Geol Consultants, Morehead, KY 40351 - USA

^[5] Univ Estadual Paulista, Inst Biociencias, BR-18618970 Botucatu, SP - Brazil

^[6] Univ Missouri, Dept Geol Sci, Columbia, MO 65211 - USA

^[7] Univ Cincinnati, Dept Geol, Cincinnati, OH 45221 - USA

^[8] Univ Kentucky, Dept Earth & Environm Sci, Lexington, KY 40506 - USA

• Document type: Journal article
• Source: Quaternary Research; v. 81, n. 2, p. 274-283, MAR 2014.
• Web of Science Citations: 11

Abstract

To evaluate the potential of using surficial shell accumulations for paleoenvironmental studies, an extensive time series of individually dated specimens of the marine infaunal bivalve mollusk Semele casali was assembled using amino acid racemization (AAR) ratios (n = 270) calibrated against radiocarbon ages (n = 32). The shells were collected from surface sediments at multiple sites across a sediment-starved shelf in the shallow sub-tropical Sao Paulo Bight (Sao Paulo State, Brazil). The resulting C-14-calibrated AAR time series, one of the largest AAR datasets compiled to date, ranges from modem to 10,307 cal yr BP, is right skewed, and represents a remarkably complete time series: the completeness of the Holocene record is 66% at 250-yr binning resolution and 81% at 500-yr binning resolution. Extensive time-averaging is observed for all sites across the sampled bathymetric range indicating long water depth-invariant survival of carbonate shells at the sediment surface with low net sedimentation rates. Benthic organisms collected from active depositional surfaces can provide multi-millennial time series of biomineral records and serve as a source of geochemical proxy data for reconstructing environmental and climatic trends throughout the Holocene at centennial resolution. Surface sediments can contain time-rich shell accumulations that record the entire Holocene, not just the present. (c) 2013 University of Washington. Published by Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 00/12659-7 - Brachiopod and Bivalve taphonomy in subtropical siliciclastic settings of northern coast of São Paulo State: enviromental variation in taphonomic signatures, biostratinomic style and time-averaging
• Grantee: Marcello Guimarães Simões
• Support Opportunities: Regular Research Grants