Research Article| April 01, 2003 Constancy in the vegetation of the Amazon Basin during the late Pleistocene: Evidence from the organic matter composition of Amazon deep sea fan sediments Thomas P. Kastner; Thomas P. Kastner 1Organic Geochemistry Laboratory, Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Search for other works by this author on: GSW Google Scholar Miguel A. Goñi Miguel A. Goñi 1Organic Geochemistry Laboratory, Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Search for other works by this author on: GSW Google Scholar Geology (2003) 31 (4): 291–294. https://doi.org/10.1130/0091-7613(2003)031<0291:CITVOT>2.0.CO;2 Article history received: 15 Oct 2002 rev-recd: 27 Nov 2002 accepted: 05 Dec 2002 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Thomas P. Kastner, Miguel A. Goñi; Constancy in the vegetation of the Amazon Basin during the late Pleistocene: Evidence from the organic matter composition of Amazon deep sea fan sediments. Geology 2003;; 31 (4): 291–294. doi: https://doi.org/10.1130/0091-7613(2003)031<0291:CITVOT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Analyses of more than 60 sediment samples from the Amazon deep sea fan show remarkably constant terrigenous biomarkers (lignin phenols and cutin acids) and stable carbon isotopic compositions of organic matter (δ \(^{13}C_{OM}\) ) deposited from 10 to 70 ka. Sediments from the nine Amazon deep sea fan channel-levee systems investigated in this study yielded relatively narrow ranges for diagnostic parameters such as organic carbon (OC) normalized total lignin yields (Λ = 3.1 ± 1.1 mg/100 mg OC), syringyl:vanillyl phenol ratios (S/V = 0.84 ± 0.06), cinnamyl:vanillyl phenol ratios (C/V = 0.08 ± 0.02), isomeric abundances of cutin-derived dihydroxyhexadecanoic acid (f10,16-OH = 0.65 ± 0.02), and δ \(^{13}C_{OM}\) (−27.6% ± 0.6 ‰). Our measurements support the hypothesis that the vegetation of the Amazon Basin did not change significantly during the late Pleistocene, even during the Last Glacial Maximum. Moreover, the compositions obtained from the Amazon deep sea fan are similar to those of modern Amazon River suspended sediments. Such results strongly indicate that the current tropical rainforest vegetation has been a permanent and dominant feature of the Amazon River watershed over the past 70 k.y. Specifically, we found no evidence for the development of large savannas that had been previously postulated as indicators of increased glacial aridity in Amazonia. Climate models need to be modified to account for the uninterrupted input of moisture to the tropical Amazon region over the late Pleistocene–Holocene period. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.