Stable carbon isotopes (δ13C) of total organic carbon and long-chain n-alkanes as proxies for climate and environmental change in a sediment core from Lake Petén-Itzá, Guatemala
- 956 Downloads
Sediment core PI-6 from Lake Petén Itzá, Guatemala, possesses an ~85-ka record of climate and environmental change from lowland Central America. Variations in sediment lithology suggest large and abrupt changes in precipitation during the last glacial and deglacial periods, and into the early Holocene. We measured stable carbon isotope ratios of total organic carbon and long-chain n-alkanes from the core, the latter representing a largely allochthonous (terrestrial) source of organic matter, to reveal past shifts in the relative proportion of C3–C4 terrestrial biomass. We sought to test whether stable carbon isotope results were consistent with other paleoclimate proxies measured in the PI-6 core, and if extraction and isotope analysis of n-alkanes is warranted. The largest δ13C variations are associated with Heinrich Events. Carbon isotope values in sediments deposited during the last glacial maximum indicate moderate precipitation with little fluctuation. The deglacial was a period of pronounced climate variability, e.g. a relatively warm and moist Bølling–Allerød, but a cool and dry Younger Dryas. Arid periods of the deglacial were inferred from samples with high δ13C values in total organic carbon, which reflect times of greater proportions of C4 plants. These inferences are supported by stable isotope measurements on ostracod shells and relative abundance of grass pollen from the same depths in core PI-6. Similar trends in carbon stable isotopes measured on bulk organic carbon and n-alkanes suggest that carbon isotope measures on bulk organic carbon in sediments from this lake are sufficient to infer past climate-driven shifts in local vegetation.
KeywordsCompound-specific isotope analysis n-Alkanes Pleistocene paleoclimate Sediment geochemistry Tropical paleolimnology
We thank the following institutions and individuals in Guatemala who provided assistance to this project: Universidad del Valle, Universidad San Carlos, Ministerio de Ambiente y Recursos Naturales, Consejo Nacional de Areas Protegidas, Instituto de Antropología e Historia, Autoridad Para el Manejo y Desarrollo Sostenible de la Cuenca del Lago Petén-Itzá, Wildlife Conservation Society, Alex Arrivillaga, Cathy Lopez, Margaret Dix, Michael Dix, Margarita Palmieri, David, Rosita, and Kelsey Kuhn, and the staff at La Casa de Don David, Lico Godoy, Tony Ortiz, Franz Sperisen, Luis Toruño, Julian Tesucún, Liseth Perez, Melisa Orozco, Silja Ramirez, Gabriela Alfaro, and Jacobo Blijdenstein. We are grateful to our collaborators from Geoforschungszentrum (Potsdam), Swiss Federal Institute of Technology (Zurich), Université de Genève, and the personnel from DOSECC (Drilling, Observation and Sampling of the Earth’s Continental Crust). Many thanks to Anders Noren, Kristina Brady and Amy Myrbo (LacCore) for assistance with field sampling, core curation and sample preparation. We thank three anonymous reviewers for their thoughtful comments on the original manuscript. This project was funded by grants from the US National Science Foundation (ATM-0502030 and ATM-0502126), the International Continental Scientific Drilling Program, the Swiss Federal Institute of Technology, and the Swiss National Science Foundation. Radiocarbon dating was done at the US DOE Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.
- Bush MB, Correa-Metrio AY, Hodell DA, Brenner M, Anselmetti FS, Ariztegui D, Mueller A, Curtis JH, Grzesik DA, Burton C, Gilli A (2009) Re-evaluation of climate change in lowland Central America during the Last Glacial Maximum using new sediment cores from Lake Petén Itzá, Guatemala. In: Vimeux F, Sylvestre F, Khodri M (eds) Past climate variability in South America and surrounding regions: from the last glacial maximum to the Holocene. Developments in paleoenvironmental research, vol 14. Springer, New York, pp 113–128CrossRefGoogle Scholar
- Deevey ES, Brenner M, Flannery MS, Yezdani GH (1980) Lakes Yaxha and Sacnab, Peten, Guatemala: limnology and hydrology. Archiv Hydrobiol Suppl 57:419–460Google Scholar
- Escobar J, Hodell DA, Brenner M, Curtis JH, Gilli A, Mueller AD, Anselmetti FS, Ariztegui D, Grzesik DA, Perez L, Schwalb A, Guilderson TP (2012) A ~43-ka record of paleoenvironmental change in the Central American lowlands inferred from lacustrine ostracod δ18O. Quat Sci Rev 37:92–104CrossRefGoogle Scholar
- Haug GH, Hughen KA, Sigman DM, Peterson LC, Röhl U (2001) Southward migration of the intertropical convergence zone through the Holocene. Science 293:1304–1308Google Scholar
- Hodell DA, Turchyn AV, Wiseman CJ, Escobar J, Curtis JH, Brenner M, Gilli A, Mueller AD, Anselmetti F, Ariztegui D, Brown ET (2012) Late glacial temperature and precipitation changes in the lowland Neotropics by tandem measurement of delta O-18 in biogenic carbonate and gypsum hydration water. Geochim Cosmochim Acta 77:352–368CrossRefGoogle Scholar
- Kutterolf S, Freundt A, Pérez W, Mörz T, Schacht U, Wehrmann H, Schmincke Hu (2008) Pacific off-shore record of plinian arc volcanism in Central America: 1. Along-arc correlations. Geochem Geophys Geosyst 9:Q02S01Google Scholar
- Leyden BW, Brenner M, Hodell DA, Curtis JH (1993) Late Pleistocene climate in the Central American lowlands. In: Swart PK, Lohmann KC, McKenzie J, Savin S (eds) Climate change in continental isotopic records. Geophysical monograph No. 78, American Geophysical Union, Washington, DC, pp 165–178Google Scholar
- Lundell CL (1937) The vegetation of Peten. Carnegie Institution publication No. 478. Carnegie Institution, Washington, DCGoogle Scholar
- Mueller AD, Anselmetti FS, Ariztegui D, Brenner M, Hodell DA, Curtis JH, Escobar J, Gilli A, Grzesik DA, Guilderson TP, Kutterolf S, Plotze M (2010) Late Quaternary palaeoenvironment of northern Guatemala: evidence from deep drill cores and seismic stratigraphy of Lake Petén Itzá. Sedimentology 57:1220–1245Google Scholar
- Newell SD (2005) An analysis of compound specific carbon isotopes of lipid biomarkers: a proxy for paleoenvironmental change in the Maya lowlands of Petén, Guatemala. M.S. thesis, University of Florida, GainesvilleGoogle Scholar