Bulk and Compound-Specific Isotope Analysis of Long-Chain, n-alkanes From a 85-kyr Core From Lake Peten Itza, Guatemala
Abstract
Drill cores obtained from Lake Petén Itzá, Guatemala, contain a ~85-kyr record of terrestrial climate from lowland Central America. Variations in sediment lithology suggest rapid changes in precipitation during the last glacial and deglacial periods. Previous work in nearby Lake Quexil demonstrated the utility of using the carbon isotopic compositions of leaf wax n-alkanes to infer changes in terrestrial vegetation (Huang et al., 2001). Here we report carbon isotopes of bulk organic and long-chain n-alkanes in 60 samples to reconstruct changes in the relative proportion of C3 and C4 biomass in the watershed under changing climate and atmospheric CO2 conditions during the past 85 kyrs. Compound-specific carbon isotope results are compared directly with pollen analysis from the same samples. Huang, Y., F.A. Street-Perrott, S.E. Metcalfe, M. Brenner, M. Moreland, and K.H. Freeman. 2001. Climate change as the dominant control on glacial-interglacial variations in C3 and C4 plant abundance. Science 293:1647-1651.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFMPP43B1269M
- Keywords:
-
- 0746 Lakes (9345);
- 1041 Stable isotope geochemistry (0454;
- 4870);
- 3344 Paleoclimatology (0473;
- 4900)