Evaluating Isotope and Geochemical Tracers of Paleosalinity, Freshwater Input, and Regional Climate Change at Celestun Lagoon, Yucatan Peninsula
Abstract
Several studies have attempted to reconstruct Quaternary climate variability in Meso-America and the Caribbean region (e.g., Hodell et al. 1995; Hughen et al. 2004). Interest in this region has been driven in part by evidence that changes in tropical ocean conditions may drive climate on a global scale and by the realization that the region is well-placed to track past shifts in the average position of the Intertropical Convergence Zone, a major control on precipitation and drought cycles in tropical and sub-tropical areas of the world. With this in mind, we seek to develop a new record of regional paleoprecipitation and environmental change based on the Sr and O isotope composition and Ba/Ca ratios of benthic foraminifera tests recovered from estuarine sediment cores collected in Celestun Lagoon, on the northwestern Yucatan Peninsula. In addition, we have investigated changes in foraminiferal assemblages and the C and N isotope composition of sedimentary organic matter from these cores. The groundwater that dominates freshwater input into Celestun is recharged over a large area of the Yucatan, suggesting that a record of paleosalinity and groundwater discharge to Celestun will integrate a regional signal. We will present modern correlations between salinity and δ87Sr, δ18O and Ba/Ca of both the water column and core-top benthic foraminifera from lagoon sites along a head-to-mouth transect (as a means of tracer calibration), as well as preliminary down-core results for all tracers. We will compare the utility of the various tracers for estuarine paleoclimate reconstruction and evaluate our results in the broader regional context.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMGC21A1314S
- Keywords:
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- 0442 Estuarine and nearshore processes (4235);
- 0473 Paleoclimatology and paleoceanography (3344;
- 4900);
- 1616 Climate variability (1635;
- 3305;
- 3309;
- 4215;
- 4513);
- 4924 Geochemical tracers