84 Interaction between Shallow and Deep Karst: Geologic, Hydrologic, Geochemical, and Biologic Indicators (Posters)

Tuesday, 16 March 2010
1:30 PM - 5:35 PM
International ABCDF

TRACE ELEMENT VARIATIONS IN AN ANNUALLY-LAMINATED 2300-YEAR STALAGMITE FROM YUCATAN, MEXICO: A TALE OF VOLCANIC ASHFALL AND HURRICANE-INDUCED FLOODING

Paper number: 84-6
Program: Theme Sessions
Time: 1:30 PM – 5:35 PM

Authors

Abstract

Trace elements in speleothems have been known to vary in response to environmental factors of interest such as volcanoes and seasonal changes in climate. Recently, a 1982 volcanic eruption of El Chichón in southern Mexico was recorded as a major pulse of trace element impurities in a calcite stalagmite from Belize. We present a trace element record from CH-1, an annually layered stalagmite from the Yucatán, Mexico that has been radiometrically dated from ~2300 ybp to 2007 AD. Laser Ablation- Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) analysis shows trace element variations in a modern section of the stalagmite including an analysis of sensitivity to recent regional eruptions, as well as instrumental climate records and local land use history. We will compare the modern layers of CH-1 LA-ICPMS record to the pre-historic sections to test for the presence of a volcanic eruption circa 1250 AD known from ice cores. We also explore other trace element signals of interest that could indicate environmental changes influencing the local Maya culture and global climate. Detecting deposition of tephra in stalagmites from the Maya lowlands could dramatically improve cross-dating for low-U content stalagmites in the region, and may ultimately contribute to weighing the relative importance of the many causes attributed to the destruction of the powerful Maya empire.