Article ID Journal Published Year Pages File Type
4436122 Applied Geochemistry 2012 8 Pages PDF
Abstract

The Yucatan Peninsula consists of a karstic terrain that allows the aquifer to directly recharge from rainfall. Due to the various dissolution/precipitation reactions occurring during groundwater flow, the groundwater discharge in the coastal zone becomes a source of trace elements including Ba. The aim of this study was to use the coralline Ba/Ca record as a proxy of precipitation under the consideration that rainfall rates vary at inter-annual time scales. Annual Ba/Ca ratios, both the total content (Ba/CaTC) and the Ca-substitutive fraction (Ba/CaCaF), were quantified in a 52-a old coral colony of Montastraea annularis from the Punta Nizuc Reef, Mexican Caribbean. Average Ba/CaTC (5.90 ± 0.56 μmol/mol) was ∼20% higher than Ba/CaCaF (4.85 ± 0.33 μmol/mol) indicating that Ba is also incorporated in other fractions. Correlation between annual precipitation and Ba/CaTC time-series is significant (r = 0.77, p < 0.05), allowing the use of the Ba/CaTC ratio as a proxy of precipitation, and hence, enabling the reconstruction of precipitation patterns through time. Likewise, the Ba/CaCaF ratio can be used for the reconstruction of dissolved Ba in coastal seawater.

► The Montastraea annularis Ba/Ca record was used as a proxy of precipitation. ► Correlation between annual precipitation and Ba/Ca time-series was significant. ► Total Ba/CaTC was ∼20% higher than Ba/Ca in the Ca-substitutive fraction. ► Coralline Ba/CaTC can be used for the reconstruction of historical precipitation. ► Coralline Ba/CaCaF can be used for the reconstruction of dissolved seawater Ba.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Geochemistry and Petrology
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