Investigating δ¹³C values in stalagmites from tropical South America for the last two millennia

Abstract

Due to the many factors controlling δ¹³C values in stalagmites, complicating their paleoclimatic and paleoenvironmental interpretation, most studies do not present δ¹³C values, but instead focus mainly on δ¹⁸O values. This is also the case for most cave studies from tropical South America, where many new δ¹⁸O stalagmite records covering the last millennia were recently published. Here, we review the δ¹³C values in stalagmites, investigating the influence on this proxy of local hydroclimate, altitude, temperature and vegetation types, by employing a new dataset composed of published and unpublished carbon isotope records from various sites in tropical South America. The main factors influencing δ¹³C values are associated with the local hydroclimate, followed by minor effects from temperature. Most of the isotopic records show a significant correlation between the δ¹³C and δ¹⁸O values, indicating a close relationship between local hydroclimate and atmospheric convective processes related to the South American Monsoon System.