Episodes of late Holocene aridity recorded by stalagmites from Devil's icebox Cave, Central Missouri, USA

Abstract Two stalagmites from Devil's Icebox Cave, central Missouri, display similar δ 13 C and δ 18 O values and trends during the late Holocene. Positive δ 13 C excursions at 3.5–2.6 ka and 1.2–0.9 ka are interpreted to reflect drier conditions. These elevated stalagmite δ 13 C values could have plausibly been driven by increasing C 4 plant abundances over the cave or an increased contribution of bedrock carbon, both of which could reflect decreased effective moisture. A lack of corresponding oxygen isotopic anomalies during these intervals suggests that neither mean annual temperature nor the seasonality of precipitation changed concomitantly with dryness. Both of the δ 13 C excursions identified in our stalagmite record are roughly coincident with dry intervals from a number of sites located across the Great Plains.