A 4,600-year stalagmite high resolution geochemical and petrologic paleoclimate record for northeast Namibia

Abstract

Multiple lines of evidence from an aragonite and calcite stalagmite from northeastern Namibia combine to provide a 4600-yr record of climate change. U/Th-series dating indicates that three episodes of very slow deposition (S(n)), occurred at ca. 3000 to 2060 BP (S3), 1120 to 800 BP (S2), and 600 to 370 BP (S1). Each of these intervals of slower growth is coincident with greater δ13C and δ18O, a decrease in stalagmite width, deposition of aragonite, and variations in petrographic fabrics that indicate a positive correlation between greater δ13C and increased crystal widths. All three Sn periods show both in and out-of-phase relationships with other southern African paleoclimate records that suggest evidence of climate change within the Little Ice Age (AD 1300-1800) and before the Medieval Warm Period (AD 1000-1300), respectively. The synthesis is one the first high-resolution paleoclimate records for this region of Namibia.