Records of Great Basin precipitation during MIS 11 from two Lehman Cave stalagmites

Abstract

Trace elements (Mg/Ca and Sr/Ca) and stable isotopes ([delta]13C and [delta]18O) were measured in two coeval stalagmites, LC3 and BT1, from the Lehman Caves, Nevada. BT1 spans 388 to 384 ka. The LC3 record is split into two parts due to a hiatus observed through fluorescent imaging. The section prior to the hiatus spans 411 ka to 402 ka. The post-hiatus section of the stalagmite has a single age of 383 ka; an age model cannot be constructed for this part of the record. These stalagmites span Marine Isotope Stage 11 (MIS 11), a long interglacial that occurred around 424-374 ka. Comparison with more recent stalagmite records has shown prior calcite precipitation to be the dominant control on Mg/Ca and [delta]13C in the cave. The trace element and stable isotope records obtained point to an arid climate in the Great Basin during MIS 11.