Fig. 3.

Late Miocene, Pliocene, and Middle Pleistocene vegetation change in semiarid southern Australia. Monte Carlo simulations of the late Miocene–Pliocene (A) and Middle Pleistocene (B) U-Pb–dated Nullarbor speleothem pollen record, accounting for Gaussian uncertainties in speleothem ages and in pollen percentage counts, and of the Nullarbor mean annual precipitation reconstruction derived from the pollen assemblages. The chenopod-dominated Middle Pleistocene assemblage is very similar to the composition of Late Pleistocene and Holocene pollen records (C) from Nullarbor cave/doline infills (43), confirming that the speleothem pollen assemblages register the surrounding vegetation in comparable ways to conventional fossil pollen records. U/Pb ages ±2σ errors are shown for 13 polleniferous samples (color-coded by cave), against the backdrop of other Nullarbor speleothems investigated for pollen (gray).