Figure 4    Temporal correlation of the Holocene varnish climate record in the drylands of western USA with the deep sea sediment record in the subpolar North Atlantic. Radiometric age calibration (Liu and Broecker, 2007) indicates that Holocene wet events represented by dark layers (WH1-WH12) in the varnish record largely correlate with Holocene cooling events represented by pulses of detrital carbonate in the deep sea sediment record (Bond et al., 1999). The chronology of WH1 - WH12 is taken from Bond et al. (1999). The color scheme represents relative concentrations of Mn and Ba in varnish microstratigraphy (see Fig. 3 for explanation). LIA = Little Ice Age, WH = wet event in Holocene, WP = wet event in Pleistocene, YD = Younger Dryas.