title: Comment on "Deep-sea temperature and ice volume changes across the Pliocene-Pleistocene climate transitions".
abstract: Sosdian and Rosenthal (Reports, 17 July 2009, p. 306) used magnesium/calcium ratios in benthic foraminifera from the North Atlantic to reconstruct past bottom-water temperatures. They suggested that both ice volume change and ice-sheet dynamics played important roles during the late Pliocene and mid-Pleistocene climate transitions. We present evidence that their record of deep ocean temperature is not reliable, thus raising doubts about their conclusions.
authors.affiliation: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Post Office Box 1000, Palisades, NY 10964-8000, USA. jiminyu@ldeo.columbia.edu
authors.forename: Jimin
authors.initials: J
authors.lastname: Yu
authors.forename: Wally S
authors.initials: WS
authors.lastname: Broecker