Minimal Pliocene-Pleistocene uplift of the dry valleys sector of the Transantarctic Mountains; a key parameter in ice-sheet reconstructions: Comment

In the comment, Behrendt et al. state that Wilch et al. (1993) challenged the hypothesis of Behrendt and Cooper (1991) that the shoulder escarpment of the West Antarctic rift system (partly in the Transantarctic Mountains) has episodic differential uplift rates as great as about 1 km/m.y. in crustal blocks containing the highest peaks (but not the dry valleys), since Pliocene time, and that they also challenged the speculation that uplift of the rift shoulder may have forced the climatic changes that led to one or more of the advances of the antarctic ice sheet. In the reply, Wilch et al. agree with Behrendt and Cooper that the Transantarctic Mountains consist of many tectonic blocks that were probably uplifted episodically, but the present authors disagree that an episode of rapid widespread surface uplift occurred in Pliocene-Pleistocene time. This disagreement bears on the suggestion that rapid uplift beginning 2-5 m.y.a. caused a climatic change from temperate to polar conditions in Antarctica at 2.5 Ma.