Asymmetric extension associated with uplift and subsidence in the Transantarctic Mountains and Ross Embayment

Abstract

Apatite fission track data combined with regional geological observations indicate that the uplift of the Transantarctic Mountains has been coeval with thinning and subsidence of the crust beneath the Ross Embayment. In the Dry Valleys region of south Victoria Land, the mountains have been uplifted about 5 km since the early Cenozoic at an average rate of about 100 m/Ma. During uplift, the crust remained at constant thickness or was slightly thickened by magmatic underplating. In contrast, the crust beneath the Ross Embayment has been extended and consequently thinned beginning in the Late Cretaceous but mainly during Cenozoic times. We suggest here that the uplift of the Transantarctic Moun..