Introduction

The aim of the CIROS project is to obtain a record of the Cenozoic (and possibly Cretaceous) history of the southwest corner of the Ross Sea by coring the sedimentary strata offshore (Barrett, 1982). There is no record exposed on land to represent the time between the Jurassic basalts 180 m.y. ago and the rocks of the McMurdo Volcanic Group, erupted over the last 15 m.y., though this interval includes two poorly documented events of wide interest and which may be related - the growth of the Antarctic Ice Sheet and the rise of the Transantarctic Mountains.