Terrestrial and Fjordal Sedimentary Environments of the Transantarctic Mountains and Lambert Glacier Region

Two main pre-Quaternary sedimentary sequences recording glacial events are found on land in East Antarctica, the Sirius Group in the Transantarctic Mountains and the Pagodroma Group in the Prince Charles Mountains flanking the Lambert Glacier. The Sirius Group is a mainly terrestrial glacigenic succession, commonly a few tens of metres thick or as a thin drape, but whose age has proved highly controversial, with Pliocene, Middle Miocene or even older ages suggested. The Pagodroma Group is an ice-proximal fjordal sequence up to several hundred metres thick, and is well dated on the basis of in situ marine fossils. All these well-exposed deposits are important in unravelling the history of the EAIS, as they are the nearest deposits to the heart of the ice sheet, and yield valuable information concerning palaeogeography and palaeoclimate.

The two regions described above represent the best studied examples of pre-Quaternary onshore glacigenic successions, but there are others elsewhere, e.g. the Antarctic Peninsula and the Grove Mountains (Fang et al., 2004). When a better dated Sirius Group can be linked to the offshore record in McMurdo Sound, and the data from the Prince Charles Mountains fully integrated with the emerging Prydz Bay record, we will have a good understanding of the behaviour of the EAIS since its inception.

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