The history of glacial advances and retreats of the East Antarctic ice sheet during the Holocene is not well-known, due to limited field evidence in both the marine and terrestrial realm. A 257-cm-long sediment core was recovered from a marine inlet in the Rauer Group, East Antarctica, 1.8 km in front of the present ice-sheet margin. Radiocarbon dating and lithological characteristics reveal that the core comprises a complete marine record since 4500 yr. A significant ice-sheet expansion beyond present ice margins therefore did not occur during this period.

The Rauer Group, in Prydz Bay, contains reworked Archaean-Proterozoic crust in high-strain zones that formed during a pervasive high-temperature ductile deformation event related to intracratonic mechanisms. The effects of this event extend southwards from Prydz Bay into the southern Prince Charles Mountains. The associated structural evolution involved development of ductile and brittle structures that formed during an approximately north–south directed transpressional deformation event that is confined to high-grade (>800°C) shear zones in the Rauer Group. Minerals from the Rauer Group, yield 40Ar/39Ar cooling ages ranging from 560 to 460 Ma. Thermal histories derived from hornblende, biotite and feldspar suggest that the onset of rapid cooling began sometime prior to 510 Ma with cooling rates of c. 42 to 33°C myr-1 from c. 510 Ma to c. 500 Ma. Whereas, 40Ar/39Ar data obtained from plagioclase and K–feldspar suggest a slower cooling from c. 500 Ma to c. 460 Ma with cooling rates from 5 to 2°C myr-1. These results demonstrate that the early Palaeozoic cooling history and comparable palaeostress regimes are regionally extensive, which has important implications for the tectonothermal and stress-field variability across Gondwana. The elevated thermal conditions would induce lithospheric weakening and promote the early Palaeozoic intraplate orogeny observed in eastern Antarctica with the development of a large intracratonic shear system.

Archaean gneisses in the Rauer Group of islands, East Antarctica, record a prolonged history of high-grade deformational episodes, many of which predate that identified in mid-Proterozoic gneisses. Eleven generations of mafic dykes, belonging to discrete chemical suites, have been used as relative time markers to constrain this deformational history. Based on the timing of intrusion with respect to structures, dykes in the Rauer Group have been correlated with largely undeformed and dated dyke suites in the adjacent Vestfold Hills. This has allowed absolute ages to be inferred for the early- to mid-Proterozoic mafic dyke suites in the Rauer Group, and a correlation of the interspersed structural events. Most structures in the Rauer Group, however, developed in response to high-grade progressive deformation at approximately 1000 Ma. During this deformational episode, strains were repeatedly partitioned into sub-vertical, noncoaxial, high-strain zones recording NW-directed sinistral transpression, that separated zones of lower strain dominated by coaxial folding with axes parallel to the shear direction. Three additional mafic dyke suites intruded during this deformation which was followed by three stages of brittle-ductile deformation and a final suite of lamprophyre dykes. Due to the numerous intrusive time markers, the Rauer Group serves as an excellent illustration of how complicated gneiss terrains may be.