Abstract There are two distinct stratigraphic levels of Neoproterozoic glacigenic deposits in central Australia, both Cryogenian in age, spread over an area greater than 2.5×10 6 km 2 . They were deposited in a once continuous intracratonic sag basin and are now preserved in four major structural basins: the Officer, Amadeus, Ngalia and Georgina Basins. In all four basins there are units that correlate with the (older) Sturt Tillite and equivalent glacial deposits in the Adelaide Rift Complex – the Sturt glaciation ( Preiss et al. 2011 ) – and with the (younger) Elatina Formation (Fm.) and equivalents – the Elatina glaciation ( Williams et al. 2008 , 2011 ). The clearest evidence for glacial activity is the occurrence of diamictites that contain clasts of lithologically diverse origin which are often striated, faceted and polished, and the occurrence of dropstones. Most glacial deposits were deposited in shallow marine to fluvio-lacustrine palaeoenvironments. In all basins, the Elatina glacial deposits are overlain (at least locally) by dolostone units that mark the onset of post-glacial transgression and contain unique sedimentary and geochemical features. The cap dolomite units are distinct from dolomite beds within glaciogenic sediments, and those that occur near the top of Sturt glacial units in the Amadeus (Areyonga Fm.) and eastern Officer Basins (Chambers Bluff Tillite). None of the central Australian glacial units have direct geochronological constraints. There are, however, radiometric dates for a Sturt glacial unit in the Adelaide Rift Complex (Wilyerpa Fm.) and post-glacial shales in the Amadeus Basin (Aralka Fm.), Stuart Shelf (Tapley Hill Fm.) and Adelaide Rift Complex (Tapley Hill Fm.) that indicate a c. 660 Ma age for the Sturt glaciation in Australia ( Kendall et al. 2006 , 2007 ; Fanning & Link 2008 ). The age of the Elatina glaciation in Australia is constrained only by the age of the Sturt glaciation and the presence of the Ediacara fauna in overlying strata of all the basins except the Ngalia Basin. Consequently, correlations have been mainly established by means of lithostratigraphy, chemostratigraphy, palynology, and to a lesser extent, stromatolite biostratigraphy, mainly on the successions above and below the glacial units. Results from each of the above techniques show a remarkable consistency, and indicate that the two major Cryogenian glacial episodes are of similar age across Australia.

Abstract The record of two Neoproterozoic glaciations in South Australia has been known for about a century. The earlier glaciation, of Sturtian age, is represented by the Yudnamutana Subgroup and is characterized by widespread diamictites with both intrabasinal and extrabasinal clasts, some locally faceted and striated. Associated facies include shallow-water sandstone, bedded and laminated siltstone with lonestones and dropstones, and sedimentary ironstones (mainly ferruginous siltstone and diamictite). Proximal settings adjacent to the Curnamona Province display massive basement-derived conglomerate and gigantic basement megaclasts (up to hundreds of metres across). Sturtian glaciogenic sediments of the Yudnamutana Subgroup unconformably overlie a variety of older rock units, including crystalline basement near basin margins and uppermost Burra Group sediments in the depocentre, and were deposited both in shallow marine shelf environments and in tectonically active rift basins encircling the Curnamona Province, with corresponding increases in total thickness from 100–300 m to more than 5 km. Recent U–Pb zircon SHRIMP dating of a thin volcaniclastic layer indicates that the waning stages of the Sturtian glaciation occurred at c. 660 Ma. Unlike the deposits of the younger Elatina glaciation, the Yudnamutana Subgroup has so far not yielded reliable palaeomagnetic data.

Abstract Nineteen large (2348–4285 m above sea level) central polygenetic alkaline shield-like composite volcanoes and numerous smaller volcanoes in Marie Byrd Land (MBL) and western Ellsworth Land rise above the West Antarctic Ice Sheet (WAIS) and comprise the MBL Volcanic Group (MBLVG). Earliest MBLVG volcanism dates to the latest Eocene (36.6 Ma). Polygenetic volcanism began by the middle Miocene (13.4 Ma) and has continued into the Holocene without major interruptions, producing the central volcanoes with 24 large (2–10 km-diameter) summit calderas and abundant evidence for explosive eruptions in caldera-rim deposits. Rock lithofacies are dominated by basanite and trachyte/phonolite lava and breccia, deposited in both subaerial and ice-contact environments. The chronology of MBLVG volcanism is well constrained by 330 age analyses, including 52 new 40 Ar/ 39 Ar ages. A volcanic lithofacies record of glaciation provides evidence of local ice-cap glaciation at 29–27 Ma and of widespread WAIS glaciation by 9 Ma. Late Quaternary glaciovolcanic records document WAIS expansions that correlate to eustatic sea-level lowstands (MIS 16, 4 and 2): the WAIS was +500 m at 609 ka at coastal Mount Murphy, and +400 m at 64.7 ka, +400 m at 21.2 ka and +575 m at 17.5 ka at inland Mount Takahe.

Abstract The Erebus Volcanic Province is the largest Neogene volcanic province in Antarctica, extending c. 450 km north–south and 170 km wide east–west. It is dominated by large central volcanoes, principally Mount Erebus, Mount Bird, Mount Terror, Mount Discovery and Mount Morning, which have sunk more than 2 km into underlying sedimentary strata. Small submarine volcanoes are also common, as islands and seamounts in the Ross Sea (Terror Rift), and there are many mafic scoria cones (Southern Local Suite) in the Royal Society Range foothills and Dry Valleys. The age of the volcanism ranges between c. 19 Ma and present but most of the volcanism is <5 Ma. It includes active volcanism at Mount Erebus, with its permanent phonolite lava lake. The volcanism is basanite–phonolite/trachyte in composition and there are several alkaline petrological lineages. Many of the volcanoes are pristine, predominantly formed of subaerially erupted products. Conversely, two volcanoes have been deeply eroded. That at Minna Hook is mainly glaciovolcanic, with a record of the ambient mid–late Miocene eruptive environmental conditions. By contrast, Mason Spur is largely composed of pyroclastic density current deposits, which accumulated in a large mid-Miocene caldera that is now partly exhumed.

Abstract Neogene volcanism is widespread in northern Victoria Land, and is part of the McMurdo Volcanic Group. It is characterized by multiple coalesced shield volcanoes but includes a few relatively small stratovolcanoes. Two volcanic provinces are defined (Hallett and Melbourne), with nine constituent volcanic fields. Multitudes of tiny monogenetic volcanic centres (mainly scoria cones) are also scattered across the region and are called the Northern Local Suite. The volcanism extends in age between middle Miocene ( c. 15 Ma) and present but most is <10 Ma. Two centres may still be active (Mount Melbourne and Mount Rittmann). It is alkaline, varying between basalt (basanite) and trachyte/rhyolite. There are also associated, geographically restricted, alkaline gabbro to granite plutons and dykes (Meander Intrusive Group) with mainly Eocene–Oligocene ages (52–18 Ma). The isotopic compositions of the plutons have been used to infer overall cooling of climate during the Eocene–Oligocene. The volcanic sequences are overwhelmingly glaciovolcanic and are dominated by ‘a‘ā lava-fed deltas, the first to be described anywhere. They have been a major source of information on Mio-Pliocene glacial conditions and were used to establish that the thermal regime during glacial periods was polythermal, thus necessitating a change in the prevailing paradigm for ice-sheet evolution.

Abstract Now that a Global Stratotype Section and Point (GSSP) has been ratified and a new system defined for the terminal Proterozoic era, the Ediacaran, the next step is to develop global correlations and to further subdivide this system. Means of correlating and subdividing older parts of the Proterozoic era are also needed. This is not a simple task. Phanerozoic correlations depend on biostratigraphic zonation made possible by biodiversity, supported by geochronology. Proterozoic biotas are more restricted, geochronological data is often sparse, and although rapid and significant carbon isotope excursions are present through some time intervals, the curve is essentially quiescent and of limited utility at other times. Nevertheless, a foundation for Ediacaran acritarch biostratigraphy has now been established in Australia and linked to the carbon-isotope curve using sample splits. In conjunction with other correlation techniques, this has allowed the development of a continent-wide correlation scheme. The Australian Ediacaran experience suggests that an integrated approach offers the best way forward for Proterozoic subdivision. However, it raises issues about some aspects of Neoproterozoic correlation; in particular, it indicates that reliance on a two-main-glaciations model may be over simplistic.

Abstract Cryogenian correlation in Australia is based on an extensive data set from the Centralian Superbasin and Adelaide Rift Complex and integrates biostratigraphy and isotope chemostratigraphy to provide a three-dimensional interpretation based on outcrop and drill holes. Studies are ongoing, but newer data are consistent with the distributions discussed here. From the chemostratigraphic and biostratigraphic viewpoint, the first appearance of the acritarch Cerebrosphaera buickii , coupled with a large negative isotope excursion at c. 800 Ma, supported by the first appearance of the stromatolite Baicalia burra , seems to have potential for boundary placement. It is widely recognized across Australia and seems to have potential globally.