Jurassic magmatism in western Gondwana produced the most voluminous episode of continental volcanism in the Phanerozoic era. During the Early to Middle Jurassic, some 2.5–3 million km3 of dominantly basalt, and to a lesser extent rhyolite, were erupted onto a supercontinent in the early stages of break-up. The major silicic portion of the Gondwana magmatic province is exposed in Patagonian South America. The volcanic rocks of Patagonia have been collectively termed the Chon-Aike Province and constitute one of the world's most voluminous silicic provinces. The volcanic rocks are predominantly pyroclastic, dominated by ignimbrite units of rhyolite composition. Volcanic rocks crop out sporadically across much of the once contiguous Antarctic Peninsula, and are considered to form an extension of the Chon-Aike Province. A continuation of the province to include the Antarctic Peninsula would extend its strike length along the active Pacific margin by c. 2000 km.

Volcanic rocks exposed along the east coast of the Antarctic Peninsula, defined here as the Mapple Formation, are also dominated by rhyolitic ignimbrite flows, with individual units up to 80 m in thickness, and a total thickness of c. 1 km. The ignimbrites vary in degree of welding, from high-grade rheomorphic ignimbrites with parataxitic textures, to unwelded, lithic-rich ignimbrites. Rhyolite lava flows, air-fall horizons, debris flow deposits and epiclastic deposits are volumetrically minor, occurring as interbedded units within the ignimbrite succession.

The lithology and stratigraphy of the Jurassic volcanic rocks of the Mapple Formation are presented, and comparisons are made to the Chon-Aike Province. A consistent stratigraphy of Permo-Triassic metasedimentary rocks, unconformably overlain by terrestrial mudstone–siltstone sequences, which are in turn conformably overlain by largely silicic, subaerial volcanic rocks, is present at several localities along the Antarctic Peninsula, and at localities in the Chon-Aike Province. Precise (zircon U–Pb) Middle Jurassic ages exist for two volcanic formations from the Antarctic Peninsula, and a Middle–Lower Jurassic age has been suggested for the underlying sedimentary formations based on fossil flora analysis. The Antarctic Peninsula chronostratigraphy, coupled with lithological similarities, indicate a close relationship to those sequences of the Chon-Aike province.

The Upper Cretaceous chalk of northwest Europe was deposited in an open epicontinental sea during a period of high global eustatic sea-level – a unique depositional setting requiring modification of the sequence-stratigraphical approach. In this paper, a framework for the sequence-stratigraphical analysis of the Upper Cretaceous chalk is discussed, and an ideal sequence model presented.

Analysis of the Coniacian succession has identified eight third-order (short-term) cycles of relative sea-level change (∼400 Ka duration), superimposed upon a second-order (longer term) cycle (∼3.2 Ma duration). The third-order cycles represent frequent, basin-wide oceanographic changes for which there are no known tectonic mechanisms. These cycles show a visual correlation with both the δ13C and the δ13C stable isotope curves, indicating a climatic control on sedimentation, probably linked to a Milankovitch eccentricity rhythm.

The long-term trend in independently derived δ13C stable isotope values parallels the long-term relative sea-level curve, reflecting increased production as the shelf area expands. By contrast, the δ18C stable isotope values show little change over the long term, suggesting that tectonics, rather than climate, was the controlling factor on second-order relative sea-level change. This is corroborated by the fact that the long-term cycle is coincident with a phase of increased activity at the mid-ocean ridges, which is thought to allow for a 60 m rise in global sea level.

The Leonian (early Middle Cambrian) regional Stage of Iberia is revised from a lithostratigraphic and biostratigraphic point of view in order to propose it as a chronostratigraphic unit for the Mediterranean subprovince (outcrops in Spain, France, Italy, Germany, Morocco and Turkey). This revision now permits a correlation of the Leonian Stage with the other early Middle Cambrian regional Stages. For this correlation the first appearance datum (FAD) of Eoparadoxides mureroensis, Macannaia spp., Schistocephalus antiquus and Oryctocara granulata are employed for the lower boundary; while the FADs of Badulesia tenera, Ctenocephalus (Hartella) spp., Parasolenopleura aculeata and Triplagnostus gibbus are employed for the upper boundary.

An episode of remarkable biotic, climatic, sea-level and facies changes took place during the late Viruan (Caradoc) epoch in the Baltoscandian area. We studied the carbon isotopic composition of carbonate sediments from this period. Data on the stable carbon isotopic composition of whole-rock carbonates from three south Estonian core sections, together with those on ostracode, distribution are presented. In two core sections, a positive δ13C shift of 2 ‰ was revealed in the upper part of the Keila Stage (mid-Caradoc). The comparison of isotope and ostracode data in the sections suggested the occurrence of a gap of late Keilan age in the marginal area of the basin equivalent to the North Estonian Confacies Belt. The beginning of the excursion approximately coincided with climatic and sea-level changes in the shallow shelf area. The peak of the late Keilan excursion preceded the biotic crises and maximum black shale accumulation in the Baltoscandian palaeobasin. An approximately synchronous carbon isotopic event has been reported from North America, referring to a possible global oceanographic event in the Caradoc epoch. Although the positive carbon isotopic excursion and related environmental events of the late Keilan age have some unique features, they show more similarities to the end-Ordovician and Silurian events, characterized by oceanic change from stratified state to thermohaline circulation state, than to warm anoxic events related to eustatic sea-level rise.

A newly measured and sampled section in the upper part of the early Neoproterozoic Visingsö Group, south central Sweden, has been investigated for its stable carbon and oxygen isotope geochemistry. The 30 m-thick succession crops out on the southeastern shore of Lake Vättern, close to the village of Boeryd, and consists mainly of black mudstones with carbonate lenses, some of which have been dolomitized. High H/C ratios of the kerogen preserved in the investigated succession indicate that organic carbon generally is well preserved. The observed δ13Corg values are comparable to previously observed Neoproterozoic organic carbon values, with the exception of a few exceptionally 13C-depleted kerogens, with δ13Corg[ges ]−41.1 ‰. The latter are interpreted to be the result of fermentative bacterial reworking of sedimentary organic matter. The Boeryd carbonates display an unusual array of heavy δ18O values (with δ18O[les ]+3.3 ‰) that are interpreted as reflecting deposition in an arid climate. Geochemical data indicate that the carbonates have been diagenetically altered, but only to a limited extent, and a range of δ13Ccarb values from +2.4 to +4.7 ‰ appears to be representative of the primary seawater composition for the time of deposition of the upper Visingsö unit. Positive carbonate isotope values are typical for lower Neoproterozoic, pre-Varangerian successions elsewhere. The C isotope values obtained from the Boeryd section, although not conclusive by themselves, are consistent with the formerly biostratigraphically and radiometrically inferred early Neoproterozoic age for the upper Visingsö Group.

The Silurian succession of North Galway is relatively well constrained in terms of environmental analysis and, in its lower half, palaeontologically. The initiation of a late Llandovery marine transgression can be demonstrated over fluviatile red sandstones. The deposition of shallow-water conglomerates at the base of a turbidite sequence within the succession indicates the long-lived presence of a channel system that was probably fault controlled. The back-stripping method allows a subsidence curve to be constructed for this succession. It demonstrates an initial period of rapid rift-related subsidence followed by a short-lived hiatus that may be due to the cessation of subduction in this part of the Caledonides. A comparison of the Galway subsidence curve with that of the Silurian succession at Girvan in Scotland shows strong, but diachronous, similarities. This tends to support an earlier suggestion that they formed part of a single but partitioned basin throughout most of the Silurian period. Although the eustatic fall in sea level at the Llandovery–Wenlock boundary can be recognized, the influence of tectonic regime and sedimentation rates were the controlling factors in determining relative sea levels.