Abstract In contrast to the Triassic–Jurassic boundary, there is no consensus on the definition and age of the Norian–Rhaetian boundary (NRB), which hampers the global correlation of Rhaetian strata and thus interpretation of the patterns and driving mechanism of the end-Triassic mass extinction. Recent works show that a significant negative carbon isotope excursion (N-CIE) occurs in the NRB interval (c. 205.7 Ma), which probably provides a physical marker for the NRB. However, no such records have so far been reported from high-latitude continental deposits. Here we present high-resolution bulk organic carbon isotope data from the Upper Triassic continuous lacustrine-to-fluvial deposits in the Haojiagou section of the high-latitude continental Junggar Basin in northwestern China. A significant N-CIE is shown at an age of c. 205 Ma, which is most probably the expression of the NRB N-CIE in the Junggar Basin owing to their very close occurrence times. The NRB is thus probably along the N-CIE in the Haojiagou section, and a short Rhaetian stage is then supported. The Late Triassic climate in the high-latitude Junggar Basin was consistent with the global changes in climate, characterized by a long-sustained cooler and humid climate interrupted by the late Norian and latest Rhaetian warm events.

Abstract The metamorphic conditions of the Natal Metamorphic Province (NMP) have been the focus of previous studies to assist with Rodinia reconstructions but there are limited constraints on the age of metamorphism. We use a combination of modern techniques to provide new constraints on the conditions and timing of metamorphism in the two southernmost terranes: the Mzumbe and Margate. Metamorphism reached granulite facies, 780–834°C at 3.9–7.8 kbar in the Mzumbe Terrane and 850–892°C at 5.7–6.1 kbar in the Margate Terrane. The new pressure and temperature constraints are supportive of isobaric cooling in the Margate Terrane as previously proposed. Peak metamorphism of the two terranes is shown to have occurred c. 40 myr apart, which contrasts strongly with previous assumptions of coeval metamorphism. While the age of peak metamorphism of the Margate Terrane (1032.7 ± 4.7 Ma) coincides with the tectonism and magmatism associated with the emplacement of the Oribi Gorge Suite (c. 1050–1030 Ma), the age of metamorphism of the Mzumbe Terrane (987.4 ± 8.1 Ma) occurs c. 30–40 myr after tectonism is previously thought to have finished. We propose that models of advective cooling during transcurrent shearing can explain the metamorphic conditions and timing of the NMP.

Abstract The Late Pennsylvanian was a time of ice ages and climate dynamics that drove biotic changes in the marine and non-marine realms. The apex of late Paleozoic glaciation in southern Gondwana was during the Late Pennsylvanian, rather than the early Permian as inferred from more equatorial Pangaea. Waxing and waning of ice sheets drove cyclothemic sedimentation in the Pangaean tropics, providing an astrochronology tuned to Earth-orbital cycles, tied to climatic changes, reflected in aeolian loess and palaeosol archives. Vegetation change across the Middle–Late Pennsylvanian boundary was not a ‘Carboniferous rainforest collapse’, but instead a complex and drawn out step-wise change from one kind of rainforest to another. Changes in marine invertebrate and terrestrial vertebrate animals occurred across the Middle–Late Pennsylvanian boundary, but these did not lead to substantive changes in the organization of those communities. The base of the Upper Pennsylvanian is the base of the Kasimovian Stage, and this boundary needs a GSSP to standardize and stabilize chronostratigraphic usage. To avoid further chronostratigraphic confusion, the Cantabrian Substage should be abandoned, and the traditional Westphalian–Stephanian boundary should be returned to and recognized as the time of major floristic change, the lycospore extinction event.

Abstract The Kasimovian Stage is the lower stage of the Upper Pennsylvanian Subsystem, in which a series of considerable biotic and abiotic events happened and changed the Earth. The Variscan orogeny and the Late Paleozoic Glaciation are two major events that caused geographical isolation of marine faunas and difficulties for a global correlation of biostratigraphy. Regional timescales of the Kasimovian across major continents are reviewed here. A global correlation of the Kasimovian is tentatively established based on a detailed review of major fossil groups such as conodonts, fusulines and some macrofossils. The index taxon for the base of the Kasimovian Stage has not been selected. The conodont species Swadelina subexcelsa , Idiognathodus heckeli , I. turbatus and I. sagittalis have good potential. Among them, I . heckeli is considered the best marker for the base of the Kasimovian Stage because it can mark a bioevent in a wide geographical range, and more importantly, it has a clear taxonomic definition within a phylogenetic lineage. The fusuline Montiparus might be regarded as an auxiliary marker to define the base of the Kasimovian based on its wider distribution. Other proxies, i.e. isotopic dating and strontium, carbon and oxygen isotopic stratigraphy throughout the Kasimovian, are also reviewed. The Global Boundary Stratotype Section and Point (GSSP) candidates for the Kasimovian Stage include the Naqing section, South China, the Usolka section, South Urals and the Afanasievo section, Moscow Basin. The Naqing section is regarded as the most appropriate GSSP candidate in terms of its complete sedimentary succession, well-recorded conodont lineages and well-studied bio-, chemo- and cyclo-stratigraphy.

Abstract For the west European regional chronostratigraphic framework, the Cantabrian substage was conceived as covering a widely apparent stratigraphic gap between the top of the Westphalian and the base of Stephanian A, the lowest unit of the Stephanian. A continuous depositional history covers this time gap in the Cantabrian region of Spain; the upper limit of this interval was defined by the succeeding Barruelian substage, equivalent to Stephanian A. Intense tectonic and magmatic activity characterizes this period; the Iberian orogenic belt was an essentially linear feature buckled through the Late Pennsylvanian into the tightly folded Cantabrian Orocline. This evidences an extensive southern foreland to the Variscides, in which the coal-swamp biome persisted through the Late Pennsylvanian, supporting biostratigraphical correlation with the Donbass. New high precision U–Pb CA-ID-TIMS radiometric dating of tonstein horizons supports a preliminary time-framework of regional substages: base of the Asturian (proposed, ex-Westphalian D) c. 310.7 Ma; base of the Cantabrian c. 307.5 Ma; base of the Barruelian (ex-Stephanian A) c. 304.9 Ma; base of the Saberian (proposed) c. 303.5 Ma. The Cantabrian and Barruelian embrace the entire Kasimovian of the global time-scale, and the top of the Barruelian is essentially coincident with the base of the Gzhelian.

Abstract In spite of numerous revisions from 1966 to present, the Cantabrian Substage of the Stephanian Stage (Pennsylvanian) was never properly defined as a chronostratigraphic unit. Defined and redefined at least three times, the Cantabrian lacks boundary stratotypes that correspond to clear and correlateable biochronological signals. Thus, instead of using a biochronological datum of well-established validity and utility, Cantabrian advocates have relied on ill-defined macrofloral assemblage zones and on lithostratigraphic boundaries to define the substage. As a result, the Cantabrian is demonstrably diachronous, even within Europe; indeed, the Cantabrian has proven to be unusable for correlations outside its type area in northern Spain. To resolve these problems, we recommend that the Cantabrian Substage be abandoned, and the Westphalian–Stephanian boundary be redefined at the major floral turnover that has been documented in the USA, western and central Europe, and in the Donets Basin. We further recommend that the bases of the Kasimovian Series, Stephanian Series, Missourian Series, and Upper Pennsylvanian Series all be aligned with this same floral turnover.

Abstract The Ordovician was a key period in the biological and geological history of the Earth. ‘A Global Synthesis of the Ordovician System’ is presented in two volumes of The Geological Society, Special Publications series. The first volume (SP532) covers general aspects of the Ordovician and also includes the syntheses of the Ordovician successions of Europe. To provide a comprehensive global overview, this second volume (SP533) represents a journey through the Ordovician System around the world. Reviews of the Ordovician of North America include syntheses of Alaska, Greenland, Canada, the USA and Mexico, whereas the South American Ordovician is summarized in a specific chapter related to Argentina and neighbouring countries. The Ordovician System of Africa is presented in chapters covering the north and the south of the continent where significant Ordovician successions occur. Australia and New Zealand, as well as Antarctica, are visited in separate chapters. Asia provides the most complex Ordovician successions that are reviewed in chapters covering Turkey and the Levant region, the Middle East, Central Asia, Kazakhstan, India, SE Asia, China, Korea, and Japan. Our journey covers a great number of locations but, with many successions still to be fully described, our knowledge of the Ordovician of the world remains incomplete.

Abstract The Ordovician System was introduced by Charles Lapworth as a solution to the overlapping unit stratotypes loosely defined by Adam Sedgwick, for the Cambrian, and Roderick Murchison, for the Silurian. The Ordovician has emerged as one of the longest and most significant of the geological periods. Following an interval of intensive research of all the key regions of the globe, unit stratotypes in the type areas of England and Wales have been replaced by seven global stages and three series based on Global Stratotype Sections and Points (GSSPs), enhancing the definition of these chronostratigraphic units and facilitating global correlation. As a consequence, the biological and geological events during the period can be recognized and the magnitude and significance of biotic originations and extinctions understood with some confidence.

Abstract This paper summarizes recent knowledge on the palaeontology, biostratigraphy, correlation, sea-level and climate history and isotopic geochemistry of the Ordovician rocks in the western and central parts of the East European Craton, in the area extending from the southern margin of the Fennoscandian Shield to the western margin of the Ukrainian Shield. The regional chronostratigraphic standard is briefly summarized and its correlation to the global standard of the Ordovician is addressed. A two-part correlation chart of 10 areas with unique local Ordovician successions is aligned with the most recent international correlation standard of the Ordovician System and presented against the regular timescale. An updated summary of the evolution of the marine assemblages is provided, the principal gaps in the existing extremely rich palaeontological database are identified and the main bioevents are discussed.