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The geodynamic process from the evolution of supercontinent has distinct isotope characteristics explorable using zircon Hf isotopic composition. Since Peninsular Malaysia associates with Gondwana dispersal and Pangaea formation, analyzing the U-Pb and Hf-isotopic content of its 500–200 Ma magmatic zircon could reveal the signal left by the transitional geodynamic process between the supercontinents. We collected two groups of magmatic rocks from West Malaya: Ordovician meta-volcanics (n = 8), and Triassic Main Range granitoid province (MRGP) (n = 6); and three groups from East Malaya: Carboniferous meta-volcanics (n = 2), Permian-Triassic Eastern granite province (EGP) (n = 6), and Permian-Triassic EGP volcanics (n = 8). Difference in magmatic zircon Hf isotopic crustal model ages uphold the previous rationale which separates Peninsular into two blocks: West Malaya (part of Sibumasu terrane) magmatic zircon Hf isotopic crustal model ages (Average TDM2: 1.3 Ga) are older than East Malaya (part of Chanthaburi-Sukhothai-Lincang arc of Indochina terrane) (Average TDM2: 0.9 Ga). During the final assembly of Gondwana from 500 to 450 Ma, West Malaya and East Malaya were at the outboard of Gondwana Proto-Tethys margin. The shift of East Malaya zircon Hf array towards higher eHf(t) (external orogenic system) after ca.370 Ma may infers Paleo-Tethys ocean broadening and East Malaya separation from Gondwana. The 370–350 Ma juvenile zircon Hf isotopic composition in East Malaya is a significant improvement over radiolarian age to show the broadening and subduction of the Paleo-Tethys ocean between the two terranes. After ca.280 Ma, East Malaya zircon Hf array shifted towards lower eHf(t) (internal orogenic system). Coinciding with the Indosinian collision at ca.230 Ma, crustal reworking signal increases in both blocks, signifying the end in Peninsular Malaysia Gondwana to Pangaea transitional geodynamic process. As the Paleo-Tethys segment was completely subducted after 230 Ma, the peninsular crustal thickening starts from 230 to 218 Ma. The post-collision phase would begin at ca.215 Ma.

Supercontinents signify self-organization in plate tectonics. Over the past ~2 billion years, three major supercontinents have been identified, with increasing age: Pangaea, Rodinia and Columbia. In a prototypal form, a cyclic pattern of continental assembly and breakup likely extends back to ~3 billion years ago, albeit on the smaller scale of Archaean supercratons, which, unlike global supercontinents, were tectonically segregated. In this Review, we discuss how the emergence of supercontinents provides a minimum age for the onset of the modern global plate tectonic network, whereas Archaean supercratons might reflect an earlier geodynamic and nascent tectonic regime. The assembly and breakup of Pangaea attests that the supercontinent cycle is intimately linked with whole-mantle convection. The supercontinent cycle is, consequently, interpreted as both an effect and a cause of mantle convection, emphasizing the importance of both top-down and bottom-up geodynamics, and the coupling between them. However, the nature of this coupling and how it has evolved remains controversial, resulting in contrasting models of supercontinent formation, which can be tested by quantitative geodynamic modelling and geochemical proxies. Specifically, which oceans close to create a supercontinent, and how such predictions are linked to mantle convection, are directions for future research. Repeated amalgamation and dispersal of continents over Earth history is known as the supercontinent cycle; however, the geodynamic processes driving this cyclicity remain debated. This Review synthesizes observations, plate reconstructions and geodynamic models of supercontinent, and older Archaean supercraton, cycles.

Herbivory is a common ecological function among extant lepidosaurs, but little is known about the origin of this feeding strategy within Lepidosauria. Here we describe a sphenodontian (Lepidosauria) from the Late Triassic of western North America, Trullidens purgatorii n. gen. n. sp., that reveals new aspects of the earliest radiation of herbivorous lepidosaurs. This taxon is represented by an isolated lower jaw with robust structure bearing transversely widened dentition and extensive wear facets, suggesting a masticatory apparatus specialized for herbivory. An unusual 'incisor-like' tooth is present at the anterior end of the jaw; a unique feature among lepidosaurs, this tooth is convergent with the incisors of extant rodents and lagomorphs. Phylogenetic analyses support the placement of this taxon within opisthodontian sphenodontians, a group sharing derived cranio-dental morphologies specialized for herbivory. The new taxon was recovered in a recently discovered and unnamed series of Upper Triassic strata in southeastern Colorado, USA, exposed in Canyons incised by the Purgatoire River and its tributaries. These strata comprise a dominantly red-bed sequence of conglomerates, sandstones, and siltstones deposited in a fluvio-lacustrine setting, preserving a Late Triassic biota of invertebrate and vertebrate ichnofossils, plant macrofossils, bony fish, temnospondyl amphibians, and reptiles. We use aetosaur osteoderms as biostratigraphic links to the nearby Chinle Formation of Arizona, USA, establishing a middle Norian age for these strata. The presence of an opisthodontian from western equatorial Pangaea in the Norian Stage reveals a near-global radiation of this clade across the Pangaean supercontinent during the Late Triassic. UUID: http://zoobank.org/A737c03f-863a-488e-a860-5cc914548774. Virginia Tech Paleobiology Group Published version M.R. Stocker and S.J. Nesbitt of the Virginia Tech Paleobiology Group provided funding for and conducted mu CT scanning, which was conducted at the Duke Shared Instrumentation Facility and facilitated by J. Gladman. J. Autry, the Southeast Colorado Project Director at The Nature Conservancy, facilitated access to the J.E. Canyon Ranch and provided logistical support, supplies, and housing for the authors. B. Preston, S. Korbitz, B. Small, and Y. Huang assisted in field work. The Virginia Tech Paleobiology Research Group provided useful critiques and suggestions for figures in the manuscript. M. R. Stocker provided useful critiques and discussions on the manuscript. W.G. Parker of Petrified Forest National Park provided assistance in identifying aetosaur osteoderms. K. MacKenzie and J. Sertich of the DMNH facilitated curation of specimens used in this study. B. Creisler provided valuable etymological assistance. D. Whiteside and an anonymous reviewer provided valuable reviews of the manuscript. Public domain – authored by a U.S. government employee

A fragment of Hadean continental crust has been postulated to underlie the North China Craton based on the discovery of >3.8 Ga detrital zircons, but these detrital zircons may be transported from a lateral source. Here we report new U Pb ages of 3823 to 230 Ma for zircon xenocrysts directly from Cretaceous granites (129 Ma), which rules out a lateral source. Our results for the first time demonstrate the existence of 3.85 Ga crustal precursors beneath the southern North China Craton based on the Hf isotopic compositions of the 3.82 Ga zircon. The crustal precursors might be a granitic source that was produced by the wet melting of ancient continental crust. We further show that the southern North China Craton has experienced the global Columbia, Gondwana, and Pangaea supercontinent events, based on the inherited zircon age groups of 2017–1896 Ma, 1792–1776 Ma, 584–570 Ma and 251–230 Ma. These Eoarchaean to Triassic U Pb ages document the evolution of the early continental crust and the geological process in the development of the North China Craton.

U Pb geochronology along a north-south transect from central Sonora to northern Sinaloa in northwestern Mexico indicates several changes in provenance sources through time and space. Lower Cambrian arenites of the Proveedora Quartzite yield a single main age peak at 1075 Ma with minor Paleoproterozoic contribution. Arenites from the Sonobari Complex of southwestern Sonora-northwestern Sinaloa, purportedly assigned to the early Paleozoic, yield main peaks at 1424, 1662, and 1736 Ma, probably derived from the Yavapai and Mazatzal provinces, which are pervasively intruded by early Mesoproterozoic granites coeval to those forming the Granite-Rhyolite Province. Lower to Upper Ordovician units deposited on shelf, slope, and abyssal environments display very similar zircon age patterns, with main peaks ca. 2700 and 1850 Ma, indicating a large drainage system arising from the Archean cratons of Laurentia such as the Wyoming or Superior Provinces, and Paleoproterozoic sources similar to the Trans-Hudsonian orogen, which are older than the Yavapai Province. The Rio Fuerte quartzites from southern Sonora-northern Sinaloa contain main peaks at 534, 542, and 637 Ma whose sources may be peri-Gondwanan blocks similar to Avalonia or Carolina terranes. A minor peak at 475 Ma suggests input from igneous suites reported from the Acatlan Complex in southern Mexico. U Pb geochronology permit inference of a late Paleozoic collisional orogen in northwestern Mexico that was originated by the collision of Gondwanan blocks against southern Laurentia and outline the boundary between terranes related to continental blocks in the Pangaea supercontinent.

Deep lithospheric processes associated with the formation of major orogens, including the removal of lower crust and underlying mantle through delamination associated with orogen building are poorly constrained. With a view to evaluate the potential link between deep geodynamic processes and magmatic events, we performed in situ zircon Hf-O-Li isotopic analyses of granitoids from the Eastern and Western Junggar, Altai and Beishan orogens, within the Central Asian Orogenic Belt (CAOB). The eHf(t) and δ18O values of magmatic zircons crystallized during 443 Ma and 252 Ma indicate diverse and heterogeneous magma sources. The corresponding δ7Li peaks at ~440 Ma and ~250 Ma, suggesting two distinct high-temperature magmatic events. Based on a comparison with global data, we argue that large-scale delamination formed through Gondwana and Pangaea supercontinent assembly, may have occurred at Ordovician to Silurian boundary (OSB) and Permian to Triassic boundary (PTB), which we term as super-delamination. The subsequent widespread magmatism and volcanism might have made significant impact on the Earth surface ecosystems, ultimately leading to the OSB and PTB mass extinction events. We propose super-delamination as a potential mechanism to explain the link between Earth's internal and external processes, thus providing novel insights into the trigger for mass extinction events.

The Earth’s mantle is currently divided into the African and Pacific domains, separated by the circum-Pacific subduction girdle, and each domain features a large low shear-wave velocity province (LLSVP) in the lower mantle. However, it remains controversial as to whether the LLSVPs have been stationary through time or dynamic, changing in response to changes in global subduction geometry. Here we compile radiogenic isotope data on plume-induced basalts from ocean islands and oceanic plateaus above the two LLSVPs that show distinct lead, neodymium and strontium isotopic compositions for the two mantle domains. The African domain shows enrichment by subducted continental material during the assembly and breakup of the supercontinent Pangaea, whereas no such feature is found in the Pacific domain. This deep-mantle geochemical dichotomy reflects the different evolutionary histories of the two domains during the Rodinia and Pangaea supercontinent cycles and thus supports a dynamic relationship between plate tectonics and deep-mantle structures. Earth’s deep-mantle domains are geochemically distinct. The African domain is enriched in subducted material, which suggests a different history from the Pacific domain and a dynamic relationship between plate tectonics and deep-mantle structures.

The Middle Permian Guadalupian witnessed significant environmental changes in the Phanerozoic such as large-scale sea-level drop, supercontinent Pangaea assembly, and transition from Early Permian glaciation to Late Permian non-glacial intervals. Carbonisotope tracers can provide insights for these environmental changes. The δ13C studies of the entire Guadalupian epoch are rare, and most of them has focused on near the end of Guadalupian and carbon isotopes of inoragnics. Here, we present carbon isotopic compositions of organic matters in the Guadalupian from two sections (Chaohu and Xiaolao) in the Lower Yangtze area, South China. Our results show that δ13Corg profiles in the Guadalupian show a peak in the Roadian and a gradual negative shift from the Roadian to the middle Capitanian. These trends can be matched by δ13C changes of carbonate rocks or organic matter in South China and other places in the world, representing a global carbon cycle signal. The Roadian positive peak was probably due to high productivity which was caused by upwelling during cooling time. The gradual negative shift of δ13C was caused mainly by a decrease of organic matter burial on land and in the ocean, resulting from global sea-level drop and anoxia-caused benthos decline, respectively. The less important causes for the gradual δ13C negative shift are volcanic-gases releasing, decreased mountain belts, and the resultant reduced silicate weathering-consumption of CO2. The gradual negative shift of δ13C coincides with the gradual extinction in the Guadalupian. Therefore, global sea-level drop and marine reducing conditions may be the main causes of the gradual extinction in the Guadalupian.

The supercontinent of Pangea formed through the diachronous collision of Laurussia and Gondwana during the late Paleozoic. While magmatism associated with its formation is well documented in the Variscan orogeny of Europe and Alleghanian orogeny of the United States, little is known about the Sonora orogeny of northern Mexico. This paper reports geochronology (U-Pb zircon), whole-rock geochemistry, and Lu-Hf zircon isotope data on basement cores from the western Gulf of Mexico, which were used to develop a tectonomagmatic model for pre- to post-Pangea amalgamation. Our results suggest the existence of three distinct phases of magmatism, produced during different stages of continental assembly and disassembly. The first phase consists of Early Permian (294–274 Ma; n = 3) granitoids with geochemical signatures indicative of a continental arc tectonic setting. This phase formed on the margins of Gondwana during the closure of the Rheic Ocean, prior to the final amalgamation of Pangea. It likely represents a lateral analogue of late Carboniferous–Early Permian granitoids that intrude the Acatlán and Oaxacan Complexes. The second phase of magmatism includes Late Permian–Early Triassic (263–243 Ma; n = 13) granitoids with suprasubduction geochemical affinities. However, Lu-Hf isotope data indicate that these granitoids formed from crustal anatexis, with εHf values and two-step Hf depleted mantle model ages (TDM[Hf]) comparable to the Oaxaquia continental crust into which they intrude. This phase of magmatism is likely related to coeval granitoids in the Oaxaca area and Chiapas Massif. We interpret it to reflect late- to postcollisional magmatism along the margin of Gondwana following the assembly of Pangea. Finally, the third phase of magmatism includes Early–Middle Jurassic (189–164 Ma; n = 2) mafic porphyries, which could be related to the synchronous suprasubduction magmatism associated with the Nazas arc. Overall, our results are consistent with Pangea assembly through diachronous collision of Laurussia and Gondwana during subduction of the Rheic Ocean. They suggest that postorogenic magmatism in the western termination of the Rheic suture occurred under the influence of a Panthalassan subduction zone, before opening of the Gulf of Mexico.

The sequential breakup of the supercontinent Pangaea since the Middle Jurassic is one of the crucial factors that has driven the biogeographical patterns of terrestrial biotas. Despite decades of effort searching for concordant patterns between diversification and continental fragmentation among taxonomic groups, increasing evidence has revealed more complex and idiosyncratic scenarios resulting from a mixture of vicariance, dispersal and extinction. Aquatic insects with discreet ecological requirements, low vagility and disjunct distributions represent a valuable model for testing biogeographical hypotheses by reconstructing their distribution patterns and temporal divergences. Insects of the order Megaloptera have exclusively aquatic larvae, their adults have low vagility, and the group has a highly disjunct geographical distribution. Here we present a comprehensive phylogeny of Megaloptera based on a large-scale mitochondrial genome sequencing of 99 species representing >90% of the world genera from all major biogeographical regions. Molecular dating suggests that the deep divergence within Megaloptera pre-dates the breakup of Pangaea. Subsequently, the intergeneric divergences within Corydalinae (dobsonflies), Chauliodinae (fishflies) and Sialidae (alderflies) might have been driven by both vicariance and dispersal correlated with the shifting continent during the Cretaceous, but with strikingly different and incongruent biogeographical signals. The austral distribution of many corydalids appears to be a result of colonization from Eurasia through southward dispersal across Europe and Africa during the Cretaceous, whereas a nearly contemporaneous dispersal via northward rafting of Gondwanan landmasses may account for the colonization of extant Eurasian alderflies from the south.

The Mesozoic era (∼252 to 66 million years ago) was a key interval in Earth's evolution toward its modern state, witnessing the breakup of the supercontinent Pangaea and significant biotic innovations like the early evolution of mammals. Plate tectonic dynamics drove a fundamental climatic transition from the early Mesozoic supercontinent toward the Late Cretaceous fragmented continental configuration. Here, key aspects of Mesozoic long‐term environmental changes are assessed in a climate model ensemble framework. We analyze so far the most extended ensemble of equilibrium climate states simulated for evolving Mesozoic boundary conditions covering the period from 255 to 60 Ma in 5 Myr timesteps. Global mean temperatures are generally found to be elevated above the present and exhibit a baseline warming trend driven by rising sea levels and increasing solar luminosity. Warm (Triassic and mid‐Cretaceous) and cool (Jurassic and end‐Cretaceous) anomalies result from pCO2 changes indicated by different reconstructions. Seasonal and zonal temperature contrasts as well as continental aridity show an overall decrease from the Late Triassic‐Early Jurassic to the Late Cretaceous. Meridional temperature gradients are reduced at higher global temperatures and less land area in the high latitudes. With systematic sensitivity experiments, the influence of paleogeography, sea level, vegetation patterns, pCO2, solar luminosity, and orbital configuration on these trends is investigated. For example, long‐term seasonality trends are driven by paleogeography, but orbital cycles could have had similar‐scale effects on shorter timescales. Global mean temperatures, continental humidity, and meridional temperature gradients are, however, also strongly affected by pCO2., Key Points We assess global long‐term climate trends through the Mesozoic era with an ensemble of climate model simulationsVarying carbon dioxide levels cause anomalies around an overall warming trend due to changing paleogeography and increasing insolationSeasonal and zonal temperature contrasts as well as aridity decrease with time, while meridional gradients vary with paleogeography

Tethyan ophiolites have played a major role in the development of the ophiolite concept during the past 200 years, and contributed significantly to the formulations of the suprasubduction-zone (SSZ) ophiolite paradigm and the plate-tectonics theory. Their melt evolution and magmatic construction witnessed the dispersal of the supercontinent Pangaea via continental rifting and seafloor spreading, opening and closure of multiple seaways in an eastward widening, latitudinal ocean basin (Neotethys), and deep mantle recycling processes through subduction-zone tectonics and plume activities. Neotethyan ophiolites are highly diverse in their crustal–mantle structures and compositions, pointing to major differences in their melt sources and tectonic settings of magmatic construction. The papers in this thematic set demonstrate these differences in the Neotethyan ophiolite record through new structural, geochemical, isotopic and geochronological data and interpretations. The Jurassic Western Alpine Ophiolites formed in a narrow basin (Alpine Tethys) that developed between Europe and North Africa–Adria–Iberia. Their peridotites represent exhumed, continental lithospheric mantle. The Triassic, Jurassic and Cretaceous ophiolites east of Adria formed in different Neotethyan seaways, and their SSZ magmatic construction involved multiple episodes of melting, depletion and refertilization of subduction-modified oceanic mantle. The Late Cretaceous peri-Arabian and peri-Indian ophiolites, which are discontinuously exposed along a c. 9000 km long belt from SW Anatolia to SE Tibet, formed above a Trans-Tethyan subduction–accretion system within Southern Neotethys. Diachronous collisions of Arabia and India with this intraoceanic subduction–accretion system in the latest Mesozoic and the Paleogene (respectively) resulted in diachronous ophiolite emplacement in the Mediterranean and Tibetan–Himalayan orogenic belts. Thematic collection: This article is part of the ‘Tethyan ophiolites and Tethyan seaways collection’ available at: https://www.lyellcollection.org/cc/tethyan-ophiolites-and-tethyan-seaways

The periodic dispersal and assembly of continental fragments has been an inherent feature of the continental crust. Based on the discovery of large-scale supercontinent cycle and the theory of plate tectonics, several supercontinents have been identified, such as Columbia/Nuna, Rodinia, Gondwana and Pangaea. Neoproterozoic magmatic events related to the break-up of Rodinia are globally well preserved. Although Neoproterozoic magmatic events were very weak in the North China Craton (NCC), they are crucial in reconstructing the geometries of the NCC and could facilitate the completion of the Neoproterozoic configuration of the supercontinent. In this study, c. 853–835 Ma magmatic rocks are identified in the western margin of the NCC. Precise zircon U–Pb age determination yields 206Pb/238U average ages of 835.5 ± 5.3 Ma (HL-39) and 853.7 ± 4.5 Ma (HL-30). In situ zircon Hf isotope compositions of the samples reveal that their parental magma was formed by the reworking of ancient crust evolved from Mesoproterozoic mantle. In summary, the discovery of Neoproterozoic magmatic rocks in the western margin of the NCC, and reported synchronous rocks in other parts of the NCC indicate that the NCC might be conjoined with the supercontinent Rodinia during the Neoproterozoic. This discovery is of significant help in unravelling the early Neoproterozoic history of the NCC and the evolution of the supercontinent Rodinia.

Altres ajuts: CERCA Programme/Generalitat de Catalunya During the Early-Middle Triassic, the biosphere was recovering from the most severe mass extinction event of multicellular life, in the Permian-Triassic transition. Continental basins corresponding to present-day Mallorca (Balearic Islands, western Mediterranean) were located in the equatorial region of the supercontinent Pangaea, in the western peri-Tethys. Its recorded stratigraphic succession can be divided in four alluvial/fluvial formations, formally described here: Punta Roja Formation, Estellencs Formation, Pedra Alta Formation and Son Serralta Formation. Based on an exhaustive review of all available literature and new stratigraphic and palaeontological data, an upper Olenekian-lower Anisian interval is proposed for the whole succession. The richest fossil assemblage is that of Estellencs Formation, with abundant invertebrate and vertebrate trace fossils, and remains of plants, arthropods and rare fishes, which together represent a lotic/riverine ecosystem with a relatively complex food web. Plants and insects show strong biogeographical affinities with those of the Vosges, in central Europe; clam shrimps are similar to those of central Europe and Asia; and tetrapod tracks are also reminiscent to those of Eurasia and North America. Ultimately, integration of all these data provides a comprehensive and multidisciplinary characterisation of one of the oldest Triassic ecosystems of equatorial Pangaea, providing new insights to understand the evolution of palaeoenvironments of Iberian Plate, an area that has historically suffered from severe undersampling.

Earth’s history can be viewed as a series of processes and events that transformed a glowing molten sphere into a habitable planet. This astonishing outcome was the effect of the complex interplay of both normal chemical-physical processes, such as heat loss, gravity and magmatism, and the occurrence of anomalous, sometimes catastrophic events such as gigantic volcanic eruptions and the fall of large meteorites. The primordial Earth was characterised by very high internal and external temperatures related to the heat released by the decay of radioactive isotopes and meteorite impacts. Its heat slowly dissipated to outer space, and the planet solidified and differentiated to a stratified crust, mantle, and core. Solidification released gaseous substances that migrated to the external portions of the Earth and generated a primitive atmosphere rich in nitrogen, water vapour, methane and hydrogen sulphide. When the external temperature dropped, water condensed and fell as rain. The slow but continuous dispersion of heat from inside the Earth led to the cooling and stiffening of the crust that broke up into various rigid blocks and gave birth to an early-stage plate tectonic regime between the Hadean and the Archaean, some 4.0-3.5 billion years ago. Modern-style plate tectonics started around 3.0 billion years ago. Early embryos of continents appeared during the Hadean. These slowly increased in size and began moving across the surface of the Earth, gathering together and then separating several times until the last supercontinent Pangaea was formed about 250 Ma ago. The breakup and disaggregation of Pangaea started about 170 Ma ago and gave rise to various continental blocks that gradually drifted to their present-day position. Some 3.7 Ga ago, the first unicellular prokaryotic organisms appeared in aquatic environments. Successively, cyanobacteria started to proliferate in shallow marine waters and, being capable of performing photosynthesis, they slowly accumulated vast quantities of oxygen in the atmosphere. About 2100 to 1600 million years ago, or perhaps earlier, unicellular eukaryotic cells appeared and successively aggregated into multicellular organisms that used oxygen for metabolism. An explosion of life occurred in the Cambrian. Most Cambrian phyla have survived until the present time, after several mass extinctions that removed a countless number of species, but also favoured the evolution and spreading of the surviving organisms. The arrival of Homo sapiens some 0.3 million years ago had a profound impact on terrestrial life, affecting many animal species. The effects of human activities on the environment are a fundamental concern of modern science.

International audience; Jurassic flora of the Tibetan Plateau is poorly known, with limited fossil records. The paleobiogeography of terres- trial biota is, however, one of the major evidences to reconstruct the intricate paleogeography of an area. Well- preserved fossil wood is described from the Middle Jurassic Xiali Formation (Callovian) in the South Qiangtang terrane of the Tibetan Plateau, SW China. The wood specimen is a well-preserved secondary xylem without growth rings. Bordered pits on the radial tracheid walls are mostly uniseriate distant, locally contiguous. Cross- fields have 1–2 large oopores. A systematic study indicates that the current fossil wood represents a new species, Circoporoxylon tibetense sp. nov. This is the earliest Laurasian data for the genus Circoporoxylon, which has a Gondwanan origin and subsequently became common in Laurasia during the Cretaceous. The present new find- ing indicates that Circoporoxylon might have reached the Laurasia via a Tibetan terrane. The presence of fungal remains and wood rotting structures resembling the extant white-rot testifies for the plant–fungal interaction in the Callovian. The absence of growth rings in Circoporoxylon wood and the absence of gypsum layers in the South Qiangtang terrane, together with the widely occurrence of gypsum layers in the North Qiangtang terrane, suggests the South Qiangtang terrane might be wetter than the latter during the Callovian age. The paleogeomorphological highlands of Central Uplift were most likely the boundary between the two. This paleoclimate zonation implies that the Permian to Mesozoic megamonsoon of the supercontinent Pangaea might have terminated in the northern of Paleo-Tethys before the Callovian.

Gondwana Supercontinent in eastern and southern Africa formed by collision and amalgamation of two crustal plates, provisionally named East Gondwana and West Gondwana and the Mozambique Ocean intake between 841 and 632 Ma. East Gondwana consists of the Arabian–Nubian Shield (ANS) and the older crystalline basement in Madagascar, India, Antarctica and Australia, while West Gondwana consists of much of Africa and South America. Collision and amalgamation of East and West Gondwana formed the East African Orogeny. The supercontinent of Gondwana ranged from Neoproterozoic (~550 Ma ago) to Carboniferous (~320 Ma ago). Gondwana became the largest continental crust during the Paleozoic Era (~100 million km2). During the Carboniferous, Gondwana amalgamated with Euramerica resulting in the formation of the supercontinent, Pangaea. Three orogeneses were recognized during the 1990s: the East African Orogeny (650–800 Ma), Kuunga Orogeny (including the Malagasy Orogeny in southern Madagascar) (550 Ma)—the collision between East Gondwana and East Africa in two steps—and the Brasiliano Orogeny (660–530 Ma)—the collision between South American and African Cratons. Formation of arcs in the ANS occurred over a ~300-million-year period including supercontinent Rodinia break-up and the assembly of supercontinent Gondwana. The ANS represents one of the best documented examples of Late Proterozoic to Early Paleozoic (950–450 Ma) crustal growth through processes of lateral arc–arc terrane accretion. The tectonic development of the ANS spans three phases spanning over 600 Ma: accumulation of arc terrains inside the Hijaz Magmatic Arc, accompanied by accretion of the Hijaz Magmatic Arc against the Nile Craton and reworking of the accreted arc after accretion. The Egyptian Nubian Shield (ENS) covers ~100,000 km2, crops out along the Red Sea Hills in the Eastern Desert and southern Sinai, as well as limited areas in the south Western Desert (Oweinat area, 2673 ± 21 Ma). The ENE covers the northeastern part of the East African Orogeny and stretches over approximately 800 km parallel with the Red Sea coast between latitudes 22° 00΄ 00˝ and 28° 40΄ 00˝ N. The rocks are covered by Nubia sandstone, Miocene and later sediments in their western and eastern margins. The Eastern Desert of Egypt is divided into three domains, namely, the northern Eastern Desert (NED), central Eastern Desert (CED) and southern Eastern Desert (SED); these domains were developed in different tectonic settings and show a characteristic younging from (SED) to (NED). Geologically, gneisses, migmatites and schists dominate the SED as the oldest units, and are followed by ophiolites, volcanic arc lithologies and granitoid plutons. The amount of ophiolites increases and forms with the arc metavolcanics the main types in the CED. The ophiolites and the metavolcanics are occasionally unconformably and tectonically overlained by Dokhan volcanics and molasse sediments. The older gneisses and migmatites form prominent domal structures (e.g. Meatiq, Sibai, Hafafit, El-Shalul). Syn-tectonic and late tectonic granitoids are also present. The NED is characterized by younger rocks, such as Gattarian granites, Dokhan volcanics and Hammamat molasse sediments, whereas older rock types rarely occur. The bulk of the crust of the SED was created prior to 650 Ma, while the major pulses of the CED occurred in the interval (685–575 Ma). In the NED and Sinai, the crust was principally formed in the period (625–575 Ma).

The Earth is currently 180 Myr into a supercontinent cycle that began with the break-up of Pangaea and which will end around 200–250 Myr (million years) in the future, as the next supercontinent forms. As the continents move around the planet they change the geometry of ocean basins, and thereby modify their resonant properties. In doing so, oceans move through tidal resonance, causing the global tides to be profoundly affected. Here, we use a dedicated and established global tidal model to simulate the evolution of tides during four future supercontinent scenarios. We show that the number of tidal resonances on Earth varies between one and five in a supercontinent cycle and that they last for no longer than 20 Myr. They occur in opening basins after about 140–180 Myr, an age equivalent to the present-day Atlantic Ocean, which is near resonance for the dominating semi-diurnal tide. They also occur when an ocean basin is closing, highlighting that within its lifetime, a large ocean basin – its history described by the Wilson cycle – may go through two resonances: one when opening and one when closing. The results further support the existence of a super-tidal cycle associated with the supercontinent cycle and gives a deep-time proxy for global tidal energetics.

The formation and subsequent breakup of the supercontinent Pangaea has dominated Earth’s evolution for the last 320 million years. Although its configuration at the time of breakup is widely accepted, there remains uncertainty about its configuration at the time of its amalgamation. The classic Pangaea-A model, widely known as “Wegenerian” configuration, implies that Pangaea did not deform internally between amalgamation and breakup. Palaeomagnetic studies suggest the possibility of a Pangaea-B configuration, in which Gondwana was located about 3000 km farther east relative to Laurasia compared its location in Pangaea-A. Here, we provide firm evidence of an Iberian-Appalachian connection in the Late Pennsylvanian (307–299 Ma) which confirms a Pangaea-A configuration for the relative locations of Gondwana and Laurasia in the late Palaeozoic, negating the possibility of Pangaea-B at that time. This evidence is based on palaeobotanical and biostratigraphic findings recently documented in the Carboniferous successions of Iberia (Douro Basin, Portugal). These new findings also precisely constrain the timing of uplift of the Appalachian and Iberian (Variscan) orogens and climatic changes during the amalgamation of Pangaea and final closure of the Rheic Ocean.

Unicellular dinophytes include a considerable number of harmful algae and potent producers of toxins. The dinophyte fossil record is one of the richest among protists and indicates a geologically old origin of the group dating back to the Triassic. Besides of these records, very few molecular dating studies of dinophytes have been published to date, precluding an understanding of the diversification history of these organisms. In the present study, we used first appearances in the fossil record for the best-represented dinophyte lineages, namely Gonyaulacales and Peridiniales, to calibrate a molecular phylogeny. It is inferred from ribosomal RNA sequence data covering a representative taxon sampling of all currently recognised lineages. Dinophytes may have started diversifying during main tectonic events of the supercontinent Pangaea, witnessing and surviving some of the biggest mass extinction events on Earth. Groups including harmful dinophytes originated at different points in time, but they all predate the Cretaceous–Paleogene boundary. Our chronogram provides a first time frame and may stimulate studies in future bringing molecular phylogenetics of dinophytes and their impressive fossil record together in more detail.

A supercontinent is generally considered to reflect the assembly of all, or most, of the Earth's continental lithosphere. Previous studies have used geological, atmospheric and biogenic ‘geomarkers’ to supplement supercontinent identification. However, there is no formal definition of how much continental material is required to be assembled, or indeed which geomarkers need to be present. Pannotia is a hypothesized landmass that existed in the interval c. 0.65–0.54 Ga and was comprised of Gondwana, Laurentia, Baltica and possibly Siberia. Although Pannotia was considerably smaller than Pangaea (and also fleeting in its existence), the presence of geomarkers in the geological record support its identification as a supercontinent. Using 3D mantle convection models, we simulate the evolution of the mantle in response to the convergence leading to amalgamation of Rodinia and Pangaea. We then compare this supercontinent ‘fingerprint’ to Pannotian activity. For the first time, we show that Pannotian continental convergence could have generated a mantle signature in keeping with that of a simulated supercontinent. As a result, we posit that any formal identification of a supercontinent must take into consideration the thermal evolution of the mantle associated with convergence leading to continental amalgamation, rather than simply the size of the connected continental landmass.

The Eastern Siberian Arctic Shelf (ESAS) represents a geologically complex realm with a tectonic history that is related to the final stages of the formation of the Pangaea supercontinent during the Mesozoic and its subsequent disintegration during the Late Cretaceous and Cenozoic. It is a key region to constrain the origin of the deep-water basins and intervening ridges of the Amerasia Basin. We present results of gravity modeling of published seismic refraction and reflection profiles acquired between 1989 and 2012 over the ESAS and adjacent Arctic Ocean along five composite geotransects using Getech’s satellite altimeter-derived gravity data. Our main goal was to examine published crustal models and to present new models for the ESAS that are constrained by both seismic data and 2D gravity forward modeling. We consider several topics important for understanding Arctic geology: (i) hyperextension within the Laptev Rift System and the possible extent of the exhumed mantle, (ii) the relationship between the New Siberian Shelf and the Lomonosov Ridge, (iii) the nature of the collapsed upper Mesozoic fold belt in the southern part of the East Siberian Sea, (iv) the character of transition between the De Long Massif and the deep-water Podvodnikov Basin, (v) the lateral extent of the hyperextended North Chukchi Basin and the nature of its basement, and (vi) relationship between the Mendeleev Ridge and Chukchi Plateau crustal domains. Our results do not confirm the previously inferred extent of continental crust beneath the oceanic realm. The latter is dominated by High Arctic Large Igneous Province (HALIP) igneous crust. We discuss the existence of a dismembered continental Bennett-Barrovia block that is currently represented by three smaller fragments/massifs. When restored to its possible single state, this block can play a crucial role in reconstructing the pre-Canada Basin Arctic.

The South Atlantic Igneous Province comprises the Parana Basalts, Rio Grande Rise, Tristan archipelago and surrounding guyot province, Walvis Ridge, Etendeka basalts and, in some models, the alkaline igneous lineament in the Lucapa corridor, Angola. Although these volcanics are often considered to have a single generic origin, complexities that suggest otherwise are observed. The Parana Basalts erupted ~ 5 Ma before sea-floor spreading started in the neighborhood, and far more voluminous volcanic margins were emplaced later. A continental microcontinent likely forms much of the Rio Grande Rise, and variable styles of volcanism built the Walvis Ridge and the Tristan da Cunha archipelago and guyot province. Such complexities, coupled with the northward-propagating mid-ocean ridge crossing a major transverse transtensional intracontinental structure, suggest that fragmentation of Pangaea was complex at this latitude and that the volcanism may have occurred in response to distributed extension. The alternative model, a deep mantle plume, is less able to account for many observations and no model variant can account for all the primary features that include eruption of the Parana Basalts in a subsiding basin, continental breakup by rift propagation that originated far to the south, the absence of a time-progressive volcanic chain between the Parana Basalts and the Rio Grande Rise, derivation of the lavas from different sources, and the lack of evidence for a plume conduit in seismic-tomography- and magnetotelluric images. The region shares many common features with the North Atlantic Igneous Province which also features persistent, widespread volcanism where a propagating mid-ocean ridge crossed a transverse structural discontinuity in the disintegrating supercontinent.

Earth's penultimate icehouse (ca. 340-285 Ma) was a time of low atmospheric pCO(2) and high pO(2), formation of the supercontinent Pangaea, dynamic glaciation in the Southern Hemisphere, and radiation of the oldest tropical rainforests. Although it has been long appreciated that these major tectonic, climatic, and biotic events left their signature on seawater Sr-87/Sr-86 through their influence on Sr fluxes to the ocean, the temporal resolution and precision of the late Paleozoic seawater Sr-87/Sr-86 record remain relatively low. Here we present a high-temporal-resolution and high-fidelity record of Carboniferous-early Permian seawater Sr-87/Sr-86 based on conodont bioapatite from an open-water carbonate slope succession in south China. The new data define a rate of long-term rise in Sr-87/Sr-86 (0.000035/m.y.) from ca. 334-318 Ma comparable to that of the middle to late Cenozoic. The onset of the rapid decline in Sr-87/Sr-86 (0.000043/m.y.), following a prolonged plateau (318-303 Ma), is constrained to ca. 303 Ma. A major decoupling of Sr-87/Sr-86 and pCO(2) during 303-297 Ma, coincident with the Paleozoic peak in pO(2), widespread low-latitude aridification, and demise of the pan-tropical wetland forests, suggests a major shift in the dominant influence on pCO(2) from continental weathering and organic carbon sequestration (as coals) on land to organic carbon burial in the ocean.

Although Plate Tectonics cannot be effectively tested by palaeomagnetism in the Precambrian aeon due to the paucity of high precision poles spanning such a long time period, the possibility of Lid Tectonics is eminently testable because it seeks accordance of the wider dataset over prolonged intervals of time; deficiencies and complexities in the data merely contribute to dispersion. Accordance of palaeomagnetic poles across a quasi-integral continental crust for time periods of up to thousands of millions of years, together with recognition of very long intervals characterised by minimal polar motions (∼2.6–2.0, ∼1.5–1.25 and ∼0.75–0.6 Ga) has been used to demonstrate that Lid Tectonics dominated this aeon. The new PALEOMAGIA database is used to refine a model for the Precambrian lid incorporating a large quasi-integral crescentric core running from South-Central Africa through Laurentia to Siberia with peripheral cratons subject to reorganisation at ∼2.1, ∼1.6 and ∼1.1 Ga. The model explains low levels of tidal friction, reduced heat balance, unique petrologic and isotopic signatures, and the prolonged crustal stability of Earth's “Middle Age”, whilst density concentrations of the palaeomagnetic poles show that the centre of the continental lid was persistently focussed near Earth's rotation axis from ∼2.8 to 0.6 Ga. The exception was the ∼2.7–2.2 Ga interval defined by ∼90° polar movements which translated the periphery of the lid to the rotation pole for this quasi-static period, a time characterised by glaciation and low levels of magmatic activity; the ∼2.7 Ga shift correlates with key interval of mid-Archaean crustal growth to some 60–70% of the present volume and REE signatures whilst the ∼2.2 Ga shift correlates with the Lomagundi δ13 C and Great Oxygenation events. The palaeomagnetic signature of breakup of the lid at ∼0.6 Ga is recorded by the world-wide Ediacaran development of passive margins and associated environmental signatures of new ocean basins. This event defined the end of a dominant Lid Tectonic phase in the history of Earth's continental lithosphere recorded by the quasi-integral Precambrian supercontinent Palaeopangaea and the beginning of the comprehensive Plate Tectonics which has characterised the Phanerozoic aeon. Peripheral modifications to the lid achieved a symmetrical and hemispheric shape in Neoproterozoic times comparable to the familiar short-lived supercontinent (Neo)Pangaea (∼350–150 Ma) and this appears to be the sole supercontinent cycle recorded by the palaeomagnetic record. Prolonged integrity of a large continental nucleus accompanied by periodic readjustments of peripheral shields can reconcile divergent tectonic analyses of Precambrian times which on the one hand propose multiple Wilson Cycles to explain some signatures of Plate Tectonics, and alternative interpretations which consider that Plate Tectonics did not commence until the end of the Neoproterozoic.

A high-resolution aeromagnetic survey was carried out in the Anti- Atlas, Morocco covering the main areas traversed by the Great CAMP Foum Zguid dyke (FZD). This “doleritic” dyke belongs to the Central Atlantic Magmatic Province (CAMP), a Large Igneous Province which is associated with the fragmentation of the supercontinent Pangaea and the initial stages of rifting of the Central Atlantic Ocean. It also coincides in time with the mass extinction of the Triassic - Jurassic boundary. Based on the study of geological maps and Google Earth satellite images, it appears that the FZD is poorly exposed and, often covered by Quaternary deposits. This work proposes aeromagnetic modelling and interpretation of the FZD in order to better constrain its structural extent. The data have allowed (i) mapping of the dyke over great distances, under the Quaternary deposits and through areas where it was poorly characterized on the geological map; (ii) identifying major tectonic lineaments interpreted as faults; (iii) recognizing magnetic anomalies related to mafic intrusive bodies; and (iv) informing about regional structural context.

Scattered T DM2 (3.8–3.2 Ga) for 3.28–2.99 Ga zircons from the Proterozoic Delhi Supergroup in northwestern India provide evidence for generation of juvenile crust and reworking of older crust. Depleted mantle-like e Hf( t ) values (+7.2 to +5.6) for 2.86–2.71 Ga zircons indicate that generation of juvenile crust occurred during this period and ceased at 2.71 Ga. Extensive magmatism at 2.66–2.34, 2.11–2.01 and 1.60–1.37 Ga was dominated by reworking of pre-existing crust with variable ages, and the last two periods were accompanied by formation of juvenile crust. An Eoarchaean age of 3671 ± 15 Ma represents the oldest age found in NW India. Zircons formed during supercontinent assembly have positive to negative e Hf( t ) values, suggesting involvement of juvenile and ancient crust, whereas largely positive e Hf( t ) values for zircons crystallized subsequent to supercontinent amalgamation suggest involvement of predominantly juvenile crust. Correlation of detrital age patterns and tectonomagmatic events indicates a conjugate position for northern Indian and the Cathaysia Block of South China during the assembly of Nuna. The South China Block remained juxtaposed to India until its separation from Pangaea in the late Palaeozoic. Supplementary material: Supplementary data, including detailed metadata related to laboratory and sample preparation methods, U-Pb and Lu-Hf isotopic compositions of the analyzed samples and standards are available at https://doi.org/10.6084/m9.figshare.c.3711847

The first phylogeny of the lacewing family Osmylidae is presented here based on a total evidence analysis of DNA sequences for multiple gene loci and morphology for representatives of almost all extant genera. Our phylogeny shows a basal dichotomy in the family, with subfamilies Protosmylinae, Spilosmylinae and Gumillinae comprising one lineage, and the other lineage including Osmylinae, Porisminae, Eidoporisminae, Kempyninae and Stenosmylinae. The status of Paryphosmylus Kruger and Lysmus Navas as members of Protosmylinae is affirmed as well as the placement of Gumillinae near Protosmylinae and Spilosmylinae. Our results suggest that Porisminae, Eidoporisminae and Stenosmylinae evolved from a common ancestor, and their relationships, including likely paraphyly of Stenosmylinae, requires further assessment. Divergence time analysis revealed that the family originated during the Late Permian before the break-up of the supercontinent Pangaea and that present generic distributions are not due to Gondwanan biogeographic events. All major subfamily-level lineages were present by the end of the Triassic, in agreement with the rich Mesozoic-aged fossil record for the family.

Comparative tectonic analysis of passive margins of the Atlantic Ocean has been performed. Tectonotypes of both volcanic and nonvolcanic margins are described, and their comparison with other passive Atlantic margins is given. The structural features of margins, peculiarities of magmatism, its sources and reasons for geochemical enrichment of melts are discussed. The important role of melting of the continental lithosphere in the development of magmatism is demonstrated. Enriched EM I and EM II sources are determined for the lower parts of the volcanic section, and a depleted or poorly enriched source is determined for the upper parts of the volcanic section based on isotope data. The conclusions of the paper relate to tectonic settings of the initial occurrence of magmatism and rifting and breakup during the period of opening of the Mesozoic Ocean. It was found out that breakup and magmatism at proximal margins led only to insignificant structural transformations and reduction of the thickness of the ancient continental crust, while very important magmatic events happened later in the distal zone. New growth of magmatic crust at the stage of continental breakup is determined as a typical feature of distal zones of the margins under study. The relationship of development of margins with the impact of deep plumes as the source of magmatic material or a heat source only is discussed. Progradation of the zone of extension and breakup into the areas of cold lithosphere of the Atlantic and the formation of a single tectonomagmatic system of the ocean are under consideration.

Made available in DSpace on 2021-06-25T10:49:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The superfamily Lepisosteoidea, popularly known as gars, is the only group of extant ginglymodian fishes that has its history traced back to the Mesozoic. The extant diversity of the superfamily comprises one family, two genera and seven species. The oldest fossils of Lepisosteoidea are known from Upper Jurassic deposits in Mexico. From the Early Cretaceous onwards, lepisosteoids diversified into two major lineages: Lepisosteidae, that encompasses modern gars, and the currently extinct family Obaichthyidae. In this paper, we report new lepisosteid remains, attributed for the first time to Atractosteus sp., from the Turonian–Santonian Adamantina Formation, Bauru Group, Brazil. The anatomical description and assessment of taxonomically relevant characters was employed with the support of data from Scanning Electron Microscopy (SEM) and histological analyses. The presence of plicidentine tooth structure and lepidosteoid-type scales, without an intercalated dentine layer, allows the assignment of these remains to Lepisosteidae. The size and density of the microornamentations of the scales of the new remains were also compared to measurements of other lepisosteoids, which allowed their assignment to Atractosteus. These new fossils allow biogeographical inferences regarding Lepisosteoidea origins and their distributions along the Mesozoic. The origin of Lepisosteoidea may have occurred in the Sinemurian-Toarcian of Tethys, whereas the origin of Lepisosteidae can be explained by a cladogenetic event associated with the break-up of the Pangaea supercontinent. Both vicariance or dispersal events could explain the presence of lepisosteids, originally from Africa or North America, in South America. Laboratório de Paleobiologia Curso de Ciências Biológicas Campus de Porto Nacional Universidade Federal do Tocantins (UFT) Departamento de Biologia e Zootecnia Faculdade de Engenharia de Ilha Solteira Universidade Estadual Paulista (UNESP) Laboratório de Paleontologia Departamento de Biologia FFCLRP Universidade de São Paulo Laboratório de Estudos Paleobiológicos Departamento de Biologia de Sorocaba Universidade Federal de São Carlos Departamento de Biologia e Zootecnia Faculdade de Engenharia de Ilha Solteira Universidade Estadual Paulista (UNESP) CAPES: 001 CNPq: 15146/2018-3 CNPq: 40808/2016-7

Cratons are conventionally assumed to be areas of long-term stability. However, whereas Precambrian basement crops out across most of the Baltic Shield, Palaeozoic and Mesozoic sediments rest on basement in southern Sweden, and thus testify to a complex history of exhumation and burial. Our synthesis of published stratigraphic landscape analysis and new apatite fission-track analysis data reveals a history involving five steps after formation of the extremely flat, Sub-Cambrian Peneplain. (1) Cambrian to Lower Triassic rocks accumulated on the peneplain, interrupted by late Carboniferous uplift and exhumation. (2) Middle Triassic uplift removed the Palaeozoic cover along the south-western margin of the shield, leading to formation of a Triassic peneplain with a predominantly flat relief followed by deposition of Upper Triassic to Lower Jurassic rocks. (3) Uplift that began during the Middle Jurassic to earliest Cretaceous caused denudation leading to deep weathering that shaped an undulating, hilly relief that was buried below Upper Cretaceous to Oligocene sediments. (4) Early Miocene uplift and erosion produced the South Smaland Peneplain with scattered hills. (5) Early Pliocene uplift raised the Miocene peneplain to its present elevation leading to reexposure of the sub-Cretaceous hilly relief near the coast. Our results thus provide constraints on the magnitude and timing of episodes of deposition and removal of significant volumes of Phanerozoic rocks across the southern portion of the Baltic Shield. Late Carboniferous, Middle Triassic and mid-Jurassic events of uplift and exhumation affected wide areas beyond the Baltic Shield, and we interpret them as epeirogenic uplifts accompanying fragmentation of Pangaea, caused by accumulation of mantle heat beneath the supercontinent. Early Miocene uplift affected north-west Europe but not East Greenland, and thus likely resulted from compressive stresses from an orogeny on the Eurasian plate. Early Pliocene uplift related to changes in mantle convection and plate motion affected wide areas beyond North-East Atlantic margins.

The Qinling Orogen, central China, was constructed during the Mesozoic collision between the North China and Yangtze continental plates. The orogen includes four tectonic units, from north to south, the Huaxiong Block (reactivated southern margin of the North China Craton), North Qinling Accretion Belt, South Qinling Fold Belt (or block) and Songpan Fold Belt, evolved from the northernmost Paleo-Tethys Ocean separating the Gondwana and Laurentia supercontinents. Here we employ detrital zircons from the Early Cretaceous alluvial sediments within the Qinling Orogen to trace the tectonic evolution of the orogen. The U–Pb ages of the detrital zircon grains from the Early Cretaceous Donghe Group sediments in the South Qinling Fold Belt cluster around 2600–2300 Ma, 2050–1800 Ma, 1200–700 Ma, 650–400 Ma and 350–200 Ma, corresponding to the global Kenorland, Columbia, Rodinia, Gondwana and Pangaea supercontinent events, respectively. The distributions of ages and eHf(t) values of zircon grains show that the Donghe Group sediments have a complex source comprising components mainly recycled from the North Qinling Accretion Belt and the North China Craton, suggesting that the South Qinling Fold Belt was a part of the united Qinling–North China continental plate, rather than an isolated microcontinent, during the Devonian–Triassic. The youngest age peak of 350–200 Ma reflects the magmatic event related to subduction and termination of the Mian-Lue oceanic plate, followed by the collision between the Yangtze Craton and the united Qinling–North China continent that came into existence at the Triassic–Jurassic transition. The interval of 208–145 Ma between the sedimentation of the Early Cretaceous Donghe Group and the youngest age of detrital zircons was coeval with the post-subduction collision between the Yangtze and the North China continental plates in Jurassic.

Subduction initiation is a cornerstone in the edifice of plate tectonics. It marks the turning point of the Earth's Wilson cycles and ultimately the supercycles as well. In this paper, we explore the consequences of subduction zone invasion in the Atlantic Ocean, following recent discoveries at the SW Iberia margin. We discuss a buoyancy argument based on the premise that old oceanic lithosphere is unstable for supporting large basins, implying that it must be removed in subduction zones. As a consequence, we propose a new conceptual model in which both the Pacific and the Atlantic oceans close simultaneously, leading to the termination of the present Earth's supercycle and to the formation of a new supercontinent, which we name Aurica. Our new conceptual model also provides insights into supercontinent formation and destruction (supercycles) proposed for past geological times (e.g. Pangaea, Rodinia, Columbia, Kenorland).

The Rheic Ocean is the most significant Paleozoic ocean that detached peri-Gondwana terranes from the northern Gondwana margin throughout the closure of the Iapetus Ocean. The suture of the Rheic Ocean spreads from Mexico to the Middle East, and the timing of its final closure is well-documented by the rocks formed in the Variscan-Alleghanian-Ouachita orogeny which led to the formation of the supercontinent Pangaea. However, as robust paleomagnetic and quantitative data are mostly lacking, the onset and evolution of the subduction of the Rheic Ocean are highly speculative, and they require further confirmation. Recently, the well-preserved metagranitoids along the western Sakarya Zone (SZ) in Anatolia have been identified, and they provide new data that improve our knowledge on the evolution of the Early Paleozoic Rheic Ocean along the northern Gondwana. Here, we present new geochronological, in situ zircon Hf isotope, and whole-rock geochemical analyses of these metagranitoids from the western SZ to enhance our understanding of the subduction processes of the Rheic Ocean. LA-ICP-MS zircon U Pb dating demonstrated that the Bozuyuk and Borcak metagranitoids from the western SZ were emplaced during the Silurian to Early Devonian (431 ± 2.7 to 403 ± 3.5 Ma). The both granitoids have medium- to high-K, calc-alkaline magmatic character, and exhibit peraluminous to slightly metaluminous geochemical signature. They showed a typical arc pattern in terms of trace elements and have a uniform, moderate negative eHf (t) of −3.2 to −9.7, with Mesoproterozoic Hf depleted mantle model ages (TDM1 = 1.2 to 1.4 Ga). The geochemical and isotopic characteristics are not consistent with those of depleted mantle melts and melts derived from the crustal rocks in an intracontinental environment. Instead, the parental magma is likely generated from the partial melting of a homogeneous and enriched mantle wedge source. We propose that the Silurian to Early Devonian arc-related magmatism is associated with a northward subduction episode of the Rheic Oceanic lithosphere beneath the peri-Gondwana terranes. Hence, we consider that the opening of Paleotethys Ocean formed in a back-arc basin of subduction in Andean style to the north rather than a continental rift to the south in response to south-directed and short-lived supra-subduction zone (SSZ)-type subduction during the Silurian to Early Devonian.

Phylogenetic analysis based on mitochondrial genomic data from 25 stonefly species recovered a well-supported tree resolving higher-level relationships within Plecoptera (stoneflies). The monophyly of both currently recognized suborders was strongly supported, concordant with previous molecular analyses of Plecoptera. The southern hemisphere suborder Antarctoperlaria formed two clades: Eustheniidae + Diamphipnoidae and Austroperlidae + Gripopterygidae; consistent with relationships proposed based on morphology. The largely northern hemisphere suborder Arctoperlaria also divided into two groups, Euholognatha and Systellognatha, each composed of the five families traditionally assigned to each infraorder (the placement Scopuridae by mt genome data remains untested at this time). Within Euholognatha, strong support for the clade Nemouridae + Notonemouridae confirmed the northern origin of the currently southern hemisphere restricted Notonemouridae. Other family level relationships within the Arctoperlaria differ from those recovered by previous morphology and molecular based analyses. A fossil-calibrated divergence estimation suggests the formation of two suborders dates back to the Jurassic (181 Ma), with subsequent diversification of most stonefly families during the Cretaceous. This result confirms the hypothesis that initial divergence between the suborders was driven by the breakup of the supercontinent Pangaea into Laurasia and Gondwanaland (commencing 200 Ma and complete by 150 Ma).

The breakup of the supercontinent Pangaea in the Middle Jurassic and the subsequent breakup of Gondwana with the formation of the South Atlantic Ocean, were two of the most prominent paleogeographic events of the Phanerozoic. Acting as a major obstacle for the Gondwanan rift propagation, the Congo-Sao Francisco Craton was an ancient and one of the most stable regions on the Eastern/Central South America and Africa. Based on paleontological and on paleogeographical data, the present manuscript discusses how the main drainage of the Sao Francisco Craton connected both northeastern marginal and the central intracratonic Brazilian regions as it does nowadays. It also deals with the history of one of the oldest and most resilient South American drainages during the transitional phase of the Gondwanan breakup. Based on the occurrence of fishes, ostracods, palynomorphs, and aquatic plants, the results presented herein suggest the existence of a previous drainage interconnecting the marginal and interior rift-related basins in a time anterior to the Aptian/Albian transgressions.

Carbonatitic dykes surrounded by K-Na-fenites were discovered in the Pelagonian Zone in Greece. Their carbonate portions have an isotopic mantle signature of δ13C and δ18O ranging from −5.18 to −5.56 (‰ vs. VPDB) and from 10.68 to 11.59 (‰ vs. VSMOW) respectively, whereas their mafic silicate portions have high Nb, Ta and ɛNd values, typical of alkaline basalts. Textural relationships hint at a cogenetic intrusion of silicate and carbonate liquids that according to antithetic REE profiles segregated at shallow depths (, Lithos, 302-303, ISSN:0024-4937

The Carboniferous and Permian were crucial intervals in the establishment of terrestrial ecosystems, which occurred alongside substantial environmental and climate changes throughout the globe, as well as the final assembly of the supercontinent of Pangaea. The influence of these changes on tetrapod biogeography is highly contentious, with some authors suggesting a cosmopolitan fauna resulting from a lack of barriers, and some identifying provincialism. Here we carry out a detailed historical biogeographic analysis of late Paleozoic tetrapods to study the patterns of dispersal and vicariance. A likelihood-based approach to infer ancestral areas is combined with stochastic mapping to assess rates of vicariance and dispersal. Both the late Carboniferous and the end-Guadalupian are characterised by a decrease in dispersal and a vicariance peak in amniotes and amphibians. The first of these shifts is attributed to orogenic activity, the second to increasing climate heterogeneity., The late Paleozoic was a time of major transition for tetrapods. Here, Brocklehurst and colleagues analyse the biogeography of Paleozoic tetrapods and find shifts in dispersal and vicariance associated with Carboniferous mountain formation and end-Guadalupian climate variability.

The much improved fossil record of the Phanerozoic allows for a more detailed analysis of changes in animal and plant assemblages. Disappearance of some animals and plants, and the proliferation of new types can be at least partly quantified. Sudden extinction and rapid development of new groups of animals provide a picture of evolutionary history which suggests that there were rather spectacular extinction events as well as both sudden and gradual emergence of new forms. The extinction events are typically the most striking, with significant percentages of extant species wiped out in a very short time, even almost instantly. Extinction events were usually followed by rapid development of new types to fill the vacated ecological space, and this has happened several times over the last 500 million years. One of the most interesting developments in the early Phanerozoic was the proliferation of animals during the Ordovician, followed by a significant extinction event at or near its close. This was soon followed by the colonization of dry land previously inaccessible to life adapted to aquatic living. This innovation opened up an enormous area of ecological space and was a key step toward the Earth as we know it. An important part of geologic study is to understand what processes may be responsible for both extinction events and the way in which long-term geological changes may result in biological “opportunities”.

Two end-member models have been invoked to accommodate the Mesozoic dispersal of the supercontinent Pangaea. In one end-member, the opening of the Atlantic Ocean is inferred to have been balanced by the closure of the Panthalassan Ocean related to subduction off the western margins of the Americas. In the other end-member model, the opening of the Atlantic Ocean is accommodated by the closure of the paleo-Tethys and Tethys oceans linked to subduction off the southern margins of Eurasia. Here, I re-evaluate global plate circulation data compiled for the middle Mesozoic Era. The present evaluation confirms that closure of the paleo-Tethys and Tethys oceans compensated for the early opening of the central Atlantic and proto-Caribbean oceans. This result implies that the tectonic evolution of the North American Cordillera was independent from the processes governing Pangaea breakup in the Jurassic and Early Cretaceous Periods. As well, the opening Atlantic and closing Tethys realm must have been tectonically connected through the Mediterranean region in terms of a transform fault or point yet to be factored into geological interpretations. Tight geometric and kinematic correlations evident between the opening Atlantic and closing Tethyan domains can be demonstrated, which are most readily explained if the forces causing Pangaea breakup were transmitted from the Tethyan domain into the Atlantic domain, and not vice versa. Thus, slab sinking–based forces produced during the evolution of the Tethyan subduction zones are hypothesized to have controlled the early Atlantic breakup of Pangaea.

The Song Ma region, which is located in the northwestern Vietnam represents the zone of amalgamation between Indochina and South China blocks. Numerous scattered ultramafic rocks occur in this region in association with Early to Middle Palaeozoic greenschists and paragneisses, and all these rocks were subjected to hydrous metamorphism and deformation. Here, we present new field data, mineral chemistry and geochemistry from a suite of hydrated peridotites within the Song Ma region and discuss the tectonic significances of the region. We also combine the available data within the Song Ma region and Indochina–South China blocks to discuss the tectonic evolution of the subduction zone. Based on the results, we suggest that the peridotites from the Song Ma are mantle residues that suffered a high degree of partial melting in a forearc tectonic setting. The present data together with the available data within the Song Ma region and the Indochina and South China blocks clearly represent a southward directed Middle Palaeozoic subduction system. The Middle Palaeozoic subduction and accretion events mark the evolutionary history along an active convergent margin between the Indochina and South China blocks, possibly related to the amalgamation of the Pangaea supercontinent. Copyright © 2015 John Wiley & Sons, Ltd.

The Late Triassic was the time of the Early Cimmerian and Indosinian orogenies that closed the Paleotethys Ocean, which occurred earlier in the Alpine-Carpathian-Mediterranean area, later in the Eastern Europe-Central Asia and latest in the South-East Asia. The Indochina Southeastern Asian and Qiangtang plates were sutured to South China. The new, large Chinese-SE Asian plate, including North and South China, Mongolia and eastern Cimmerian plates, was consolidated by the end Triassic, leaving open a large embayment of Panthalassa, known as Mongol-Okhotsk Ocean, between Mongolia and Laurasia,. The Uralian Orogeny, which sutured Siberia and Europe continued during Late Triassic times and was recorded in Novaya Zemlya. The onset of Pangaea break-up constitutes the main Late Triassic extensional event. Continental rifts originating then were filled with clastic deposits comprising mainly red beds. The pulling force of the north-dipping subduction along the northern margin of Neotethys caused drifting of a new set of plates from the passive Gondwana margin, dividing the Neotethys Ocean. Carbonate sedimentation dominated platforms on the Neotethys and Paleotethys margins as well as the Cimmerian microplates. Synorogenic turbidites and postorogenic molasses were associated with the Indosinian orogeny. The late stages of the Uralian orogeny in Timan-Pechora, Novaya Zemlya and eastern Barents regions filled the foreland basin with fine-grained, molasse sediments. Siliciclastics were common in the Siberia and Arctic regions. The widespread, large magnitude, base-level changes of the Late Triassic are interpreted as an expression of relatively rapid and substantial changes in the horizontal and vertical stress fields that affected the Pangaea supercontinent. Such stress changes may be due to abrupt changes in the speed and/or direction of plate movements, which episodically affected Pangaea.

With the amalgamation and assembly of Pangaea in the late Paleozoic, a hypothetical visitor could have traveled entirely by land from the western edge of the supercontinent in Nevada, across Laurentia and the Appalachian crest, to the plains of Eastern Europe, across the Ural Mountains in Russia, and then southward through Africa, India, Australia, and Antarctica (Fig. 6.1). The equator now trended from just south of Arizona through Texas, North Carolina, on to Algeria and out to the Paleo-Tethys Sea, a part of the Panthalassa Ocean.

The breakup of the supercontinent Pangaea over the past ~ 180 million years has left its imprint on the global distribution of species and resulted in vicariance-driven allopatric speciation. Here we test the idea that the molecular clock dates for the divergences of species whose geographic ranges were divided, should agree with the palaeomagnetic dates for the continental separations. Our analysis of recently available phylogenetic divergence dates of 42 pairs of vertebrate taxa, selected for their reduced ability to have undergone dispersal-driven speciation, demonstrates that the divergence dates in phylogenetic trees of continent-bound terrestrial and freshwater vertebrates are consistent with the palaeomagnetic dates of continental separation.

Valentine and Moores [Valentine JW, Moores EM (1970) Nature 228:657-659] hypothesized that plate tectonics regulates global biodiversity by changing the geographic arrangement of continental crust, but the data required to fully test the hypothesis were not available. Here, we use a global database of marine animal fossil occurrences and a paleogeographic reconstruction model to test the hypothesis that temporal patterns of continental fragmentation have impacted global Phanerozoic biodiversity. We find a positive correlation between global marine invertebrate genus richness and an independently derived quantitative index describing the fragmentation of continental crust during supercontinental coalescence-breakup cycles. The observed positive correlation between global biodiversity and continental fragmentation is not readily attributable to commonly cited vagaries of the fossil record, including changing quantities of marine rock or time-variable sampling effort. Because many different environmental and biotic factors may covary with changes in the geographic arrangement of continental crust, it is difficult to identify a specific causal mechanism. However, cross-correlation indicates that the state of continental fragmentation at a given time is positively correlated with the state of global biodiversity for tens of millions of years afterward. There is also evidence to suggest that continental fragmentation promotes increasing marine richness, but that coalescence alone has only a small negative or stabilizing effect. Together, these results suggest that continental fragmentation, particularly during the Mesozoic breakup of the supercontinent Pangaea, has exerted a first-order control on the long-term trajectory of Phanerozoic marine animal diversity.

Survey data of geodynamic studies, completed during the latest 20 years in Ukraine for most of its regions, have been generalized in order to summarize the results of regional studies into geo-historical line from Eoarchean to Anthropogen. For this purpose the data of stratigraphy and isotopic geochronology obtained by Ukrainian and foreign scientists within the studied territory have been used in the work. It has been shown that the basic role in contemporary concepts on the character of geodynamic processes within the territory of Ukraine is played by the results of thorough studies of deep structure of the crust and mantle, fulfilled by the Institute of Geophysics NAS of Ukraine at the high methodic level with participation of many international organizations. Methods of seismometry and seismotomography, gravimetry and magnitometry, geothermic and deep electrometry as well as paleomagnetic and tectonophysical data were actively used. The data obtained show that geodynamic processes based on plate tectonics mechanisms arc clearly manifested in the studied territory since Neoarchean. For Eoarchcan and Mesoarchean plum-tectonic mechanisms are more probably specific. Present-day structure of the shield was definitely formed between 1,8 and 1,7 Ga isochronously with formation of the micro- continent Sarmatia, its affiliation with Fennoscandia and Volgo-Uralia into the continent Baltics on the background of the supercontinent Pangea-1. Geodynamic processes in Meso-Proterozoic and Early Paleozoic are examined in discussion form and it has been shown that up to Middle Devonian they were mainly concentrated in the western part of Ukraine in the territory of the present-day Carpathians and Volyn-Podolian plate. These processes were manifested as formation of Volyn-Polessian flexure (Middle Riphean), Galitsian-Belostok basin (Late Riphean), which joined the oceans Proto-Tethys and Proto-Yapetus westward of Baltic, formation in its place of orogen of Pre-Carpathians (Vendian), formation of the Dnister pericraton and (Upper Vendian) which finishes in the southwest by Pre-Galitsian foothills, TESZ zone and the Thornquist sea. Independent study of Vendian deposits of Ukraine by paleomagnetic and tectonophysical methods has shown that at this period virtual rotation axis of the Earth was sub-parallel to present-day latitudes. Activation of geodynamic processes in the remaining territory of Ukraine began in the Devonian after formation of supcrcontinent Euro-America: formation of the Donbass branch of the ocean Paleotethys and the Prypiat-Dnieper-Donets riftogen with possible sub- oceanic crust (Upper Devonian); separation of Misian, Scythian and Turanian microplates from East-European platform and their transformation into terrains of Paleotethys; affiliation of Gondvana with Lavrasia and formation of the supercontinent Pangaea (the Permian-Triassic). Paleomagnetic studies of the Permian and Triassic dyke complexes of the western part of the Ukrainian Shield allowed to make a choice between two models of Pangaea (A and B) and to prefer the model A (vengerovskaya). In Mesozoic-Cenozoic active geodynamic processes were concentrated in the Alpine margin of the East-European platform; formation of the Mesotethys ocean and its western part Alpine Tethys (Middle Triassic); opening of the Taurean basin (Middle Triassic—Early Jurassic), its closure and formation of folding of Taurean series of rocks in North Dobrogea and West Crimea (Middle Jurassic); the opening of the West Black Sea (Upper Cretaceous) and East Black Sea (Eocene) basins; closure of the oceans of the Alpine Tethys, westward movement of micro-plates Alcapa and Tissia-Dakia and formation of the arc of the Carpathian orogen (Upper Cretaceous-Neogene); collision process in the Crimean—Black Sea region in the variant of two-layered plate tectonics and the uplift of the Mountain Crimea (Pliocene—present-day). The data resulted show that the mechanisms of paleo- and present-day geodynamics — plate tectonics and plum-tectonics explain appropriately enough all geological and geophysical phenomena observed in nature, especially those ones which were revealed during the second part of the 20 th — and 21 st centuries.

International audience; Handling Editor: M. Santosh Keywords: Marine reptiles Mesozoic Pangaea break-up Dispersal Endemism During the Mesozoic, various groups of reptiles underwent a spectacular return to an aquatic life, colonizing most marine environments. They were highly diversified both systematically and ecologically, and most were the largest top-predators of the marine ecosystems of their time. The main groups were Ichthyosauria, Sauropterygia, Thalattosauria, and several lineages of Testudinata, Crocodyliformes, Rhynchocephalia and Squamata. Here we show that the palaeobiogeographical distribution of these marine reptiles closely followed the break-up of the supercontinent Pangaea and that they globally used the main marine corridors created by this break-up to disperse. Most Mesozoic marine reptile clades exhibit a cosmopolitan, or at least pandemic, distribution very early in their evolutionary history. The acquisition of morphological adaptations to a fully aquatic life, combined to special thermophysiological characteristics, are probably responsible for these animals to become efficient long-distance open-marine cruisers. Generally, Early Triassic taxa were near-shore animals mainly linked to the Tethys or Panthalassa coastlines. By the end of the Triassic and during the Jurassic, the break-up of Pangaea resulted in the formation of large marine corridors connecting the Tethys to the North Atlantic and Pacific realms, a trend increasing on during the Cretaceous with the expansion of the Atlantic Ocean and the break-up of the southern Gondwana, allowing open-sea marine reptiles to spread out over large distances. However, if large faunal interchanges were possible at a global scale following a dispersal model, some provinces, such as the Mediterranean Tethys, were characterised by a peculiar faunal identity, illustrating an absence of migration with time despite the apparent lack of barriers. So, if Continental Drift enabled global circulations and faunal interchanges via dispersals among Mesozoic marine reptiles, other parameters, such as ecological and biological constraints, probably also played a role in the local endemic distribution of some of these marine groups, as they do today.