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Breakup and sea-floor spreading between Greenland and Eurasia established a series of new plate boundaries in the North Atlantic region since the Late Palaeocene. A conventional kinematic model from pre-breakup to the present day assumes that Eurasia and Greenland moved apart as a two-plate system. However, new regional geophysical datasets and quantitative kinematic parameters indicate that this system underwent several adjustments since its inception and suggest that additional short-lived plate boundaries existed in the NE Atlantic. Among the consequences of numerous plate boundary relocations is the formation of a highly extended or even fragmented Jan Mayen microcontinent and subsequent deformation of its margins and surrounding regions. The major Oligocene plate boundary reorganization (and microcontinent formation) might have been precluded by various ridge propagations and/or short-lived triple junctions NE and possibly SW of the Jan Mayen microcontinent from the inception of sea-floor spreading (54 Ma) to C18 (40 Ma). Our model implies a series of failed ridges offshore the Faeroe Islands, a northern propagation of the Aegir Ridge NE of the Jan Mayen microcontinent, and a series of triple junctions and/or propagators in the southern Greenland Basin.

The Central Asian Orogenic Belt (c. 1000-250 Ma) formed by accretion of island arcs, ophiolites, oceanic islands, seamounts, accretionary wedges, oceanic plateaux and microcontinents in a manner comparable with that of circum-Pacific Mesozoic-Cenozoic accretionary orogens. Palaeomagnetic and palaeofloral data indicate that early accretion (Vendian-Ordovician) took place when Baltica and Siberia were separated by a wide ocean. Island arcs and Precambrian microcontinents accreted to the active margins of the two continents or amalgamated in an oceanic setting (as in Kazakhstan) by roll-back and collision, forming a huge accretionary collage. The Palaeo-Asian Ocean closed in the Permian with formation of the Solonker suture. We evaluate contrasting tectonic models for the evolution of the orogenic belt. Current information provides little support for the main tenets of the one- or three-arc Kipchak model; current data suggest that an archipelago-type (Indonesian) model is more viable. Some diagnostic features of ridge-trench interaction are present in the Central Asian orogen (e.g. granites, adakites, boninites, near-trench magmatism, Alaskan-type mafic-ultramafic complexes, high-temperature metamorphic belts that prograde rapidly from low-grade belts, rhyolitic ash-fall tuffs). They offer a promising perspective for future investigations.

Analysis of the distribution of detrital zircon grains is one of the few parameters by which Precambrian palaeogeography may be interpreted. However, the break-up of Pangea and the subsequent dispersal of some of its fragments around the Indian Ocean demonstrate that zircon analysis alone may be misleading, since zircons indicate their original derivation and not their subsequent plate-tectonic pathways. Based on analysis of Precambrian–Ordovician zircon distributions, the presence of microcontinents and separating oceans in the north Gondwanan realm has been rejected in favour of an undivided pre-Variscan continental northwards extension of Africa to include Iberia, Armorica and neighbouring southern European terranes, based on analysis of Precambrian–Ordovician zircon distribution. However, contrasting views, indicating the presence of three peri-Gondwanan oceans with complete Wilson cycles, are reinforced here by a critical reappraisal of the significance of that Variscan area detrital zircon record together with a comparison of the evolution of the present-day Indian Ocean, indicating that Iberia, Armorica and other terranes were each separate from the main Gondwanan craton during the early Palaeozoic Era.

A rich but poorly preserved Lower Tithonian faunal assemblage is reported from the abandoned limekilns at Zengővárkony (Mecsek Mountains, Hungary). Except the Darwini Zone, all Lower Tithonian ammonite chronozones (Hybonotum, Semiforme, Fallauxi, and Peroni/Ponti) zones are recognised Fallauxi and Ponti/Peroni zones are first recorded from the region. The pelagic fauna is dominated by ammonites and their aptychi. Brachiopods, belemnites, and very rarely bivalves are accessory elements of the fauna. The mollusc fauna comprises 167 specimens that represent 18 genera and 13 species. Volanoceras sp. ex gr. volanense, Pseudopallasiceras? sp., Biplisphinctes pseudocolubrinus, Aulacosphinctoides sp. ex gr. infundibulum, and Physodoceras cf. widerai are first records from the Mecsek Mountains. The ammonite fauna has typical Mediterranean character. Based on cluster analysis, the fauna is closest to the ammonite assemblages of the Transdanubian Range (Hungary).

This contribution provides an overview on geology, geochronology, and tectonics of Precambrian basement massifs and adjoining Gyeonggi Marginal Belt (GMB), Korea. The three massifs (Gyeonggi, Yeongnam, and Nangrim) record tectonothermal events represented by ∼2.0–1.85 Ga arc-related magmatism and collisional orogenesis, culminating at ∼1.88–1.85 Ga. The oldest (∼2.51 Ga) migmatitic gneisses limitedly occur in the Nangrim and Gyeonggi massifs, suggesting the North China Craton (NCC) affinity of both massifs. The Yeongnam Massif is characterized by the occurrence of ∼1.87–1.86 Ga anorthosite-mangerite-charnockite-granite suite. This anorthositic suite is a late-orogenic product linked to the amalgamation of ‘Paleoproterozoic Korean arc’ with the North China Craton, forming the Columbia/Nuna supercontinent. The majority of Hf and Nd model ages of basement gneisses are in the range of ∼3.5–2.5 Ga, attesting to the crustal evolution since the Paleoarchean. P-T paths of the Paleoproterozoic basement gneisses are apparently variable, and the Gyeonggi and Yeongnam massifs are characterized by the kyanite-sillimanite and andalusite-sillimanite facies types, respectively. The GMB comprises three fold-and-thrust sub-belts (Imjingang Belt, Taean–Hongseong Complex, and Ogcheon Metamorphic Belt) which are correlative with each other in terms of tectonostratigraphy and detrital zircon geochronology. Two (meta)sedimentary units are diagnostic of this belt: (1) the Neoproterozoic Sangwon Supergroup sharing the provenance with younger rocks in the Ogcheon Belt; and (2) the Devonian turbiditic sequences present in all the three sub-belts. The latter are most distinctive in their detrital zircon age distribution characterized by two major populations at ∼1000–950 Ma and 450–430 Ma. This age pattern as well as the turbiditic lithology is critical for the correlation between the GMB and the Qinling Belt. Taken together, we suggest that the South China Craton-like GMB units are built upon the NCC-like basement (Gyeonggi Massif); this feature is the key to the Qinling–Gyeonggi microcontinent model which accounts for the assembly of a variety of tectonic slivers in the GMB.

Volcanostratigraphic and igneous province mapping of the Jan Mayen microcontinent (JMMC) and Iceland Plateau Rift (IPR) region have provided new insight into the development of rift systems during breakup processes. The microcontinent's formation involved two breakup events associated with seven distinct tectono‐magmatic phases (∼63–21 Ma), resulting in a fan‐shaped JMMC‐IPR igneous domain. Primary structural trends and anomalous magmatic activity guided initial opening (∼63–56 Ma) along a SE‐NW trend from the European margin and along a WNW‐ESE trend from East Greenland. The eastern margin of the microcontinent formed during the first breakup (∼55–53 Ma), with voluminous subaerial volcanism and emplacement of multiple sets of SSW–NNE‐aligned seaward‐dipping reflector sequences. The more gradual, second breakup (∼52–23 Ma) consisted of four northwestward migrating IPR (I–IV) rift zones along the microcontinent's southern and western margins. IPR I and II (∼52–36 Ma) migrated obliquely into East Greenland, interlinked via segments of the Iceland‐Faroe Fracture Zone, in overlapping sub‐aerial and sub‐surface igneous formations. IPR III and IV (∼35–23 Ma) formed a wide igneous domain south and west of the microcontinent, accompanied by uplift, regional tilting, and erosion as the area moved closer to the Iceland hotspot. The proto‐Kolbeinsey Ridge formed at ∼22–21 Ma and connected to the Reykjanes Ridge via the Northwest Iceland Rift Zone, near the center of the hotspot. Eastward rift transfers, toward the proto‐Iceland hotspot, commenced at ∼15 Ma, marking the initiation of segmented rift zones comparable to present‐day Iceland. Plain Language Summary The Jan Mayen microcontinent within the central NE‐Atlantic formed during two breakup processes that involved seven distinct magmatic and tectonic phases over a period of ∼40 million years (∼63–21 Ma). Compilation of geophysical, geological, and geochemical data has illuminated details of rifting processes during the two breakup events. The first breakup event separated the eastern margin of the Jan Mayen microcontinent (JMMC) from the Norwegian margin, at the opening of the NE‐Atlantic by rifting along the now extinct Aegir Ridge. The second breakup, separation of the western margin from E‐Greenland, was encompassed four IPR (I‐IV) rift zones migrating north‐westward into the microcontinent's southern and western margins. The IPR rift zones, interlinked via fracture zone segments, produced overlapping sub‐aerial and sub‐surface igneous sequences, and anomalously thick igneous crust. The separation of the JMMC‐IPR area from East Greenland (∼35–23 Ma) was accompanied by uplift, regional tilting, and erosion under the influence of the Iceland hotspot. The proto‐Kolbeinsey Ridge formed during the next rift event (∼22–21 Ma) connecting to the Reykjanes Ridge, via the Iceland region. Rift transfer towards the centre of the hotspot beneath proto‐Iceland (∼15 Ma) shifted the plate boundary eastward, similar to the layout of present‐day Iceland. Key Points Structural inheritance, oblique rift‐transform, and tectonics characterize continental breakup and seafloor spreading in the NE Atlantic Asymmetric rift propagation and hotspot‐ridge interaction from breakup to present‐day Iceland Four rift stages within the Iceland Plateau conditioned the breakup of the Jan Mayen microcontinent from Greenland

New detrital U–Pb zircon ages from the Sanandaj–Sirjan metamorphic zone in the Zagros orogenic belt allow discussion of models of the late Neoproterozoic to early Palaeozoic plate tectonic evolution and position of the Iranian microcontinent within a global framework. A total of 194 valid age values from 362 zircon grains were obtained from three garnet-micaschist samples. The most abundant detrital zircon population included Ediacaran ages, with the main age peak at 0.60 Ga. Other significant age peaks are at c. 0.64–0.78 Ga, 0.80–0.91 Ga, 0.94–1.1 Ga, 1.8–2.0 Ga and 2.1–2.5 Ga. The various Palaeozoic zircon age peaks could be explained by sediment supply from sources within the Iranian microcontinent. However, Precambrian ages were found, implying a non-Iranian provenance or recycling of upper Ediacaran–Palaeozoic clastic rocks. Trace-element geochemical fingerprints show that most detrital zircons were sourced from continental magmatic settings. In this study, the late Grenvillian age population at c. 0.94–1.1 Ga is used to unravel the palaeogeographic origin of the Sanandaj–Sirjan metamorphic zone. This Grenvillian detrital age population relates to the ‘Gondwana superfan’ sediments, as found in many Gondwana-derived terranes within the European Variscides and Turkish terranes, but also to units further east, e.g. in the South China block. Biogeographic evidence proves that the Iranian microcontinent developed on the same North Gondwana margin extending from the South China block via Iran further to the west.

Seven granitoid gneisses from the contact zone between the eastern margin of the Variscan belt and the Brunian microcontinent in SW Poland have been dated by ion-microprobe and 207Pb/206Pb single zircon evaporation methods. The zircons define two age groups for the gneiss protoliths: (1) late Neoproterozoic c. 576–560 Ma and (2) early Palaeozoic c. 488–503 Ma granites. The granitoid gneisses belonging to the basement of the Brunian microcontinent contain abundant Mesoproterozoic to latest Palaeoproterozoic inherited material in the range of 1200–1750 Ma. The gneisses of the Variscan crustal domain lack Mesoproterozoic inherited zircon cores. Trace element geochemistry of Proterozoic gneisses reveals features resembling either volcanic arc or post-collisional granites. The studied rocks are geochemically similar to other Proterozoic orthogneisses derived from the basement of the Brunian microcontinent. Gneisses with early Palaeozoic protolith ages are geochemically comparable to granitoid gneisses widespread in the adjacent Sudetic part of the Bohemian Massif and are considered characteristic of peri-Gondwanan crust. Our data prove the dissimilarity between the Brunia plate and the westerly terranes of the Variscan belt. The occurrence of granitic gneisses with late Neoproterozoic protolith ages and widespread Mesoproterozoic inheritance in our dated samples support an East Avalonian affinity for the Brunian microcontinent. In contrast, the abundance of gneisses derived from an early Palaeozoic granitic protolith and devoid of Mesoproterozoic zircon cores supports the Armorican affinity of the Variscan domain bordering on the Brunia plate from the west. Structural evidence shows that the eastern segment of the Variscan belt is juxtaposed against the Brunian microcontinent along a N–S-trending tectonic contact, possibly equivalent to the Rheic suture.

Throughout the high Arctic, from northern Canada (Pearya) to eastern Greenland, Svalbard, Franz Josef Land, Novaya Zemlya, Taimyr and Severnaya Zemlya and, at lower Arctic latitudes, in the Urals and the Scandinavian Caledonides, there is evidence of the Grenville–Sveconorwegian Orogen. The latest orogenic phase (c. 950 Ma) is well exposed in the Arctic, but only minor Mesoproterozoic fragments of this orogen occur on land. However, detrital zircons in Neoproterozoic and Palaeozoic successions provide unambiguous Mesoproterozoic to earliest Neoproterozoic (c. 950 Ma) signatures. This evidence strongly suggests that the Grenville–Sveconorwegian Orogen continues northwards from type areas in southeastern Canada and southwestern Scandinavia, via the North Atlantic margins to the high Arctic continental shelves. The widespread distribution of late Mesoproterozoic detrital zircons far to the north of the Grenville–Sveconorwegian type areas is usually explained in terms of long-distance transport (thousands of kilometres) of either sediments by river systems from source to sink, or of slices of lithosphere (terranes) moved on major transcurrent faults. Both of these interpretations involve much greater complexity than the hypothesis favoured here, the former involving recycling of the zircons from the strata of initial deposition into those of their final residence and the latter requiring a diversity of microcontinents. Neither explains either the fragmentary evidence for the presence of Grenville–Sveconorwegian terranes in the high Arctic, or the composition of the basement of the continental shelves. The presence of the Grenville–Sveconorwegian Orogen in the Arctic, mainly within the hinterland and margins of the Caledonides and Timanides, has profound implications not only for the reconstructions of the Rodinia supercontinent in early Neoproterozoic time, but also the origin of these Neoproterozoic and Palaeozoic mountain belts.

During the early Bajocian, a conspicuous coal-bearing siliciclastic succession was deposited in the northern Tabas Bock, which is important for understanding the regional geodynamics of the Central-East Iranian Microcontinent (CEIM) as well as for the Jurassic coal genesis in this part of Laurasia. Sedimentary facies analysis in a well-exposed section of the lower Bajocian Hojedk Formation (Kalshaneh area, northern Tabas Block) led to the recognition of ten characteristic sedimentary facies and three facies associations, representing channels with point bars and floodplains of a Bajocian meandering river system. Modal analysis indicates that the mature quartz arenites and quartzo-lithic sandstones of the Hojedk Formation originated from the erosion and recycling of older, supracrustal sedimentary rocks on the Yazd Block to the west. The coal petrography and maturity show an advanced maturation stage, whereas the great thickness of these continental strata points to a pronounced extension-related subsidence in the northern Tabas Block. The rapid rate of differential subsidence can be explained by accelerated normal block-faulting in the back-arc extensional basin of the CEIM, facing the Neotethys to the south. Compared to the thick Jurassic, the post-Jurassic strata are relatively thin and played a limited role in the thermal history of the coal in the northern Tabas Block. A relatively high geothermal gradient in the tectonically highly mobile area of the northern Tabas Block and/or heating by regionally widespread Palaeogene intrusions were most probably the key drivers of the thermal maturation of the Middle Jurassic coals.