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<jats:p>Using pattern classification algorithms can help recognise and predict patterns in large and complex multivariate datasets. Utilising competitive learning, self-organising maps (SOMs) are known unsupervised classification tools that are considered very useful in pattern classification and recognition. This technique is based on the principles of vector quantification of similarities and clustering in a high-dimensional space, where the method can handle the analysis and visualization of high-dimensional data. The tool is ideal for analysing a complex combination of categorical and continuous spatial variables, with particular applications to geological features.</jats:p> <jats:p>In this paper, we employ the tool to predict geological features based on airborne geophysical data acquired through the Tellus project in Northern Ireland. SOMs are applied through 8 experiments (iterations), incorporating the radiometric data in combination with geological features, including elevation, slope angle, terrain ruggedness (TRI), and geochronology. The SOMs proved successful in differentiating contrasting bedrock geology, such as acidic versus mafic igneous rocks, while data clustering over intermediate rocks was not as apparent. The presence of a thick cover of glacial deposits in most of the study area presented a challenge in the data clustering, particularly over the intermediate igneous and sedimentary bedrock types.</jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.6603098">https://doi.org/10.6084/m9.figshare.c.6603098</jats:ext-link> </jats:p>

<jats:p>Dinosaur tracks are a key means of determining the palaeoecology and distribution of dinosaurs through time. They provide a highly complementary information source to the body (skeletal) fossil record but differ in preserving direct evidence of animals’ interactions with their environment. The UK has a rich history of ∼200 yrs of dinosaur track discovery but no recent synthesis exists. Here, we present a new dataset of dinosaur tracks in the UK. This dataset shows a close correlation between the distribution of terrestrial sediments and the preservation of dinosaur tracks through the Mesozoic, providing discrete snapshots into dinosaur communities in the Upper Triassic, Middle Jurassic and Lower Cretaceous. The dinosaur track record shows similar broad patterns of diversity and relative abundance of the major dinosaur groups (Theropoda, Sauropodomorpha, Ornithopoda, and Thyreophora) through time to the body fossil record, although differs in that body fossils are found (albeit infrequently) in marine sediments. There is a broad trend towards higher numbers of track occurrences through time and a notable increase in the relative abundance of ornithopod tracks following the Jurassic-Cretaceous boundary. The track record remains an underutilised resource with the potential to provide a much fuller view of Mesozoic dinosaur ecosystems.</jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.6606634">https://doi.org/10.6084/m9.figshare.c.6606634</jats:ext-link> </jats:p>

<jats:p>Regional structural cross-sections based on seismic, borehole and surface data portray the foothills geometry of the Tierra del Fuego fold-thrust belt. Andean contraction was accommodated by two main deformation mechanisms: 1) A lower duplex thrust system that involves mainly Cretaceous deposits, with floor and roof thrusts at the base of the Cretaceous and close to the base of the Cenozoic, respectively; and 2) A series of detachment and faulted detachment anticlines in the Cenozoic, detached in mudstones above the roof thrust of the underlying duplex thrust system. Less common structures include fault bend and fault propagation folds. Basement fault reactivation is only locally important, with most Jurassic grabens and half-grabens preserved without inversion. Shortening along the foothills is modest, with values ranging from ∼8 to 4.6 kilometers. This region of the fold-thrust belt has hydrocarbon exploration interest; however, it is largely underexplored. Several large anticlines preserving Cenozoic clastic rocks have not been tested to date. The key risk for these structures is the charge, as the thick mudstone package forming their detachment isolates potential Cenozoic reservoirs from the Lower Cretaceous source rocks. Duplex thrust systems at depth may constitute a potential exploration play, provided brittle intervals were naturally fractured.</jats:p>

<jats:p>While the Flemish Cap played a pivotal role in the opening of the North Atlantic, the tectonic history of this continental ribbon has been poorly constrained due to insufficient seismic coverage. In this study, we present thirteen newly acquired seismic reflection profiles over the Flemish Cap, on which seismic reflectors show highly variable seismic facies both on and beneath the top acoustic basement, with exceptional imaging of layered crustal structure. The upper crust is primarily characterized by transparent, chaotic amplitude reflectivity. The lower crust, particularly on the flanks of the cap, exhibits relatively bright and coherent reflection packages interpreted as Appalachian orogenic fabrics based on onshore-offshore correlations from pre-rift plate reconstructions. Extensional systems within the continental crust of the Flemish Cap record a transitional stage between Paleozoic orogenic collapse and pre-Jurassic rifting. The crustal architecture associated with Mesozoic rifting of the Flemish Cap is also mapped and the interpreted distinct rift domains display along-strike variations. Overall, the complex tectonic history of the Flemish Cap involved dominantly ductile deformation during the Paleozoic orogenic stage, multiple deformation styles (primarily ductile and brittle-ductile) during the orogen-to-rift transitional stage, and brittle deformation during the major Jurassic-Cretaceous rifting stage.</jats:p>

<jats:p>Global synchronisation of environmental change in terrestrial successions in deep-time is challenging due to the paucity of dating methods, a case also applicable to the Middle to Upper Triassic Mercia Mudstone Group in Britain. Using coastal cliff sections, magnetostratigraphy was evaluated at 263 horizons, defining 53 magnetozones. Magnetozones from the lower 140 m of the group demonstrate correspondence to those from the mid Ladinian to early Carnian polarity timescale, dating which is compatible with magnetostratigraphy from the underlying Sherwood Sandstone Group. Magnetostratigraphy of the Dunscombe Mudstone Formation, and associated palynological data, suggest a late Carnian to earliest Norian age, and a dramatically lower accumulation rate than adjacent formations. The polarity record demonstrates coeval flooding events, evaporite deposits and intervals of sand supply between the Wessex Basin and the Central European Basin in the Carnian. This is the result of linked climatic and eustatic changes between these separate basins, related to aeolian dust supply and the shrinkage of hyper-arid source regions for the fines. Magnetostratigraphy from the Branscombe Mudstone and Blue Anchor formations demonstrates their Norian and early Rhaetian age. These and other data suggest an alternative synchronization of marine and non-marine polarity records for the Norian polarity timescale. 198 words</jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Section details and detailed logs of the sampled sections and inferred sequence boundaries, magnetic mineralogy data, demagnetisation behaviour and mean directions, summary of virtual geomagnetic pole data and a comparison to other European poles, construction of other composite reference sections and revised polarity scales. Excel sheet of magnetic data statistically evaluated correlation models, and age models. </jats:p> <jats:p> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.6613788">https://doi.org/10.6084/m9.figshare.c.6613788</jats:ext-link> </jats:p>

<jats:p> The Bylot basins of northeastern Canada and northwestern Greenland comprise the Borden, Aston-Hunting, Fury and Hecla, and Thule basins. This system of late Mesoproterozoic ( <jats:italic>c.</jats:italic> 1.27–1.0 Ga) sedimentary basins preserves an important record of present day northeastern Laurentia coincident with the emplacement of the Mackenzie large igneous province, the Shawinigan and Ottawan phases of the Grenville Orogeny, and the development of the Midcontinent Rift. However, establishing correlations between the sedimentary successions of the Bylot basins has been hindered by the absence of robust chronostratigraphic constraints. As a result, the degree to which these basins were interconnected, whether they share a common tectonostratigraphic history, and how their sedimentary patterns relate to regional tectonic events remain open questions. Recent Re–Os geochronology from organic-rich strata has yielded depositional ages from the Borden (1048 and 1046 Ma) and Fury and Hecla (1087 Ma) basins, which we integrate with existing models for the depositional history of these basins to derive three tectonostratigraphic assemblages from the Bylot basins. We project our refined tectonostratigraphic framework for the Borden and Fury and Hecla successions to Greenland to establish a testable hypothesis for how the Thule Supergroup fits into this tectonostratigraphic picture. </jats:p>

<jats:p>The Ediacaran to Cambrian succession in the NW Yangtze Block has long been considered to have formed in a passive margin. The Ediacaran is dominated by thick carbonate rocks, whereas the Lower Cambrian comprises a thick clastic succession. The transition from carbonate to clastic rocks and the provenance and tectonic setting of the clastic succession are poorly understood. Stratigraphic correlation shows a distinct stratigraphic absence from the Lower Cambrian to Devonian in the Bikou terrane. A regional seismic profile shows a wedge geometry of the Lower Cambrian from NW to SE. Outcrops reveal an overall coarsening-upward Lower Cambrian succession. The petrographic analysis of clastic rocks indicates immaturity, implying a proximal source. Palaeocurrent measurements of clastic rocks point to dominant SE-vergent orientations. The age spectra of detrital zircons imply that they were derived from Early Cambrian continental arcs and older continental crust. Geological, geophysical and geochemical evidence indicates that an Early Cambrian foreland basin was formed in the NW Yangtze Block. This foreland basin appears to have been strongly influenced by orogenic loading northwestward. We propose that this orogenic event should be named the Motianling orogeny, the origin of which may be related to subduction of the Proto-Tethys ocean beneath the NW Yangtze Block.</jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Supplementary tables A–D and a petrological description of detrital zircons are available at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://doi.org/10.6084/m9.figshare.c.6332980">https://doi.org/10.6084/m9.figshare.c.6332980</jats:ext-link> </jats:p>

<jats:p> The Johnston Complex represents a rare inlier of the Neoproterozoic basement of southern Britain and offers a window into the tectonomagmatic regime of East Avalonia during the assembly of Gondwana. This work presents <jats:italic>in situ</jats:italic> zircon (U–Pb, Lu–Hf), apatite (U–Pb), and trace element chemistry for both minerals from the complex. Zircon and apatite yield a coeval crystallization age of 570 ± 3 Ma, and a minor antecrystic zircon core component is identified at 615 ± 11 Ma. Zircon Hf data imply a broadly chondritic source, comparable to Nd data from East Avalonia, and T <jats:sub>DM</jats:sub> <jats:sup>2</jats:sup> model ages of <jats:italic>c.</jats:italic> 1.5 Ga indicate source extraction during the Mesoproterozoic. Zircon trace element chemistry is consistent with an ensialic calc-alkaline continental arc setting and demonstrates that magmatism was ongoing prior to terrane dispersal at 570 Ma. Apatite trace element chemistry implies a sedimentary component within the melt consistent with voluminous S-type granite production during the formation of Gondwana. The similarity of the ɛHf and geochemistry between both zircon age populations suggest derivation from a uniform source that did not undergo significant modification between 615–570 Ma. Time-constrained apatite–zircon chemistry addresses complexities in dating S-type granitoids (zircon inheritance) and permits inferences on post-magmatic thermal histories. </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Zircon U–Pb, Lu–Hf and trace element data, and apatite U–Pb and trace element data are available at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.6484464">https://doi.org/10.6084/m9.figshare.c.6484464</jats:ext-link> </jats:p>

<jats:p> The behaviour of sulfur in magmas is complex because it dissolves as both sulfide (S <jats:sup>2−</jats:sup> ) and sulfate (S <jats:sup>6+</jats:sup> ) in silicate melt. Interesting aspects of the behaviour of sulfur are the solubility minimum (SS <jats:sup>min</jats:sup> ) and maxima (SS <jats:sup>max</jats:sup> ) observed with varying oxygen fugacity ( <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> ). We use a simple ternary model (silicate–S <jats:sub>2</jats:sub> –O <jats:sub>2</jats:sub> ) to explore the varying <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> paths where these phenomena occur. Both SS <jats:sup>min</jats:sup> and SS <jats:sup>max</jats:sup> occur when S <jats:sup>2−</jats:sup> and S <jats:sup>6+</jats:sup> are present in the silicate melt in similar quantities owing to the differing solubility mechanisms of melt species containing these oxidation states of sulfur. At constant <jats:italic>T</jats:italic> , a minimum in dissolved total S content in vapour-saturated silicate melt ( <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mi>w</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">T</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> <mml:mi>m</mml:mi> </mml:msubsup> </mml:math> </jats:inline-formula> ) occurs along paths of increasing <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> and either constant <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> or constant <jats:italic>P</jats:italic> . For paths on which <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mi>w</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">T</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> <mml:mi>m</mml:mi> </mml:msubsup> </mml:math> </jats:inline-formula> is held constant with increasing <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> , the SS <jats:sup>min</jats:sup> is expressed as a maximum in <jats:italic>P</jats:italic> . The SS <jats:sup>min</jats:sup> occurs when the fraction of S <jats:sup>6+</jats:sup> in the melt ([S <jats:sup>6+</jats:sup> /S <jats:sub>T</jats:sub> ] <jats:italic> <jats:sup>m</jats:sup> </jats:italic> ) is 0.25 for constant <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> and [S <jats:sup>6+</jats:sup> /S <jats:sub>T</jats:sub> ] <jats:italic> <jats:sup>m</jats:sup> </jats:italic>   <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>≈</mml:mo> </mml:math> </jats:inline-formula>  0.75 for constant <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mi>w</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">T</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> <mml:mi>m</mml:mi> </mml:msubsup> </mml:math> </jats:inline-formula> and <jats:italic>P</jats:italic> . A minimum in <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mi>w</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">T</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> <mml:mi>m</mml:mi> </mml:msubsup> </mml:math> </jats:inline-formula> is not encountered during closed- or open-system depressurization in the simple system we modelled. However, the SS <jats:sup>min</jats:sup> marks a change from reduction to oxidation during degassing. Various SS <jats:sup>max</jats:sup> occur when the silicate melt is multiply saturated with at least two phases: vapour, sulfide melt, and/or anhydrite. The SS <jats:sup>min</jats:sup> and SS <jats:sup>max</jats:sup> are potentially important features of magmatic process involving S, such as mantle melting, magma mixing, and degassing. These concepts influence calculations of the pressures of vapour-saturation, <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>f</mml:mi> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:msub> </mml:math> </jats:inline-formula> , and SO <jats:sub>2</jats:sub> emissions using melt inclusions. </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Additional information and data used to create the figures are available at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" specific-use="dataset is-supplemented-by" xlink:href="https://doi.org/10.6084/m9.figshare.c.6274527">https://doi.org/10.6084/m9.figshare.c.6274527</jats:ext-link> </jats:p> <jats:p content-type="thematic-collection"> <jats:bold>Thematic collection:</jats:bold> This article is part of the Sulfur in the Earth system collection available at: <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://www.lyellcollection.org/topic/collections/sulfur-in-the-earth-system">https://www.lyellcollection.org/topic/collections/sulfur-in-the-earth-system</jats:ext-link> </jats:p>

<jats:p>The Altai region of China features abundant granitoids, which can be used to reconstruct the tectonic evolution of the orogen. We conducted petrological, geochronological, geochemical and isotopic analyses on several representative granitoids from the Altai region. U‒Pb dating revealed ages of 444 ± 3 Ma for gneissic granites, 406 ± 8 Ma for syenogranites, 280 ± 6 Ma for diorites, 278 ± 3 Ma for two-mica monzonitic granites and 269 ± 3 Ma for muscovite granites. The Ordovician gneissic granites have I-type arc-related element characteristics and are derived from volcanic magmas extracted from the mantle wedge and then metasomatized by subducted sediment in a continental arc. The Devonian syenogranites show dual I-type arc and within-plate granite geochemical signatures, suggesting derivation from volcanic magmas extracted from the lithospheric mantle metasomatized by subducted fluid/melt in a back-arc basin. The Permian diorites are Mg-diorites derived from a mixed-magma source involving residual subducted basaltic oceanic crust and lithospheric mantle. The two-mica monzonitic granites are S-type granites originating from the crustal recycling of sedimentary rocks, whereas the muscovite granites are leucogranites resulting from the anatexis of ancient metasedimentary rocks. Their tectonic setting is syn-/post-collisional. By combining these results with previously published data, we propose that the Chinese Altai region experienced mid- to late Ordovician continental arc magmatism, early to mid-Devonian back-arc extension and early to mid-Permian arc–arc syn-/post-collision.</jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Supplementary Tables S1–S3 are available at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://doi.org/10.6084/m9.figshare.c.6420236">https://doi.org/10.6084/m9.figshare.c.6420236</jats:ext-link> </jats:p>