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<jats:p> The Pb isotope composition of crustal rocks often varies in its proportions of radiogenic Pb, formed by the decay of Th and U. In most cases, it is impossible to trace this radiogenic Pb from its source, through dilution, to a reservoir dominated by common Pb. Nolans Bore is a Th-rich REE ore deposit in the Northern Territory, Australia, in which this progression is recorded in various minerals. We show <jats:sup>208</jats:sup> Pb/ <jats:sup>204</jats:sup> Pb ratios greater than 100 000 in thorianite and 10 000 in thorite, with subsequent dilution by common Pb recorded by stetindite and ekanite ( <jats:sup>208</jats:sup> Pb/ <jats:sup>204</jats:sup> Pb = 600–800) and, relative to common Pb, a strongly radiogenic signal contained in late-stage zeolite veins ( <jats:sup>208</jats:sup> Pb/ <jats:sup>204</jats:sup> Pb = 40–80). Pyrite intimately associated with thorite inherits a highly radiogenic <jats:sup>208</jats:sup> Pb/ <jats:sup>204</jats:sup> Pb ratio of <jats:italic>c.</jats:italic> 2000, and nearby galena crystallized during a regional fluid flow event (Alice Springs Orogeny) is likewise radiogenic at <jats:sup>208</jats:sup> Pb/ <jats:sup>204</jats:sup> Pb = 100–120. Microbeam chemical dating of primary thorianite records the magmatic formation of Nolans Bore at 1521 ± 54 Ma (2 <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>σ</mml:mi> </mml:math> </jats:inline-formula> ), and secondary thorite records the Alice Springs Orogeny at 359 ± 10 Ma (2 <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>σ</mml:mi> </mml:math> </jats:inline-formula> ). </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material</jats:bold> : Sample locations, LA-ICP-MS measuring conditions and data, geochemical data and R code for data processing and figure generation 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.6086210">https://doi.org/10.6084/m9.figshare.c.6086210</jats:ext-link> </jats:p>

<jats:p> The detrital zircon grains from two catchments in the East Eifel Volcanic Field consist of crystals sourced from proximal deposits of Quaternary trachytic–phonolitic volcanic centres, Hocheifel Paleogene trachytic rocks and the Paleozoic basement. The outcrop patterns indicate the derivation of a significant detrital zircon population from deposits of the <jats:italic>c.</jats:italic> 13 ka Lower and Upper Laacher See Tephra. Intercalated Middle Laacher See Tephra, consisting of valley-filling ignimbrites, by contrast, is a minor zircon source despite thick ignimbrite deposits in one of the catchments. This reflects zircon undersaturation in the hotter and less evolved phonolite tapped from deeper parts of the magma reservoir as the eruption unfolded, as well as fewer antecrysts recycled from the plutonic carapace. A previously unrecognized zircon age population of <jats:italic>c.</jats:italic> 63 ka, mostly derived from Lower Laacher See Tephra, marks the onset of the presence of evolved magma at the top of the reservoir. Correlative Hf and O isotopic analysis reveals significant crustal interactions during phonolite differentiation in a shallow reservoir, with the assimilation of cogenetic, but hydrothermally modified, plutonic margins. Raman spectra indicate that magmatically heated crustal zircon xenocrysts are absent. Detrital zircon can thus provide more integrated insights into the evolution of Quaternary magma systems than the punctuated sampling of volcanic or cogenetic plutonic rocks. </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Data tables presenting U–Th, U–Pb, O–Hf and Raman geochronology results 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.6123823">https://doi.org/10.6084/m9.figshare.c.6123823</jats:ext-link> </jats:p>

<jats:p>Charred fossils from the Wenlock (Wales) and Ludlow (Poland) are evidence of the earliest wildfires to date, showing this phenomenon was contemporaneous with the earliest records of land plant macrofossils. These data indicate fires began to influence Earth system processes alongside those wrought by the advent of an embryophytic terrestrial flora. By the mid-Silurian, fires affected atmospheric composition, sedimentary systems, carbon-and-nutrient cycling, landscape diversity, community composition, and species interactions. As global-heating alters wildfire regimes, greater recognition is being given to fires and their ecosystem impacts, a relationship we now know extends back &gt;430 million years.</jats:p> <jats:p>Here we document the taxonomic composition of charred phytoclasts, evidence of wildfire activity, from two discrete Silurian localities–the Pen-y-lan Mudstone, Rumney, Wales, and the Winnica Formation, Holy Cross Mountains, Poland. Nematophytes dominate each mesofossil assemblage and quantitative reflectance data indicate generally low-temperature fires at both sites, but with locally intense conditions. These and other Silurian assemblages, herein documented as bearing-charcoal, are used to evaluate the systematics, fuel load, and burn temperatures of these earliest wildfires. We propose a diagrammatic reconstruction to explain the seeming disparity between the diminutive size of the embryophytic biota and the highest temperatures (&gt;700˚ C) recorded in these charcoals.</jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> [Raw Mean Random Reflectance (R <jats:sub>o</jats:sub> %) data from Rumney Borehole, Winnica, Ludford Lane and North Brown Clee Hill sorted by both Locality and Morphotype] is 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.6179309">https://doi.org/10.6084/m9.figshare.c.6179309</jats:ext-link> </jats:p>

<jats:p> The Normalized Hotspot Indices (NHI) is a multi-channel algorithm developed to map thermal anomalies through the Multispectral Instrument onboard the Sentinel-2 satellite and the Operational Land Imager onboard the Landsat-8 satellite. The algorithm runs operationally under the Google Earth Engine platform and allows the analysis of volcanic thermal features (e.g. lava flows/lakes) through plots of the number of hot pixels, the total shortwave infrared radiance and the area of the hotspot. We present here the automated module of this tool: the NHI system. This system provides automated notifications about volcanic thermal anomalies detected at the global scale over the previous 48 h whenever the NHI web site ( <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://sites.google.com/view/nhi-tool">https://sites.google.com/view/nhi-tool</jats:ext-link> ) is accessed. The results of the first six months of operation are assessed through the analysis of satellite imagery and comparison with well-established programmes for global volcano monitoring. The low false positive rate (around 15%, including vegetation fires and data issues) and the successful identification of small, high-temperature features show that the NHI system may successfully integrate information from high temporal/low spatial resolution satellite data, despite some limitations (e.g. temporal sampling of the combined Sentinel-2 and Landsat-8 observations; delay of data ingestion in the Google Earth Engine platform). The recent ingestion of Landsat-9 data within the system has further extended the performance of the NHI system in supporting the surveillance of active volcanoes from space. </jats:p>

<jats:p> Histories of vertical lithospheric motions provide important clues about geodynamic processes. We present evidence of an ancient ( <jats:italic>c.</jats:italic> 58–55 Ma) landscape that probably underwent rapid uplift and subsidence during the initiation of the Icelandic plume. Now buried beneath <jats:italic>c.</jats:italic> 0.4–0.8 km of rock in the North Bressay region in the North Sea, this landscape is located within a sedimentary basin on the margin of the North Atlantic Ocean. We use high-resolution 3D seismic reflection data to map this ancient surface. Correlation of stratigraphy with a survey in the Bressay region constrains the age and depositional environment. The landscape contains excellent evidence of meandering fluvial channels, some of which record avulsions, that terminate against a coastline to the east where deltaic landforms are identified. The landscape was depth-converted and decompacted to generate a digital elevation model from which river profiles were extracted. Their geometries indicate that the landscape was generated by three phases of uplift. This history of uplift and subsidence is analogous to similar-aged landscapes in the Judd area <jats:italic>c.</jats:italic> 400 km to the west and Bressay <jats:italic>c.</jats:italic> 30 km to the south, and appears to be another manifestation of lithospheric motions generated by the passage of warm thermal anomalies away from the Icelandic plume. </jats:p>

<jats:p> The Jurassic magmatism in the southeastern South China Block has been interpreted as extension-related, yet its tectonic drivers remain unclear. Tectonic models vary between two end-members: (1) Palaeopacific subduction-related; and (2) intracontinental extension-related. This study presents new geochronological and geochemical data for the Late Jurassic mafic rocks in the southeastern South China Block that allow us to differentiate between these tectonic models. The Late Jurassic mafic rocks yielded crystallization ages of 162–157 Ma. Our new geochemical data, together with previously published data, can be divided into three groups: group A with variable <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> </mml:math> </jats:inline-formula> <jats:sub>Nd</jats:sub> ( <jats:italic>t</jats:italic> ) (+0.1 to +3.4) and zircon <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> </mml:math> </jats:inline-formula> <jats:sub>Hf</jats:sub> ( <jats:italic>t</jats:italic> ) (−4.1 to +15.9) values has slightly negative Nb–Ta anomalies; group B is characterized by negative Nb–Ta anomalies with varying <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> </mml:math> </jats:inline-formula> <jats:sub>Nd</jats:sub> ( <jats:italic>t</jats:italic> ) (+1.4 to +1.5) and <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> </mml:math> </jats:inline-formula> <jats:sub>Hf</jats:sub> ( <jats:italic>t</jats:italic> ) (–3.0 to +2.6) values; and group C displays significant Nb–Ta anomalies with high <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> </mml:math> </jats:inline-formula> <jats:sub>Nd</jats:sub> ( <jats:italic>t</jats:italic> ) (+4.5 to +6.6) and <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> </mml:math> </jats:inline-formula> <jats:sub>Hf</jats:sub> ( <jats:italic>t</jats:italic> ) (+6.4 to +14.4) values. The geochemical characteristics suggest that groups A and B are mainly the products of asthenosphere–lithosphere interactions and group C was derived from the asthenosphere. Our new data, together with geological observations, suggest that the Late Jurassic magmatism in the southeastern South China Block probably resulted from asthenospheric upwelling in an intracontinental extension setting due to the far-field effects of the subduction of the Palaeopacific Ocean. </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Tables of geochronological data, geochemical data, and additional 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.6080871">https://doi.org/10.6084/m9.figshare.c.6080871</jats:ext-link> </jats:p>

<jats:p> Apatite (U–Th)/He and apatite fission-track thermochronology is used to constrain the cooling and uplift history of the southern Antarctic Peninsula where easterly-directed subduction of the Phoenix Plate, including ridge–trench collisions, has been taking place along its western margin since the Late Cretaceous. Apatite ages and thermal history models are similar on eastern Palmer Land but are younger and vary across westernmost Palmer Land and Alexander Island. Transformation of thermal history models to a single plot shows how cooling rates varied as a function of distance from the trench zone. Eastern Palmer Land preserves a record of uplift during the Late Cretaceous that coincides with changes in Phoenix Plate convergence rates and direction. In contrast, western Palmer Land and Alexander Island experienced a period of increased rates of cooling between <jats:italic>c.</jats:italic> 25 and 15 Ma. This younger phase of exhumation is bounded by major fault zones related to the extension and rifting that formed the present-day George VI Sound. It was probably triggered by cessation of subduction owing to trench collision of a ridge segment NE of the Heezen fracture zone. No evidence was found for slab window influences as seen along the northernmost part of the Antarctic Peninsula. </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> QTQt thermal models, a PDF with analytical protocols and supplementary tables 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.6086234">https://doi.org/10.6084/m9.figshare.c.6086234</jats:ext-link> </jats:p>

<jats:p> One of the fundamental questions about Earth processes that is still outstanding is how far a moving plate can drag plume material at its base after its initial impact with the plume. The IODP-362 Expedition recovered igneous samples from drilled sites near Ninetyeast Ridge (NER) in the Indian Ocean. A detailed geochemical and isotopic (Sr–Nd) investigation of these samples found that the basement basalts of the core are typical N-MORB tholeiites, but the igneous sills intruding the upper layer of sediments are highly alkaline, with a composition equivalent to the Kerguelen plume magma. Based on biostratigraphy, the minimum age of the alkaline samples was calculated as <jats:italic>c.</jats:italic> 58 Ma, which is younger than the adjacent NER crust ( <jats:italic>c.</jats:italic> 82–78 Ma). The existence of such young plume magma amidst the older blocks of the NER is unusual and contrary to its southwards-younging age pattern. We propose that the fast-moving Indian plate dragged a considerable amount of Kerguelen plume material underneath the Indian Ocean lithosphere northwards during the Cretaceous–Paleocene, covering a longitudinal distance of <jats:italic>c.</jats:italic> 2220 km. The reactivation of deep fractures triggered decompression melting of the underlying plume material and emplaced this as magmatic sills and lava flows near the NER at <jats:italic>c.</jats:italic> 58 Ma. </jats:p>

<jats:p> Aseismic ridges and oceanic plateaux, typically buried under thick post-rift sediments, are isolated entities of enigmatic crustal character. Limited availability of deep seismic soundings hinders their precise characterization. Here, we present new crustal images from the Comorin ridge and adjoining basins in the Central Indian Ocean. Further, we seismically characterize the oldest oceanic crust south of Sri Lanka. We observe that the NW–SE-trending Comorin ridge, having distinct topography, is bounded by crustal blocks of contrasting ages and characters. Using seismic interpretation and potential field modelling, we propose its genesis as a transverse ridge with an anomalously thick ( <jats:italic>c.</jats:italic> 14 km) oceanic crust including considerable magmatic underplating. Additional constraints from plate reconstruction modelling suggest that a linear oceanic transform developed between India and Madagascar during their separation while the Marion hotspot remained in their close proximity. Based on several lines of evidence, we infer that shearing motion along the transform and coeval hotspot interactions are the likely emplacement mechanism for the ridge. The high-resolution seismic images demonstrate widespread crustal deformation in the form of high-angle faulting and long-wavelength folding. New findings have important implications for an improved understanding of the early Gondwana break-up, seafloor creation and subsequent compressional tectonics in the Indian Ocean. </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material</jats:bold> : Supplementary figures and tables 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.6073139">https://doi.org/10.6084/m9.figshare.c.6073139</jats:ext-link> </jats:p>

<jats:p> Detrital zircon U–Pb geochronology is a widely used technique for interpreting sedimentary provenance in basin systems. This, combined with detailed sedimentary facies interpretation and stratigraphy evolution, has been extensively applied in foreland basin settings to understand tectonic processes by tracking the exposure and erosion of distinct sediment source areas through time. We present a case study in the Miocene foreland sedimentary record of the NW Austral–Magallanes Basin ( <jats:italic>c.</jats:italic> 47° 30′ S), which is associated with the main phase of Andean uplift. We define three sedimentary units (SU) for palaeoenvironmental interpretation from shallow-marine deposits (SU-I) to mixed-load fluvial deposits (SU-II) to an alluvial fan (SU-III). Also, we constrain the timing of this synorogenic clastic wedge between <jats:italic>c.</jats:italic> 20 and <jats:italic>c.</jats:italic> 12 Ma applying U–Pb zircon maximum depositional ages of six sandstones and one tuff sample. From detrital zircon provenance analysis, we document a progressive upsection loss of contribution from younger units and an enrichment of older units derived from hinterland sources, suggesting the development of an unroofing erosional process owing to coeval Andean uplift of the cordilleran sources. Tectonostratigraphic stages determine the initial stages of orogenic uplift (Stage 1), the subsequent advance of the orogenic belt and progressive loss of accommodation space (Stage 2) and finally foreland clogging (Stage 3). </jats:p> <jats:p content-type="supplementary-material"> <jats:bold>Supplementary material:</jats:bold> Geochronological U–Pb isotopic ratios 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.6132000">https://doi.org/10.6084/m9.figshare.c.6132000</jats:ext-link> </jats:p>