To investigate whether the presence of helium in apatite slows fission track (FT) annealing, we performed isothermal annealing experiments on large Durango apatite crystals in which we had created He-depleted rims and He-retaining cores. Single crystals were annealed at 310 °C under vacuum for 30–270 min to stimulate helium diffusion and damage annealing, after which spontaneous FT lengths were measured separately in rim and core regions. An unannealed control sample showed no rim–core length difference, indicating negligible geometric or etching bias. With increasing annealing duration, rim tracks shorten more than core tracks, and rim–core length distributions and means diverge significantly after ∼90 min. We interpret this rim–core contrast as evidence that helium impedes FT annealing, consistent with helium stabilization of defect structures known to occur in irradiated solids. These results imply that FT annealing kinetics is affected by helium content, with potential consequences for both apatite FT and (U–Th)/He thermochronometry.

Apatite fission-track (FT) thermochronology is widely used for constraining the thermal evolution of crustal rocks. However, manual FT identification is time-intensive and subjective. Although recent AI-based approaches have shown promise, performance often declines for complex, natural samples due to limited and overly idealised training data. We introduce two open-access convolutional neural networks (CNNs) for automatic detection of surface-intersecting FTs in apatite and mica. The first, HALtracks 2D, uses paired reflected- and transmitted-light surface images, while HALtracks 3D incorporates an additional 3D stack of transmitted light images. HALtracks 2D exhibits mean accuracies (94.2-91.6 %) that are as good or better than both HALtracks 3D and all previous FT algorithms across a broad range of apatite fission track densities (up to 8.54 x 10(6) tracks/cm(2)) on expert-curated reference data. This improvement is due to a comprehensive training dataset comprising a wider range of track densities and etch-pit morphologies. Unexpectedly, HALtracks3D performed worse (91.5-80.1 %), likely because reflected-light information-critical for recognising track openings-became underrepresented among multiple transmitted-light inputs during CNN training. At very high track densities (>8.54 x 10(6) tracks/cm(2)) pushing the analytical boundaries of optical fission-track counting, Coincidence Mapping (Gleadow et al., 2009) remains more accurate than HALtracks 2D. Thermochronologists might therefore consider utilising a combination of automated fission-track algorithms depending on FT density. Future work could expand the open-access training dataset to include a broader range of apatite FT specimens, and increased metadata for targeted CNN training on spurious features such as surface imperfections and dislocations, which are misidentified as fission tracks by existing algorithms. The open-access testing dataset presented here provides a benchmark for evaluating future FT algorithms. Nevertheless, HALtracks 2D's enhanced accuracy brings apatite FT analysis significantly closer to full automation, with the potential to mitigate observer bias, reduce inter-laboratory variability, and broaden the accessibility of the technique to the wider geoscience community.

A combined laser-induced breakdown spectroscopy (LIBS) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) method is demonstrated for comprehensive apatite analysis. These measurements provide elemental imaging that can be used as a screening technique for chemical selection of grains for subsequent analysis (e.g., U-Pb geochronology) or can be used to understand elemental distributions within a single grain that would have direct textural-chemical implications (e.g., zoning patterns). Adding LIBS as a simultaneous measurement, to LA-ICP-MS U-Pb geochronology, allowed for the direct determination of F (H and O show promise for future applications) in addition to major and trace elements of interest. The quantitative measurements were validated against a series of apatites with known values and used to characterise a wide range of samples. Fluorine detection limits were determined to be as low as 70 mu g g-1 F (broadband CMOS detector) and 4.2 mu g g-1 F (ICCD detector). U-Pb age dating was simultaneously collected by LA-ICP-MS with the quantitative elemental data from LIBS, providing a comprehensive method for geochronology.

New apatite fission track (AFT) data from Estonia together with previously published data from Finland, all from crystalline basement drill core, constrain the Phanerozoic thermal history. Models show a consistent pattern of heating from Cambrian to end-Carboniferous, with peak paleotemperatures of 60 +/- 10 degrees C when sediment cover was similar to 0.5 km thicker in the Baltic Paleobasin and similar to 1.5 km over Precambrian basement in Finland. Prior to the Phanerozoic, the Fennoscandia basement was exhumed to a peneplain by late Neoproterozoic. The evolution of Phanerozoic sedimentary cover can be linked to (1) the Scandinavian Silurian-Devonian Caledonian orogeny, (2) foreland basin and foreland uplift bulge development, (3) pre-drift extension and lithospheric uplift from Permo-Triassic to Cretaceous, and (4) Cenozoic rift-phase uplift following North Atlantic opening at similar to 54 Ma. In the Devonian, Caledonian mountains attained elevations of similar to 7-8 km, causing significant lithospheric elastic flexure resulting in a 6-7 km deep foreland basin and similar to 500 m of foreland bulge uplift affecting Fennoscandia and the Baltic Paleobasin. The flexure relaxed and the foredeep basin was partly inverted as the mountain range exhumed and eroded during late orogenic collapse (similar to 400 Ma). The present shield area in Finland may have outcropped for a short time in the Devonian during the Caledonian forebulge phase but was covered shortly thereafter with sediments. The cover persisted until the final exhumation of Finland in the Mesozoic - Cenozoic. Some AFT data indicate hydrothermal disturbance by expulsion of hot fluids from the Caledonian thrust belt into the unconsolidated basal Cambrian sediments and crystalline basement. This craton-wide flow resulted in the precipitation of Devonian calcite-fluorite-Pb-Zn veins, Mississippi Valley type Pb-Zn deposits in the Swedish Caledonian front and dolomitic alteration of Ordovician-Silurian limestones in Estonia. Moreover, our model contributes to the interpretation of the evolution of topography in Norway and distribution of deep biosphere in Fennoscandia.

Low-temperature thermochronology has been widely used in eastern Africa and Arabia (Afro-Arabia) to investigate the long-term thermal evolution of the crust in response to Phanerozoic tectonism. Yet, utilisation of this invaluable thermochronology record to inform numerical investigations into the long-term tectonothermal, geodynamic and landscape evolution of the region has been limited by the dispersion of these data across numerous disparate case studies. Here, we present a relational database of apatite (1787), zircon (68) and titanite fission-track (97) analyses, and apatite (1,945), zircon (3310), and titanite (U-Th)/He (83) ages, including 465 new fission-track and 2,583 new single-grain (U-Th)/He analyses from the region. Where available, all detailed data needed for performing thermal history modelling are presented. Also included are 668 digitised thermochronology-derived thermal history simulations. Collectively, this comprehensive database records the Phanerozoic thermal evolution of Afro-Arabia through space and time. The machine-readable database is made publicly available through the EarthBank platform, enabling 4D (3D through time) geospatial data interrogation.

The syntaxes at the eastern and western ends of the Himalaya located in the Tsangpo and Indus gorge regions provide examples of the interplay between tectonics and erosion. A previous borehole study along the Yarlung River in the Eastern Himalayan Syntaxis (EHS) revealed an ∼1 km thick sedimentary wedge upstream of the Tsangpo gorge with a >2.5 Ma depositional age. However, the mechanism of formation of this sedimentary wedge remains under debate. Here, we combine low-temperature thermochronology data and thermomechanical modelling to discuss how a sedimentary wedge formed at the highly eroded EHS. Our low-temperature thermochronology results show late Miocene fast cooling episodes focused at the Gyaca and Tsangpo gorges, which are interpreted to be related to coeval rifting at the former and rapid erosion and hot-crust upwelling at the latter. Constrained by the geological and geophysical observations, we apply thermomechanical models to illustrate the mechanism of formation of the sedimentary wedge and present high relief of the EHS. The numerical geodynamic model shows that localized erosion triggers middle ‘crust extrusion’ and regional topographic adjustment at the EHS. Supplementary material : Supplementary figures and tables are available at https://doi.org/10.6084/m9.figshare.c.7008098 Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change

Conventional low-temperature thermochronology can resolve cooling typically associated with ~2 – 6 km of erosion. Lower magnitudes of erosion produced by surface processes and climatic variations are often difficult to quantify. Here, we apply a new, low-temperature thermochronometer (closure temperature

The axial Arcabuco-Floresta segment of the Eastern Cordillera basin, Colombia exhibits a complex geological history characterized by both along and across strike variations in deformation and exhumation, as well as magmatic activity, all of which provide valuable insights into the broader tectono-thermal evolution of the Andean region. In this study, we combine existing thermochronological data, with 16 new zircons (U-Th)/He and 9 new fission-track dates, and numerical modeling to investigate the thermal history in response to such anomalies across the axial Arcabuco-Floresta segment. Single grain ZHe data from Devonian to Lower Cretaceous strata range from 74 to 20 Ma. ZFT data from the same samples show a broader age distribution ranging from 200 to 70 Ma. The integration of different inverse modeling approaches suggests that cooling, here interpreted as exhumation, occurred in three distinct episodes which can each be linked to different regional tectonic interactions since the Late Cretaceous. Over this time, exhumation commenced in the northern and western parts of the basin and extended progressively through to the eastern and southern parts. The first episode, from the Late Cretaceous to Eocene is related to the accretion of different oceanic terranes related to Farallon Plate. The second, from the Oligocene to Middle Miocene, is interpreted as a probable compressional response to accretion of the Panamá-Chocó Arc, Nazca Plate and the Gorgona Terrane. The third, extending from the Middle Miocene to Pleistocene, may be associated with exhumation driven by far-field deformation resulting from the final collision phase of the Panamá-Chocó block with South America and its interaction with the Nazca and Caribbean plates. This last phase led to the complete emergence of the Eastern Cordillera and its development as an orographic barrier. No evidence was found suggesting any possible influence of thermal overprinting on the thermochronological data in the basin.

The evolution of normal fault arrays during rift extension reflects paleo-plate boundary conditions and lithospheric rheology, while controlling seismic hazard and the distribution of basin-hosted resources. Yet, constraining their spatiotemporal development is challenging, particularly where geophysical and subsurface data are absent. Here, we test footwall exhumation modelling using thermochronology as a means of elucidating 4D normal fault array evolution, using the Miocene Central Basin of the Malawi Rift as a natural laboratory. Along-strike trends in exhumational cooling recorded by vertical transects of apatite fission-track and (U-Th)/He data from the basin-bounding Usisya fault scarp reveal a diachronous footwall uplift history that closely reflects 4D trends in hangingwall subsidence recorded by previously published seismic and well data. Initially, pronounced footwall exhumation is restricted to the centres of a series of four isolated normal faults, mirroring the distribution of early syn-rift depocentres. The later onset of footwall exhumation in the intervening areas marks subsequent fault segment propagation and linkage as they formed the through-going Usisya fault system. Elsewhere, cumulative exhumation recorded in the Usisya footwall remains low, coinciding with more significant intra-basinal faulting. This study shows that footwall exhumation modelling constrained by thermochronologic data can reveal the spatiotemporal evolution and strain partitioning within normal fault arrays.

It is widely accepted that tectonics generally enhances river incision. However, why rivers have not incised further into orogenic plateaus to destroy terrains over long-time scales remains ambiguous. Here we hypothesize that the diverse nature of regional tectonics could have impeded river erosion, taking Yarlung River in Tibetan Plateau as a case. We constrain the incision history and effect of a tectonic rift on fluvial incision by low-temperature thermochronology. Results show focused cooling near the rift, but markedly reduced cooling in the upstream and downstream regions since ~7 Ma. This coincides with an episode of rapid exhumation of Eastern Himalaya Syntaxis downstream. We propose that these two co-phased tectonic systems resulting from accelerated extension of southern Tibetan Plateau prevented upstream migration of river knickpoints. Our study highlights that the activity of fault systems may hinder regional erosion, thereby facilitating the preservation of topography and high plateaus in active orogenic belts.

Traditional low-temperature thermochronology techniques such as apatite fission track (AFT) and apatite (U-Th-Sm)/He (AHe) have so far produced limited information on the neotectonic (late Miocene and younger) evolution of Japan. However, the development of monazite fission track (MFT) dating, which has an ultra-low temperature sensitivity (<similar to 25 - 46 degrees C), provides a fresh opportunity to directly analyse recent denudation histories. Low-temperature thermochronology methods have been applied to granitoid samples from the Ryoke belt, located in eastern Yamaguchi and Nara Prefectures, SW Japan. Zircon (U-Th)/He (ZHe), AFT and AHe data and modelled thermal histories reveal Late Cretaceous - Pliocene cooling related to granitoid thermal relaxation combined with paleo-Izanagi and Pacific plate subduction along the eastern Eurasian continental margin. MFT dating reveals Plio - Pleistocene cooling ages, coincident with elastic loading caused by Philippine Sea plate subduction since the Middle - Late Miocene, along with the Quaternary collision of NE and SW Japan at the Itoigawa-Shizuoka Tectonic Line. Silica concentration, non-thermal "radiation assisted" annealing, and changing climatic conditions are proposed as possible caveats on MFT annealing kinetics since the samples are residing in an "open" system. Taking all these factors into consideration, the apparent MFT ages are interpreted as minimum cooling ages, being slightly younger than the thermal events that cooled the samples through the MFT nominal closure temperature. Estimated denudation rates based on MFT dating are higher in Nara relative to eastern Yamaguchi Prefecture, with the difference likely reflecting variations in the tectonic regime, timing of uplift and uplift mechanisms of the two regions.

The fast‐slipping Alpine (∼30 mm/yr), Hope (∼10–20 mm/yr) and Kelly (∼6 mm/yr) faults in the South Island of New Zealand form a complex intersection zone that accommodates tectonic strain along the Australian‐Pacific plate boundary. Analysis of digital topography reveals evidence for stream capture, drainage divide migration, landscape responses to incipient fault development, and preserved enclaves of relic topography that collectively reflect complex interplays between active faulting and landscape evolution. (U‐Th)/He thermochronology of zircon (ZHe) and apatite (AHe) is used to investigate the low‐temperature thermal evolution of rocks in the intersection zone. Weighted mean sample ages for ZHe single grain ages ( n = 13 samples) range from ∼9 to 2 Ma, and AHe multi‐grain and single grain aliquot ages ( n = 9 samples) range from ∼1.5 to 0.5 Ma. Inverse and forward thermal history modeling reveals distinct spatiotemporal variations in thermal histories. Late Miocene exhumation rates (∼0.6–3.5 km/Myr, assuming geothermal gradients of 33–40 °C/km) through crustal depths of approximately 5–6 km, are interpreted to be controlled by proximity to the Alpine fault, with rocks proximal to the fault recording faster exhumation rates relative to distal samples. Establishment of the Hope‐Kelly fault system in the Quaternary structurally juxtaposed rocks with discordant cooling histories. Rocks throughout the study region record increased cooling rates from ∼2 Ma. Possible causal mechanisms include, spatial changes in rock uplift associated with transport toward the Alpine Fault, increased erosion rates associated with Quaternary climate change, or increased rock mass erodibility associated with development of the Hope‐Kelly fault system.

Mafic rocks are the most common type of igneous rocks on Earth, however, constraining the crystallization age of mafic rocks can be challenging. Apatite is a common accessory phase in mafic rocks and is amenable to dating using the U-Pb system. However, the U-Pb system in apatite has a relatively low closure temperature (-350 degrees- 550 degrees C) and is therefore prone to resetting by later thermal and metasomatic events. Here, a recently developed Lu-Hf dating method using laser ablation reaction-cell mass spectrometry is applied to apatite from mafic rocks. The Lu-Hf system in apatite has a higher closure temperature (-650 degrees -750 degrees C) compared to U-Pb, increasing the chances of obtaining primary crystallization ages. Furthermore, the laser-ablation method allows rapid data collection compared to traditional solution-based Lu-Hf dating techniques. Four study areas were selected to compare the Lu-Hf vs U-Pb systematics of apatite in mafic igneous rocks: the Paleoproterozoic Sudbury Igneous Complex (Canada), the Neoproterozoic Borborema Province (NE Brazil), the Paleoproterozoic Fennoscandian Shield (Finland), the Archean Yilgarn Craton and adjacent Mesoproterozoic Albany Fraser Orogen (Western Australia). For all analyzed samples that have apatite trace element compositions typical of an undisturbed primary mafic igneous lithology, the Lu-Hf system retains primary igneous apatite crystallization ages, whereas the U-Pb system in the same grains often records isotopic disturbance or a cooling age. In few cases, the Lu-Hf system has also been disturbed in response to recrystallization, however, such disturbance is readily detected with trace element data. Hence, this study demonstrates the potential of laser ablation apatite Lu-Hf dating to obtain primary crystallization ages for otherwise difficult to date mafic rocks.

NW Iran, situated between the Arabian and Eurasian plates, carries a record of both Paleo-Tethyan and Neo-Tethyan tectonic evolution. During the Wilson Cycle of Tethys Ocean opening and closing, several episodes of magmatism from Late Paleozoic to latest Cenozoic generated a massive volume of intrusive rocks. These intrusives, which record cooling histories from high-temperatures to final exhumation, are ideal for multiple geo-thermochronological studies. Our new zircon and apatite U-Pb results suggest three regional magmatic events in the Late Carboniferous, mid-Cretaceous and middle Eocene, which could be related to Paleo-Tethys subduction, Neo-Tethys subduction and Neo-Tethyan ridge subduction, respectively. New apatite fission track and (U-Th)/He data reveal post-magmatic cooling and differential exhumation related to subduction and collision. By integrating published regional thermochronological data from northeastern part of the Middle East, a broader tectono-thermal framework is outlined as follows: 1) Cretaceous cooling signals are most pronounced in the Alborz and Caucasus, and reflect back-arc extension during Neo-Tethyan subduction; 2) diachronous Neo-Tethyan evolution led to the Paleocene assemblage of Anatolia in the west, and subduction associated with a late Paleocene-Eocene magmatic flare-up in Iran. Subsequent westward escape of Anatolia and extensive surface uplift were driven by propagation of Arabia-Eurasia collision in the Miocene; 3) Continuous northward indentation of Arabia into Eurasia triggered late Miocene-Pliocene fast exhumation of the Zagros, Alborz and the Caucasus.

Low-temperature thermochronology is a powerful tool for constraining the thermal evolution of rocks and minerals in relation to a breadth of tectonic, geodynamic, landscape evolution, and natural resource formation processes through deep time. However, complexities inherent to these analytical techniques can make interpreting the significance of results challenging, requiring them to be placed in their geological context in 4-dimensions (3D + time). We present a novel tool for the geospatial archival, analysis and dissemination of fission-track and (U-Th)/He data, built as an extension to the open-access AusGeochem platform ( https://ausgeochem.auscope.org.au ) and freely accessible to scientists from around the world. To demonstrate the power of the platform, three regional datasets from Kenya, Australia and the Red Sea are placed in their 4D geological, geochemical, and geographic contexts, revealing insights into the tectono-thermal evolutions of these areas. Beyond facilitating data interpretation, the archival of fission track and (U-Th)/He (meta-)data in relational schemas unlocks future potential for greater integration of thermochronology and numerical geoscience techniques. The power of formatting data to interface with external tools is demonstrated through the integration of GPlates Web Service with AusGeochem, enabling thermochronology data to be readily viewed in their paleogeographic context through deep time from within the platform.