Cosmogenic nuclide surface-exposure dating (SED) is a rapidly growing tool in geoscience owing to its unrivalled potential for directly dating rock surfaces and thus the geomorphic and climatic events they represent. Fundamental to the efficacy of the SED method is reliable constraint of the in situ production rate, which is typically calculated via calibration experiments: cosmogenic nuclide concentrations are measured in surfaces for which the true exposure age is known independently, allowing the production rate to be derived (in atoms g−1 yr−1) for the specific calibration site. This value can then be extrapolated to distal field sites using numerical scaling methods designed to account for spatial and elevational differences in geomagnetic and atmospheric shielding. Thanks to successive and increasingly co-ordinated calibration efforts, production rate estimates for the most widely used cosmogenic nuclide, beryllium-10 (10Be), have improved in recent decades, with the majority converging on sea-level high-latitude (SLHL) values of ∼ 3.8–4.1 atoms g−1 yr−110Be concentrations from deglacial surfaces on the Redpoint Peninsula in north-west Scotland that were exposed during retreat of the last British ice sheet. By comparing the surface-exposure results from eight current 10Be production rates to local radiocarbon constraint for deglaciation, we (1) evaluate the viability of each production rate for this site and (2) report a maximum SLHL value of 3.925 ± 0.07 atoms g−1 yr−110Be production rate, calibrated against independently dated glacial landforms in the central Scottish Highlands, gives the best match with the 14C control and thus is appropriate for Late Pleistocene applications at these geomagnetic latitudes.
High-temperature contact metamorphism in the aureole of the 1322 Ma Makhavinekh Lake Pluton, Labrador, led to progressive consumption of 1850 Ma garnet formed during upper-amphibolite facies regional metamorphism that produced migmatitic paragneiss (Tasiyuak Gneiss). Biotite Rb–Sr isotope measurements were carried out in situ by laser ablation ICP-MS/MS allowing biotite in a variety of textural settings to be characterized. This natural laboratory provides important information about the nature of Rb–Sr closure temperature (Tc) as a function of textural setting in high-grade metamorphic rocks. Intact biotite inclusions armoured in garnet preserved in the outer aureole (>4 km from the contact) display a range of Rb–Sr isochron ages between ∼1850∼1322 Ma consistent with a zone of partial retention of Sr in biotite. Isotopic resetting in the outer aureole was controlled by microfractures in garnet that provided short-circuit diffusion pathways for redistribution of radiogenic Sr into plagioclase-bearing contact metamorphic assemblages; biotite inclusions isolated from microfractures retain 1850 Ma Rb–Sr isochron ages. Biotite grains falling along a ∼1322 Ma isochron attest to efficient intra- and intercrystalline Sr diffusion at T≥500 °C≥5 Myr. Samples in the central part of the contact aureole (3.7 to 1.1 km from the contact) contain partly resorbed biotite surrounded by contact metamorphic Opx + Crd coronal assemblages in addition to armoured inclusions in relict garnet. These display similar Rb–Sr behaviour to outer aureole samples with the exception that ∼1322 Ma biotite domains display higher
Post-infrared infrared stimulated luminescence (post-IR IRSL) signals from potassium feldspars are gaining prominence in both luminescence dating and luminescence-based sediment tracing techniques. To enhance the accuracy and reliability of these applications, it is essential to develop a comprehensive understanding of how post-IR IRSL signals undergo bleaching. While previous studies have explored post-IR IRSL bleachability using multi-grain approaches, a systematic single-grain investigation on modern analogues has not been conducted. In this study, we examined the bleaching behaviour of the post-infrared infrared stimulated luminescence signal measured at 200 °C (post-IR IRSL200) at the single-grain level in eleven modern floodplain samples from the tectonically active Southern Central Andes. Our study demonstrated considerable variation in the residual doses following 2 d of laboratory solar simulator bleaching across the sample set. This variability was evident not only between different samples but also among individual grains within the same sample. Thus, we evaluated the influence of bleaching duration, grain-specific geochemical composition, catchment-scale lithological variability, and the size of the natural dose on the laboratory-measured residual doses.Our laboratory bleaching experiments in which single grains were given a fixed regenerated dose of 30 Gy prior to solar simulator exposure showed similar post-IR IRSL200R2= 0.89) between residual dose and natural remnant dose, revealing dose-dependent bleaching efficiency and the presence of a negligible unbleachable component at the time of deposition. This relationship between residual dose and natural remnant dose also suggests that while the youngest samples (with low natural remnant dose) could reach zero residual dose, the relatively older samples (with more than 10 Gy of natural remnant dose) could show a significant amount of residual dose. By integrating insights on bleachability with the information on the unbleachable component and remnant doses derived from modern analogues, we highlight the limitations of correcting palaeodoses by directly using either residual or remnant doses and evaluate three context-sensitive correction strategies. Finally,
The Christiana Islands group consists of three at present uninhabited islands 20 km SW of Santorini, Aegean Sea, Greece, that are the subaerial remnants of the Christiana volcano. The age of the Christiana Islands has been unclear and has been previously assumed to have started around the same time as the emergence of Santorini (600 ka). Other studies, based on seismic reflection, have correlated volcanic deposits of the Christiana archipelago to Pliocene sedimentary layers. Five subaerial Christiana volcanic rocks of the Upper Lava formation cluster tightly between 2.57–2.69 Ma with relatively small uncertainties (0.02–0.03 Ma). One sample dated much younger: 133 ka; this obsidian from a pyroclastic deposit is most likely derived from the Middle Pumice Plinian eruption of Santorini. The 2.5–2.7 Ma age for Christiana volcano shows that all volcanic fields of the South Aegean Volcanic Arc (SAVA) were active around 3 Ma ago and started when oceanic crust arrived at 100 km depth below the SAVA volcanic fields after a long period of continental lithosphere subduction. The Christiana volcano was constructed when the local stress field showed NNE-SSW extension. During the transition from NNE-SSW to NW-SE extension the Christiana volcano became extinct and a period of >1.0 Ma with volcanic quiescence and/or low volcanic output followed until the start of submarine volcano Poseidon and present-day volcanic centres Santorini and Kolumbo.
Cosmogenic-nuclide surface exposure ages provide empirical data for validating models simulating the timing and pace of ice-sheet response to a warming climate. Increasing emphasis is being placed on obtaining exposure ages that both accurately constrain Holocene deglaciation and are precise enough to capture ice sheet change at the sub-millennial scale. However, longer-lived nuclides such as 10Be14C14C) is largely insensitive to nuclide inheritance pre-dating the last glacial maximum (LGM), and when combined with longer-lived nuclides can be used to constrain complex ice sheet histories over Holocene timescales. Here, we present new in situ 14C10Be14C–10Behttps://version2.ice-d.org/, last access: 29 March 2024). Our analysis reveals that neither variations in geologic setting nor modelled scenarios of subsurface nuclide production can explain the conflicting Mt Murphy ages. However, replicate in situ 14C14C2σ14C2σ14C
This study examines the feasibility of dating pluvial lake beach ridges using rock surface luminescence dating techniques. Dating pluvial lake highstands in the internally drained Great Basin of the United States helps us understand the timing of changes in precipitation and temperature patterns in western North America during the Late Pleistocene. The majority of highstand ages have relied on few radiocarbon ages of shell and/or charcoal sometimes coupled with luminescence dating of sand. Within our study area in the south-central Great Basin, luminescence ages of sand-size particles have successfully dated aeolian influxes of sand during arid intervals, but have not successfully dated the highstand beach ridges, the best preserved of which are largely gravel.Directly dating when these gravel clasts were last exposed to sunlight via luminescence is ideal but their limestone and volcanic lithologies prove challenging. Initial measurements from these lithologies show that feldspar luminescence signals are suited to single-aliquot regenerative (SAR) dose measurement protocols and show evidence for heterogeneous bleaching of rock surfaces. Polymineral extracts from dissolved limestone clast surfaces from Coal Valley that contain sufficient detrital sediment exhibit infrared signals measured at 50 °C (IR50) with low to moderate fading rates. Single-grain ages from detrital sediment from three clasts, calculated using the central dose model, are statistically consistent with the radiocarbon age estimate of the Pluvial Lake Coal highstand.Crushed slices from volcanic clasts from Cave Valley could be dated using a high-temperature (290 °C) post-infrared infrared stimulated luminescence (pIRIR) signal with a correction for fading. Many ages obtained from volcanic clast surfaces are observed to be several thousand years younger than the expected age of the ∼ 18–20 ka beach ridge. This suggests that the volcanic rocks have been exposed to light long after the pluvial lake highstand, likely because of bioturbation, and that their most recent burial occurred in response to climatically driven soil formation processes. Comparisons between age-depth profile plateau ages from inside volcanic rocks and independent age control suggest that gravel-sized volcanic rocks were small enough to have been bleached throughout their entire thickness in the pluvial lake beach environment and that pIRIR signals that record the time of beach ridge formation and subsequent soil formation during the Pleistocene-Holocene transition may be preserved within the rock sub-surface.This study develops novel dating approaches for challenging rock lithologies. Rock surface dating techniques for pluvial lake beach ridges in the Great Basin should be further developed with consideration of local bedrock type(s), clast size, sample collection and preparation methods, gravel bleaching processes in pluvial lake environments and the impact of soil development and bioturbation on study sites.
Low-temperature thermochronology provides a powerful means of extracting quantitative information on the thermal evolution of different tectonic settings from rocks exposed at the surface of the Earth. Geodynamic numerical models enable tracking the entire thermal structure of simulated tectonic settings throughout their evolution. Despite the highly complementary nature of these two approaches, few geodynamic modeling studies have used the thermal information in models to predict thermochronometric ages as a means of comparing model results with observational data. Here, we present Geodynamic Thermochronology (GDTchron): an open-source Python package designed to forward model large numbers of low-temperature thermochronometric ages from time–temperature paths output by geodynamic numerical models. This package uses existing techniques to estimate apatite
Bayesian modelling is often implemented in geochronology and its applications to geomorphology, archaeology, etc. The rationale behind such practices is the aim to improve robustness, precision and accuracy thanks to the use of prior knowledge regarding the studied sites, and in particular the order of samples constrained by stratigraphy. All chronological models tested in this study (OxCal, Chronomodel and BayLum) use the same mathematical model to handle stratigraphic constraints. However, this model has been shown to lead to estimation biases. First, this bias is illustrated with BayLum modelling on a high-resolution OSL dataset. Then, this paper compares statistical inferences obtained with the three above-mentioned modelling software on the Neolithic East mound of Çatalhöyük (Turkey). For this site, 49 radiocarbon ages were obtained with the aim to determine the start of occupations at this locality. Interestingly, age uncertainties are rather large, because of calibration curve plateaus. Therefore, the conditions for estimation biases are met. We discuss the behaviour of the different models and show that caution must be taken when modelling results are at odds with measurements. While OxCal, Chronomodel and BayLum are all affected by a spread in ages resulting from their common model of stratigraphic errors, Chronomodel suffers from a great loss of precision and OxCal, through the phase model, concentrates ages undesirably. We also conclude that the onset of occupations at Çatalhöyük was probably earlier than previously thought based on the OxCal model.
(U-Th-Sm) 
The dating of supergene copper minerals has been widely used as a proxy to investigate the evolution and onset of hyperaridity in the Atacama Desert. However, investigation of supergene copper mineralisation in the Atacama Desert has been restricted to two physiographic units favourable for the industrial extraction of copper: the Central Depression and the Precordillera. Furthermore, these studies dated the timing of supergene mineralisation by secondary non-copper minerals like alunite. In this study, we present new results of LA-ICP-MS U-Pb dating of chrysocolla from supergene deposits hosted in the western part of the Coastal Cordillera of northern Chile. The obtained U-Pb ages range from 8.0±1.20.045±0.027 Ma. Supergene mineralisation ages point to significantly reduced precipitation, necessary for leaching and mineral precipitation process, since the Late Miocene to Pleistocene in the Coastal Cordillera, later than the secondary supergene mineralisation ages from the Precordillera. The data point to repeated phases of sufficient moisture along the Coastal Cordillera that promoted chrysocolla mineralisation during the Pliocene and Pleistocene. We propose that due to the position of the study areas near the coastal escarpment, and the predominant hyperarid environment in this part of the Coastal Cordillera since at least the Mid-Miocene, pluvial periods and/or intensification of coastal fog events caused alternating phases of supergene activity.
The rate at which ice sheets erode rock and produce sediment is poorly known. Here, we use paired cosmogenic nuclides in both deglacial and modern sediment to understand better the efficacy with which the Quebec-Labrador Ice Dome (QLID) of the Laurentide Ice Sheet eroded bedrock and generated sand and boulders across the landscape of eastern Canada. We sampled deglacial sediment (esker and delta sand, n= 10), sediment from modern streams (n= 11), one bedrock outcrop, and a bedrock depth profile (n= 7), measuring concentrations of 10Be and 26Al in quartz isolated from all samples. We also collated published cosmogenic nuclide measurements of boulders and bedrock from eastern Canada (n= 237 samples), and using independent estimates of deglaciation timing, calculated initial nuclide concentrations when the material was exposed by the most recent deglaciation, between 6.3 to 15.2 ka.At the time of deposition, all 10 deglacial sand samples contained 10Be and 26Al, on average equivalent to several thousand years of surface exposure. The ubiquitous presence of 10Be and 26Al in eastern Quebec deglacial sediment is consistent with older-than-expected exposure ages for bedrock outcrops (n= 26 of 46 samples) and boulders (n= 65 of 192 samples) once covered by the QLID. Error-weighted averages of 26Al 
Fission track thermochronology is based on the visual analysis of optical images. This visual process is prone to observer bias. Fission track datasets are currently reported as numerical summary tables. The interpretation of these tables requires a high degree of trust between the fission track analyst and the user of the data. geochron@home is software that removes this requirement of trust. It combines a browser-based “virtual microscope” with an online database to provide FAIR (Findable, Accessible, Interoperable and Reproducible) access to fission track data.geochron@home serves four different purposes. It can be used (1) to count fission tracks in “private mode”, i.e. hidden from other users on the internet; (2) to archive fission track images and counts for inspection by other users; (3) to create tutorials for new students of the fission track method; and (4) to serve randomly selected selections of images to citizen scientists. We illustrate these four applications with examples that demonstrate (1) geochron@home's ability to compare and combine fission track counts for multiple users within a lab group; (2) the value of the geochron@home archive in the peer review system; (3) the use of simple tutorials in teaching novice users how to count fission tracks; and (4) the opportunities and challenges of crowd-sourced fission track analysis.geochron@home was written in Python and Javascript. Its code is freely available for inspection and modification, allowing users to set up their own geochron@home server. Alternatively, users who would like to upload data to the archive, but do not have the facilities to set up their own server, may use the server at University College London free of charge. The archive accepts image stacks acquired on any type of digital microscope, and accommodates fission track data (counts and length measurements) from external fission track analysis suites such as Fission Track Studio and TrackFlow.We anticipate that the introduction of FAIR workflows will make fission track data more accurate and more future proof. Storing fission track data online will benefit future developments in fission track thermochronology. For example, archival datasets of peer reviewed fission track counts can be used to train and improve machine learning algorithms for automated fission track analysis. We invite other geochronological methods to follow the fission track community's lead in FAIR data processing. This would benefit all the Earth Science disciplines that depend on geochronological data.
Constructing accurate age models for Pleistocene marine sediments is crucial for our understanding of glacial-interglacial cycles and other climatic processes. Benthic foraminiferal δ18O stacks, a proxy for ice sheet and climate evolution, are often used for stratigraphic alignment and chronology development in deep-sea sedimentary records, in combination with biostratigraphy, paleomagnetism, and radioisotopic constraints. Selection of an appropriate benthic δ18O alignment target influences the derived chronology at a given site, and divergent regional trends in benthic δ18O highlight the need for ocean-specific benthic δ18O stacks. The specific scientific question to be addressed by a study may also influence whether the alignment target should include astronomical tuning. Here, we introduce three benthic δ18O stacks – Atlantic, Pacific, and global – with three distinct chronologies for the global stack that incorporate astronomical forcing constraints to various degrees. The new global stack utilizes data from 221 cores and includes 45 % more data than the previous “ProbStack” (Ahn et al., 2017). Hand-tuned regional and global stacks, intended as updates to the “LR04” stack (Lisiecki and Raymo, 2005), incorporate chronologies transferred from absolutely dated archives during 0–654 thousand years ago (ka) and an astronomically forced ice sheet model during 654–2700 ka. Due to the heterogeneous nature of the age constraints used for these stacks, we call them BIGSTACKmixed, BIGSTACKmixedA, and BIGSTACKmixedP. For applications where astronomical tuning should be minimized, we present a global stack primarily constrained by geomagnetic reversal age estimates, BIGSTACKmagrev. We also develop a third age model, BIGSTACKauto, which uses an automated optimization algorithm to “minimally tune” the stack to the pervasive ∼ 41 kyr obliquity cycle, while avoiding assumptions about astronomical phase relationships. This suite of stacks offers flexibility in choosing δ18O stratigraphic alignment targets, to allow a wide range of applications in paleoceanographic hypothesis testing.
Quantifying timescales and establishing robust eruption chronologies is critical for understanding the evolution and hazards of volcanic systems. U-Th disequilibrium dating on zircon is especially valuable for young and active systems (< 300 ka). However, there is no consensus on how to calculate U-Th crystallization ages. To address this, we applied an optimized LA-ICP-MS U-Th-Pb double-dating strategy that simultaneously retrieves U-Th and U-Pb ages from the same zircon ablation volume. This dating routine increases confidence in crystallization ages across 150–300 ka, where the resolution of either dating technique alone is limited. We applied this strategy to the Kos Plateau Tuff, which spans this critical interval, and compared U-Th model age calculation approaches against the well-established U-Pb age calculations. U-Th model ages calculated using the two endmember approaches, either using a constant melt composition or a constant zircon-melt U 
Quartz Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) and Electron Spin Resonance (ESR) offer valuable quantitative tools both for understanding sediment provenance and surface processes. However, the variability of quartz sensitivity remains an issue, attributed either to the intrinsic properties of source bedrock, to processes during sediment transport and deposition, or to both. This study addresses these questions by investigating quartz from magmatic, metamorphic, and sedimentary formations in the Strengbach catchment (Vosges Massif, France). Using a combination of ESR, TL, OSL, and LA-ICPMS (Laser-Ablation Inductively Coupled Plasma Mass Spectrometry) trace element analyses, our study reveals significant relationships between quartz TL-OSL/ESR sensitivities and source bedrock characteristics, such as lithology, crystallization conditions, and deformation histories. ESR Ti-centre and TL-OSL signals are notably influenced by trace elements like Al, Li, and Ti. Quartz that underwent high pressure during metamorphism along with those located in the tectonic shear zone show both lowest TL-OSL and ESR intensities, while higher sensitivities are observed in quartz from plutonic rocks and sandstones. This suggests that (i) pressure can be one of the prevailing factors driving changes in quartz TL-OSL/ESR sensitivities (ii) enhanced quartz TL-OSL sensitivity in mature and recycled sediments (sandstones) highlight the importance of sedimentary transport and reworking on TL-OSL and ESR signals.Our results highlight the need for careful interpretation of ESR and TL-OSL signals, both for dating or sourcing, particularly in sediments derived from metamorphic terrains.
We describe a “virtual mineral separation” method for measuring the cosmogenic 3He concentration in pyroxene in mafic rocks that consist mainly of plagioclase and pyroxene, without physically separating the minerals. This approach is significantly faster and more cost-effective than the conventional method, which requires physical separation and purification of pyroxene grains by time-consuming and labor-intensive crushing, acid cleaning, magnetic separation, HF etching, and handpicking under a microscope. The premise of the method is that helium diffusivity is much higher in plagioclase than in pyroxene, so controlled preheating of a mixed whole-rock sample can degas 3He from plagioclase while retaining all 3He in pyroxene. A second heating step releases all 3He from pyroxene for measurement. To then obtain a 3He concentration in pyroxene rather than the whole rock, we determine the pyroxene weight fraction in the sample using X-ray computed tomography (CT). A comparison of 3He concentrations in pyroxene measured using virtual mineral separation with those measured in the same samples by physical mineral separation in previous work shows no evidence of systematic bias between the methods. Virtual mineral separation greatly simplifies the workflow for 3He exposure-dating of mafic rocks, reduces time, effort, and cost, and permits measurements on very small samples. This enables new emerging applications of exposure dating, such as quantifying stochastic surface processes, ecosystem studies, and potential subglacial bedrock exposure dating.
Quantifying environmental radiation dose rates is an essential step in age calculation using trapped charge dating methods. A means of rapid dose rate estimation would therefore be useful for a variety of reasons, especially in contexts where rapid equivalent dose estimates are available. For instance, for informing sampling strategy, providing initial age estimates, or supporting portable luminescence studies. However, high-precision methods often used to calculate dose rates are typically time consuming and expensive and are impractical for such “range-finder” applications. Portable X-ray fluorescence (pXRF) offers a rapid means of measuring the potassium (K) concentration of sediment, although the other radionuclides typically used to calculate dose rates, uranium (U) and thorium (Th), fall beneath its detection limits at the quantities at which they are usually present in sediments. In this study, we investigate whether pXRF measurements of KKKKµmKK±10 % of unity for scenarios where the alpha dose rate contribution is assumed to be negligible. Whilst alpha dose rate contributions are predicted the least accurately, scenarios including an alpha component result in at least 80 % of predictions lying within uncertainties of ±10 % of unity. The use of simplified attenuation factors to correct estimated infinite matrix dose rates does not contribute significantly to resulting scatter. This study serves as a proof of concept that pXRF measurements, along with a set of regression equations and a simplified correction procedure, can be used to rapidly calculate range-finder environmental dose rates.
Chemical abrasion (CA), a two-step process of annealing and partial dissolution, is routinely applied to zircon grains prior to U–Pb geochronology to dissolve portions of the grains affected by Pb loss prior to analysis. Despite the utility of the technique, it is not clear what the more HF-soluble material produced in the annealing step is, what degree of lattice damage causes it to form instead of zircon, how to predict if a specific sub-volume of a zircon will survive CA, or how any of these processes relate to Pb mobility. In this study, we use secondary ion mass spectrometry (SIMS), Raman spectroscopy, and atom probe tomography (APT) to constrain what happens to both concordant and discordant zircon during each step of the CA process. We find that zircon in SIMS sputter craters which have undergone Pb loss generally have more heterogeneous Raman band widths than in those sputter craters where Pb has been retained. Annealing drastically reduces Raman band widths, but some heterogeneity is still present in discordant sputter craters. APT results from all samples which successfully ran were homogeneous in U, Pb, Th, and most other elements in all cases. This makes it hard to link Pb loss and lattice damage at the submicrometre scale by direct imaging in this study. However, as the zircon sputter craters with Pb loss show homogeneous APT results, we recommend against using homogeneous APT results as an indicator of closed-system U–Pb behaviour.
The Llanos de Moxos, in the Bolivian Amazon, preserves a remarkable archaeological record, featuring thousands of forest islands. These anthropogenic sites emerged as a result of activities of the earliest inhabitants of Amazonia during the Early and Middle Holocene. Excavations conducted to date on the forest islands have revealed that many assemblages contain a high number of ancient freshwater snail remains. In these shell middens, the most represented mollusc taxon, and in most cases the sole one, is PomaceaPomacea14C measurements. However, it remains undetermined if these measurements are subject to radiocarbon reservoir effect (RRE). To determine if a freshwater RRE could affect the age estimations of Amazonian archaeological and other paleoecological deposits, we collected modern coeval Pomacea
Polishing mounted zircon crystals prior to bulk grain (U-Th)/He thermochronology analysis provides opportunities for characterizing and subsampling each grain via in situ methods to obtain additional information relevant for (U-Th)/He date interpretation and the broader geologic questions of interest. However, polishing introduces complications for classifying grain geometry and determining grain volume (V), on which many derived (U-Th)/He data partially depend. Derived data that depend on volume include isotope concentrations, effective uranium (eU; a proxy for radiation damage), and alpha-ejection correction factors (FT), which are used to correct (U-Th)/He dates. These derived data are integral to interpreting (U-Th)/He dates, and, without a way to accurately calculate these values for polished grains, a choice must be made between polishing zircon to provide robust in situ data at the expense of the thermochronologic data or not polishing and limiting in situ data to grain rims or one-dimensional depth profiles. To address this issue, this paper presents a comprehensive protocol for calculating volume and alpha-ejection surface area for polished zircon grain fragments, from which additional data, including eU and FT, are derived. This protocol is implemented after grains have been polished and in situ measurements have been made and can easily be integrated into existing workflows for characterizing and measuring grains for conventional (U-Th)/He analysis. An R script accompanying this paper can be used to perform the required calculations and assign uncertainties during analytical data reduction. Applying the new protocol to a synthetic dataset covering a range of zircon geometries, sizes, and grinding conditions shows that the method is an improvement over existing methods to calculate polished grain FT, which only apply to a small subset of possible grain geometries and grinding conditions. The new protocol also calculates all derived data and uncertainties necessary and recommended for (U-Th)/He data reporting, aside from the (U-Th)/He dates themselves, to facilitate integrations with existing data reporting, date interpretation, and thermal history modeling.