The northeastern Arabian Peninsula has an extreme arid climate. To establish past variations in precipitation intensity during the late Quaternary, the oxygen isotope ratios (δ18O) of meteoric calcite cements of the late Quaternary aeolianites of the Ghayathi Formation in Abu Dhabi and Dubai have been analysed. The Ghayathi Formation is a carbonate-rich aeolianite, stabilised by calcite cement precipitated from rising groundwater during humid intervals. The calcite cements are well developed inside and outside a thin micrite rim of now hollow grains, formed by leaching of unstable carbonate grains. The δ18O values of cement analysed in thin sections by secondary ion mass spectrometry vary from −9.1‰ (VPDB) in coastal to +12.7‰ (VPDB) inland areas. This exceptionally wide range of the otherwise petrographically uniform aeolianite is due to the contrasts in humidity and evaporation rate between the coastal and inland areas. The δ18O values as low as −9.1‰ suggest intense precipitation in the late Quaternary, possibly due to the northward expansion of the intertropical convergence zone and intensified Indian summer monsoon. The exceptionally high values must be due to intense evaporation at low humidity in low-salinity, playa-type environments during intermittent arid intervals.

Luminescence dating has developed over the last ∼60 years as a powerful technique for placing environmental and anthropogenic change into a secure temporal framework. However, over time, many have forgotten, or were never introduced to, the history of how of the method developed, particularly the role of unique instruments built in-house that enabled key methodological advances. In this paper we provide a concise history of the technique’s evolution, drawing on our own experiences.

An ∼0.2-km-long gravel spit (1398 m above sea level) at Sunstone Knoll in the Sevier basin, Utah, prograded into Lake Gunnison, a shallow lake in the Sevier basin that overflowed northward into the Great Salt Lake basin during the regressive phase of Lake Bonneville. Six radiocarbon dates for Anodonta shells and one optically stimulated luminescence age, which overlaps with the uncertainty range of the radiocarbon dates, yield an age for spit development and therefore, the initiation of Lake Gunnison overflow, at ∼15.5 cal ka. This age is older than the age of a larger spit 8 m lower in elevation that ended its progradation in Lake Gunnison about 12 cal ka. Strontium isotope ratios of the Anodonta shells from Sunstone Knoll (0.71049, 0.71059, 0.71064) are within the range of values for Lake Gunnison. The new date from Sunstone Knoll is consistent with cosmogenic dates from the Provo shoreline for the initiation of the regressive phase of Lake Bonneville (about 70 m higher than the spit). The major climatic shift, which caused the lake water budget and hydrology to change from overflowing while the Provo shoreline was forming to closed-basin conditions during the regressive phase, occurred by about 16.5 cal ka.

The East Asian monsoon is a key component of the global climate system; our understanding of its long-term variability and seasonal dynamics remains incomplete. Here we evaluate calcified root cells (CRCs) as a novel paleoenvironmental proxy. We apply this approach to the Fanshan loess–paleosol sequence, northeast China, on the northern margins of East Asian monsoon influence. We present the first continuous down-profile record of CRC concentrations together with carbonates, stable isotopes (δ1⁸Ocarb, δ13Ccarb), and organic matter (δ13Corg) and compare these with grain-size and stratigraphic indicators. CRC concentrations correlate with glacial–interglacial variability: high concentrations within paleosol reflect enhanced vegetation and moisture availability, and low values within primary loess units reflect colder, drier conditions. The estimations of δ1⁸O values of precipitation during the Marine Isotope Stage 5 (MIS 5) indicate an intensification of the monsoon rainfall as compared with present-day scenarios. The δ13Ccarb values are unusually low, which is attributed to kinetic isotope effects, thereby suggesting that CRC formation occurs under quasi-closed conditions dominated by soil organic matter respiration. Internal isotopic variability and CRC concentrations within the MIS 5 paleosol point to multiple episodes of pedogenesis. Our results demonstrate the potential of CRCs to record both long-term monsoon variability and short-term hydroclimatic seasonality, informing past East Asian monsoon dynamics.

Understanding the local to regional history of extreme events such as debris flows and floods provides context to plan for and mitigate these hazards to life, property, and infrastructure. The Klamath Mountains of northwestern California have experienced both debris flows and devastating wildfires. Whiskeytown National Recreation Area (WHIS) is at the heart of this range and has a wealth of debris flow–related landforms. Gaining an understanding of prehistoric flows and their relationship with fire or other potential triggers can help mitigate future problems. Optically stimulated luminescence and radiocarbon analyses from sediment and entrained organics in undisturbed facies, including beneath partially buried boulders, establishes a chronology of paleo-events in WHIS. The levee deposits indicate a repetition of debris flows during the latest Holocene, every 125–150 years, since 850 yr. Larger flows occurred, with a record elucidated from debris-flow deposits along Clear Creek, with Middle Holocene ages, ca. 2600 to 5500 yr, most of which have sufficient concentrations of charcoal to indicate origins as postfire debris flows. Deposits at higher elevations show events from the latest Pleistocene ca. 13,000 yr. This geochronology indicates that these are not singular events but are relatively common and inherent to the geomorphic processes shaping this landscape.

Paleolake coring initiatives result in large datasets from various proxies taken at different resolutions, ranging from continuous scans to samples collected at coarser intervals. Higher-resolution data (e.g., core-scan X-ray fluorescence [XRF]) can detect short-duration changes in the paleolake and help identify unit boundaries with precision; however, interpreting the causes of such changes may require sampling and more intensive laboratory analysis like X-ray diffraction (XRD). This study applies a published wide and deep learning model, developed for the Olduvai Gorge Coring Project (OGCP) 2014 cores from the Pleistocene Olduvai basin, Tanzania, to reconstruct the mineral assemblages from saline-alkaline paleolake Olduvai using core-scan XRF data and core lithology. A classification model (predicting mineral presence or absence) and a regression model (predicting relative abundances of minerals) yielded predictions for two OGCP cores (2A and 3A), which were compared with published XRD mineral data and detailed core sedimentological descriptions. The models were excellent at identifying dolomite-rich layers, carbonate-rich intervals, intervals of sandstone within claystone, and altered tuffs within claystone and at predicting whether illitic or smectitic clays dominate. The models struggled with less-altered tuffs and with zeolites in non-tuff sediments, especially when XRD identified chabazite and erionite (rather than phillipsite) as the dominant, non-analcime zeolite.

The chronology of Late Pleistocene and Holocene aeolian sand activity in midcontinent North America provides important insight into paleoenvironmental change and associated surface processes. Near the limit of Marine Isotope Stage 2 glaciation of the Huron-Erie Lobe (Laurentide Ice Sheet) in south-central Indiana, aeolian sand deposits found along the eastern margin of outwash plains in the East Fork and West Fork White River valleys provide an opportunity to test the causal mechanisms for aeolian sand activity. Twenty-five optically stimulated luminescence ages on aeolian sand and four radiocarbon ages on gastropod shells document two phases of aeolian sand activity. The first phase, between 26 and 19 ka, records deflation from active outwash plains in the East Fork and West Fork White River valleys during and after the local glacial maximum. These ages overlap with the chronology of Huron-Erie Lobe advance into and out of the White River drainage basin based on a radiocarbon-dated slackwater succession. The second phase, between 16 and 12 ka, records reworking of older aeolian sand and outwash during a period of no-analog vegetation during the Bølling-Allerød/Younger Dryas and is in general agreement with the timing of dune activity from previous studies in the Great Lakes region.

Loess–paleosol sequences (LPSs) provide valuable archives of Quaternary paleoenvironments. Here we present new data from the Baix LPS, comprising the entire Late Pleistocene. The Baix LPS is located at the western edge of the Rhône Rift Valley, France, in the transition zone from the presently temperate to the Mediterranean region of Europe. This LPS provides a missing link between the analyzed LPSs in the presently temperate regions farther north and those in the Mediterranean region. Reddish Btg horizons of a Stagnic Luvisol at the base of the Baix LPS represent the remains of an MIS 5 pedocomplex formed under warm and, at least temporarily, relatively moist conditions. Two brown Bw horizons of truncated Cambisols have been preserved in the overlying MIS 5a/4 to MIS 3 deposits. The upper Bw horizon is associated with large carbonate nodules, indicating that considerable amounts of calcium carbonate were leached from a former MIS 3 Cambisol and accumulated in the underlying loess unit. This truncated MIS 3 Cambisol is very similar to the MIS 3 paleosol remains in the LPS Collias that we investigated 87 km farther south in the present Mediterranean climate. No paleosols were observed in the late MIS 2 deposits.

The optically stimulated luminescence (OSL) sensitivity of quartz ranges across five orders of magnitude. Previous studies suggested that quartz OSL sensitivity is enhanced by solar exposure–burial irradiation cycles. Spatially resolved luminescence measurements and laboratory illumination–irradiation experiments were used to investigate the OSL sensitivity of quartz crystals from a granodiorite cobble and quartz grains from a fluvial sand. Quartz from the granodiorite cobble has low OSL sensitivity, showing an approximately linear sensitization path that resulted from laboratory illumination–irradiation cycles. The mean OSL sensitivity of quartz sand grains (100 grains) increased from ∼40 to 80 counts after 1260 illumination–irradiation cycles. Each grain has a specific sensitization trajectory due to illumination–irradiation cycles, suggesting that quartz crystal composition heterogeneities drive the OSL sensitization of their daughter sediment grains. Maximum OSL sensitivity of quartz sand grains is reached after illumination–irradiation cycles representing an accumulated dose of around 4000 Gy. This dose corresponds to sediment burial time of 2–4 Ma, which is unlikely to occur during a single sediment transport route. This study suggests that illumination–irradiation cycles are unable to produce quartz sand grains with OSL sensitivity up to five orders of magnitude higher than the sensitivity of parent crystals in igneous or metamorphic rocks.

Our analysis of 61 versions of the Great Basin (GB) Indigenous oral-history narrative, Theft of Pine Nuts, provides valuable new paleoecological insights into late Pleistocene (LP) and Holocene biogeography of pinyon pine (Pinus monophylla). Pinyon homelands indicated by Indigenous sources were located not only within the current pinyon distribution but also north of the known range, in northern California and Nevada, southern Oregon and Idaho, and western Wyoming. These extramarginal pinyon locations corroborate and expand a Western science hypothesis that proposed LP or Early Holocene refugial populations for pinyon in northern GB that subsequently became extirpated. The narratives also provide new evidence for pre-contact distributions of native mammals in the GB. From analysis of the “ice-barrier” accounts in the Indigenous narratives, we propose parts of this oral-history narrative may have been transmitted since LP times. Whereas most prior efforts have assessed Indigenous oral histories that describe catastrophic geologic events, we document that important ecological dynamics are also embedded in these stories. Our analysis joins other studies in recognizing that oral-history narratives can contain reliable eyewitness observations that are useful for reconstructing paleoenvironmental events and conditions.

Hydrothermal explosions are a significant geological hazard in some active volcanic systems; however, the timing and triggering mechanisms of these explosions are poorly constrained. This study applies luminescence dating techniques to hydrothermal explosion deposits in the Yellowstone Plateau volcanic field to constrain explosion chronologies and evaluate potential triggering mechanisms. We tested four luminescence dating techniques: K-feldspar post-infrared infrared stimulated luminescence (pIRIR225), quartz blue light optically stimulated luminescence (BLOSL), quartz blue thermoluminescence (BTL), and quartz red thermoluminescence (RTL). The pIRIR225 and RTL protocols produce consistent age estimates that agree with independent radiocarbon ages and with the timing of the Pinedale deglaciation. This study focuses on two craters, Mary Bay, along the northern shore of Yellowstone Lake, and Pocket Basin in Lower Geyser Basin. The mean pIRIR225 ages from Mary Bay deposits (11.99 ± 0.68 ka) agree with previous radiocarbon constraints. The mean pIRIR225 results from Pocket Basin deposits (13.44 ± 1.06 ka) suggest a history of explosion following Pinedale deglaciation, followed by recent hydrothermal alteration. Luminescence dating techniques are a promising tool for reconstructing the timing of hydrothermal explosions in the Late Pleistocene and Holocene, helping to constrain recurrence intervals of the largest hydrothermal systems, informing risk, and improving hazard assessments.

The Middle Dnieper region, situated within a transitional glacial–periglacial zone, preserves complex loess–palaeosol archives. This study reconstructs the environmental evolution of the Velyka Andrusivka sequence using a multiproxy approach integrating sedimentological, geochemical, mineralogical, magnetic, and palynological data supported by luminescence dating. The succession rests on Dnieper glacial till and comprises loess units from the last and penultimate glacial cycles, palaeosols, and an upper chernozem formed after loess deposition had ceased. Optically stimulated luminescence ages range from ∼22 to 187 ka, revealing hiatuses and diachronous boundaries relative to Marine Isotope Stage divisions. The older loess is more heterogeneous and enriched in Zr-Hf-REE with mixed provenance, whereas the younger loess is more homogeneous and dominated by distal dust. These contrasts demonstrate how local sediment recycling and regional dust supply jointly shaped the environmental signal. Palaeosols record phases of weathering, while the upper chernozem largely retains the parent-loess texture within a sequence overprinted by postdepositional alterations in colour, geochemistry, and magnetic properties. Comparison along the 50°N transect shows that robust interpretation of the sequence requires integration with neighbouring loess–palaeosol records, as only multi-site correlation captures shared stratigraphic patterns and site-specific deviations, enabling reconstruction of environmental processes across multiple spatial scales.

Nussloch (Germany) is a distinctive site of interest, particularly as a reference sequence for Late Pleistocene European loess, because it provides a comprehensive record of millennial climate variability. A notable feature of this site is its location within an active quarry. Consequently, the stratigraphic profiles documented constitute an ephemeral record, susceptible to rapid disappearance or brief accessibility, contingent on the operational status of the quarry. In order to guarantee the maintenance of a complete record of the sequence, three separate cores were collected and labelled S1, S2, and S3. The results of core S2, which is the most complete and thoroughly examined, are presented here. A comparison is drawn with the most recent P8 profile that is currently available. XRF measurements, conducted after the cores had been opened and described, are also presented. Borehole logging was carried out in the field after core retrieval, and the resulting measurements are also presented. The findings of this study demonstrate that a high degree of correlation can be established between the records from outcrop investigations and core studies, demonstrating the importance of preserving such archives for future research.

Luminescence dating researchers benefit from many community-led software packages. These packages assist with data reduction, statistical modeling, calculation of dosimetric values, and plot production. Yet few resources are simultaneously intuitive, meant for simulating the reduction and growth of luminescence signals, and accessible to non-specialists. The Luminescence Sample Simulator (LuSS) is an application with a graphical user interface that simulates how apparent age and fractional saturation respond to three key scenarios in luminescence dating: sunlight exposure, heat exposure, and burial. Users can simulate these scenarios for an individual cobble or sand grain, or for a population of 100 sand grains. The underlying kinetic parameters can be adjusted manually or taken from a built-in library of published values. Plots of apparent age histograms, luminescence depth profiles, or fractional saturation and apparent age histories are visualized and can be exported. LuSS is written in MATLAB and can operate as a free-to-use, standalone application, or as an app within an existing MATLAB installation. A typical user workflow and three worked examples show how LuSS can model luminescence signal evolution in response to geologic scenarios. Limitations of LuSS include its inability to capture athermal fading or between-grain variability in geologic dose rate or sensitivity.

Our group has previously characterised a post-violet infrared stimulated luminescence (pVIRSL) signal and developed a post-violet infrared single-aliquot regenerative-dose (pVIR-SAR) protocol for estimation of paleodoses. The protocol provides an opportunity for measuring polymineral samples as violet stimulation prior to IRSL measurement, bleaches natural luminescence signal of quartz, and makes it possible to probe photo-transferred charges in feldspar through IR stimulation. This study presents the results of the pVIR-SAR protocol on natural polymineral fine- (4–11 μm) and coarse-grain (90–150 μm) samples, including volcanic ash, pottery, and fluvial deposits from varied geological provenances. The results show that pVIR-SAR ages of both these fine- and coarse-grain samples are consistent with geological reasoning and available age controls thereby suggest that with the use of the pVIR-SAR protocol, mineral separation can be dispensed. This study also reports on the bleachability, athermal fading rates, and alpha efficiencies of pVIRSL for these samples and corresponding results are compared with IRSL at 50°C and post-IR IRSL (pIRIRSL) at 290°C. The pVIRSL signal has a better bleachability and reproducibility compared to the pIRIRSL signal. For the fluvial deposits dated in this study, the fine-grain samples provide ages consistent with the expected chronology.

The results of the taxonomic, taphonomic, and paleoecological analyses of Late Pleistocene micromammals from the Salto de Piedra paleontological locality are presented in this paper. Our results support the conclusion that the microfaunal remains were mainly accumulated by diurnal raptors in areas close to where the remains were deposited, as there is no evidence of transport. Taxonomically, the recovered micromammals include rodents currently inhabiting the Humid Pampa (Calomys cf. C. musculinus-laucha, Ctenomys sp., and Reithrodon auritus) and species that became extinct during the Late Pleistocene (Microcavia cf. M. robusta) and Holocene (Galea tixiensis). Additionally, remains of the Patagonian marsupial Lestodelphys halli and the amphibious sigmodontine Holochilus brasiliensis were identified. These analyses, along with the paleoecological and malacological studies at Salto de Piedra, confirm a trend toward increased humidity, consistent with the paleoenvironmental evidence documented for the region at the end of the Pleistocene. This study of the central Humid Pampa based on this small mammal record is of particular interest for interpreting the paleoenvironmental and paleoecological scenario, coinciding with the arrival of the first humans in the area and the extinction of the megafauna.