Slack-water deposits are archives of paleoflood frequency, magnitude, and provenance. In the eastern Himalaya, deposits along the Siang River document Quaternary outburst megafloods originating from southeastern Tibet. Here we present new observations of slack-water deposits within aggradational terraces of the Siyom River, the Siang’s largest tributary. Terrace stratigraphy reveals distinct, regionally extensive sedimentary facies including laminated sands, clays, and detrital organic-rich deposits consistent with slack-water deposition from temporarily impounded waters. Radiocarbon dates from clay and organic horizons range from 34,020 to 10,630 cal yr BP, overlapping with age constraints for Tibetan paleolake deposits. Detrital zircon (U-Th)/Pb geochronology confirms a local source for the underlying fluvial facies, whereas event-deposit silts contain young zircons derived from Tibet, supporting their interpretation as megaflood deposits. This evidence, combined with the deposits’ temporal overlap with Tibetan paleolakes and distinctive slack-water sedimentology, demonstrates that event facies formed through megaflood backflooding sourced from southeastern Tibet. The results point to the likelihood of similar deposits in other tributaries, providing a framework for regional investigation. Our findings further show that megafloods in steep terrain can produce substantial deposition and terrace formation tens of kilometers upstream in tributaries—far beyond the main stem floodway—revealing an overlooked geomorphic imprint of extreme floods.

We present isotopic data from mammalian megafauna from the Jirau Paleontological Site (Itapipoca, Ceará State, Brazil) and Rio Miranda (Mato Grosso do Sul State), both located in the Brazilian Intertropical Region, dating to the Mid–Late Holocene. The isotopic composition (δ13C) of eight tooth fragments was determined for the following taxa: E. laurillardi, N. platensis, T. platensis, S. populator, X. bahiense, and P. major. Results indicate that the herbivorous taxa had mixed diets, consistent with deciduous to semi deciduous forest and wooded savannah environments. S. populator likely preyed upon herbivores with mixed diets and inhabited wooded savannahs. E. laurillardi, N. platensis, and T. platensis exhibited generalist feeding behavior with a high proportion of C₃ plants in their diet, associated with the fragmentation and reduction of open environments (savannah and wooded savannah) and the concurrent expansion of forested areas during the Holocene Climatic Optimum. X. bahiense and P. major exhibited browser-type diets in Itapipoca, suggesting adaptation to the expansion of deciduous and semi deciduous forests during the Holocene Climatic Optimum. By comparing isotopic data with paleoecological, palynological, and paleobiogeographical evidence, we infer that the Intertropical Region represented one of the last environmental refuges for extinct meso- and megamammal faunas during the Holocene.

Indian banyan trees, with their complex network of secondary trunks, support entire ecosystems and are often favored for large rural gatherings due to their vast canopy. However, dating these heritage trees in South Asia has traditionally relied on written records and local lore, resulting in imprecise age estimates that limit our understanding of their historical significance. This study establishes a precise minimum age for a monumental banyan tree located on the Indian Tobacco Company campus, founded in 1901 CE in Munger, Bihar, India. According to local lore, the tree has long been a gathering place for both rulers and commoners. Radiocarbon dating of the pith from an exposed secondary trunk and a primary branch of the Munger Banyan were 276 ± 36 and 652 ± 37 years BP, respectively, indicating when each sample of wood stopped exchanging carbon with the atmosphere. These findings suggest a minimum radiocarbon age of ca. 700 years, making it the oldest accurately dated Ficus benghalensis in the world. The study refines radiocarbon dating approaches for tropical hardwoods by emphasizing precise pith targeting, a method rarely applied due to indistinct growth-ring boundaries. By integrating advanced calibration techniques, the study enhances chronological accuracy and improves understanding of the longevity and significance of heritage trees and tropical forest ecosystems.

Four new Pleistocene track-bearing aeolianite surfaces have been identified on South Africa’s Cape south coast, each portraying evidence of tortoise tracks. Together, they add to and buttress previous reports of tortoise tracks and trackways from the region. Globally, this remains the only area from which fossilized tortoise tracks have been recorded, and for the first time we illustrate the preservation of typical tortoise trackway morphology (involving a ‘tramline’ pattern with a wide straddle and closely spaced tracks), as observed in the trackways of extant tortoises. One site provides further evidence for the inferred presence of a very large tortoise trackmaker from the region during the Pleistocene. This tortoise was substantially larger than the largest extant tortoises in southern Africa, which bolsters the inference of either an extinct very large tortoise or a large chrono-subspecies of the extant leopard tortoise (Stigmochelys pardalis). The mismatch between the body fossil record and trace fossil record with respect to the presence of large tortoises in the southern Cape persists. One trackway was probably registered by a smaller leopard tortoise, and the other trackways may have been registered by an angulate tortoise (Chersina angulata).

Stable carbon isotopes in Holocene soils provide key insights into past climate and ecosystems. This study presents high-resolution isotope analyses of pedogenic carbonates and organic carbon from modern loess-derived soils in northern Iran across a strong precipitation gradient (150–850 mm mean annual precipitation [MAP]). Eight soil profiles span five soil orders: Alfisols, Mollisols, Inceptisols, Aridisols, and Entisols. The mean δ13Cpc values show strong linear relationships with MAP (δ13Cpc = −0.0093 × MAP + 1.8878; R2 = 0.98) and with the ratio of precipitation to potential evapotranspiration, P/PET (δ13Cpc = −8.6842 × P/PET + 1.608; R2 = 0.99), indicating that δ13Cpc reliably reflects moisture availability during carbonate formation. Values range from −6.2‰ in wetter sites to −0.1‰ in dry areas, reflecting changes in soil respiration and CO₂ flux. δ13Coc values (−25.6‰ to −23.3‰) indicate dominant C₃ vegetation and exhibit a bimodal response to precipitation, increasing from arid to semiarid zones and decreasing in wetter forests. Oxygen isotopes in carbonate (δ1⁸Opc = −7.9‰ to −6.6‰) show limited climate sensitivity, reflecting precipitation mainly from the Caspian Sea with minimal evaporative enrichment. Overall, δ13Cpc, δ13Coc, and δ1⁸Opc provide robust proxies for soil moisture, vegetation structure, and water sources, supporting paleoenvironmental reconstruction in loess systems.

The Kovrizhka sites are some of the most studied and highly informative for the entire northern Cis-Baikal region of Siberia and illustrate the history and development of ancient cultures in the Vitim area during the Late Upper Paleolithic to Early Neolithic. To better understand human settlement practices during this time, we constructed a model of Late Quaternary landscape formation and human occupation in the Vitim River valley based on a geomorphological study and radiocarbon dating of archaeological sites Kovrizhka I–VI in the Baikal-Pathom Highlands. The model reconstructs human habitation of the valley from 19.9 to 6.7 ka and connects settlement patterns to general landscape features, stone (mineral) and food resources, the flood regime of the Vitim River, and dynamics of landscape formation. A secondary focus of this study is to assess the timing and geomorphological remnants of megafloods originating from breakthroughs of the Muya (Vitim) glacial paleolake in Marine Isotope Stages (MIS) 3 and 2, and their impact on human settlement. The last megaflood could not have been later than the earliest settlement on Kovrizhka II (19.9 ka). However, erosive flood activity is observed at all stages, especially a shift in floods at the Pleistocene–Holocene boundary.

New cosmogenic 10Be exposure ages and a proglacial lake sediment archive provide the first record of local ice cover following the deglaciation of the Cordilleran Ice Sheet (CIS) in southeast Alaska. Exposure ages from Necker Bay corroborate existing evidence for a CIS deglaciation age of ∼15–14 ka from the outer coast of Baranof Island. We date retreat farther inland on the western and eastern flanks of the island to the Early Holocene, providing evidence for an ice cap persisting on Baranof Island ∼3 ka after CIS retreat. Baranof Lake sediment cores document continued local ice cover until ∼10.4 ka, after which glaciers receded to their Holocene minima until ∼8 ka. Glaciers grew through the remainder of the Holocene, reaching their maxima during the last millennium before retreating rapidly during the last century. Remote sensing analysis of glacial change around Baranof Lake from 1948 to 2023 CE shows that the rate of glacier area loss increased by an order of magnitude after 1986 CE, from −0.03 km2/yr to −0.29 km2/yr. This trend in glacier area loss is reflected across Alaska and western Canada, highlighting the sensitivity of Beringian glaciers to climate changes and the significant contribution they will make to sea-level rise this century.

Low optically stimulated luminescence (OSL) sensitivity is commonly observed in quartz from tectonically active catchments, suggesting limited or short-lived conditions favorable for sensitization. We characterize the OSL sensitivity of quartz sand within a small, tectonically active catchment in Sicily using modern fluvial samples and a hillslope soil sample. We investigate how OSL sensitivity varies with bedrock lithology, weathering proxies, and topographic metrics. OSL sensitivity spans three orders of magnitude (60–2800 counts/Gy/mm3) with no clear linkage to bedrock source. The soil sample exhibits the highest OSL sensitivity, and positive relationships between OSL sensitivity, magnetic susceptibility, and weathering intensity suggest that pedogenic hillslope processes enhance quartz OSL sensitivity. In contrast, fluvial sediments show low OSL sensitivity and a modest inverse relationship to channel steepness and hypsometry. OSL sensitivity decreases downstream, suggesting that highly sensitized grains from hillslope soils are progressively diluted by low OSL sensitivity sediment likely generated by rapid bedrock erosion in the catchment. These results highlight a hierarchy of controls: bedrock lithology sets the initial OSL sensitivity, hillslope processes enhance it, rapid erosion dilutes it, and fluvial transport modulates it through mixing, explaining why tectonically active catchments rarely preserve quartz with high OSL sensitivity.

The 7.7-m loess–paleosol sequence in Trzebnica records a short (ca. 3 ka) but intense phase of loess accumulation that preceded the onset of the Weichselian Late Glacial (MIS 2). The stratigraphy contains a well-defined erosional unconformity, marking a hiatus prior to the deposition of the youngest loess unit (L1LL1). The Trzebnica loess contains numerous signals of slope redeposition, as evidenced by lithological indicators. In this paper, we present optically stimulated luminescence (OSL) and radiocarbon data for the Trzebnica site, as well as granulometric analyses and end-member modeling of grain-size data. Our findings refine the regional loess stratigraphy and challenge an earlier hypothesis regarding the age of the Trzebnica 2 archeological site, which pointed to its evolution beginning around MIS 11. Limitations of 14C dating and its comparison to OSL dates are discussed.

The efficacy of using luminescence dating on glacial deposits is tested for a portion of the Marine Isotope Stage (MIS) 6 Laurentide Ice Sheet margin in southwestern Indiana. We assess small-aliquot quartz optically stimulated luminescence (OSL) and feldspar infrared-stimulated luminescence (IRSL) dating of glaciofluvial, glaciodeltaic, and aeolian sediments against a well-established soil stratigraphy and a cosmogenic 10Be depth profile. Results indicate that standard blue-light OSL regenerative protocols used on MIS 2 glacial sediments in the region warrant caution when duplicated for MIS 6 sediments. Quartz OSL ages underestimate age by up to 50% compared with cosmogenic and feldspar post-IR IRSL200 ages. Presence of unstable or hard-to-bleach OSL signal components that cannot be removed with modified preheat protocols yields unreliable data. While dates obtained using post-IR IRSL200 protocols on feldspar are affected by partial bleaching and anomalous fading, these factors can be accounted for. Discrimination of negligible-fading small-aliquot data allowed us to obtain post-IR IRSL200 ages between 103 ± 12 and 241 ± 28 ka. Post-IR IRSL200 ages are mostly consistent with 10Be depth-profile dating and stratigraphic constraints and represent a viable option to study glaciofluvial sedimentation during MIS 6 and older glaciations in the region.

The Sauce Grande River Basin (Buenos Aires Province, Argentina) presents a late Pliocene–Holocene sedimentary succession that preserves key evidence of Quaternary paleoenvironmental change in the southern Pampas. This study integrates stratigraphy, sedimentology, paleopedology, geochemistry, mineralogy, and stable isotope data to reconstruct paleoenvironmental evolution from the late Pliocene to the Late Pleistocene. Three paleosol types (Calcisols, Calcic Protosols, and Protosols) were identified and characterized through field descriptions, micromorphology, and molecular indices. Their development reflects shifts in landscape stability, sediment supply, and soil moisture regimes, consistent with glacioeustatic fluctuations and climatic oscillations during the late Plio-Pleistocene transition and the Quaternary. Stable isotope analyses of pedogenic carbonates reveal a trend from C₃-dominated vegetation under more humid conditions in the late Pliocene–Early Pleistocene, to more arid Late Pleistocene–Holocene environments, with increased δ13C values indicating reduced vegetation density and a higher potential contribution of C₄ plants. These findings align with palynological and faunal evidence, highlighting the value of paleosols as sensitive indicators of environmental change. The multiproxy approach adopted here provides new insights into soil formation dynamics and Quaternary palaeoecological transitions in non-glaciated midlatitude settings of South America.

Bender’s Cave on the Edwards Plateau of Texas contains evidence of Late Pleistocene biodiversity that contrasts with the record from 17 regional sites dating to the last glacial interval, Marine Isotope Stage 2 (MIS 2). Bender’s Cave is a groundwater conduit system with an underground stream. Fossils occur in the cave primarily as an underwater lag assemblage and represent taxa that are typical of the Rancholabrean Land Mammal Age and common to central Texas (e.g., Bison, Mammuthus, Camelops). Megalonyx jeffersonii and Mammutidae also occur in Bender’s Cave but are rare elsewhere in the region. Other fossils provide the first regional records of Holmesina septentrionalis and a species of giant Hesperotestudo. The paleoecology of those novel taxa is inconsistent with regional paleoenvironmental proxies for MIS 2, which document a relatively open, dry grassland and cool climate. The novel composition of the assemblage may be the product of sample bias, and the fossils may be vastly time-averaged. However, the identified taxa frequently co-occur in other Texas sites interpreted as dating to interstadial/interglacial intervals of the late Pleistocene (i.e., MIS 3 or MIS 5), suggesting that fossils in Bender’s Cave may also date to one of those earlier warm periods.

The Mission Creek fault strand (MCF) of the San Andreas Fault is proposed to be the primary strand accommodating slip between the Pacific and North American plates in Southern California, but its Holocene activity northwest of Indio is debated. This study presents new depositional ages for alluvial deposits near the mouth of the Mission Creek drainage to investigate potential Holocene activity of the MCF. We estimate a mean depositional age of 0.7 ± 0.2 ka for the alluvium deposited in the drainage valley, contradicting previously inferred ages of >3–18 ka. The young ages for alluvium, often indistinguishable from the age of modern alluvium, suggest that grains are transported during high-energy flash flood–like events. A comparison of luminescence and cosmogenic 10Be ages from alluvial surfaces adjacent to the Mission Creek suggests a possible reworking event at ∼30 ka. Young alluvium ages, together with evidence for frequent flash floods, suggest that this site is rapidly resurfacing and therefore unlikely to preserve surficial rupture signatures older than a few hundred years. Therefore, the lack of observable offsets in deposits overlying the MCF does not imply Holocene inactivity.

We examined trends in sediment deposition, organic carbon sourcing, and carbon and nitrogen isotopes in a transect of four lake sediment cores from eastern Glacier National Park (GNP), Montana, USA to understand how a connected chain of subalpine lakes downvalley from a retreating Grinnell Glacier have responded to environmental change over the last two centuries. Based on 210Pb ages, all three lakes showed a two- to five-fold increase in mass accumulation rate (MAR), with increased MAR beginning at most sites just prior to when GNP was established in 1910 CE, and again at the start of “The Great Acceleration.” Changes in MAR as a result of glacier retreat occurred at the most upvalley site, complicated by shifts in lake size and hydrology. A decrease in C:N ratios and slightly enriched δ13C values since ∼1850s CE reflect a shift toward decreasing terrestrial organic contributions and increased lake productivity. Concurrently, δ15N values were increasingly depleted across all sites over time. The most downvalley site captured spikes in MAR, C:N, and δ13C coincident with recorded flood events. This work demonstrates how organic geochemical and isotopic proxies together capture evolving connectivity between glaciers, catchments, lakes, and human activity under a warming climate.

Climate oscillations may strongly modify continental precipitation and temperature patterns, therefore understanding their history is relevant for comprehending effects of past and ongoing climate changes. For this purpose, temperature and precipitation reconstructions beyond the instrumental record are extremely useful. As widespread terrestrial archives, loess–paleosol sequences are viable targets for such analyses. Consequently, cost-efficient geophysical proxies have gained increasing attention, but little is known about their capability to reflect even narrow climatic differences. Here we assess the sensitivity of rock-magnetic and photo-spectrometric properties of topsoil samples (n = 50) along uncorrelated, mean annual precipitation (MAP: 525±1 mm/yr to 584±1 mm/yr) and mean annual temperature (MAT: 10.8±0.1 °C to 11.2±0.1 °C) gradients across the Bačka Loess Plateau (Serbia) and test a multivariate approach. Most proxies are sensitive to MAP <565±1 mm/yr, especially anhysteretic remanent magnetization (r2 = 0.81). Applying a multivariate approach to hysteresis data reveals a robust relationship between precipitation (r2 = 0.63), aridity (r2 = 0.67) and physical properties over the entire MAP range. Although the approach needs to be further tested considering different climates, regression analyses, and timescales, our study indicates that multi-proxy approaches may increase the robustness with respect to single-proxy measurements for MAP and aridity reconstructions.

Lake sediments record past hydrologic variability, but natural lakes are often sparse in semiarid and arid regions, making the calibration of paleohydrologic models a challenge. At Lake Elsinore, the largest of the few natural lakes in Southern California, we explore and develop a novel transfer function approach for reconstructing lake depth. Using 32 modern surface sediment samples spanning Lake Elsinore’s littoral to profundal zones, we establish a statistical relationship between lake depth and sediment elemental geochemistry composition analyzed via X-ray fluorescence (XRF). We develop lake depth transfer functions using weighted averaging-partial least squares (WA-PLS) and modern analog technique (MAT). Application of the WA-PLS C5 elemental geochemistry-based transfer function to Lake Elsinore sediment cores reveals a climatically sensitive and variable lake hydrology over the past 32,000 years. The reconstruction suggests a prolonged shallowing during an early Marine Isotope Stage 2 (MIS 2) mega-drought between 28,000 and 25,000 cal yr BP, a deep lake spanning the last glacial maximum, a wet–dry response to the Younger Dryas, and a highly dynamic MIS 1/Holocene lake. This single-lake elemental geochemistry technique may be useful in similar settings for reconstructing lake depth and inferring past hydrologic changes.

The prehistoric cultural material at the Lodoso Site, a Middle Archaic to Late Prehistoric campsite near Driscoll, Texas, is dominated by irregularly shaped heat-hardened fragments of earth called burned clay objects (BCOs). These artifacts are a common component of coastal plain archaeology in Texas and elsewhere in the state. Many such sites, especially those situated in sandy soils, do not preserve charcoal well, which renders dating the occupations challenging. The clayey matrix of the Lodoso Site does preserve charcoal, which presents an opportunity to assess the suitability of luminescence dating of burned clay objects by thermoluminescence (TL) and optically stimulated luminescence (OSL), and directly compare those results with charcoal collected from the same excavation provenience, as well as OSL dating of the sedimentary matrix. The TL and OSL results generally track together well but are consistently slightly older than charcoal collected from the same level. The charcoal dates suggest the midden formed between approximately 1500 and 2300 years ago, whereas the luminescence ages suggest formation occurred between 2000 and 3000 years ago. Where the luminescence ages occur out of stratigraphic order, so do the paired charcoal samples, indicating that this is a result of pedoturbation. The results of both radiocarbon and luminescence dating indicate that the midden is a diachronic feature resulting from use over a prolonged period rather than the product of a single burning event.

Mountain permafrost is a climatically sensitive but poorly constrained component of the terrestrial cryosphere. We use 108 U-Th dates from speleothems in two limestone caves in the Uinta Mountains of northern Utah, USA, to reconstruct a 600,000 year history of permafrost presence and absence in this alpine setting. Speleothem growth in both caves is confined almost entirely to discrete intervals that align with interglacial conditions of Marine Isotope Stages (MIS) 5e, 7e, 9e, 11c, and 13. In contrast, growth hiatuses correspond to glacial periods, when permafrost apparently inhibited infiltration of liquid water. Regional lapse rates indicate that cooling of ∼3°C to 5°C relative to present would be sufficient to generate permafrost above the caves. The persistence of age clustering across multiple speleothems in two independent cave systems suggests that mountain permafrost repeatedly formed and degraded in concert with orbitally paced climate cycles. Comparison with nearby paleoclimate records confirms that these changes reflect regional-scale climate forcing. Our results provide rare empirical evidence for the extent of alpine permafrost over Quaternary timescales. As mountain permafrost degrades under modern warming, such records are essential for refining climate models, assessing geomorphic and hydrologic risks, and placing recent changes within the context of natural variability.

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.