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.

According to its 2022 national glacier inventory, Chile is home to 26,169 glaciers and roughly 80 percent of the glaciers in South America. Yet much of this ice is not legally protected. Diverse local communities whose lifeworlds depend on the spiritual and material integrity of Andean glaciers and their meltwaters are placing growing demands on Chilean glaciologists to accompany grassroots campaigns to defend these ecosystems from the direct impacts of anthropogenic interventions amid the climate crisis and years of megadrought. This article builds off a feminist glaciology framework to examine if, how, and to what extent an emerging generation of Andean glacier scientists is learning to question the masculinist and Western modes of knowledge, thinking, and action embedded in their disciplinary training. Through ethnographic fieldwork with glacier scientists, arrieros (herders), and grassroots organizations in the municipality of Putaendo in Central Chile, and the author’s participation in codesigning a knowledge exchange between Mapuche communities and glacier scientists in the province of Araucanía, this article analyzes the possibility for dialogues between ancestral, local, and technoscientific knowledges to transform the dominant discourses and practices of glaciology. It demonstrates the ontological openings that occur when knowledges that have been systematically marginalized from the technoscientific domain of glacier science are taken seriously in conversations over the present and future of the cryosphere. And it argues that these ontological exchanges not only impact the possibility of climate justice for those communities most directly affected by glacier loss but also can contribute to building more feminist, plural, and decolonial praxis within contemporary glaciology.