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.

Chile has undergone two consecutive failed attempts at constitutional replacement (2021–2022 and 2023), positioning it as a globally interesting case. While existing literature identifies macropolitical and institutional factors underlying such failures, certain key causal mechanisms remain unexplored. This article addresses the central question of why majority-controlling political actors, aware of the need for broad national consensus, ultimately fail to achieve it. Framed as a two-level process—one at the elite negotiation level and the other at the electoral ratification level—this study elucidates the mechanisms operating at each stage that contributed to this dual failure. By analyzing these dynamics in detail, the article offers valuable lessons for future efforts to replace a constitution in a democratic setting.

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.