Journal of Quaternary Science最新文献

Blanket peat is widespread in maritime extra-tropical environments. Prehistoric land-use activity was traditionally invoked as the stimulus of blanket peat initiation in the British Isles, but recently, climate has been viewed as the driver of peat formation. Understanding of the timing and thus cause of blanket peat initiation is, however, confounded by uncertainties that primarily pertain to dating well-humified peat deposits. Here, we seek to address challenges in dating blanket peat with a view to better understanding its initiation in Ireland. Through a study of blanket peat profiles from five sites in the Mourne Mountains, Northern Ireland, we show that radiocarbon ages from different peat fractions are younger than contemporaneous cryptotephra ages by several centuries, probably due to the translocation of humic acids and root material down sediment profiles. Peat initiation was, therefore, dated in the Mourne Mountains using tephrochronology, and reveals initiation centred on ~8700 BP, ~7900–6800 BP and ~3500 BP. Reanalysis of Irish basal peat ages emphasises climate as the driver of blanket peat from ~7500 BP, but highlights that its development was time-transgressive at intra- and inter-regional scales. We conclude that blanket peat is a natural feature of the Irish landscape and highlight the uncertainties of radiocarbon dating blanket peat deposits.

Chronologic and geomorphic evidence of past glaciations is largely recorded in areas at relatively low elevation and/or landscapes defined by high glacial erosion. As a result, data from areas that did not experience significant glacial erosion and the highest elevation locations are lacking from reconstructions of past ice masses. Here, we use paired ¹⁰Be and ¹⁴C exposure dating on quartz derived from glacial erratics and bedrock to resolve past ice mass fluctuations across an elevation and geomorphic gradient in the Cairngorm Mountains of Scotland. We find that the highest elevation samples in our dataset, at 1140 m above sea level, yield ¹⁰Be ages indicating 23 000 years of exposure and are at secular equilibrium for ¹⁴C, indicative of a single period of exposure starting as a nunatak during the Last Glacial Maximum. Other samples from above 1000 m elevation produce ¹⁴C exposure ages indicating deglaciation during the Bølling–Allerød Interstadial, while ¹⁰Be concentrations display varying levels of inheritance due to local variations in glacial and non-glacial erosion. Samples from lower elevations indicate a Lateglacial moraine building event 15 000 years ago, coincident with the Wester Ross readvance, followed by a period of glacier retreat interrupted by moraine deposition at ~14 000 and ~11 000 years ago. This dataset reconstructs both thinning and marginal recession of paleo-ice masses within the Cairngorm Mountains across a >600 m vertical gradient during the most recent glacial–interglacial transition, demonstrating the utility of paired ¹⁰Be/¹⁴C exposure dating in ice mass reconstructions in areas of low glacial erosion, increasing the geomorphic diversity of chronologic data available for glacial reconstructions.

Des-Cubierta Cave, part of the Calvero de la Higuera complex, is situated in the intramountainous upper valley of the Lozoya River within the Guadarrama Range. The cave's geological, palaeontological, and archaeological record reveals a complex history of sedimentary and anthropogenic processes spanning hundreds of thousands of years, represented in 12 lithostratigraphic units. Among these, Unit 3 stands out for its archaeological significance, containing evidence of Neanderthal activity, including Mousterian lithic tools and an unusual assemblage of large mammal crania, which suggests symbolic behaviour. Geological data indicate that Unit 3 was deposited during cold periods (MIS 4) through multiple rockfall episodes, implying that these symbolic practices persisted across generations. The cave's geomorphology points to a possible Neanderthal entrance via a side opening created by erosion in the southern part of the cave. This study enhances our understanding of Des-Cubierta Cave's geological development and the long-term Neanderthal occupations, offering valuable insights into their symbolic and cultural behaviours.

Glacial erratics are geologically distinctive rocks transported away from their source area by ice sheets and deposited in lithologically different bedrock areas. They have attracted much scientific curiosity with >24 000 observations across the British Isles. A common misinterpretation is that they took a nearly direct line of transport from source to resting position, neglecting to change ice flow directions during ice sheet growth and decay. To rectify this, we sequentially modelled erratic time-space trajectories at 1000-year timesteps using ice flowlines in an empirically constrained ice sheet model simulation to predict erratic deposition areas. We addressed the processes of entrainment and deposition by combining all potential trajectories into a single footprint of possible locations. Erratic dispersal is predicted for three geologically distinctive lithologies; Shap Granite of Northern England, Galway Granite of Ireland and the Glen Fyne igneous complex from Scotland. The footprint of predicted trajectories compared against 1883 observations of erratic locations was found to successfully explain 77% of the observed erratics. Most erratics were explained by flow directions during ice retreat; however, some required earlier ice divide shifts to produce potentially long-duration, multiphase pathways. Our analysis demonstrates the possibility of explaining many erratics without explicitly modelling the complex processes of entrainment and deposition.

1920s/30s excavation of a Middle Devensian sequence in the northern part of Kents Cavern recovered important Late Middle and Early Upper Palaeolithic archaeological material, including Britain's oldest known Homo sapiens remains. Questions remain about this material, including how it came to be in the cave. Judged by the recorded distribution of finds it may have entered via the Northeast Gallery. A previously unrecorded entrance into the cave from the Northeast Gallery was identified in 2014, and a column through the entrance's sedimentary fill was excavated during 2015–2016. The results of that work are reported here. The entrance retains an intact and well-stratified Pleistocene sequence comparable to the ‘Cave Earth’ unit described previously inside the cave. The uppermost part of the newly recognised Northeast Gallery entrance sequence has been removed by historical excavation, with most of the remaining sediments spanning the Middle Devensian and earlier part of the Late Devensian. The sequence contains bone and pollen, and ancient mammalian DNA is preserved within the sediments. The base of the Northeast Gallery entrance sequence is formed of a clayey diamict comparable to the cave's ‘Breccia’ unit, a deposit currently understood as Middle Pleistocene, and previously identified only in Kents Cavern's southern chambers. Comparison of the excavated sequence with the historical record of the Vestibule excavation shows that the basal cave earth deposits in the Northeast Gallery entrance are significantly higher than those inside the cave. Although requiring further work to confirm, this suggests that the Northeast Gallery could have played a major role in the accumulation of material in the Vestibule during the Middle Devensian.

Fumane Cave, located in Northern Italy, is a major prehistoric site for understanding late Neandertal and early modern human behaviours. The cave contains a 12-m-thick stratigraphic sequence of Middle and Upper Palaeolithic layers, which have yielded a number of flint artefacts and faunal remains. The upper part of the stratigraphic sequence is well-dated using radiocarbon analysis, placing the last Middle Palaeolithic occupations at ca. 44–45 ka cal BP and the first Upper Palaeolithic occupations (Uluzzian and Aurignacian) after around 43 ka cal BP. However, the lower part of the stratigraphic sequence remains less well-documented chronologically. Previous thermoluminescence (TL) dating placed the entire sequence within the last climatic cycle, following the last Interglacial stage (MIS 5e). In this study, we present a revised chronology for the Middle Palaeolithic levels at Fumane Cave, based on combined Electronic Spin Resonance/Uranium (ESR/U)-series dating of herbivorous teeth spanning much of the sequence. Our results diverge from earlier TL data, indicating that the oldest layers date to MIS 7–6 (units S9–S3) and MIS 6–5 (units BR12–BR9). For the late Mousterian (units A11–A4) and the Upper Palaeolithic (unit A2), recalculated ages using new in situ gamma measurements align with existing radiocarbon and TL dates. However, our findings highlight the methodological challenges of applying ESR/U-series dating to samples younger than 50 ka, particularly in heterogeneous layers. These new results suggest that Middle Palaeolithic occupations at Fumane Cave spanned over 200 ka, covering the two most recent climatic cycles. This extended temporal framework parallels that of San Bernardino cave, another key site in Northern Italy, and underscores the prolonged presence of Levallois technology in the region.

A Late Upper Paleolithic (LUP) site containing Ahrensburgian-type stone tools has been discovered at South Cuidrach, Isle of Skye, Scotland. Together with a group of intertidal stone circular alignments also recently discovered on the island, this new evidence for the occupation of northern Scotland also represents the most northerly LUP site in Britain. The timing of the continental Ahrensburgian culture is closely linked to the later part of the Younger Dryas, also known regionally as the Loch Lomond Stadial (LLS), a cold period that saw a significant ice cap and glacier expansion across the mainland of western Scotland. Here, we examine the climatic, environmental and relative sea-level contexts and reflect on the location of this site on an island to the north-west of the Younger Dryas ice mass. South Cuidrach is situated on the north coast of Skye, lying around 25 km north-west of the maximum known local extent of the Younger Dryas ice mass. Most of the lithic assemblage is made from locally available baked mudstone. The site has good access to coastal and riverine resources and readily available ochre, suggesting it was deliberately chosen. Together with the new stone alignments and several other nearby sites, this region now contains more evidence for the LUP than anywhere else in Scotland. The geography and Late Glacial environment of west Scotland comprised a volatile landscape of water, mountains and fluctuating glaciers and coastlines, a challenging area at the north-westerly limit of the European landmass that was very different to the Ahrensburgian core territories in mainland Europe. We anticipate that by examining this new evidence within the various broad geographical and geomorphological conditions, there is significant potential for the discovery of further LUP locations both on and off-shore in this region.

The high mountains of Taiwan provide a unique location for Quaternary palaeoclimate research in East Asia and the north-western Pacific. This study applies geomorphological field mapping and rock surface exposure dating with paired (¹⁰Be/²⁶Al) in situ-produced terrestrial cosmogenic nuclides to identify and date glacial landforms and boulders in a relatively low-elevated (<3300 m) section of the Taiwanese Central Mountain Range, the southern Nenggao Shan. We propose two major glacial phases during the last glacial cycle: 1) During the Marine Isotope Stage 3 to the early Marine Isotope Stage 2, a small plateau glacier covered the main crest with a glacier equilibrium line altitude at 2800 m. This is the lowest ever reported equilibrium line altitude in Taiwan. The ice retreated during or just before the global Last Glacial Maximum. This is consistent with scenarios from other East Asian mountain ranges. 2) During the late glacial until the early Holocene, six cirque glaciers formed exclusively in east-facing topographically favorable downwind positions. Their cirque floor elevations indicate an orographic equilibrium line altitude between 2700 m and 2800 m. These cirque positions confirm the dominant influence of the mid-latitude westerlies above the shallow winter monsoon on the high-altitude precipitation regime in East Asia.