Coastal dunes along Lake Michigan's eastern shoreline are a unique system comprising perhaps the largest complex of freshwater coastal dunes in the world. Here, we examine the blowouts in this region and determine how they have evolved since the 1930s. We conducted a spatiotemporal analysis of 435 blowouts by comparing repeat aerial images of the coast beginning in 1938. Using an unsupervised machine learning classification known as iso-clustering, we mapped blowout morphologies at three timestamps: 1938, 1986–1988, and 2018. We then compared the blowout geographies through a technique known as a spatial-temporal analysis of moving polygons (STAMP) model, which allowed us to analyze how each blowout changed in time and space. Results show blowouts have contracted ~37% in size since 1938, mostly at the expense of vegetation, with many fragmenting. These findings comport with other regional and global studies detailing a trend in coastal dune stabilization from vegetation and suggest that an increase in precipitation or other environment drivers could be responsible. Moreover, we detected no new blowouts since 1938 along the ~500 km shoreline or on any of the Lake Michigan islands. This suggests blowouts here are artifacts of premodern conditions, perhaps the result of prior stormier or drier eras.

In this paper, we apply standard zooarchaeological methods and novel osteological approaches to analyse faunal remains from five Middle–Late Holocene sites in the southern Tibetan Plateau (STP). Framed by direct radiocarbon dates on taxonomically classified bioarchaeological remains and compared with published palaeoclimate data, our findings revealed a three-stage process of agro-pastoral development in the STP ca. 5.5 to 1.0 ka. In the first phase, habitation was restricted to the lower southeastern part of the plateau and human subsistence essentially based on foraging and low-level pig–millet farming. With the onset of colder and drier climatic conditions ca. 3.8 ka, the study area witnessed a growing human presence at higher elevations in its central and western parts, together with a shift towards bovid husbandry and barley cultivation, that is, agricultural practices that originated in west Asia; these were likely introduced to the STP following the eastern margin of the TP and/or arrived by sub-Himalayan transfer. Climate and ecological degradation might have contributed to the decline of local game in favour of cold-and-dry-tolerant pastoral livestock and crops. Our work shows that Middle–Late Holocene climate change, ecological change, human subsistence shifts, and prehistoric cultural transmissions are intimately connected.

A robust understanding of the impact of anthropogenic activities on high-altitude tropical aquatic ecosystems is key for the conservation and protection of the Tropical Andean biodiversity hot spot. We present the results of a multiproxy study of lake sediments from the high Andean páramo of El Cajas National Park, a UNESCO biosphere reserve in Ecuador. The main site, Laguna Pallcacocha, is well known for recording El Niño–driven clastic flood layers that are triggered by high-intensity rainfall anomalies from the eastern Pacific. The second site, Laguna El Ocho, does not contain clastic laminations, providing a control. The records show abrupt shifts in diatom assemblages ca. AD 1991 in both high-elevation Andean lakes accompanied by local changes in páramo composition that suggest a sudden nutrient enrichment of the environment. The diatom assemblages from Laguna Pallcacocha, in relation to the clastic input events, are remarkably stable and do not show evident El Niño signals at the analysed resolution. Based on comparison with the nonlaminated El Ocho record, we deduce the main source of this nutrient enrichment to be the construction of a heavily transited road that runs through the park, while climate warming played secondary role by amplifying its effects.

From 300 BC to AD 300, the city of Pergamon underwent a profound transformation that impacted the rural settlement patterns and the concomitant geomorphodynamics. We present a geoarchaeological study in a long-term settled catchment in the Pergamon micro-region to disentangle the Holocene geomorphodynamics and triggering factors, for example, climate change and human activity. The analyses of eight radiocarbon-dated sediment profiles from the Tekkedere alluvial fan and its catchment indicate four principal sedimentation phases. Phase 1 (ca. 6.2 to 5–4 ka) is dominated by the floodplain aggradation of the receiving Bakırçay River, which is followed by the formation of floodplain soils (phase 2). Substantial geomorphodynamic changes occurred around 4 ka (phase 3), when the edge of the floodplain was buried by fan sediments of the tributary Tekkedere creek. This is attributed to supraregional aridization and rapid climate change events, superimposed by the onset of local human activities. Repeated cycles of coarse- and fine-textured fan sediments with age inversions after ca. 3.8 ka and valley infills younger than 1300 yr BP indicate the strong erosion and redeposition of sediments in phase 4. These increased geomorphodynamics may coincide with the changing settlement pattern and thus reflect human–environment interactions.

We examine major reorganizations of the terrestrial ecosystem around Mono Lake, California during the last deglacial period from 16,000–9,000 cal yr BP using pollen, microcharcoal, and coprophilous fungal spores (Sporormiella) from a deep-water sediment core. The pollen results record the assemblage, decline, and replacement of a mixed wooded community of Sierran and Great Basin taxa with Alkali Sink and Sagebrush Steppe biomes around Mono Lake. In particular, the enigmatic presence of Sequoiadendron-type pollen and its extirpation during the early Holocene hint at substantial biogeographic reorganizations on the Sierran-Great Basin ecotone during deglaciation. Rapid regional hydroclimate changes produced structural alterations in pine–juniper woodlands facilitated by increases in wildfires at 14,800 cal yr BP, 13,900 cal yr BP, and 12,800 cal yr BP. The rapid canopy changes altered the availability of herbaceous understory plants, likely putting pressure on megafauna populations, which declined in a stepwise fashion at 15,000 cal yr BP and 12,700 cal yr BP before final extirpation from Mono Basin at 11,500 cal yr BP. However, wooded vegetation communities overall remained resistant to abrupt hydroclimate changes during the late Pleistocene; instead, they gradually declined and were replaced by Alkali Sink communities in the lowlands as temperature increased into the Early Holocene, and Mono Lake regressed.

The giant Cape zebra (Equus capensis) is one of the extinct Quaternary large mammal species of southern Africa, and the largest equid from the Quaternary of Africa. Twenty-six Pleistocene equid tracksites have been identified in aeolianites on the Cape south coast of South Africa. An age range of 161 ± 12 ka to 43 ± 4 ka has been established through Optically Stimulated Luminescence. More than half of the sites contain large-equid tracks, representing the first ichnosites attributed to E. capensis. Smaller equid tracks may have been registered by the quagga (E. quagga quagga). The abundance of E. capensis tracksites on the Cape south coast contrasts with the paucity of body fossils of the species from the region, contrasting with the impression obtained from the body fossil record that E. capensis was predominantly a west coast species in the region. The new data illustrate the capacity of the body fossil and trace fossil records to complement each other. The loss of suitable habitat provided by the Palaeo-Agulhas Plain was probably a contributing factor in the extinction of this large-bodied grazer. A long trackway at Driefontein, attributed to E. capensis, adds to a sparse global record of fossil horse trackways.

The White River Badlands (WRB) of South Dakota record eolian activity spanning the late Pleistocene through the latest Holocene (21 ka to modern), reflecting the effects of the last glacial period and Holocene climate fluctuations (Holocene Thermal Maximum, Medieval Climate Anomaly, and Little Ice Age). The WRB dune fields are important paleoclimate indicators in an area of the Great Plains with few climate proxies. The goal of this study is to use 1 m/pixel-resolution digital elevation models from drone imagery to distinguish Early to Middle Holocene parabolic dunes from Late Holocene parabolic dunes. Results indicate that relative ages of dunes are distinguished by slope and roughness (terrain ruggedness index). Morphological differences are attributed to postdepositional wind erosion, soil formation, and mass wasting. Early to Middle Holocene and Late Holocene paleowind directions, 324°± 13.1° (N = 7) and 323° ± 3.0° (N = 19), respectively, are similar to the modern wind regime. Results suggest significant landscape resilience to wind erosion, which resulted in preservation of a mosaic of Early and Late Holocene parabolic dunes. Quantification of dune characteristics will help refine the chronology of eolian activity in the WRB, provide insight into drought-driven landscape evolution, and integrate WRB eolian activity in a regional paleoenvironmental context.

This study uses luminescence and 14C accelerator mass spectrometry procedures to date relevant glaciofluvial and glacial deposits from the south-central and southeastern Pyrenees (Andorra–France–Spain). We distinguish two types of end-moraine complexes: (1) those in which at least a far-flung moraine exists beyond a frequently nested end-moraine complex (the most common) and (2) those in which a close-nested end moraine encompasses at least two glacial cycles. Both types formed within six distinctive glacial intervals: (1) A penultimate glacial cycle during Marine Oxygen Isotope Stage (MIS) 6 and older glaciofluvial terraces occurred beyond the range of the luminescence dating method. (2) An early glacial advance in MIS 5d (~97 −15/+19 ka) was followed by glacial retreat during MIS 5c (< 91 ± 9 ka). (3) The last maximum ice extent (LMIE) was in early MIS 4 (~74 ± 4.5 ka). (4) Unexpectedly, glaciers thinned during the second half of MIS 3 (~39 −6/+11 ka). (5) During the MIS 3–2 transition, glaciers subsequently fluctuated behind the LMIE limits. (6) The global last glacial maximum (LGM) started as early as ~26.6 ± 0.365 ka b2k, and the corresponding end moraines were built behind the LMIE limits or merged with it, forming close-nested moraines.

We developed a high-resolution magnetochronology of the Pleistocene stratigraphy of the Monte Netto hillock, a tectonically uplifted structure in the Po Plain of northern Italy. Our data allowed reconstructing the depositional age of the sequence and assessing rates of deformation and rock uplift of the neotectonic structure, thus providing constraints on the tectono-sedimentary evolution of this seismically active part of the buried Southern Alps. Using a combination of magnetostratigraphy and paleosecular variation analysis, we generated an age-depth model for the Monte Netto stratigraphy that encompasses, from the top, Upper Pleistocene (11–72 ka) loess-paleosols overlaying fluvial sediments spanning the Brunhes-Matuyama boundary (773 ka) and the top of the Jaramillo (990 ka). The identification of the same magneto-chronostratigraphic surfaces in nearby drill cores from regions of the Po Plain that have not been affected by neotectonic deformation allowed estimating a mean rate of tectonic uplift of the hillock relative to the neighboring plain of 11.3 ± 1.5 cm/ka, and an absolute uplift relative to sea level of ~19.3 cm/ka. Finally, our paleomagnetic analyses from the uppermost loess sequence disclosed the complexity of the tectonic evolution of the Monte Netto structure, which shows evidence of a two-phase rotational deformation linked to coseismic surface faulting due to recent seismic activity.

Mollusk shells from archeological deposits are often exposed to high temperatures through human-caused or natural heating events. While heat exposure affects reliability of mollusk shells for environmental reconstructions based on geochemistry, it can provide a valuable source of information on past human behaviors and human–environment interactions. We analyzed burned and not-burned bivalve and gastropod specimens collected within two megalithic circular structures in the HAS1 settlement in Oman (Late Iron Age and Classical Period). Through a multi-methodological approach, we investigated shell microstructure using scanning electron microscopy (SEM), shell mineralogy using X-ray diffraction (XRD), and shell stable-isotopic composition (δ18O, δ13C) using isotope-ratio mass spectrometry (IRMS) to infer the temperatures these specimens were exposed to and to reconstruct the processes responsible for heating the shells. Thermal response of aragonite and calcite shells having different microstructures were also determined. We found that mollusk shells at this site were exposed to three temperature ranges: a) no exposure or <300°C, b) between 250°C and 500°C, and c) ≥500°C. The heat source was likely a fire which engulfed the entire settlement, which is also supported by evidence of carbonized wooden poles found in situ inside the circular structures.

There are very few records of past terrestrial environmental change of any time period for the Australian tropical savannas. Here we document the hydrological development of Sanamere Lagoon, north Queensland, from a 1.72 m sediment sequence with a basal age of ca. 33 ka. We measure a variety of proxies reflecting environmental change within and around the lagoon, including grain size, elemental and diatom abundance, and carbon and nitrogen isotope composition. By integrating the interpretation of multiple proxies, we show that regional climatic events, such as the reactivation of the monsoon at 15 ka and sea-level rise ending at 7 ka, are reflected in local ecosystem change and a diversity of biogeochemical responses in Sanamere Lagoon. This record makes a significant contribution to the development of records of environmental change from an under-studied region in tropical Australia through the Holocene to the LGM and beyond—a step towards enabling a more detailed understanding of regional monsoon (paleo)dynamics. In particular, this study highlights nuances in the effect of Indonesian-Australian Summer monsoon dynamics in a region less affected by sea level and continental shelf drowning complexities.

The impact of Indigenous populations on historical fire regimes has been controversial and beset by mismatches in the geographic scale of paleofire reconstructions and the scale of land-use behaviors. It is often assumed that anthropogenic burning is linearly related to population density and not different cultural practices. Here we take an off-site geoarchaeology strategy to reconstruct variability in historical fire regimes (<1000 years ago) at geographic scales that match the archaeological, ethnohistorical, and oral tradition evidence for variability in the intensity of Indigenous land use by two different cultural groups (Ancestral Pueblo and Western Apache). We use multiple, independent proxies from three localities in ponderosa pine (Pinus ponderosa) forests in east-Central Arizona to reconstruct fire regime variability during four phases of cultural use of different intensities. Elevated charcoal with domesticate pollen (Zea spp.) but otherwise unchanged forest pollen assemblages characterized intensive land use by Ancestral Pueblo people during an early phase, suggesting fire use to support agricultural activities. By contrast, a phase of intensive pre-reservation Western Apache land use corresponded to little change in charcoal, but had elevated ash-derived phosphorus and elevated grass and ruderal pollen suggestive of enhanced burning in fine fuels to promote economically important wild plants.

The relict beach deposit of the Cala Mosca marine terrace is considered an important section of Marine Isotopic Stage (MIS) 5e (ca. 125 ka) sea-level highstands. Analysis of the stratigraphy and sediments of the deposit indicates the presence of a composite marine terrace comprising two superimposed marine units, luminescence dated to the MIS 5e (137 ± 7, 134 ± 7 ka) and MIS 5c (92 ± 6 ka) substages. The stratigraphic superimposition of the two highstands, both placed ~5 m above present sea level, agrees with other areas along the Sardinia coasts. The evident superimposition of two sea-level highstands and development of the composite terrace cannot be accounted solely by high-frequency sea-level oscillation that occurred within MIS 5 for the Mediterranean Sea. This suggests controversial, but significant, regional versus local tectonic activity occurred during the Late Pleistocene.

The “tablelands” in Taiwan are sedimentary terraces occurring in the foreland basin west of the Neogene mountain ranges. The Miaoli Tableland consists of elevated Late Quaternary sedimentary successions, representing a change from tidal to coastal and fluvial to eolian depositional environments. The present-day morphology is a result of combined processes, including differential tectonic uplift, ongoing fluvial aggradation, and incision. Selected deposits in 10 outcrops were sampled and studied by optical dating. The deposition of fluvial sediments started after the last interglacial (<100 ka) in the southeast of the tablelands. Uplift and sea-level lowering caused a base-level fall, resulting in a stepwise redeposition of the fluvial sediments. Additionally, enhanced remobilization of fluvial sediments occurred during the cold/dry climate during Marine Oxygen Isotope Stages (MIS) 4 and 2. The depositional ages of the coastal sediments enabled the estimation of long-term uplift rates of ca. 0.5 to 3.5 mm/yr. The eolian cover sediments yielded MIS 3 (east) to Holocene ages (west). Our results provide new insight into the interplay of climate, sea-level changes, remobilization of sediments, and tectonism leading to tableland formation during the Late Quaternary.

Continuous records of sediment yield spanning from the late glacial through the Holocene to the present day provide an important opportunity to investigate landscape evolution over various timescales in response to a variety of natural and anthropogenic forcing mechanisms. This study investigates variations in sediment yield and landscape evolution in the 768 km2 watershed of Ossipee Lake, New Hampshire, USA. We pair subbottom sonar observations with analyses of lacustrine sediment cores to interpret a 12,000+ yr record of lake sedimentation in terms of changes in sediment yield and landscape evolution. Our results indicate high rates of sediment redistribution following deglaciation at ~14,500 to ~12,000 cal yr BP, followed by a period of gradually decreasing sediment yield until ~9000 cal yr BP, marking the termination of the most intense period of paraglacial landscape adjustment. From 9000 cal yr BP to 1850 CE, sediment yield is highly variable and reveals a slightly increasing trend that we attribute to a dominant hydroclimatic control on erosion driven by increasing effective precipitation in the region throughout the Holocene. Despite evidence for a highly dynamic landscape and an abundance of unconsolidated glacigenic surface deposits throughout the watershed, we interpret a modest erosional impact from anthropogenic land use.

The relationship between prehistoric populations and water is often poorly understood, partly as a function of historical reliance on qualitative and fragmentary datasets in many regions. Here, we adopt a quantitative approach to analyze a specific aspect of the relationship between prehistoric populations and water for the Cotswold Hills, southwest UK; an area of documented hydrogeological change and extensive Neolithic (ca. 5.5 ka) activity. Using a database of all known Neolithic monuments, we interrogate the significance of water to their habitation. By marshaling a large dataset of recent (ca. 100 years) changes in the discharge and elevation of 259 springs, we establish a striking negative relationship between present-day spring discharge and annual elevation change. We then formulate an inverse problem to predict spring elevations in Neolithic times. Spring elevations are predicted to be closer to, and higher than, Neolithic-dated sites relative to the location of modern springs. These results emphasize a utilitarian and/or reverential link between water and prehistoric populations. Our approach of reconciling markedly different datasets and timescales can easily be adapted to other regions. While groundwater had behaved reasonably predictably since Neolithic times, recent human activity is (and will continue to be) far more significant in influencing groundwater behavior.

Quaternary environments on the Arabian Peninsula shifted between pronounced arid conditions and phases of increased rainfall, which had a profound impact on Earth surface processes. However, while aeolian sediment dynamics are reasonably well understood, there is a lack of knowledge with regard to variability in the fluvial systems. Presented here are the findings from several locations within wadi drainage systems to the west of the Hajar Mountains (United Arab Emirates). The performance of optically stimulated luminescence dating using a customized standardized growth curve approach is investigated, showing that this approach allows reliable determination of ages by reducing the machine time required. Three main periods of fluvial activity occurred at 160–135, 43–34, and ca. 20 ka. Additional ages fall into the latest Pleistocene and Late Holocene. None of the ages coincides with major wet periods in SE Arabia that have been identified in stalagmites and by the deposition of lake sediments. It is shown that fluvial activity was partly contemporaneous (within the given time resolution) with phases of aeolian deposition and was almost continuous, but likely sporadic, during the Middle to Late Pleistocene. This highlights the need for regionally defined paleoenvironmental records to fully understand the response of dryland systems to long-term climatic change.

Paleoecological and modern studies at Priyatnoye Lake, which is located within an intermontane depression in the interior of northeastern Siberia, indicate a similar paleovegetation record as has been documented for nearby mountain valleys, but a history of basin stability and instability that is uncharacteristic of the valley lakes. Analyses of a 385-cm-long core from the western basin of Priyatnoye Lake shows that sediment accumulation began in late Marine Oxygen Isotope Stage 3 (MIS 3), followed by a hiatus during MIS 2, and then continuous accumulation over the past ca. 14,000 cal yr BP. The eastern basin of the lake has a sediment thickness of ~35 cm, suggesting that it intermittently contained water and/or is younger than the western basin. A drop in lake levels between AD 2005 and AD 2009 resulted in the formation of two distinct lakes. This change was caused by the melting of underlying ice wedges and the formation of sinkholes through which the lake water drained. Although the northern coastal lowlands have been the geographic focus of permafrost global warming research, the Priyatnoye study draws attention to the intermontane depressions in northeastern Siberia. While less extensive, these depressions contain organic-rich deposits, are underlain by permafrost, and have the potential to affect future carbon budgets as global temperatures rise and permafrost melts.

Although tortoises (Testudinidae) are a familiar clade of reptiles, with a body fossil record extending to at least the Eocene, hitherto no tortoise ichnosites have been described. Here, a number of sites attributed to tortoise trackmakers are identified within Pleistocene aeolianites on South Africa's Cape south coast. These date from late Marine Isotope Stage 6 to Marine Isotope Stage 4. The findings indicate large trackmakers, with evidence of a trackmaker length of more than a meter—substantially longer than the largest extant tortoises in southern Africa. This suggests either the presence of an extinct very large tortoise species, or that Pleistocene leopard tortoises in the region were larger than their descendants. Variations in substrate properties are responsible for a variety of track and trace forms. A mismatch exists between the reported ichnological evidence for large tortoises, and the regional archaeological and body fossil records, which almost exclusively comprise smaller tortoises. The findings illustrate the potential of ichnology to complement and augment the paleontological and archaeological records.