It has been unclear whether Holocene lake evolution in the Badain Jaran Desert of northwestern China, an area in which lakes are mainly recharged by groundwater, responded to climate change. In this study, we analyzed the Mg/Ca ratio and phytolith assemblages from 10 Holocene calcareous root tube samples from the desert to reconstruct changes in effective moisture and mean annual precipitation (MAP) at the millennial scale during the Holocene and to explore the factors affecting lake evolution. Our results revealed that the effective moisture at 7000–5000 cal yr BP was higher than that of 5000–2000 cal yr BP. Similarly, the MAP was higher at 7000–5000 cal yr BP (175 ± 37 to 205 ± 37 mm) than at 5000–2000 cal yr BP (145 ± 37 to 165 ± 39 mm). The expansion of the lakes during the Early Holocene would have resulted from the input of groundwater from the meltwater in the recharge area. High lake levels in the Middle Holocene corresponded to increased monsoonal precipitation and groundwater recharge. The gradual decline of lake levels in the Late Holocene indicated a relatively arid climate with decreased monsoonal precipitation and groundwater recharge.

Constructional sedimentary history of coastal barriers can provide insights regarding meteorological and oceanographic processes, and relative sea-level changes. We investigated the Holocene evolution of a segment of the Rio Grande do Sul Coastal Plain in southernmost Brazil. Data were obtained from ground-penetrating radargrams, optically stimulated luminescence dating, altimetry measurements, Google Earth imagery, and aerial photographs. These data allowed a qualitative and quantitative analysis of the beach profiles recorded in the radargrams. From which eolian, backshore/foreshore, breaker bars, and upper and lower shoreface radar facies were identified. The beach-related radar facies are recorded in twenty-eight progradational sand units (sigmoidal bodies). These units record increments of relatively steady deposition bounded by erosional surfaces produced by anomalous, high-magnitude storm events taking place about every 250 years. The upper shoreface strata include two to three breaker bars. Several pieces of evidence (number of breaker bars, upper shoreface gradient and progradation rate) suggest an alternation between dissipative and intermediate stages of barrier morphodynamics and a decrease of wave energy from 2 ka onwards. The barrier prograded during the last 7.1 ka, and initially, barrier progradation occurred because of a normal regression during a relative sea-level rise followed by a stillstand. Later, barrier progradation took place as a forced regression driven by a relative sea-level fall.

To explore sea level transgression in low-lying inland areas and its possible influence on prehistoric cultures, we investigated the physical and geochemical features of 20-m-long sedimentary cores from the previously seawater-filled Daesan Basin located in the middle reach of the present Nakdong River in Korea as proxies for seawater transgression deep inland areas due to Holocene sea level rise. Based on the relationships among grain size, total sulfur content (TS%), and carbon/sulfur (C/S) ratio, the first transgressive event was detected at ca. 8500 cal yr BP, caused by seawater influx along the present Nakdong River. Higher TS% (0.8–1%) and interbedded fossil oysters at 8000–6000 cal yr BP indicate marine environments, supporting a paleo-Daesan Bay with water depth of ~10–8 m. The common peaks in TS%, in both inland paleo-Daesan Bay and a present coastal area (Suncheon Bay) in southern Korea (e.g., at 3200 and 4700 cal yr BP), may indicate intervals of higher salinity, which suggests simultaneous responses to changes in sea level or hydroclimate. The duration of marine environment (paleo-Daesan Bay) in the remote inland from ca. 8000–3200 cal yr BP provides an analog for inland paleo-bay studies in East Asia.

Detrital sediments of the Sea of Galilee are predominantly pedogenic products of settled dust and local bedrocks transported from Upper Galilee and the Golan Heights. Using the mineralogy, chemistry, and Nd and Sr isotope ratios of the core LK12-22 collected offshore of the Ginosar valley and of contemporaneous soils from the Nahal Tzalmon and Nahal Amud catchments, we reconstructed Late Holocene regional hydroclimate. The core samples span ɛNd isotope values of −6 to −2 and 87Sr/86Sr ratios of 0.7075 to 0.7077 between the isotope fields of the Terra rossa soils and basaltic soils. Sediments from the drier Iron Age and Arabic and Ottoman periods are closer in Nd-Sr isotope ratios of the basaltic soils, while those of the wetter Middle to Late Bronze and Roman–Byzantine periods are closer to the Terra rossa soils, reflecting enhanced mobilization of sediments from the Tzalmon catchment where Terra rossa–type soils accumulated. This result corroborates other regional data that indicate semiarid to temperate conditions in the south Levant during most of the Late Holocene. Wetter conditions over the Galilee Mountains and the Ginosar valley catchment during the Roman period could have promoted the flourishing farming-fishing society that heralded the rise of Christianity.

The wettest portion of the interior of western North America centers on the mountainous region spanning western Montana, Idaho, British Columbia, and Alberta. Inland ranges there capture the remnants of Pacific storms. Steep east–west hydroclimate gradients make the region sensitive to changes in inland-penetrating moisture that may have varied greatly during the Holocene. To investigate potential hydroclimate change, we produced a 7600-yr lake-level reconstruction from Silver Lake, located on the Montana–Idaho border. Ground-penetrating radar profiles and a transect of four shallow-water sediment cores that were dated using radiocarbon dating and tephrachronology revealed substantial changes in moisture through time. An organic-rich mud unit indicating wet and similar to modern conditions prior to 7000 cal yr BP is overlain by an erosional surface signifying drier than modern conditions from 7000–2800 cal yr BP. A subsequent time-transgressive increase in water levels from 2800–2300 cal yr BP is indicated by a layer of late Holocene muds, and is consistent with glacier expansion and increases in the abundance of mesic tree taxa in the region. Millennial-scale trends were likely driven by variations in orbital-scale forcing during the Holocene, but the regional outcomes probably depended upon factors such as the strength of the Aleutian Low, Pacific sea-surface temperature variability, and the frequency of atmospheric rivers over western North America.

A multiproxy oxygen and carbon isotope (δ13C and δ18O), growth rate, and trace element stalagmite paleoenvironmental record is presented for the Early Holocene from Ethiopia. The annually laminated stalagmite grew from 10.6 to 10.4 ka and from 9.7 to 9.0 ka with a short hiatus at ~9.25 ka. Statistically significant and coherent spectral frequencies in δ13C and δ18O are observed at 15–25 and 19–23 years, respectively. The observed ~1‰ amplitude variability in stalagmite δ18O is likely forced by nonequilibrium deposition, due to kinetic effects during the progressive degassing of CO2 from the water film during stalagmite formation. These frequencies are similar to the periodicity reported for other Holocene stalagmite records from Ethiopia, suggesting that multidecadal variability in stalagmite δ18O is typical. Several processes can lead to this multidecadal variability and operate in different directions. A hydroclimate forcing is likely the primary control on the extent of the partial evaporation of soil and shallow epikarst water and associated isotopic fractionation. The resulting oxygen isotope composition of percolation water is subsequently modulated by karst hydrology. Further isotopic fractionation is possible in-cave during nonequilibrium stalagmite deposition. Combined with possible recharge biases in drip-water δ18O, these processes can generate multidecadal δ18O variability.

The alpine–subalpine Loch Vale watershed (LVW) of Colorado, USA, has relatively high natural lithogenic P5+ fluxes to surface waters. For 1992–2018, the largest number of stream samples with P5+ concentrations ([P5+]) above detection limits occurred in 2008, corresponding with the highest frost-cracking intensity (FCI). Therefore, relatively cold winters and warm summers with a comparatively low mean annual temperature partly influence stream [P5+]. Sediment cores were collected from The Loch, an outlet lake of the LVW. Iron-, Al-, and Mn-oxide-bound phosphorus (adsorbed and authigenic phosphates; NP) serves as a proxy measurement for paleolake [P5+]. The highest NP in the core occurred during the cold and dry Allerød interstade. The lowest NP concentrations in the core occurred during climatically very wet periods in the Late Pleistocene and Early Holocene. Therefore, [P5+] are highest with relatively cold winters followed by relatively warm summers, relatively low mean annual temperatures, and relatively little rainfall and/or cryospheric melting. Currently the LVW is experiencing warming and melting of the permanent cryosphere with a rapidly declining FCI since 2008. This has the potential to dramatically decrease [P5+] in surface water ecosystems of the LVW, reducing biological productivity, enhancing P-limitation, and increasing ecosystem reliance on aeolian P5+.

The lower Athabasca River basin in northeastern Alberta contains one of the highest known concentrations of prehistoric archaeological sites in the boreal forests of western Canada. This is due to the combination of readily available sources of lithic raw material stone near a major travel corridor, and extensive archaeological survey conducted in advance of oil sands mining. Typological studies have proposed immediate post-glacial occupations that were contemporaneous with, or immediately followed, the catastrophic glacial Lake Agassiz flood through the area at the end of the Pleistocene. Here, we complement the typology age estimates by using stratigraphic relations and infrared stimulated luminescence (IRSL) dating of aeolian material to determine the age of initial human occupation, and reconstruct the environment encountered by early inhabitants of the region. We find that the first occupations in our study area took place near the Pleistocene-Holocene boundary (ca. 11.3 ± 0.8 ka BP), shortly after catastrophic flooding from Lake Agassiz. The post-flood environment was dominated by cold climatic conditions that supported permafrost, presumably during the late Pleistocene, and underwent significant aeolian deposition. Our results indicate that this area represents a portion of the eastern edge of the deglacial corridor into which plants, animals, and humans dispersed following retreat of the Laurentide Ice Sheet.

The southern Red Sea is a key region for investigating the effect of climate forces on a semi-closed basin. Detailed micropaleontological (planktic foraminifera) and isotopic (δ18Ο, δ13C) analyses along with reconstructions of sea surface temperature and salinity on a sediment core from the Farasan banks revealed the imprints of sea level changes and the South Asian Monsoon on the area. Comparison with surrounding records provided insights on the Red Sea-Gulf of Aden (GoA)-Northwestern Arabian Sea (NWArS) water exchange pattern over the last 30 ka. During glacial sea-level lowstand, flow of water from the GoA prevented hypersalinity in the southern Red Sea. Deglacial sea level rise improved water mass exchange between the NWArS, GoA and the entire Red Sea, resulting in relatively similar surface water conditions during the early Holocene when sea-level rise slowed. Thus, sea level change is the major driver of Red Sea δ18O variability. Southwest Monsoon (SWM), which was dominant during the late glacial and Early–Middle Holocene, enhanced surface productivity in the southern Red Sea. Northeast Monsoon (NEM) dominated around Heinrich stadial 1, as indicated by a nearly aplanktonic zone that was probably caused by restricted GoA inflow and low productivity.

Using a multimethod approach, including polarized light microscopy (PLM), scanning electron microscopy (SEM) with X-ray energy dispersive spectroscopy (EDS), SEM with mineral liberation analyzer (MLA), X-ray diffraction (XRD), and Raman spectroscopy, we examined sub-recent ferruginous crusts in the Xingu River in the Amazon Basin that have formed since the Early Pleistocene (<1.2 Ma), as indicated by (U-Th)/He dating of goethite. Although now preserved as goethite, the size and form of the smallest components of the ironstone (nanorods) and the nature of isomorphic substitution in the goethite point to very early transformation of the original precipitate, an unstable hydrous ferrous oxide (HFO) mineral, into goethite. The fine, multiply undulating laminae of the ironstone contain abundant filamentous microbial molds and casts that together support identification of the crusts as ferruginous microbialites and suggest a role of bioinduction/bioinfluence in ironstone precipitation, although inorganic precipitation is also evident. The Xingu Quaternary ironstones are the first evidence of ferruginous microbialite in a modern freshwater system in South America and may hold clues to the recent history of the Xingu River.

Evaluating synchronies between climate and cultural changes is a prerequisite for addressing the possible effect of environmental changes on human populations. Searching for synchronies during the Middle-Upper Paleolithic transition (ca. 48–36 ka) is hampered by the limits of radiocarbon dating techniques and the large chronological uncertainties affecting the archaeological and paleoclimatic records, as well by their low temporal resolution. Here, we present a high-resolution, pollen-based vegetation record from the Bay of Biscay, sea surface temperature changes, additional 14C ages, and a new IRSL date on the fine-sediment fraction of Heinrich Stadial (HS) 6. The IRSL measurements give an age of ca. 54.0 ± 3.4 ka. The paleoclimatic results reveal a succession of rapid climatic changes during the Middle-Upper Paleolithic transition in SW France (i.e. D-O 12–8 and two distinct climatic phases during HS 4). Comparison of the new paleoclimatic record with chronologically well-constrained regional archaeological changes shows that no synchronies exist between cultural transitions and environmental changes. The disappearance of Neanderthals and the arrival of Homo sapiens in SW France encompassed a long-term forest opening, suggesting that Homo sapiens may have progressively replaced Neanderthals from D-O 10 to HS 4 through competition for the same ecological niches.

The Sumerian culture flourished within the Tigris and Euphrates rivers floodplains and along their deltaic systems, which ca. 6000 yr were located ~250–260 km inland from the present Persian Gulf. Here, large floodplains and marshes were crossed by an intricate network of channels where several human settlements developed. In this paper, we describe in detail the paleoenvironmental context where the site of Abu Tbeirah (third millennium BC) developed, near the Sumerian capital of Ur. Our interdisciplinary approach, based on remote sensing and the geomorphological study of the area, as well as on sedimentological, paleontological, and paleobotanical analyses of trenches and boreholes deposits, reveals that the site developed along a sinuous channel in a floodplain and marshy environment, where several crevasse splays occurred. This channel was cut off following a flood event. The abandoned portion of the channel was exploited by residents and used as a small river harbor. Our research contributes to better define how the landscape of the site changed over the course of its history and how humans exploited water resources of the area during occupation of the site, a process that was pivotal for the development of the Sumerian culture.