The identification, characterization, and mapping of large areas of stabilized eolian features along the tropical northeastern Brazilian coast enabled recognition of the existence of one of the largest Quaternary dune fields (16,000 km2) in South America. This paleodune system is observed inland of the Lençóis Maranhenses transgressive dune field (2.5°S, 43°W) and comprises deflation plains, stabilized parabolic dunes, and barchanoid chains developed under the action of northeast (NE) trade winds. Optically stimulated luminescence ages coupled with geomorphological analysis were used to constrain the time of dune field stabilization. Ages of stabilization of parabolic dunes and barchanoid chains throughout this paleodune system range between 19 to 14 ka showing heterogeneous dune stabilization by vegetation growth during a 5 ka time interval. Dune field stabilization is related to a decrease in NE trade wind strength and increase in precipitation as a consequence of the southward shift of the Intertropical Convergence Zone during the Heinrich stadial 1 event (18–15 ka), which resulted in a lower eolian drift potential, less sand input by alongshore transport, and low sediment availability to eolian transport, due to an increase in moisture to support vegetation growth and rising relative sea level.

The rock art and the associated natural scenery at 38 sites located in the Zuojiang River valley, in the southwest of Guangxi Zhuang Autonomous Region, southern China, were inscribed recently on UNESCO’s World Heritage List. The painted panel at the site of Mt. Huashan is probably the largest known rock art panel in the world, consisting of approximately 1900 identifiable figures and occupying an area of approximately 8000 m2. To determine a precise age on the rock art at Mt. Huashan, 56 secondary carbonate layers above and below the paintings were studied for their mineralogy, oxygen, and carbon isotopic compositions and dated by the 230Th/U method. The 230Th/U dating results demonstrate that ages of the rock paintings can be bracketed between 1856±16 and 1728±41yr BP corresponding to the middle to the end of the Eastern Han dynasty (AD 25 to 220). The results imply that the rock painting practices at Mt. Huashan probably lasted more than a century, and the Zuojiang rock art is younger than that at Baiyunwan and Cangyuan in Yunnan Province by 1 to 10 centuries.

Holocene tephrostratigraphy in Alaska provides independent chronology and stratigraphic correlation in a region where reworked old (Holocene) organic carbon can significantly distort radiocarbon chronologies. Here, we present new glass chemistry and chronology for Holocene tephras preserved in three Alaskan lakes: one in the eastern interior and two in the southern Brooks Range. Tephra beds in the eastern interior lake-sediment core are correlated with the White River Ash and the Hayes tephra set H (~4200–3700 cal yr BP), and an additional discrete tephra bed is likely from the Aleutian arc/Alaska Peninsula. Cryptotephras (nonvisible tephras) found in the Brooks Range include the informally named “Ruppert tephra” (~2700–2300 cal yr BP) and the Aniakchak caldera-forming event II (CFE II) tephra (~3600 cal yr BP). A third underlying Brooks Range cryptotephra is chemically indistinguishable from the Aniakchak CFE II tephra (4070–3760 cal yr BP) and is likely to be from an earlier eruption of the Aniakchak volcano.

Agricultural landscapes are human-manipulated landscapes, most obviously in areas modified by terracing and/or irrigation. Examples from temperate, arid, and desert environments worldwide have attracted the attention of many disciplines, from archaeologists, palaeoecologists, and geomorphologists researching landscape histories to economists, agronomists, ecologists, and development planners studying sustainable resource management. This article combines these interdisciplinary interests by exploring the role archaeology can play in assessing sustainability. Our case study is Engaruka, Tanzania, archaeologically famous as the largest abandoned irrigated and terraced landscape in East Africa. The site has been cited as an example of economic and/or ecological collapse, and it has long been assumed to have been irrigated out of necessity because agriculture was presumed to be nearly impossible without irrigation in what is now a semiarid environment. Geoarchaeological research refutes this assumption, however, demonstrating that parts of the site flooded with sufficient regularity to allow the construction of more than 1000 ha of alluvial sediment traps, in places greater than 2 m deep. Soil micromorphology and geochemistry also record changes in irrigation, with some fields inundated to create paddylike soils. Geoarchaeological techniques can be applied to both extant and abandoned agricultural systems, thereby contributing to an understanding of their history, function, and sustainability.

A multidecadal-scale lake-level reconstruction for Lago Wiñaymarca, the southern basin of Lake Titicaca, has been generated from diatom species abundance data. These data suggest that ~6500 cal yr BP Lago Wiñaymarca was dry, as indicated by a sediment unconformity. At ~4400 cal yr BP, the basin began to fill, as indicated by the dominance of shallow epiphytic species. It remained somewhat saline with extensive wetlands and abundant aquatic plants until ~3800 cal yr BP, when epiphytic species were replaced by planktic saline-indifferent species, suggesting a saline shallow lake. Wiñaymarca remained a relatively shallow lake that fluctuated on a multidecadal scale until ~1250 cal yr BP, when freshwater planktic species increased, suggesting a rise in lake level with a concomitant decrease in salinity. The lake became gradually fresher, dominated by deep, freshwater species from ~850 cal yr BP. By ~80 cal yr BP, saline-tolerant species were rare, and the lake was dominated by freshwater planktic diatoms, resembling the fresh and deep lake of today. These results reveal a more dynamic and chronologically specific record of lake-level fluctuations and associated ecological conditions that provide important new data for paleoclimatologists and archaeologists, to better understand human-environmental dynamics during the mid- to late Holocene.

Fungal spores, especially those of coprophilous fungi, are present in dung middens of Rhinoceros unicornis (greater one-horned rhinoceros) in both forest and grassland areas of the Kaziranga National Park, India. The presence of coprophilous fungi on rhino dung, chiefly Sporormiella, Saccobolus, Ascodesmis, Cercophora, and Sordaria, is documented for the first time. The Sporormiella–Ascodesmis–Saccobolus assemblage is abundant and characterizes the rhino dung in forest and grassland areas. The presence of coprophilous fungi spores allows for an examination of the relationship between rhinoceros ecology and the flora and other fauna in the region. The overall dataset is useful in interpreting the present and past distribution of rhino and other associated animals based on the relative abundance of different types of coprophilous fungi spores and their relationship to paleoherbivory and paleoecology in India and adjoining areas.

Two lake records document Holocene changes in sea level, vegetation, and climate on the Okhotsk and Pacific sides of central Iturup Island, southern Kuril Islands. The sediment cores originated within tidal flats that subsequently developed into a marine strait which crosscut the island as sea levels rose during the early Holocene. Brackish lagoons and eventually freshwater lakes formed by ~7100 cal yr BP associated with warmer than present conditions. Past vegetation changes indicate a clear Holocene thermal maximum recorded on the Pacific coast but a less distinct optimum on the western shores (~7200–6100 cal yr BP). A gradual cooling toward modern levels occurred ~6100–3500 cal yr BP. Four prominent layers of coarse sediment found in mid- to late Holocene lake deposits may correspond to intervals of climate cooling/dune formation previously documented in coastal sections. Although chronological limitations question the synchronicity of these events across the south Russian Far East, it seems probable that they have a regional signature. However, the mechanisms responsible for Holocene climatic changes are likely the result of complex interactions of hemispheric-scale atmospheric patterns, marine characteristics, and regional feedbacks rather than simply fluctuations in sea levels as suggested in the current interpretative model.

New coral microatoll data allow presenting an updated late Holocene sea-level curve for the Gilbert Islands of Kiribati. Examination of build-up elevation and spatial distribution of microatolls, along with radiocarbon age data from coral samples, suggest an approximately 1 m sea-level high stand, possibly lasting from ~3500 to 1900 cal yr BP. Our sea-level curve, which is similar to the one reported from the Marshall Islands, is a baseline to reconstruct the evolution of reef flats and reef islands. In addition, it provides important contextual data to infer human settlement on islands in the west-central Pacific.

A sediment core (14DH-C01) obtained from the mouth of Gomso Bay, on the west coast of South Korea, was used to obtain high-resolution palynomorph, grain-size, and 14C age data to investigate the Holocene sedimentary environment. The results indicated a transgressive depositional process with four stages controlled by sea-level change, as follows: river-dominated fluvial deposition from the early Holocene to 8.48 cal ka BP; tide-dominated tidal channel fill transgression from 8.48 to 8.08 cal ka BP; tide- to wave-dominated tidal channel fill transgression from 8.08 to 6.98 cal ka BP; and wave-dominated marine transgression from 6.98 cal ka BP to the present. Tidal channel filling was the primary mid-Holocene depositional process, accounting for the high sedimentation rate observed. The different hydrodynamics of the river-dominated, tide-dominated, tide- to wave-dominated, and wave-dominated processes following the changes in sea level may have controlled the transgressive depositional process. This transgressive sedimentary model differs from those of other large river mouth areas (e.g., the Changjiang River) since the mid-Holocene, perhaps resulting from the limited sediment supply in the study area.

In the Almenara marsh (western Mediterranean), four cores were analyzed to establish the relationship between the marsh record of the Almenara marshlands and the environmental factors responsible for its evolution during the Holocene. One hundred and eighty-six samples were collected for sedimentologic and paleontological study: 63 for biomarker analysis; 5 for amino acid racemization (AAR) dating; and 5 for 14C dating. Litho and biofacies analyses identified distinct paleoenvironments, with the presence of a marsh environment alternating with inputs of alluvial material and marine sediments. Biomarkers indicated the constant presence of terrestrial (herbaceous) plants, together with a variable development of aquatic macrophytes. During the Holocene transgression, the Almenara marsh was occupied by oligohaline marsh facies with an oscillating water level and peat formation, which was established at the bottom of the record at 7570 cal yr BP and persisted until 3100±780 yr (AAR). Maximum surface flooding occurred at 5480 cal yr BP, registered 450m from the current coastline. At least three peat beds (dated with 14C dating and AAR) correlated with Bond (episode 5900 cal yr BP) and Wanner (episodes 4800–4500 and 3300–3500 cal yr BP) cycles and thus correspond to a regional model that affected the Northern Hemisphere.

Although uranium series (U-series) ages of growth-position fossil corals are important to Quaternary sea-level history, coral clast reworking from storms can yield ages on a terrace dating to more than one high-sea stand, confounding interpretations of sea-level history. On northern Barbados, U-series ages corals from a thick storm deposit are not always younger with successively higher stratigraphic positions, but all date to the last interglacial period (~127 ka to ~112 ka), Marine Isotope Substage (MIS) 5.5. The storm deposit ages are consistent with the ages of growth-position corals found at the base of the section and at landward localities on this terrace. Thus, in this case, analysis of only a few corals would not have led to an error in interpreting sea-level history. In contrast, a notch cut into older Pleistocene limestone below the MIS 5.5 terrace contains corals that date to both MIS 5.5 (~125 ka) and MIS 5.3 (~108 ka). We infer that the notch formed during MIS 5.3 and the MIS 5.5 corals are reworked. Similar multiple ages of corals on terraces have been reported elsewhere on Barbados. Thus, care must be taken in interpreting U-series ages of corals that are reported without consideration of taphonomy.

Many active normal faults throughout the Aegean juxtapose footwall limestone against hanging-wall colluvium. In places, this colluvium becomes cemented and forms large hanging-wall lobes or sheets of varying thickness attached to the bedrock fault. Investigations at the Lastros Fault in eastern Crete allow us to define criteria to distinguish between cemented colluvium and fault cataclasite (tectonic breccia), which is often present at bedrock faults. Macro- and microscopic descriptions of the cemented colluvium show that the colluvium was originally deposited through both rockfalls and debris flows. Stable isotope analyses of oxygen and carbon from 83 samples indicate that cementation then occurred through meteoric fluid flow in the fault zone from springs at localised positions along strike. Palaeotemperature calculations of the parent water from which the calcite cement precipitated are indicative of a climate between 7°C and 10°C colder than Crete’s present average annual temperature. This most likely represents the transition between a glacial and interglacial period in the late Pleistocene. Ground-penetrating radar also indicates that cemented colluvium is present in the hanging-wall subsurface below uncemented colluvium. Using these results, a model for the temporal development of the fault and formation of the cemented colluvium is proposed.

In the hinterland of deserts, it is difficult to reconstruct paleovegetation using fossil pollen because of the low pollen concentration. Therefore, an efficient method is needed to reconstruct the paleovegetation of desert regions. In this study, 34 Holocene calcareous root tube (CRT) samples were collected from the Alashan Desert in northwest China, and lipid molecular proxies from CRTs were selected to address this deficiency. The results show that n-alkanes mainly maximized at C27, C29, and C16, and that the carbon preference index is close to 1. Thus, the sources of n-alkanes from CRTs were the roots of higher plants and microorganisms, and thus changes in n-alkanes from CRTs could reveal variations in vegetation cover. The n-alkane Cmax of long-chain n-alkanes (C>25) in CRTs, maximizing at C27, indicated that vegetation in the Alashan Desert was characterized by shrub vegetation during the Holocene. Changes in the ratio of (C27+C29)/(C31+C33) indicated that the biomass of shrub vegetation increased during the period 7–2 cal ka BP. Moreover, the relative concentration of short-chain to long-chain n-alkanes decreased from 7 to 2 cal ka BP, suggesting that the effective moisture decreased during that period.

New speleothem records from northeastern Iberian caves provide data to explore the climatic patterns during the Holocene. We present δ13C and Mg/Ca from three speleothems from two different caves located in the Iberian Range allowing replication of the climatic signal for several millennia. Through the integration of those stalagmites covering since the Holocene onset to 2 ka, the early Holocene (11.7–8.5 ka) appears as the wettest interval. A marked change towards aridity is observed during the middle Holocene (8.5–4.8 ka) and an increase of humidity afterwards (4.8–2 ka). This three-part pattern, contrasting with other Iberian sequences, seems to be associated with the different role that seasonality has played in the response of different proxies (or records) to changes in water availability. Interpreting our speleothem records as changes in winter-spring precipitation along the Holocene allows reconciling previous data on hydrological variability from the western Mediterranean borderlands.

The Sea of Japan (also termed the East Sea) has a circulation system isolated from the Pacific Ocean and East China Sea. The East Asian winter monsoon drives the circulation system and cools the Tsushima Warm Current (TWC) to form the Japan Sea Intermediate–Proper Water (JSIPW). The intermediate water conveys oxygen to deep-sea floors, which is available for benthic animals. During the Pliocene (3.5–2.8 Ma), Temperate Intermediate Water (TIW) was formed under the weak winter monsoon, and extinct ostracod TIW taxa were found. Little is known about early Pleistocene intermediate water and the extinction mode of benthic ostracods. We studied radiolarians and ostracods from deep-sea sediments between 2.0 and 1.3 Ma (Marine Oxygen Isotope Stage [MIS] 77 to MIS 41) at Integrated Ocean Drilling Program Site U1426, Sea of Japan. The ostracod faunas contained TIW and JSIPW taxa. The radiolarian subtropical-water taxa and the JSIPW ostracods indicate a small influx of the TWC and the JSIPW. The TIW occasionally expanded to the middle bathyal zone. By analogy with the relationship between the modern JSIPW and winter monsoon, weak winter monsoon possibly caused gentle temperature gradients in the water column and the expansion of the TIW. The JSIPW taxa expanded their ranges into the deep sea during interglacial periods.

The Rb, Sr, and Ti content, Rb/Sr ratio, grain size, magnetic susceptibility, and magnetic fabric in sediments of the BZK1 core were utilized to reconstruct the evolution of the climatic environment in the Chaohu Lake Basin between the last deglacial and the early Holocene. Multi-proxy analyses indicate that lacustrine sediments in Chaohu Lake clearly record the Bølling-Allerød interstadial, the Younger Dryas event and dry-cold climate events occurring between 10.7 cal ka BP and 10.5 cal ka BP. At approximately 15.6–14.8 cal ka BP, the waters became deeper and the climate turned cool. The climate subsequently shifted to a relatively humid period and the lake was largest from 14.8 to 12.8 cal ka BP. From 12.8 to 11.7 cal ka BP, the climate abruptly turned dry and cold and the lake shrank to its lowest level. During 11.7–10.7 cal ka BP, the climate became relatively humid but, from approximately 10.7 to 10.5 cal ka BP, suddenly reverted to a dry and cold state. These climatic change records suggest that lacustrine sediments from the Chaohu Lake Basin in the lower Yangtze region responded actively to global climate changes, comparable with the environmental records from stalagmites and other lacustrine sediments in the region.

This work introduces for the first time the concept of using sinkholes in fluvial valleys as recorders of past floods. The notion is illustrated through the investigation of a complex sinkhole located in a broad floodplain underlain by salt-bearing Cenozoic evaporites. This active sinkhole comprises a large subsidence depression affecting the floodplain and the edge of a terrace, and a nested collapse sinkhole that used to host a sinkhole pond. A borehole drilled in the buried sinkhole pond revealed an ~7.8-m-thick fill that records around 2700 yr of clayey lacustrine deposition interrupted by three types of detrital facies. Two thick pebble gravel beds have been attributed to major high-competence floods: a paleoflood that occurred in Visigothic times (1537–1311 cal yr BP) and the 1961 Great Ebro River Flood, which is the largest event of the instrumental record. A trench dug in the portion of the terrace affected by subsidence exposed a mid-Holocene slack-water paleoflood deposit. The disadvantages and advantages of sinkholes as archives of past flood histories are discussed.

The Hell Gap National Historic Landmark, located on the northwestern plains of Wyoming, is one of the most important Paleoindian archaeological sites in North America because it contains a stratified sequence of occupations spanning nearly the entirety of the Paleoindian period. Although Hell Gap is central to archaeological knowledge concerning North American Paleoindian chronology, consistently assigning component ages has been problematic due to conflicting radiocarbon determinations from individual strata, stratigraphic age reversals in age-depth relationships, and other issues related to the stratified open campsite. Toward resolving the Hell Gap chronology, we devised a procedure for correcting age-depth relationships for incorporation in chronostratigraphic models and then used the Bayesian age-depth modeling qprocedures in Bchron to estimate the ages of 11 stratified components present at Hell Gap Locality 1. We present these age estimates and discuss their significance to Paleoindian chronology. Notable aspects of our chronology include a revised age estimate for the Goshen complex, the identification of three Folsom components spanning the entirety of the Folsom temporal range, and relatively young age estimates for the Late Paleoindian Frederick/Lusk component(s) at Locality 1. More broadly, our study demonstrates a procedure for creating chronometric models of stratigraphically complicated open stratified sites of any type.

A variety of biomarkers were examined from Ocean Drilling Program Core 1202B to reconstruct temperature and phytoplankton community structures in the southern Okinawa Trough since 20 ka. Two molecular temperature proxies ( $${\rm U}_{{37}}^{{{\rm K}\prime}} $$ and TEX86) show 5°C to ~6°C warming during the glacial-interglacial transition. Prior to the Holocene, the $${\rm U}_{{37}}^{{{\rm K}\prime}} $$ -derived temperature was generally 1°C to 4°C higher than TEX86-derived temperature. This difference, however, was reduced to <1°C in the Holocene. Correspondingly, the phytoplankton biomarkers (e.g., C37:2 alkenone, brassicasterol, C30 1,15 diol, and dinosterol) indicate a shift of planktonic community structures, with coccolithophorids becoming more abundant in the Holocene at the expense of diatoms/dinoflagellates. This shift is related to the variability of nutrients, temperature, and salinity in the Okinawa Trough, likely controlled by the sea level and the intensity of the Kuroshio Current. The phytoplankton community change may have had profound implications for atmospheric CO2 fluctuations during glacial-interglacial cycles since diatoms and dinoflagellates have a higher efficiency of the biological pump than coccolithophorids.

The Ullum-Zonda tectonic depression located in the central Andes Precordillera records several lacustrine episodes from frequent natural damming of the San Juan River during the late Quaternary. We analyzed stratigraphic, geomorphic, and geologic data and obtained new radiocarbon ages for Paleolake Ullum-Zonda. Results show the existence of a late Pleistocene age (16.7–15.2 ka BP) unit and an early to middle Holocene (9475–7685 yr BP) unit. Subsurface data show lacustrine episodes were common during the late Pleistocene, with probably nine episodes occurring during that period. Two transgressive events are evident in the Holocene unit, dated to ~8420±30 and shortly after 7460±30 14C yr BP. The maximum extent of the paleolake occurred at 6930±30 14C yr BP, shortly before the lake desiccated. Fault propagation folds and growth strata in Quaternary alluvial deposits relate to the Villicum-Zonda Fault and may indicate early to middle Holocene activity for this fault. The deformation observed in an ancient shoreline of the paleolake could be related to middle to late Holocene activity of the Cerro Zonda Norte Fault at a mean vertical uplift rate of ~0.8 mm/yr in the hanging wall block.