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The paleopedological record documented in aeolian dunes of the eastern European Sand Belt comprises predominantly Arenosols and only occasionally well-developed Podzols. There are several Late Pleistocene pedostratigraphic marker horizons of varied soil types designated in the European dune and loess deposits, but none falls within the range of the Holocene. Buried Podzol occurrences found recently in 10 inland dune sites dispersed throughout Central and Eastern Poland share similar pedological properties, geomorphological setting, and age in the 5th–15th century AD range of the historical Middle Ages. Therefore, they meet the criteria for distinction as a pedostratigraphic marker under the name Grębociny soil, after a locality with the most advanced podzolization of the paleosol dated to the High Middle Ages (1000–1300 AD). Preservation of the soils was enabled by burial during anthropogenically induced dune remobilization. At least some of the investigated dunes were used as pasture during soil development, as evidenced by tetrapod hoofprints recorded in and above the buried Podzols. Prevalent podzolization during the Middle Ages, in contrast to preceding and later times, could be facilitated by not only an impact of agriculture and forestry, but also relative warmth and humidity of the Medieval Climatic Optimum (ca. 900–1400 AD). [ABSTRACT FROM AUTHOR]

Coastal barriers are the first line of defense for the mainlands against the impacts of severe storms, therefore the need for better understanding how barriers evolve is arising. Spits (barriers) are the dominant landform type of the southern and south-eastern Baltic Sea coast. The aim of this paper is to gain present a better insight into problems of the Vistula Spit origin in general, and especially on the age of formation of the dune ridges. The Vistula Spit is one of the largest barriers on the southern Baltic coast. The analysis comprised: OSL dating of dune sands, radiocarbon dating of peat and palynological studies of peat and fossil soil profiles. Results shows that the onset of the oldest dunes formation begun ca. 7000–6000 years ago and the highest ridge were formed ca. 4000–2000 years ago. The youngest dunes, located closest to the modern shore, formed in the past 2000 years. Aeolian processes were also activated locally and periodically as a result of forest wildfires and human activities. Vistula Spit emergence and development is connected to two global events; beginning of the oldest dunes formation is related to slowing down in the sea level rise around 7000–6000 years ago, whereas the onset of the highest dunes building can be clearly connected with the climate cooling and aridification around 4200 years ago. [ABSTRACT FROM AUTHOR]

The controls that affect the degree of spatio-temporal change to foredunes following scarping are reviewed herein. As sea-levels rises and climate changes, dune scarping will become more common. Thus, it is critical to understand what factors contribute to the magnitude of scarping, and what effect this has on dune systems to better manage coastal erosion into the future. Scarping occurs when foredunes are partially eroded by waves, generally during periods of high water level. The controls on the degree and magnitude of scarping examined include water level, foredune vegetation cover and species present, plant root mass, height and volume of the foredune, the original foredune morphology, surfzone–beach type, and compaction of sediment. Water-level height and duration of high water is the most significant control as it determines the elevation at which wave action can erode the dune and, therefore, the extent of scarping and dune volumetric loss. Higher plant density, greater rooting depth, high root mass, and greater compaction aid in reducing the degree of scaping. The presence of large woody debris and wrack may also influence the degree of scarping. The effects scarping has on the morphology of a foredune after the initial erosion event can range from small changes (e.g. minor, small scarps and slight slumping), to moderate changes such as the foredune translating landwards, to large change such as the transition of an entire dune system into a new transgressive dunefield phase. A new model summarising the key controls and their relationship/significance to the magnitude and extent of scarping is presented. [ABSTRACT FROM AUTHOR]

A high proportion of archaeological sites are located on the world’s shorelines and recent research has documented the vulnerability of these sites to coastal processes and climate change. However, archaeological landscapes on many temperate coasts have already been degraded as a result of changes in dune dynamics related to changes in dune vegetation. These changes have produced marked spatial and temporal variations in patterns of burial and erosion in transgressive dune systems. This paper examines the modification and conservation of archaeological landscapes from a biogeomorphic perspective, using the example of marram grass (Ammophila arenaria) invasion of dune systems in southern New Zealand. The impact of marram grass on dune system dynamics and the underlying archaeological landscape are complex. Full invasion may result in the general burial and protection of these landscapes, but the risk of degradation of sites is high during the invasion process. In southern New Zealand, marram invasion has resulted in the formation of stable foredunes, often associated with coastal progradation. Archaeological sites located close to the shoreline can be subject to either burial or erosion, or both, as marram grass establishes in the foredune zone. The spatial relationship between cultural sites and the shoreline may be lost as the coast progrades. The impact of marram invasion can extend throughout the hinterland dune system as a result of (i) dune mobility triggered by marram grass invasion and (ii) the development of a negative sand budget, which prevents or reduces beach-foredune-dune system sand exchange. The risk of degradation of the archaeological landscape can be significantly heighted by marram invasion, which can have profound implications for the preservation and interpretation of archaeological sites and materials. Paradoxically, dune system restoration may lead to the re-exposure of these sites, but the principal outcome of dune system restoration is expected to be a decline erosion (manifest as in deflation surfaces) and reburial of the archaeological landscape. [ABSTRACT FROM AUTHOR]

The 1930s Dust Bowl Drought on the US Great Plains was an environmental crisis with failure of agricultural systems, landscape denudation, and elevated atmospheric dust loads. Poor agricultural practices were implicated for triggering widespread eolian erosion and heightened dust emissions, but this assumption is called into question. This study classified land surface changes in southwest Kansas from aerial images taken in 1936 and 1939 to infer surficial processes, dust sources, and associated emissivity. In total, seven distinctive surface classes were identified from an ArcGIS analysis of spectral reflectance values connected to surface vegetation cover and eolian activity, demonstrating a strikingly heterogeneous landscape response to the drought. Stratigraphic studies indicate accumulation of up to 4 m of eolian sand in places with erosion of a subjacent silty pre-1930s soil surface. Potential dust emissivity estimates for particulate matter were derived from the distribution of classified land surfaces and from empirical relations on analogous dust-emissive surfaces in the western US. Over 60% of total suspended particles in 1939 were inferred to be derived from uncultivated sandy surfaces and eolian landforms within the study area, with the remainder from human-modified surfaces. The PM2.5 and PM10 emissivity estimates for a single dust event with winds over 6 m s−1 in the study area were 510–4514 and 4700–41,607 µg m−3 d−1, respectively, similar in magnitude to current dust storm events from North Africa and East Asia. Drought frequency is forecast to increase in late 21st century, potentially with greater severity than the Dust Bowl and may be associated with magnitude increase in atmospheric dust loads. [ABSTRACT FROM AUTHOR]

Our study aims to understand the recurring climatic conditions prevailing during the largest storms reaching NW France (Brittany). These storms are responsible for the breaching of coastal barriers and major flooding of lowlands. In a first part of our work, we examine the morphological impact and stratigraphic record of storm events along Western Brittany rocky coasts, with a special focus on the southern coast of the Bay of Audierne, the most exposed coast of the region. In a second paper (‘Middle- to Late-Holocene Storminess in Brittany (NW France): Part II’), we shall focus on the chronology of storm events and their climate forcing conditions. Drilling transects and stratigraphic analyses were first undertaken to constrain chronology, strength and wind direction during the main Holocene storm events. New dates, observations and a relative sea-level (RSL) curve were then used to inform discussion of the necessary climatic and morphologic conditions leading to destructive storm events. Most recorded events appear to be linked with cooling episodes of the Holocene and a RSL close to present. Some storms are clearly responsible for breaching and dune building or remobilisation. We demonstrate that storm frequency and intensity appear to rise in a stepwise manner during the late Holocene. Maximum efficiency is reached during the ‘Little Ice Age’ with clustered events probably lasting several days, but major storms also occurred immediately prior to the ‘Medieval Warm Period’. We suggest that recent coastal dune building from c.ad 1100 until now, despite a sea level close to present and continuously rising, may be a direct consequence of the restoration of beaches after periods of recurrent storminess. This building activity often occurred during dry negative North Atlantic Oscillation (NAO) events, in connection with the available sedimentary supply. [ABSTRACT FROM AUTHOR]

Coastal dune fields and dune-body associated lakes were studied through sedimentological, malacological and palynological analyses. Lake deposits and palaeosoil horizons gave new information about phases of aeolian activity and dune building, coastline and sea level, vegetation history and cultural impact. After a period of intense aeolian activity (Late Pleistocene) that limited soil-forming processes, a wet aeolian field, recorded by podzolized sands and interdune wetland deposits, was present in the region. Around 5000 to 4000 yr BP sea level reached the current level and the coastline was situated c. 1 km further inland compared with the present situation. Subsequently lagoon-barrier island systems developed c. 4000 yr BP. Vegetation in the region during this time was a pine/oak forest. Between 4000 and 1600 yr BP the forest was replaced by a semi-natural heathland. Later the heathland was degraded, allowing dune migration and finally formation of a desert-like landscape. This process was probably a consequence of a combination of deteriorating climate during the ‘Little Ice Age’ (LIA) and overgrazing. To counteract sand invasion, reforestation efforts were initiated in the region c. 300 years ago and locally along the coastal margin between 1924 and 1940. Formation of the row of freshwater lakes bordering the dune field at present was contemporaneous with the initial reforestation phase. A close relation between lake formation and accumulation of sand dunes was found. Various types of dunes were identified, truncated dunes, parabolic dunes and transverse/oblique dunes. Dune migration caused an eastward displacement of lakes. [ABSTRACT FROM AUTHOR]

Aeolian dune fields have been described on Earth, Mars, Venus, and Titan. The amount and fidelity of data being returned from orbiting spacecraft and landers have enabled a new era in aeolian studies. This progress report presents an overview of the latest planetary geomorphic studies characterizing aeolian processes on extraterrestrial surfaces. Our understanding of aeolian processes on other planetary surfaces comes largely from Earth analog studies, along with wind tunnel experiments and theoretical modeling. However, an important difference is that unlike terrestrial dunes most dunes on Venus and Mars are composed primarily of basaltic particles. Additional research is needed to understand how basaltic particles weather both physically and chemically so that it will be possible to apply traditional sedimentological concepts, such as sediment maturity, to understanding aeolian processes on Venus and Mars. It may also be possible to characterize sediment maturity and provenance through remote sensing data once we have a better understanding of basaltic sediments. Although there have been a variety of dune forms identified on the surfaces of the other terrestrial planets, the only dune form found on all of them is linear dunes. Even though linear dunes are the most common dune forms on Earth, we currently have a poor understanding as to how they are formed, and additional work is needed to understand these features. [ABSTRACT FROM AUTHOR]

Stratigraphic investigations of three coastal waterbodies in southeastern Tasmania reveal major paleoenvironmental phases related to sea level change and anomalous deposits consistent with tsunami inundation. Twenty-two short sediment cores were examined for their sedimentology and fossil diatom, foraminifera and macrofossil assemblages; nine radiocarbon ages were obtained. Despite diverse Holocene histories at each site, four common phases of Holocene paleoenvironmental evolution can be distinguished. In Phase I (pre-8000 yr BP) terrestrial environments existed. During Phase II (8000–6500 yr BP) ponded freshwater environments formed behind transgressive coastal barriers. In Phase III (6500–2000 yr BP) the sites were subject to varying degrees of marine influence, resulting in environments ranging from current-swept tidal inlets to sheltered brackish-marine lagoons. In Phase IV (2000 yr BP to present) there was a decrease in marine influence, one site changed to a freshwater wetland environment while the other two changed to ephemeral salt pans. This study suggests that postglacial sea level rise culminated after c. 7300 cal. yr BP in southeastern Tasmania and that there was probably a late-Holocene fall in sea level. These paleoenvironmental histories provide a framework within which to identify anomalous deposits and assess them for likely causes. Five anomalous deposits are identified, three of which are considered likely to have been deposited by tsunami occurring at c. 4000 cal. yr BP, c. 2000 cal. yr BP and <2000 cal. yr BP, although deposition by large storms cannot be ruled out. [ABSTRACT FROM AUTHOR]

Holocene forested coastal dunes fringe the Atlantic coast of western Portugal. Mapping of dunes in the field and using air photographs shows a range of forms reflecting dominant northwest and westerly onshore wind regimes. Planting of maritime pine forests in the thirteenth and twentieth centuries was initiated because of sand invasion causing problems for human settlement and agriculture. Early Holocene dunes have a well-developed podsol and date to 9.7 and 8.2 ka, suggesting at least some of these sands may have been emplaced during a global cooling event. Significant transgressive dune accretion at 2.2 and 1.5 ka, implies abundant sand supply and strong onshore winds. The most recent dune-building period dates to AD 1770–1905 and coincides with a predominantly negative winter North Atlantic Oscillation index (NAOi). Accretion of dunes along the Portuguese coast appears out of phase with dune development in southwest France, which may reflect different Atlantic storm tracks driven by changes in the dominance and state of the NAOi. [ABSTRACT FROM AUTHOR]

Thick Holocene Bignell Loess sections provide new evidence for the timing of early to middle Holocene aridity in the central Great Plains. The immediate source of loess in these sections was dune fields just upwind, based on thickness trends and grain size data. Thus, periods of rapid loess accumulation indicate episodes of extensive dune activity under drier-than-present climate. In typical Bignell Loess sections, a thick zone of coarse-textured loess with minimal pedogenic alteration is interpreted as a record of the most rapid, sustained Holocene loess accumulation. Optical ages indicate that loess in this zone was deposited beginning about 9000–10000 years ago at five study sites. Accumulation ended shortly after 6500 years ago at three sites, but possibly earlier at the other two. In two well-dated sections, the average rate of loess accumulation between 9000–10 000 and 6500 years ago was about 1.6–3.5 times greater than in the late Holocene. Thus, we infer that the most extensive, sustained Holocene dune field activity, reflecting sustained aridity, occurred from around 9000–10 000 years ago to just after 6500 years ago. Comparison of the Bignell Loess record with other proxy data from the Great Plains indicates general agreement on an early–middle Holocene dry period, but also provides new evidence for spatial variation of early to middle Holocene climatic change, with possible time transgression, both from west to east and from north to south. [ABSTRACT FROM AUTHOR]

A forested dunefield covers the Baraga Plains in western upper Michigan. The ages of five dunes, from across the dunefield, were determined by optically stimulated luminescence (OSL), employing the single-aliquot regenerative-dose (SAR) method on quartz grains. The results indicate that sand mobilization was restricted to the middle Holocene, at around 7 ka. Four environmental variables, rapid climatic oscillations, fire, strong winds and a dry climate are invoked as a combined cause of dune formation. This study provides further evidence for the wide extent of aeolian activity in the upper Midwest of North America during the middle Holocene. [ABSTRACT FROM AUTHOR]

Periglacial aeolian sand sheets and dunes of the last glacial cover extensive areas of northwest and central Europe. Four sedimentary facies have been described that could be related to fluvio-aeolian and cryogenic processes, moisture content of the depositional surface and surface morphology. Factors that favoured sand-sheet and low-dune formation were the abundance of unconsolidated sediments, absence of topographic barriers, sparseness of vegetation cover and the high ratio of wind energy to sand availability. Three phases of prominent aeolian sand deposition have been distinguished from the Last Glacial Maximum to the beginning of the Holocene. Phase I (c. 28-18 ka cal B.P.) with predominant fluvio-aeolian deposition was related to permafrost conditions of the Last Glacial Maximum. Phase II (c. 18-14 cal B.P.) represents the major period of sand-sheet or coversand formation at the waning stage of the last glacial (Late Pleniglacial and early Lateglacial). Phase III (c. 13-10 cal B.P.) with more localized deposition occurred in the later part of the Younger Dryas and early Holocene. It is stressed that the aeolian phases do not strictly coincide with glacial or stadial conditions. Climatic aridity, limited vegetation cover and delayed responses of the aeolian environment to climate change determine the timing of the aeolian phases. [ABSTRACT FROM AUTHOR]

This paper reports on nine new radiocarbon dates from marine shells collected at various heights within a Holocene aeolianite sequence on Isla Cancun in the Yucatan Peninsula, Mexico. The ages obtained from the shells provide an improved understanding of some of the geomorphological and sedimentological processes operating during the upper mid-Holocene on Isla Cancun. Carbonate sand dunes were accreting at rates in the order of 0.28 cm yr -1 between about 3570 and 4000 years BP. By around 4000 years BP sea levels were close to present-day shorelines evidenced by the presence of marine shells (SRR-5790) within a small wedge of beach material cut into the Cancun aeolianite at a height of +1.5 m above present-day sea levels. Cessation of dune growth is known to have occurred before 2500 years BP as shells (SRR-5793a, SRR-5793b, SRR-5794a and SRR-5794b) from a midden deposit overlying the aeolianite provide a minimum age for the end of dune activity. Dune formation appears, therefore, to be associated with the end of the postglacial transgression in sea level. At least one other sample is thought to be from a midden and the dates obtained from this site provide information on localized human occupation in the area during the Holocene between 4082 and 2349 years BP. [ABSTRACT FROM AUTHOR]

Fifteen samples of dune sand, and three samples from a core taken in the beach face, were collected from a sand spit which protrudes into Dingle Bay in Southwest Ireland. The potassium-rich feldspar grains from the samples were dated using a single aliquot luminescence protocol for infrared stimulated luminescence (IRSL) signals. No ages over 600 years were obtained, which demonstrates the youth of the dune forms currently observed. The youngest ages were about 150 years old, but for these samples the scatter in the equivalent dose obtained as the mean of 18 measurements was higher than for the older samples. [ABSTRACT FROM AUTHOR]

Landforms are created, reshaped or eliminated to suit human needs. These alterations affect the mechanisms of change, freedom of movement, locations of sources and sinks for sediment, internal structure, outward appearance and spatial and temporal scales of landform evolution. The processes by which landscapes are transformed by human agency follows a progression of alterations that may be subtle or overt, planned or unplanned, but most of them are predictable. Models of change for human-altered coasts may be formulated by viewing them as open or closed systems. Alternative methodologies for examining evolution of these coasts include: 1) comparing and contrasting a developed area with an undeveloped area that is assumed to have the same process controls; 2) assuming that the kind of shoreline change that occurred in the recent past will continue unabated by local actions; or 3) basing predictions on probabilities of future human action. Evidence suggests that human alterations are an integral component of landscape evolution. Future challenges for scientists include: 1) formulating conceptual and predictive models of landform dynamics that evaluate humans as an endogenic process and include assumption about human actions; and 2) providing scientific criteria for maintaining landforms in developed areas in ways that safeguard or promote an optimal diversity of landforms, species and ecosystems. Controlled disturbance may be required to create landforms compatible with natural landforms in appearance and function if not in genesis. [ABSTRACT FROM PUBLISHER]

A new method of dating potassium feldspar grains from aeolian sands is demonstrated. A luminescence signal is measured whilst the grains are stimulated in the near infrared at 880 nm. A surface sand sample gave an age of 40 ± 15 years, showing that this method is able to provide ages for very young samples. Since the measurement of an infrared stimulated luminescence (IRSL) signal can take place with a short infrared exposure, the IRSL signal of the grains is not depleted; thus growth curves can be obtained for 5 mg sample aliquots. This procedure was exploited in this paper.Dates were obtained for 10 samples from the Kelso dune field as a demonstration of the applicability of the method in a desert environment where there is no material suitable for radiocarbon dating. Although the number of dates are limited, sand from an area at the eastern end of the dune field with crescentic dunes showing a different wind direction from that of today had an age of 4115 ± 335 years, similar to the 3960 ± 385 years for another sand unit nearby. At the western end of the dune field differently oriented crescentic dunes gave ages of 1540 ± 135 and 1470 ± 145 years, indicating a different phase of aeolian activity. Reworking in the late Holocene is proposed for areas with dates ranging from 845 to 105 years. [ABSTRACT FROM PUBLISHER]