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In this short paper some examples of tafoni and similar features of cavernous weathering are described from Western Scotland and Southern Greece, including Crete and the Santorini group. All these forms belong to the younger Holocene. This age is indicated by young tectonic emergence from the sea, historical data, or the well known volcanic history of Santorini. Pre-Holocene tafoni are neither more widespread nor better developed than those of the last 2000 or 3000 years. Very different rocks are weathered into tafoni features: old and young sandstones and calcareous sandstones, pliocene conglomerates, eolianites, or lavas and holocene tephra. The tafoni are nearly in all cases strongly oriented towards the present sea front, and therefore salt weathering should be the most effective process.

This paper presents alternating periods of geo-ecological fragility and stability in a highly sensitive environmental setting: the desert-margin area of southern Peru (14.5° S). There, we have to state that fragility was dominantly triggered by climatic changes, which induced several oscillations of the desert margin. During the mid-Holocene, the study area received the Holocene maximum of precipitation, soil formation occurred and the desert retreated, as loess–paleosoil formation documents. In contrast, the Titicaca region further south-east experienced extreme drought at that time. This regional antagonism between humid and dry conditions was a result of meridional shifts in moisture transport across the Andes and occurred also during pre-Columbian times. Considering a coincidence between environmental and cultural changes, we state that success and decline of civilizations were dominated by hydrological oscillations, triggering fertility as well as a critical loss of natural resources. Fragile periods, i.e. periods of geomorphological activity, occurred contemporaneous with cultural transitions. In response to spatial changing resources cultural foci were shifted. So, the success of pre-Columbian civilizations was closely coupled to areas of geo-ecological favorability, which were directly controlled by distinct regional impacts of large-scale circulation mechanisms, including El Nino–Southern Oscillation (ENSO). This spatial view on non-uniform environmental and cultural changes has not been thoroughly considered before. Therefore, for the first time this paper offers geomorphological evidence for diachronous Andean (agri-)cultural development, which was geographically determined .

This paper reports on the development of a British database of 14C dated Holocene fluvial units over the last 15 years. Since its inception in 1989, the database has undergone substantial expansion, refinement and improvement together with considerable methodological development, so that today it serves as a powerful research tool for investigating the spatial and temporal dynamics of Holocene river development and flooding in Great Britain. The improved analytical method is here applied to the currently existing database by examining datasets of 14C dated fluvial units from river basins that lie within and beyond the limits of Late Devensian glaciation. This analysis indicates how the contrasted conditions in these two types of river environment have, to an extent, led to divergent records of flooding in response to Holocene climate and land-use change. However, even in the contrasting sedimentary records of upland glaciated, and lowland unglaciated river basins, six corresponding episodes of increased flood frequency are identified at c. 5730, c. 3540, c. 2730, c. 2280, c. 660 and c. 570 cal. BP. These represent widespread common responses from British river systems to large-scale changes in climate. The method of database construction and analysis outlined and demonstrated in this paper could be readily adopted in other parts of the world to improve our understanding of Holocene river behaviour at the continental- and global-scale.

Hummocky ground is a conspicuous feature of some cultivated pastures in the mountain forests of the Alps. In the German scientific literature, this pit and mound microrelief is termed “Buckelwiese” (literally: “hummocky meadow”) and is commonly interpreted as a fossil, Late Glacial relief of cryogenic origin. This paper suggests an alternative hypothesis, namely that relief formation was initiated by the uprooting of trees during storms. In the rootstock-pits, karst processes gradually amplified the initial relief. This alternative hypothesis is tested in a Buckelwiesen area of the Northern Limestone Alps, where pit-to-mound vertical relief amounts to 52 cm and mounds are 250–510 cm long and 170–270 cm wide, and the density of pits and mounds is 400 ha −1 . Field investigations included a ground survey using a tacheometer and the excavation of a trench to check the internal structure of one pit-mound couple. The trench was subsequently used to estimate solution rates in the subsurface material of pits and mounds. Based on the results of the field measurements and two radiocarbon dates from the test site, the paper concludes that in the study area a treethrow event occurred between 1120 and 1280 AD. Subsequently, the pits created by the uprooted trees were deepened by limestone solution at a rate of 77.2 mm/1000 years. The reconstructed formation history of the microrelief of the study area is consistent with a Holocene origin, with rates of limestone dissolution as measured in the field and with the morphometry of the features themselves.

A large number of studies have focused on water erosion in the southern Alps because of its intensity and the high erodability affecting numerous outcrops in this region. The aim of this paper is to determine the relations between natural and human factors on the one hand, geomorphologic behaviour of hillslopes and fluvio-torrential dynamics at two time scales (geological and historical) on the other hand. This paper specially focuses on the recent weakening of torrential activity and its linkage with reforestation and rural desertion on the watersheds. Another objective is to compare these results with a rich mainly French scientific production on this theme. Experimental data on: – current erosion measurements and the analysis of its processes on the one hand, – and geomorphologic background of river beds and slopes, are compared and analysed using archives and the present knowledge on historical climate. It has been shown that the overexploitation of watersheds leads to an increase in soil loss, in the number and intensity of floods in alpine valleys, as well as to an enhancement of sediment transport. However, climatic changes during the Holocene and during the past millennium have resulted in changes in morphological behaviour of the hillslopes upstream and of river beds downstream. Moreover, a strong sedimentary deficit can be observed over the last three or four decades in all the Alpine massifs. The consequences of this sediment deficit are firstly an entrenchment of river beds, which threatens bridges and embankments. This recent trend is probably due to the excessive extraction of material in gravel pits and the sedimentation in the numerous dams built between 1920 and 1980 in the entire alpine range. However, the entrenchment appeared recently on non-exploited rivers; therefore, the deficit is also due to the success of the natural and artificial reforestation and torrent correction since the end of 19th century.

The paper presents records of lithofacial succession in the sediments of the Bagno Staw alkaline fen (Western Polesie Lowland, Eastern Poland), documenting the phase of rapid morphogenetic transformations during LG/H in the Lublin chalkland. Environmental conditions responsible for the morphogenesis and evolution of the site (from a shallow periglacial lake to an alkaline fen) were reconstructed. A detailed geological survey in combination with the analysis of Cladocera assemblages revealed the presence of numerous palaeodepressions under the plain covered today by the alkaline fen, which were initially small shallow lakes with a well-developed phytolittoral zone. Geochemical data and the analysis of stable O and C isotopes indicated that these lakes were supplied by ascending waters. Karstic phenomena under periglacial conditions, including subsidence at the bottom of biogenic accumulation basins, played an important role in the transformation of this site. These changes were largely determined by the chronology and dynamics of permafrost degradation.

In eastern Africa, ecologists have found that when mobile pastoralists abandon their temporary encampments, the accumulation of burned animal dung, wood, and other organic waste enriches the concentration of nutrients (e.g., calcium, phosphorous, magnesium) essential to soil health, in comparison to other soils without prior human habitation. These nutrient-enriched soils promote glade development and greater biodiversity. Geoarchaeological research on the time depth of this anthropogenic “nutrient hotspot” phenomenon has demonstrated that soils at several archaeological sites in southern Kenya still remain enriched in these soil macro- and micro- nutrients after several thousand years. However, soil scientists and geoarchaeologists do not yet understand how these anthropogenic soils vary over the extensive geographic conditions of eastern Africa. The discovery of a Pastoral Neolithic site (ca. 3000 BP) at Luxmanda on the Mbulu Plateau, Tanzania, provides an opportunity to examine if similar patterns of nutrient enrichment can be detected in a different geological and climatic zone. In this paper, we use geochemical and sedimentary analyses to determine how archaeological soils at Luxmanda differ from adjacent off-site soils and known archaeological soils in Kenya, as well as from computationally derived soil nutrient models for eastern Africa. Our results indicate that soils derived from anthropogenic sediments and ashy dung are 4 to 16-fold more abundant in soil macro nutrients relative to off-site or modeled values. This pattern fits previous studies’ observations that elevated macro- and micro-nutrients in soils are strongly correlated with ancient pastoralist habitation sites. We conclude that anthropogenic soils found at Pastoral Neolithic archaeological sites may be a valuable, but unappreciated, soil resource in eastern Africa.

This paper addresses the timing of accelerated soil erosion and landscape degradation in central Mexico. It shows data on erosion sequences in the Valley of Teotihuacan, an area where agricultural dates back to at least since 1100 BCE, and an ideal setting to test ideas on the effect of preconquest versus post-conquest anthropogenic impacts on the environment. The methods include stratigraphy, detailed description of soil profiles and soil micromorphology, along with analysis of pottery sherds and radiocarbon dating. A chronology of events for two catenas, focusing on periods of landscape stability and change, establish the sequence of erosion events from pre-Hispanic to modern times. Six erosion phases are recognized over the last 2000 years in Teotihuacan. Although results suggest that the most intense erosion occurred after Spanish conquest, in the 16th century, several erosion phases took place during pre-Hispanic times and also in the postcolonial period, including the 20th century. Probable causes for these impacts are related to settlement dynamics, population variability, and land use changes. Thus, it provides new information for the discussion on the timing and causes of erosion, sedimentation and landscape modification in the central Mexican Highlands during the late Holocene.

The responding mechanism of wetland ecosystem to climate change is currently unclear due to a lack of long-term records incorporating multiple ecological factors. This paper presents a well-dated and multi-proxy cored record from a natural freshwater wetland developed in a paleo-pingo-related depression on the Sanjiang Plain. The study aims to reconstruct the wetland water-level and vegetational regimes during the past ~6.0 ka BP and discuss the wetland evolution response to the East Asian summer monsoon (EASM) circulation. The results show that a shallow-water lake with hygrophilous herbs developed in the depression with a strong EASM during ~6.0–4.5 ka BP. The paleolake was succeeded by a wetland with a lowered mean water level and an increase in tree cover controlled by the weakened EASM during the past 4.5 ka BP. Such an ecological lake-to-wetland transition corresponds well to the sharp decline of the EASM around 4.5 ka BP which has been well documented in various geological records across the EASM domain. During the wetland developing stage over the past 4.5 ka BP, the water-level and vegetational changes in the studied depression were also closely related to the EASM variations. The strengthened EASM usually generated higher water levels with more hygrophilous herbs around 4.0 ka BP, 3.5 ka BP, 3.0 ka BP, 2.0 ka BP, and 1.3 ka BP. Considering the prevalent EASM climate serving as the predominant water supply for the wetlands on the modern Sanjiang Plain, we suggest the EASM circulation has played a critical role in driving the wetland ecological evolution during the mid-to-late Holocene Epoch. The past 0.4 ka BP is an exception as the local Trees/Herbs ratio visibly increased with the declined water level, while the monsoonal precipitation shows no equivalent shift. The wetland evolution at this stage was attributed to human interference.

Geomorphological investigations coupled with sedimentological, petrographical, and SEM analyses allowed to identify, for the first time, a paleo-fixed and inland aeolian dune field in the Gioia Tauro Plain, on the Tyrrhenian side of southern Calabria (southern Italy). The aeolian landforms, extended over an area of 43 km2, are characterized by smoothed and elongated NW-SE trending vegetation-fixed linear dunes, varying in height from a few meters up to 20 m. Forty sand samples were collected from dunes to perform laboratory analyses. Grain size analyses showed that samples are composed of unimodal coarse-grained sands (Mz = 0.820 φ), moderately sorted (σ = 0.862), positively skewed (Sk1 = 0.173) and mesokurtic (KG = 1.115). Petrographic analyses highlighted a composition dominated by quartz and minor feldspars. Modal data, and especially the high F/Q ratio and the Rg:Rs:Rm triangular plot, suggest a plutoniclastic supply from the Aspromonte Massif crystalline source rocks. SEM analyses of sand grains clearly displayed the presence of typical wind-generated features mainly represented by rounded form with low relief, bulbous edges, and dish-shaped depressions. These results combined with morphological analyses showed that these aeolian deposits fall into the category of sand sheets. Furthermore, geological and geoarchaeological data evidenced that dune field was formed in the time interval between ~28 ka and the VI - IV century B.C. The dune filed formation has been interrupted presumably by the combined effect of Holocene tectonics, along the Gioia Tauro-San Ferdinando normal fault, and the lowering of sea level, during the Last Glacial period, originating a natural barrier to windblown sand particles. The findings of the paper will help in understanding both inland aeolian products in southern Europe associated to the second colder phase of the Last Glacial period in the Mediterranean area and the complex patterns of spatial and temporal distribution, as well as the control factors determining preservation of the aeolian sediments throughout the rock record.

The Assif n’Imserdane valley, located in the Jebel Toubkal area of the High Atlas, Morocco, is a highly dynamic geomorphological setting. The valley was glaciated during the Late Pleistocene, and subsequently experienced a catastrophic rock avalanche leading to the formation of one of the largest mass movement landforms in North Africa. Recent research (Hughes et al., GSA Bulletin 126: 1093–1104) has dated the formation of the rock avalanche to the mid-Holocene at 4.5 ± 0.5 ka. In this paper, we examine the sedimentological (organic matter content, magnetic susceptibility, particle size and XRF) and palaeoecological (pollen and spores, non-pollen palynomorphs (NPPs), microcharcoal and conifer tracheid fragments) record of a small infilled basin located adjacent to a Late Pleistocene moraine and close to the rock avalanche in the Arroumd sector. The deposits, primarily fine-grained and minerogenic with a low concentration of organic microfossils including pollen, coprophilous ascospores, wood and charcoal microfragments, are enriched in fine silts and ferrimagnetic minerals, consistent with erosional sources from surrounding slope soils. Three radiocarbon dates from the deposit indicate that the infill event occurred during the first millennium AD (after 430–640 AD). As such, the deposits point to a phase of slope instability and erosion that is not linked to either deglaciation processes or to the mid-Holocene rock avalanche. Instead, the nature and timing suggest that an anthropogenic trigger of degradation to the natural vegetation cover may be implicated, consistent with an increasing scale and intensity of pastoral activity in the southern High Atlas during the early Islamic period in Morocco. The record casts light on a previously undocumented phase of landscape instability in the dynamic setting of the Assif n’Imserdane valley, and highlights the potential for further exploration of small infilled basins in the High Atlas to illuminate the geoecological history of the region.

The River Trent, UK, is renowned for a rich palimpsest of alluvial archaeological remains buried within the Holocene sands and gravels of the valley floor. Since the late 1990's extraction of these postglacial deposits at Shardlow quarry in the middle reach of the valley, close to the confluence of the River Trent and River Derwent, has been investigated and monitored on a weekly basis by a project team including geoarchaeologists. Such monitoring of large exposures of floodplain sand and gravel and adjacent Pleistocene terrace deposits, initially by volunteer activity, but latterly, funded by the aggregate company under a formal planning agreement, has revealed significant alluvial archaeological remains including two logboats, a possible brushwood platform, several fish weirs and organic-rich palaeochannel deposits. This paper provides a summary of the wealth of this resource, but also reflects on the challenges of undertaking geoarchaeological studies in complex alluvial environments over such an extended time period. It concludes by providing advice for best practice that could be applied to other long term studies within similar environments.

Chains of ponds are a discontinuous river type found in Australia. Their unusual morphology, important ecological functions and increasing rarity make them a priority for conservation, and yet very little research has investigated their physical structure, behaviour and evolution. This paper reconstructs the Holocene evolution and environmental history of Crisp's Creek, a headwater chain of ponds in the Southern Tablelands of NSW Australia. This history establishes baseline information on the physical template that can be used to assess a range of other biophysical processes and design appropriate river rehabilitation and management strategies for these rivers. Sedimentary aggradation began in the Late Holocene, at least 3.7–1.3 ka, broadly synchronous with aggradation phases at other sites in southeast Australia. Since European arrival in the Nineteenth Century, parts of the river incised, destroying intact ponds and smothering formerly swampy floodplains with post-incision alluvium. However, sections unaffected by incision provide a rare opportunity to examine the evolutionary trajectory of an intact variant of these rivers. This research deepens our understanding of the evolutionary context for contemporary river behaviour as relevant for designing appropriate and effective conservation and rehabilitation strategies for chains of ponds.

Rhythmic nature of tufa deposits and analysis of hydrochemical proxies offer the potential to reconstruct the history of regional palaeo-hydrological and palaeo-climatic change. This paper investigates the tufa deposits of Sparkling Lake in the Jiuzhaigou gully of the eastern Tibetan Plateau (ETP). Detailed analysis of mineral composition, major elements and stable isotope (δ13C, δ18O) distinguished seven “dirty tufa layers” that are characterized by quartz-rich sediments, high kaolinite and high K, Na and Al. Compared with clean tufa deposits, dirty components in the tufa deposits were a result of surface soil erosion activity during strong monsoon rainfall periods within the catchment. The chronology of tufa deposits is established by using radiocarbon (14C) dating of organic material from the dirty tufa layers. Seven flood-rich periods and eight flood-poor periods during the early and mid-Holocene were recorded by the dirty tufa layers interbedded with clean tufa layers in the Jiuzhaigou gully. The tufa records are more sensitive response to regional hydroclimate change, in comparison with the peat, lake sediments and stalagmite records. The low values of δ18O and δ13C in the dirty tufa layers indicate the flood-rich periods (10310–8390, 7120, 6910, 6340, 5900, 5620, 5020 a BP) were mainly triggered by strong monsoon rainfall events during early and mid-Holocene. Considering the chronological uncertainties and sampling resolution, some other abrupt climate events (i.e, 8200 a BP and 5500 a BP) may be also recorded in the tufa deposits. These results greatly improve our understanding of hydroclimate change in the ETP during the early and mid-Holocene.

Understanding Holocene vegetation response regimes will improve predictions of future vegetation dynamics in mountain areas of semi-arid north China. In this paper, we statistically analyzed the relationship between a pollen record in a mountain area of semi-arid north China and influencing variables independent of pollen data, in the hope that potential vegetation forcing and response regimes can be explored. Our result suggests that the cool deciduous forest (CDF) at high elevation and the temperate deciduous forest (TDF) at middle and lower elevation were sensitive in responding to temperature before 6000 cal. yr BP, but were not sensitive to the summer monsoon (SM). Since 6000 cal. yr BP, the CDF and TDF were sensitive in responding to the SM instead of temperature. Hence, a shift of response regimes can be placed at ∼6000 cal. yr BP, which happened to be consistent with the time that forest expansion changed to deforestation. The insensitive response to the SM during the early Holocene might be attributed to the vegetation elevational movement, the topographic barrier for forest migration from refugia, and/or the topographically related high resistance and resilience of mountain forests. The sensitive response of CDF and TDF to the weakening SM since 6000 cal. yr BP was mainly caused by the cumulative moisture deficit caused by the continual weakening of the SM. Human activity had little impact on mountain forests until several centuries ago. Mountain forest expansion in response to climate warming during the early to middle Holocene can provide analogues for the prediction of forest dynamics of future warming.

This paper is devoted to a study of the nature and origin of the mineral matter in the Vasyugan Mire in Western Siberia. Based on mineralogical and geochemical analyses, new results were obtained concerning the mineral composition within the bottom part of the peat deposit for different landscape zones in the Vasyugan Mire. This part of the peat deposit represents a transition sequence from peat through organo-mineral sediments (OMS) to basal loams and is characterized by a gradient change in the physicochemical and environmental conditions with depth. In the same sequence, pH and peat ash yield increase, while moisture decreases. The clay minerals identified in the basal layers of the mire, consisting of loam, OMS and peat, include illite, chlorite, kaolinite and smectite. All these clay minerals found in the OMS and peat layers are believed to have been inherited with little change from the underlying loam layer during the initial transient stage of mire development. That this is indeed the case is strongly suggested by the extraordinary correspondence in the mean content of over 40 trace elements between the OMS and loam layers. In the overlying peat layer, however, some elements, including U, W, Sb, Sn, Mo, Zn, Cd, Nb, Ta, Br and B, are present in higher concentrations than in the OMS and loam. Scanning electron microscope observations suggest that this can be at least partly accounted for by the precipitation of sulfide phases in the strongly reducing and acidic environment of the peat, although whether by inorganic or microbial processes is unknown. The age of the Vasyugan Mire within the Holocene succession is discussed and it is concluded that it developed either during the Atlantic Period (8 ka–6 ka BP) or during the upper part of the Sub-Boreal Period (4 ka BP).

The Tafi valley (Northwest Argentina) was densely occupied by agropastoral societies during the Late Holocene. These peoples made profound changes in the landscape during the development of productive economies. Previous geomorphological and geoarchaeological studies have produced good basic information about the Holocene landscape evolution of this semiarid region. However, little is known about the relationship between human activities and landscape responses. The alluvial fans forming the valley´s piedmonts show morphosedimentary records that could be related to environmental changes and, from Late Holocene, with human activities. Agropastoral settlements started in the Formative Period (ca. 2500 yr BP) and land exploitation practices produced a profound degradative impact. This paper applies geoarchaeological techniques to explore the magnitude of the geomorphological and edaphic alterations introduced by man. Analyzed records enabled us to make an evaluation of erosive and degradative processes produced as dynamic geomorphological responses to human interventions. These processes were decisive for the current configuration of the valley. Fil: Sampietro Vattuone, Maria Marta. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Geoarqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: Peña Monné, José Luis. Universidad de Zaragoza; España Fil: Roldán, Jimena. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Geoarqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: Dip, Alejandra Belén. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Geoarqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: Maldonado, Mario Gabriel. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Geoarqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: Lefebvre, Maria Gisela. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Geoarqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina Fil: Vattuone, Marta Amelia. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina

Extreme events disturb the development paths of geomorphological systems. The effect of such events on relief tends to persist for long periods of time and affects the future development of such systems. This paper focuses on changes in middle mountain valleys associated with an extreme hydro-geomorphological event that occurred in the Western Tatra Mountains (Polish Carpathian Mountains) in June of 2007. The geomorphological effects were mapped and an analysis of valley-bottom deposits and dendro-geomorphological data on tree roots and stems was used to identify patterns in the geomorphological transformation taking place during such events. In addition, the organic material obtained from fans was dated by means of carbon-14 dating. The effects of previous extreme events in the study area and their geomorphological outcomes were compared. Four main valley section types were identified in the valley longitudinal profile. Unevenly aged (from 14C 390 ± 30 years YBP (1441–1631 cal AD) to 14C 3760 ± 70 YBP (4318–3962 cal BP)) organic material was revealed at different depths of each studied fan. A complex structure with alternating layers of fine and coarse material from the analysed fans was identified. The colluvial-alluvial structure of fans suggests that extreme high-energy events did occur more than once per century during the Holocene. This type of fan structure can be referred to as a patchwork. In the study area, rainfall with high energy potential occurs once in every 6–9 years and extreme hydro-geomorphological events occur every 15 years. This type of extreme event may not be exceptional in the history of middle mountain areas.

In this paper we explore the evidence for Holocene Rapid Climate Changes (RCCs) in Western Mediterranean records, examining similarities and differences in the timing and nature of impacts on different components of the natural environment (vegetation, fluvial and coastal sedimentation, fire activity, soil formation). Marine, lacustrine, and fluvial archives of the Western Mediterranean (Iberian Peninsula and Northwest Africa) provide evidence for both pervasive millennial-scale climatic variability and abrupt (decadal- to centennial-scale) transitions. We focus in particular on three RCCs characterised by high-latitude cooling, glacier advances and North-Atlantic ice-rafting events: the mid-Holocene RCC interval 6–5 cal ka BP, the late-Holocene RCC interval 3.5–2.5 cal ka BP, and the historical RCC interval known as the Little Ice Age (LIA, 1300–1950 AD). Evidence from multiple records indicates wide-ranging impacts of RCCs in the Western Mediterranean region. The three RCC intervals were characterised, however, by contrasting hydrological situations in the Western Mediterranean, with prevailing dry conditions including marked aridification events during the RCC intervals 6–5 and 3.5–2.5 cal ka BP, and prevailing or recurrent wet conditions during the LIA. We examine issues of proxy sensitivity in palaeoecological and geomorphological records and evaluate examples of contrasting geomorphological responses to regional climatic triggers between humid and semi-arid sectors of the Western Mediterranean. Finally, we consider the long-term sensitivity of the region to rapid climate change, the role of threshold changes, and the extent to which this region represents a “fragile” landscape.

The Tinto River shows very high concentrations of toxic elements and acidity from its source in the mining area to its mouth. In this paper, we studied the evolution of the levels of toxic elements during part of the Quaternary from the analysis of fluvial deposits that, forming terraces, were originated by the dynamics of the Tinto River. Using a detailed geomorphological cartography, up to nine terrace levels were differentiated in the lower sector of the basin, whose ages range from the Pleistocene to the Holocene. Sampling and geochemical analyses (major elements and trace) were carried out in six of these levels, in addition to sediments of the current flood plain. The results of these analyses do not show any bias from the mid Pleistocene (T8 - Terrace 8) to the early Holocene (T1). Moreover, these geochemical contents are similar to the average values obtained by other authors for the entire South-Portuguese Zone of the Iberian Massif. However, the current sediments of the Tinto River (T0) show a sharp increase in the levels of As, Cu, Pb and Zn compared to the rest, which indicates a serious increment of contamination by toxic elements. Although there are evidences on the existence of a natural process of oxidation of sulfides since the Miocene, the amounts of toxic elements released should be very small compared to those generated since the beginning of the mining activities in the Iberian Pyrite Belt., This research was funded by two Spanish-FEDER projects (AMB99-0226-C03, CGL2010-15810/BTE) and one Research Group of the Andalusia Board RNM-293.

This paper presents the results of 40 years of research on the gully system in the Doly Podmularskie catchment (0.35 km² in size), which is situated in the south-western part of the loess-covered Naleczow Plateau in SE-Poland. Topographic, stratigraphic and pedologic investigations, and monitoring of a tributary gully (gully area: 0.7 ha, catchment: 2.5 ha) were combined with historical, archaeological and palaeoecological records. The results reveal a long and complex history in terms of the temporal and spatial extent and the impact of land use on gully erosion, and the long-term feed-back mechanisms between land use changes and natural processes since the end of the Pleistocene. Phases of gully erosion and subsequent filling occurred in the Bronze Age and around the 10th to 11th centuries. The most severe deepening and expansion of the gully took place in the 17th century. The results also show that field structures and land use intensity had a significant influence on the frequency and magnitude of run-off, soil erosion, piping, and landslide events. The last significant erosion phase started in the mid-19th century with renewed headward retreat and down-cutting within older gully fills. Today, most of the catchment is either forested or the land is covered in berry shrubs. In the future, the area will continue to produce sediments, because of the steep slopes and because there are still areas of bare soil with a low resistance to erosion, a legacy from past land uses, which will remain a factor affecting soil erosion and sedimentation processes in the future. This study is an example of how important it is to observe and understand slow geomorphologic processes and rare extreme events in the light of land use changes when investigating long-term human–environment interactions.

This paper describes the results of geomorphological, sedimentological and 14C analyses of Late Holocene fluvial sequences in the Moldova River Valley of Romania. This river originates from the Carpathians mountains and is known for the extent of its large floodplain and sediment thickness. Between the Molid and Timisesti localities (river length: 86 km), numerous large fossil trunks of oak, poplar and beech trees are exposed in the riverbanks. Six wood samples were selected for radiocarbon absolute dating (conventional method), and their ages ranged from 410 to 3200 cal yrs. BP. The thickness of the alluvial sediments above the sampled fossil trunks varied between 2 and 3 m, and these sediments predominantly consisted of coarse gravel materials that had similar granulometry to sediments that were present in the modern riverbed. Additionally, in the same investigated areas, successive floodplain cross-sections were constructed based on more than 20 hydrogeological boreholes. For each cross section, all data were used to calculate the local values of bed loads, and these values were compared to the absolute ages of the fossil trunks and were in the range of 300 m3/m and 5500 m3/m. Based on the calculated values, during the last 780 years, the floodplain sedimentation rates were estimated to be in the range of 0.4 m3/year at the Molid Section, which was located in the mountainous area of the valley and 44 km downstream from the river headwater, and during the last 410 years, the sedimentation rate at the Praxia Section, which was located 125 km downstream from the river headwater, was 13.3 m3/year. In the past 100 years, the fluvial processes along the Moldova River were dominated by a narrowing (by an average of 76%) and an incision (up to 2.5 m), and a channel metamorphosis from braided to wandering was reported. These results are discussed in the context of Late Holocene regional and local palaeoclimatic reconstructions as well as that of human interventions.

Long-term changes to the Yellow River delta in China have received considerable attention not only because of the growing economic importance of the delta region but also because they provide a clear example of the dominant role played by anthropogenic effects upon a large dynamic river delta. This paper presents a detailed study on the morphological consequences of reduction in river sediment load and influence of human activities based on sediment load data at three gauging stations in the upper, middle and lower reaches of the Yellow River basin from 1950 to 2007. The results indicate that sediment loads at all three gauging stations display a gradually decreasing trend over the past 58 years. The primary reason for this decrease is shown to be due to various human activities, including the construction of Longyangxia and Liujiaxia reservoirs in the upper reaches, water–soil conservation practices and the commissioning of Sanmenxia and Xiaolangdi reservoirs in the middle reaches. It is estimated that water–soil conservation practices which are a major factor to the decrease of sediment load at Huayuankou gauging station account for 40% of the total amount of reduction, sediment trapping by Sanmenxia and Xiaolangdi reservoirs account for 30% of the total amount of reduction and the 10% decrease is caused by human activities in the upper reaches. The remaining 20% decrease is attributed to precipitation decrease. The reduction of sediment load has directly impacted on the lower Yellow River and the delta region, causing alternate changes between siltation and scouring in the lower river channel along with an increased rate of erosion over the whole Yellow River delta.

During the past 40 years colluvial and alluvial deposits have been used in Brazil as good indicators of regional landscape sensitivity to Quaternary environmental changes. In spite of the low resolution of most of the continental sedimentary record, geomorphology and sedimentology may favor palaeoenvironmental interpretation when supported by independent proxy data. This paper presents results obtained from pedostratigraphic sequences, in near-valley head sites of southern Brazilian highlands, based on geomorphologic, sedimentologic, micromorphologic, isotopic and palynologic data. Results point to environmental changes, with ages that coincide with Marine Isotopic Stages (MIS) 5b; 3; 2 and 1. During the late Pleistocene, although under temperatures and precipitation lower than today, the local record points to relatively wet local environments, where shallow soil-water saturated zones contributed to erosion and sedimentation during periods of climatic change, as during the transition between MIS 2 and MIS 1. Late Pleistocene events with ages that coincide with the Northern Hemisphere Younger Dryas are also depicted. During the mid Holocene, slope-wash deposits suggest a climate drier than today, probably under the influence of seasonally contrasted precipitation regimes. The predominance of overland flow-related sedimentary deposits suggests an excess of precipitation over evaporation that influenced local palaeohydrology. This environmental condition seems to be recurrent and explains how slope morphology had influenced pedogenesis and sedimentation in the study area. Due to relative sensitiveness, resilience and short source-to-sink sedimentary pathways, near-valley head sites deserve further attention in Quaternary studies in the humid tropics.

The andosols of south-central Chile (36–42°S) are developed on yellow-brown loams that cover the region with a thickness of several meters. In the literature, several hypotheses concerning the nature, origin, mode of transport and deposition of the andosol parent material have been advanced but no general agreement has been found. In this paper, we test these hypotheses by analyzing new representative outcrops located around Icalma (38°50′S) and Puyehue (40°40′S) lakes by a pluri-methodological approach. Our data demonstrate that the andosol parent material has the typical mineralogical and geochemical signature of the regional volcanism and that these deposits are post-glacial in age. The grain size of the deposits and the morphology of the coarse grains evidence that most of these particles haven't been re-transported by wind but are direct volcanic ash falls deposited throughout the Late Glacial and Holocene. Because of the prevailing westerly winds, most of these volcanic ashes have been transported to the East. Following the deposition of the volcanic particles, weathering and pedogenetic processes have transformed part of the volcanic glasses and plagioclases into allophane and have wiped out the original layering. This work demonstrates that most of the andosols that occur in the Andes and in the eastern part of the Intermediate Depression of south-central Chile are developed on volcanic ashes directly deposited by successive volcanic eruptions throughout the Late Glacial and Holocene.

Many studies across the central and southern Maya Lowlands of Belize, Guatemala, Honduras, and Mexico have produced records of land degradation, mostly sedimentation and soil erosion, during the ancient Maya period from before 1000 BC to the Maya Collapse of c. AD 900. This paper provides new data from two sites (Blue Creek and Cancuen), synthesizes more than a decade of the authors' research in Guatemala, Belize, and Mexico, and synthesizes other findings from this region. These research projects analyzed more than 100 excavations in upland and depression sites, cored lakes and wetland sediments, and studied sediments in the field and laboratory using radiocarbon dating, a battery of soil chemistry tests, stratigraphic analysis, magnetic susceptibility, elemental analyses, and artifact identification. Our objective was to date when sedimentation and soil erosion occurred, identify stable surfaces, and correlate them with the state of knowledge about past land use. These findings indicate three general epochs of accelerated soil erosion and identified two major paleosols. The three waves of soil erosion occurred in the Preclassic period (c. 1000 BC to AD 250), the Late Classic (AD 550 to 900), and in the last several decades. The major paleosol (‘Eklu'um’) in these sites is a well-developed Mollisol or Vertisol that started forming in the early Holocene and was buried in either the Preclassic or Classic periods (AD 250 to 900). At some sites the Eklu'um paleosol lies beneath sediments with a fainter paleosol, which in turn lies buried below Classic period and later sediments. This picture shows higher than expected soil erosion linked to the region's first pioneer farmers in the Preclassic and less than expected soil erosion in the Late Classic when population peaked and land use was the most intensive. In other regions like Cancuen, Guatemala, however, most soil erosion occurred during the Maya Late Classic (AD 550–830). Erosion here was intense but short-lived: depressions record 1–3 m of aggradation in two centuries. A third epoch of accelerated soil loss and aggradation arose with the rapid land use changes brought by new pioneers during the last several decades.

This paper describes the results of detailed surveys for the landscape systems (landforms, vegetation, topsoils and snow cover duration) of a nivation hollow in northern Japan and discusses their evolution in the Holocene epoch. The nivation hollow studied consists of three concentric zones whose landscapes and historical development are different. The outermost zone where snow disappears early is covered with dwarfed trees, Sasa kurilensis (subalpine bamboo) thicket and snowbed grasses. Fossil solifluction lobes and drainage channels are common. In this zone, slope stabilization and vegetation establishment (penetration and settlement of vegetation on slopes) followed by pedogenesis occurred after 12,350 cal BP. In the middle zone, slopes are mostly covered with snowbed plants, and turf-banked terraces and minor slumps are observed. This zone experienced slope stabilization and vegetation establishment followed by pedogenesis after 4870 cal BP. The innermost zone overlaps with the snow-induced bare ground in the centre of the nivation hollow basin. Active geomorphic processes operate here and traces of surficial wash and rills are abundant. Humic soils are not present in this zone. These differences in landscape development of the nivation hollow may reflect the temporal changes in the timings of snow disappearance associated with the Holocene climatic variabilities.

The paper presents a sedimentological, palynological, and phytolith record from a 13 m deep Holocene sedimentary sequence, located in the Tsoaing River valley, southwestern Lesotho. Six conventional radiocarbon and two AMS dates provide a relatively high resolution Holocene record for the sedimentary sequence, ranging from ca. 12 000 to 4000 years BP. Pollen is absent in the upper section but present in the lower 2 m, confirming terminal Pleistocene/Holocene conditions reported in previous published pollen and charcoal records from the region. The absence of pollen in the upper layers of ca. 9000 years BP and younger suggests that conditions over southwestern Lesotho throughout much of the Holocene was typified by a seasonal climate that prevented long-term preservation of plant remains, although other plant material like robust spores, microscopic charcoal, and phytoliths withstood oxidation. Sedimentological and phytolith results suggest that the period from ca. 8600 to 8450 years BP experienced rapid environmental change towards drier conditions. Phases of chemical disintegration with organic input (including local swamp phytoliths) are suggested at ca. 7000 years BP and again after 4500 years BP.

This paper deals with modern and ancient sedimentation in fresh water lakes and the marine shelf of the southern Marmara region, NW Anatolia, Turkey. Most of the information has been obtained from monitoring of suspended load discharged into two lakes (Manyas and Ulubat) in the last 45 years and from 8 to 11 m thick lacustrine sediments, in addition to radiocarbon-dated shelf sediments. This allows a holistic approach to the drainage basin denudation over time. The results show that the sedimentation rates in the lakes were low 0.22 cm year−1, from 4000 to 2000 years BP and then they increased (0.29 cm year−1) up to sub-recent times and reached 0.44 cm year−1 in the last century. It is suggested that deforestation created high rates of sedimentation in the basins and/or strong denudation of the region during the Late Holocene. This study also shows that for shallow freshwater lakes the calculation of sedimentation rates must include fine particles lost by the outlets and coarse-grained bed load deposited on their shores. In addition, a high rate of sedimentation has been created by short, but repetitive intense depositions. During the last century particularly during the last 45 years, the rate of sedimentation or denudation has increased dramatically in NW Turkey. The two World Wars and mismanagement of the land had important local effects by increasing deforestation and resulting in the present erosive conditions.

This paper presents the preliminary results of the geoarchaeological study of Abric de la Cativera (el Catllar, Tarragona), a rock-shelter containing late glacial and early Holocene stratification spanning between c. 11.3 and 7.9 ka 14 C BP. The site is located in the Gaia River Valley, on the southern Catalonian coast. The shelter, situated at the foot of a low limestone wall, was discovered in 1994. Preliminary fieldwork was performed in 1995, comprising excavation of the early Holocene layers and the sampling of the stratigraphic succession. The geoarchaeological study was undertaken using a descriptive approach and so far has included a geomorphological survey of the surroundings, the stratigraphic study of the site and micromorphological analysis. High priority goals are a diachronic reconstruction of environmental change at the Pleistocene–Holocene boundary and an understanding of the relationships between anthropic and non-anthropic dynamics, paying special attention to site formation processes. The site's archaeological record represents human occupations affiliated to the microlaminar Epipalaeolithic (complex C and unit B) and to early Holocene macrolithic technocomplexes (unit A), according to the lithic assemblages recovered. Artefacts, by-products, ecofacts, manuports and art objects were collected during excavations and archaeological features were detected. The results of the micromorphological study show that the abrupt climate changes around the Pleistocene–Holocene (PH) limit are well recognisable at the site. The beginning of the Younger Dryas (YD) and the PH limit are both represented by erosional surfaces and by the inwash of slope sediments cutting the late glacial pre-YD alluvial succession deposited by the Gaia River. The shift from alluvial to a gravity-driven sedimentary system is the result of an overall modification of the valley's morphodynamics. The early Holocene units record the transition to a Mediterranean environment and the stabilisation of the slope. Human inputs are abundant in the entire stratigraphic succession, except in the YD layers, where a sudden decrease is observed. Anthropic activities determined the accumulation and modification of various components and the formation of anthropogenic microfacies and features. The observation of micromorphological samples from layer A, which contains occasional potsherds, suggests its in situ position, which is in contrast with the existing models on the regional processes of neolithisation. A comparison between the pedo-sedimentary and archaeological records indicates that the timing of environmental and cultural change at Abric de la Cativera is differential, suggesting that the latter results from behavioural and cultural dynamics, rather from environmental factors.

Summary This paper deals with the geomorphology and sedimentology of hitherto undescribed dissected Pleistocene alluvial fans of the Benidorm/Alicante region of southeast Spain. A coalescent fan complex is described in detail and two main phases in its development are identified. The early phases, predominantly of fan accumulation culminated in the formation of large coalescent fans where upper surfaces are capped by a well developed caliche crust. Deposition was by fluvial processes, both within channels and on open fan surfaces, and by mass movement. There were spatial and temporal variations in sedimentation with periods of caliche formation on fan surfaces between periods of deposition. There is evidence of numberous cut and fill sequences during the fan accumulation, some of which appear to be local and others which appear to reflect major environmental changes. One such sequence occurs towards the end of the accumulation phases when large channels were cut in the fan surface then filled with gravel. The later phases of fan development were predominantly of fan dissection but include major valley cutting and filling sequences, which postdate the formation of the main caliche crust on the upper fan surfaces. The dissection sequences differ between the various valleys trenched into the fans, the most complex of which has four distinct valley fills, two of which are widespread. A broad chronology is suggested, based in part on the relationships between fan deposits and Pleistocene marine and aeolianite deposits. The accumulation phases appear to be pre-Wurm and the dissection phases Wurm and Holocene in age. The chronology of fan sequence is complicated by the problems of differentiating between the results of major environmental change and those of a complex geomorphic response, characteristic of fan environments in semi-arid areas. These problems are illustrated in relation to the modern morphology on a small fan. Localised erosion and deposition are seen in relation to channel form and slope, but the locations of dominant erosion or deposition have changed during the more recent phases of fan development.