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The Sand Dunes of Victoria Valley, Antarctica
Abstract
Transverse-barchan dunes, together with flanking sand sheets and whaleback sand mantles, stretch more than 8 kilometers between the Victoria Lower Glacier and the perennially frozen Lake Vida, forming the largest sand accumulation in Antarctica. The cold desert climate, persistent and strong summer easterly winds, thick, sandy ground moraine, and a broad valley train favor dune formation, although ubiquitous snow strata included in the sand deposits may limit movement. The dunes show short-term slip-face movements of up to 12 centimeters a day in mid-summer. Sand from the dunes is generally coarser and more poorly sorted than that from beach-derived dunes, but it is similar to that of many interior deserts. An unusually uniform and generally high degree of roundness of sand grains throughout lower Victoria Valley may be explained by inheritance of round Beacon sandstone grains and/or by a related 8-kilometer-long cyclical grainpath maintained in the valley by the combined action of winter and summer winds.
... Westerly winds interpreted as katabatic winds (Nylen et al., 2004) or foehn winds (Speirs et al., 2010) are more powerful and occur more often during the Austral winter. The bimodal wind regime has a strong influence on modern dune morphodynamics, modifying and reversing dune crests and their orientation (Lindsay, 1973;Calkin and Rutford, 1974;Selby et al., 1974;Speirs et al., 2008;Bristow et al., 2010aBristow et al., , 2010b. ...
... Selby et al. (1974) argued that as the dune cores were frozen there would be very little dune migration. However, Calkin and Rutford (1974) used photogrammetry and fi eld observations to determine rates of dune migration and obtained an average rate for dune crests of m 120 110 100 90 80 70 60 50 40 30 20 10 0 0 50 100 150 G 32212 2nd pages 6 m/yr between 7 November 1959 and 27 January 1962, with a range from 20 to -2 m/yr. The mean of dune crest movement in the same area for the following 7 yr period was only 1.1 m/yr, with a range between 4 and -2 m/yr (Calkin and Rutford, 1974). ...
... However, Calkin and Rutford (1974) used photogrammetry and fi eld observations to determine rates of dune migration and obtained an average rate for dune crests of m 120 110 100 90 80 70 60 50 40 30 20 10 0 0 50 100 150 G 32212 2nd pages 6 m/yr between 7 November 1959 and 27 January 1962, with a range from 20 to -2 m/yr. The mean of dune crest movement in the same area for the following 7 yr period was only 1.1 m/yr, with a range between 4 and -2 m/yr (Calkin and Rutford, 1974). Subsequent measurement of dune migration from historical photographs and LiDAR (light detection and ranging) data spanning a 40 yr period from 1961 to 2001 average 1.5 m/yr, with a range from 2.8 to 0.5 m/yr (Bourke et al., 2009). ...
Antarctica is the coldest, driest, and windiest continent on Earth, and contains sand dunes, like deserts elsewhere. The structure and age of the cold climate dunes found in the Victoria Valley, Antarctica, are described in the light of changing climate in the Ross Sea region of Antarctica during the late Holocene. Ground penetrating radar (GPR) was used to image sand dune stratigraphy, and optically stimulated luminescence (OSL) was used to determine when the sands were deposited. The timing of sand dune accretion identified from the GPR stratigraphy ranges from the present day to ca. 1.3 kyr B.P. The OSL ages were used to calculate end-point migration rates of 0.05–1.5 m/yr, lower than migration rates from photogrammetry and field surveys undertaken over the past 50 yr. The earliest recorded dune development, ca. 1.3 kyr B.P., was probably controlled by intensification of circumpolar westerlies at that time as well as by drier conditions and lower temperatures that promoted dune stabilization. The dune reactivation ca. 300 yr ago coincides with cooling ca. A.D. 1700–1850, and strengthening of southern circumpolar westerlies. The increase in rate of dune migration after this period and especially the past 200 yr may coincide with the modern rise in CO2 and the warmest temperatures in Antarctica during the past 800 kyr.
... However, winds blow throughout the year so that aeolian sediment transport is probably more important than fluvial transport. This is most evident in the Victoria Valley, one of the McMurdo Dry Valleys of Antarctica ( Fig. 1), where there is a variety of types of sand dunes including transverse, barchanoid, and whaleback dunes, in addition to protodunes, embryonic dunes, sand-sheets and sand-ramps (Lindsay, 1973;Calkin and Rutford, 1974;Selby et al., 1974;Miotke, 1985;Bourke et al., 2009;Bristow et al., 2009). In this paper we focus on the Packard dunefield, which is located along the northern margin of the Lower Victoria Valley beneath the Packard Glacier (Fig. 1). ...
... Research interest in the Victoria Valley dunes was stimulated in the early 1970's when the dunes were investigated by Morris et al. (1972a,b) as part of a geomorphological study that aimed to collect data for visual comparison with images expected from the Viking Mars Mission which was launched in1975, arriving at Mars in 1976. Further geomorphic and sedimentary studies of the dunes were undertaken by Lindsay (1973); Calkin and Rutford (1974); Selby et al. (1974); Miotke (1985); Speirs et al. (2008) and Bourke et al. (2009). ...
... These structures are similar to those observed by Koster and Dijkmans (1988) at the Great Kobuk Sand Dunes in Alaska where seasonal melting of snow layers produces niveo-aeolian deformation structures. Snow layers interbedded with aeolian sands have been described in the Packard dune field by Lindsay (1973), Calkin and Rutford (1974), Selby et al. (1974), and Miotke (1985). We encountered snow layers up to 40 cm thick in most of the trenches excavated for OSL sample collection. ...
GPR provides high resolution images of aeolian strata in frozen sand in the McMurdo Dry Valleys of Antarctica. The results have positive implications for potential GPR surveys of aeolian strata on Mars. Within the Lower Victoria Valley, seasonal changes in climate and a topographically-constrained wind regime result in significant wind reversals. As a consequence, dunes show reversing crest-lines and flattened dune crests. Ground-penetrating radar (GPR) surveys of the dunes reveal sets of cross-strata and low-angle bounding surfaces produced by reversing winds. Summer sand transport appears to be dominant and this is attributed to the seasonal increase in solar radiation. Solar radiation which heats the valley floor melts ice cements making sand available for transport. At the same time, solar heating of the valley floor generates easterly winds that transport the sand, contributing to the resultant westward dune migration. The location of the dune field along the northern edge of the Lower Victoria Valley provides some shelter from the powerful föehn and katabatic winds that sweep down the valley. Topographic steering of the winds along the valley and drag against the valley wall has probably aided the formation, migration and preservation of the dune field. Optically-stimulated luminescence (OSL) ages from dune deposits range from 0 to 1.3 kyr showing that the dune field has been present for at least 1000 yr. The OSL ages are used to calculate end-point migration rates of 0.05 to 1.3 m/yr, which are lower than migration rates reported from recent surveys of the Packard dunes and lower than similar-sized dunes in low-latitude deserts. The relatively low rates of migration are attributed to a combination of dune crest reversal under a bimodal wind regime and ice cement that reduces dune deflation and restricts sand entrainment.
... This rounding process is not so obvious in the Proctor Crater dune field, suggesting that these dunes may be partially cemented. [41] In Antarctic dunes, snowfall buried by subsequent slip face activity has been observed to allow oversteepened cornices of sand cemented by snow to develop on lee slopes [Calkin and Rutford, 1974]. Similar lenses of snow have remained in terrestrial dunes throughout the summer season, such as those of Wyoming [Steidtmann, 1973] and the Antarctic dunes [Calkin and Rutford, 1974], and for a good portion of spring, Alaskan dunes [Koster and Dijkmans, 1988]. ...
... [41] In Antarctic dunes, snowfall buried by subsequent slip face activity has been observed to allow oversteepened cornices of sand cemented by snow to develop on lee slopes [Calkin and Rutford, 1974]. Similar lenses of snow have remained in terrestrial dunes throughout the summer season, such as those of Wyoming [Steidtmann, 1973] and the Antarctic dunes [Calkin and Rutford, 1974], and for a good portion of spring, Alaskan dunes [Koster and Dijkmans, 1988]. Like the sides of the landslide scar shown inFigure 2e, these sharp brinks in the Proctor Crater dunes may indicate the presence of seasonal frost trapped within the dunes. ...
... Furthermore, water ice tends to accumulate along strata interfaces in terrestrial dunes. Snowfall can form icy strata within the dune that persists from year to year [e.g., Calkin and Rutford, 1974]. A similar process could occur on Mars with either H 2 O or CO 2 ice. ...
Proctor Crater is a 150 km diameter crater in Noachis Terra, within the southern highlands of Mars. The analysis leading to the sedimentary history incorporates several data sets including imagery, elevation, composition, and thermal inertia, mostly from the Mars Global Surveyor mission. The resulting stratigraphy reveals that the sedimentary history of Proctor Crater has involved a complex interaction of accumulating and eroding sedimentation. Aeolian features spanning much of the history of the crater interior dominate its surface, including large erosional pits, stratified beds of aeolian sediment, sand dunes, erosional and depositional streaks, dust devil tracks, and small bright bed forms that are probably granule ripples. Long ago, up to 450 m of layered sediment filled the crater basin, now exposed in eroded pits on the crater floor. These sediments are probably part of an ancient deposit of aeolian volcaniclastic material. Since then, some quantity of this material has been eroded from the top layers of the strata. Small, bright dune forms lie stratigraphically beneath the large dark dune field. Relative to the large dark dunes, the bright bed forms are immobile, although in places, their orientations are clearly influenced by the presence of the larger dunes. Their prevalence in the crater and their lack of compositional and thermal distinctiveness relative to the crater floor suggests that these features were produced locally from the eroding basin fill. Dust devil tracks form during the spring and summer, following a west-southwesterly wind. Early in the spring the dust devils are largely restricted to dark patches of sand. As the summer approaches, dust devil tracks become more plentiful and spread to the rest of the crater floor, indicating that the entire region acquires an annual deposit of dust that is revealed by seasonal dust devils. The dark dunes contain few dust devil tracks, suggesting that accumulated dust is swept away directly by saltation, rather than by the passage of dust devils. Spectral deconvolution indicates that the dark dunes have infrared spectra consistent with basalt-like materials. The average thermal inertia calculated from Thermal Emission Spectrometer bolometric temperatures is 277 ± 17 J m^-2 s^-0.5 K^-1 , leading to an effective grain size of 740 ± 170 um, which is consistent with coarse sand and within the range expected for Martian sand. The coarse sand that composes the large dune field may have originated from outside the crater, saltating in from the southwest. Most of the transport pathway that delivered this sand to the dune field has since been eroded away or buried. The sand was transported to the east center of the crater floor, where beneath the present-day dunes a 50 m high mound of sand has accumulated. Dune slip faces indicate a wind regime consisting of three opposing winds. Some of these wind directions are correlated with the orientations of dust devil tracks and bright bed forms. The combination of a tall mound of sand and three opposing winds is consistent with a convergent wind regime, which produces the large reversing transverse and star dunes that dominate the dune field. The dark dunes have both active slip faces and seemingly inactive slip faces, suggesting that the dunes vary spatially in their relative activity. Nevertheless, the aeolian activity that has dominated the history of Proctor Crater still continues today.
... Modern aeolian deposits of cold regions frequently have interbedded snow and ice layers which are buried under layers of sand and dust. Such deposits are described in modern Antarctic dunes, in Alaska within the Kobuk dune massif, and are called niveo-aeolian [Cailleux, 1974;Calkin, Rutford, 1974;Brookfi eld, 2011]. Numerous signs of syngenetic freezing and subsequent melting were identifi ed in European, Canadian, and Alaskan cover aeolian deposits which had formed at the end of the Late Neopleistocene in the interval of 14.0-12.5 ka Kasse, 2002;Brook-fi eld, 2011;Zieliński et al., 2015;Derbyshire, Owen, 2017;Kasse, Aalbersberg, 2019]. ...
... Modern niveo-aeolian formations composed of thin interlayering of sand, loamy sand, and fi rn (total ice content 40-50 %) were found in the dunes of the dry valley of Victoria in Antarctica [Cailleux, 1974;Calkin, Rutford, 1974;Ayling, McGowan, 2006]. The thickness of individual fi rn interlayers varies from 1 mm to 4-6 cm, some reach a thickness of 10 cm and more. ...
... Larger exposed rocks are comprised of white granular marbles, paragneisses, granulites, and quartzofeldspathic schists (Allen and Gibson, 1962). Victoria Valley contains extensive sand sheets and dunes throughout the valley floor along with various drifts originating from the east and north (Calkin and Rutford, 1974). Lacustrine algae and carbonate plate deposits are widespread, suggesting that, like the valleys to the south, portions of the Victoria Valley were inundated during the LGM (Hall et al., 2002), however much of the valley is believed to have been ice free since the Miocene (Bockheim and McLeod, 2013). ...
... There were multiple pyroxenes present within individual samples, mainly calcium, magnesium and iron pyroxenes, with d-spacings (and therefore chemical compositions) that are consistent with either pigeonite, augite, or hedenbergite (Fig. 4). Many of the minerals observed commonly occur in anorthosite, basalt, andesite, kenyte, and dolerite, rocks previously identified within the MDV region (Calkin and Rutford, 1974;Kyle et al., 1990). While the mineralogy was similar among many of the sites, there also were distinct differences. ...
In the Southern Hemisphere, the major sources of dust and other aeolian materials are from Patagonia, South Africa, Australia, and New Zealand. Dust from Patagonia and New Zealand has been identified in ice cores throughout Antarctica, suggesting that during arid and windy periods, such as glacial periods, dust can be entrained and transported onto the continent. However, little information exists on modern Antarctic dust sources, transport, and its role in the Southern Hemisphere dust cycle. We present the first geochemical characterization of aeolian materials collected at five heights (between 5 cm and 100 cm) above the surface in four valleys within the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Our mineralogy data indicate that these materials are primarily derived from local rocks of the McMurdo Volcanics, Ferrar Dolerite, Beacon Sandstone and Granite Harbor Intrusives, with varying contributions of each rock type dependent on the valley location. While major oxide, trace element and rare earth element data show that low elevation and coastal locations (with respect to the Ross Sea) are dominated by local sources, high elevation and inland locations have accumulated both local materials and dust from other distant Southern Hemisphere sources. This far-traveled material may not be accumulating today, but represents a paleo source that is resuspended from the soils. By geochemically “fingerprinting” aeolian materials from the MDV, we can better inform future studies on the transport of materials within Antarctica and between Southern Hemisphere land masses.
... [4] Aeolian transport is known to be an active geomorphic agent within the Dry Valleys [Malin, 1984[Malin, , 1985[Malin, , 1986Lancaster, 2002Lancaster, , 2004Lancaster et al., 2010;Ayling and McGowan, 2006;Bourke et al., 2009;Gillies et al., 2009] as signified by the presence of well-developed aeolian landforms [e.g., Selby et al., 1973Selby et al., , 1974Calkin and Rutford, 1974;Miotke, 1982;Gillies et al., 2009Gillies et al., , 2012. As well, it has become increasingly recognized that aeolian processes play an important role in the ecology of the MDV [Campbell et al., 1998;Moorhead and Priscu, 1998;Nkem et al., 2006]. ...
... Geomorphic evidence for aeolian processes is widespread throughout the MDV [Malin, 1992;Morris et al., 1972]. Ventifacts (rocks shaped by wind-driven abrasion) are frequently observed [Selby et al., 1973;Gillies et al., 2009], and the Victoria Valley has extensive areas of sand dunes and sand sheets [Calkin and Rutford, 1974;Speirs et al., 2008a;Bristow et al., 2010]. ...
[1] Due, in part, to the challenging environment of Earth's high-latitude regions, available information on cold climate effects on aeolian processes in these areas remains limited. Data from these areas, however, provide insight into the physics of sediment transport by wind and the controls on erosive winds in proximity to ice caps and topographic influences. This study presents a 2 year record of meteorological, saltation activity, horizontal saltation flux, and particle size distribution data from four sites in the McMurdo Dry Valleys of Antarctica, 2008 to 2010. Saltation measurements revealed daily and seasonal patterns with spring and summer sediment transport events occurring between 09:00 and 24:00 hours due to thermally generated winds. Fall and winter events occur at any time of day with the strongest associated with foehn winds. Threshold wind speed at 4.2 m in all seasons for all locations was ≈10 m s−1. Saltation occurred in the temperature range −40°C to +5°C. Westerly winds in the fall/winter and easterly winds in spring/summer are associated with the majority of transport events. The sand in transport is mainly 250 to 500 µm in diameter and poorly sorted. The integrated saltation flux varies over three orders of magnitude among the sites, with the lowest mean flux recorded in the Taylor Valley (2.9 kg m−1 day−1) and the highest in the eastern Victoria Valley (2271 kg m−1 day−1) for 24 hours of continuous saltation. The percentage of time saltation active at these locations annually is ≈2%, ≈4%, and ≈13%, respectively, for the Victoria, Taylor, and Wright Valleys.
... Collectively, these glaciers represent a wide range of thermal regimes and dynamic styles determined by the latitudinal and altitudinal variations in terrestrial glacier distribution on Earth today (Fig. 2). Although several approaches have been adopted for the study of glacigenic sediments, and methods of sedimentological analysis clearly defined (Eyles, 1983a,b;Dreimanis, 1989;Brodzikowski and Van Loon, 1991;Hambrey, 1994;Menzies, 1995Menzies, , 1996Miller, 1996;Krüger and Kjaer, 1999;Hubbard and Glasser, 2005;Benn and Evans, 2010), there have been few attempts to assemble a consistent sedimentological data-set from modern environments that can be used as a basis for interpreting the Quaternary and pre-Quaternary glacial record. However, it is recognised that a wide range of over-lapping sedimentary processes operate in most environments, but to different degrees. ...
... Sand dunes occur in some areas, the most impressive occurring in the lower Victoria Valley (e.g. Calkin and Rutford, 1974;Bristow et al., 2010). ...
This paper provides a description and evaluation of the sedimentary facies and environments associated with a range of glacier thermal and dynamic regimes, with additional consideration given to the tectonic context. New and previously published data are evaluated together, and are presented from modern terrestrial and marine glacial sedimentary environments in order to identify a set of criteria that can be used to discriminate between different glacier thermal regimes and dynamic styles in the sedimentary record. Sedimentological data are presented from a total of 28 glaciers in 11 geographical areas that represent a wide range of contemporary thermal, dynamic and topographic regimes. In the context of “landsystems”, representatives from terrestrial environments include temperate glaciers in the European Alps, Patagonia, New Zealand, the Cordillera Blanca (Peru), cold glaciers in the Dry Valleys of Antarctica and the Antarctic Peninsula region, and polythermal valley glaciers in Svalbard, northern Sweden, the Yukon and the Khumbu Himal (Nepal). The glaciomarine environment is illustrated by data from cold and polythermal glacier margins on the East Antarctic continental shelf, and from a polythermal tidewater glacier in Svalbard, along with general observations from temperate glaciers in Alaska. These data show that temperate glacial systems, particularly in high-relief areas, are dominated by rockfall and avalanche processes, although sediments are largely reworked by glaciofluvial processes. Debris in polythermal glaciers is both thermally and topographically influenced. In areas of moderate relief, debris is mainly of basal glacial origin, and the resulting facies association is dominated by diamicton. In high-relief areas such as the Himalaya, the debris load in polythermal glaciers is dominated by rockfall and avalanche inputs, resulting in extensive accumulations of sandy boulder-gravel. Cold glaciers are dominated by basal debris-entrainment, but sediments are little modified from the source materials, which are typically sandy boulder-gravel from older till, and sand (from glaciofluvial, glaciolacustrine and aeolian sources). Similar facies associations, but with different facies geometry and thickness occur in equivalent glaciomarine settings. Application of these concepts can aid the interpretation of glacier thermal regime (and hence palaeoclimate) in Quaternary and ancient glacial systems.
... However, coastal monitoring with high accuracy is still difficult owing to the complexity of the changes in coastal landforms over a range of spatial and temporal scales. Early studies used field techniques to monitor and measure sand dune movements; for example, human-made field markers (e.g., rods or stakes) and natural markers (e.g., trees) have been used as indications of dune movements (e.g., [26]). Geodetic techniques, most commonly total station, optical or laser theodolites, and GPS, have been applied to collect data to produce topographic profiles or maps (e.g., [27][28][29]). ...
Fences are commonly used in coastal regions to control wind-blown sand. Sand-trapping fences and sand-stabilizing fences have been installed at the Tottori Sand Dunes, Tottori Prefecture, Japan, to prevent damage by wind-blown sand; however, the effectiveness of these fences has not previously been quantitatively evaluated. This study analyzed the effects of sand fences on sand trapping using field observations of blown-sand flux and unmanned aerial vehicle (UAV) photogrammetry. The estimated total blown-sand flux in the near-ground surface observed inside and outside the sand fences indicated that wind-blown sand was effectively trapped by the sand fences at wind speeds lower than 17 m s−1, reducing sand flux by more than 80%. The UAV photogrammetry results demonstrated that large amounts of sand were transported from the dune to the fenced area during March and April, and sand initially accumulated on the lee side of the sand-trapping fences, forming a new foredune. Sand accumulated on the existing foredune during April and May, and the vertical accretion around the foredune was two to four times the sand deposition within the sand-stabilizing fences. This indicated the effectiveness of sand-trapping fences for controlling wind-blown sand; however, their efficiency was reduced as they were gradually buried, with sand being trapped by the sand-stabilizing fences.
... They have enabled scientists to carry out many dune-related studies, such as dune mapping and taxonomy [30,31], pattern analysis of dune fields [32][33][34], spatial analysis of dune fields [35,36], topographic and morphologic variations of dune fields [37][38][39], mineralogic and sedimentologic characteristics [40], and climatic changes [41]. In addition to these studies, the determination of the rates of dune migration has received particular emphasis from remote sensing application scientists in the field of geomorphology (e.g., [42][43][44][45][46][47][48][49][50][51][52]). From this perspective, two or more remote sensing images are accurately georeferenced and then dune boundaries or axes are delineated for eventual comparison of the boundaries and axes to calculate the lateral displacement of sand dunes. ...
The study area has three sand accumulations: Two in Wadi Fatmah and one in Wadi Ash Shumaysi, midwest of Saudi Arabia. The spatial extents of these sand accumulations have significantly increased over the last few decades. Multi-source satellite imagery, such as CORONA (1967, 1972), SPOT 5 (2013), LandSat TM (1986), and LandSat 8 OLI (2013), enabled monitoring and analysis of the interplay between the changes in the anthropogenic activities and spatial expansion of the areas of sand accumulation. The main driving force of the spatial expansion could be strongly linked to extensive changes in the anthropogenic regimes in the middle zone of Wadi Fatmah and its surrounding landforms and mountain masses. In this context, the once dominant agricultural lands of the middle zone of Wadi Fatmah have been transformed into abandoned agricultural areas. Extensive off-road driving has resulted in soil degradation. Excavation and mining activities for urban spatial expansion are widespread over the valley floor, the adjacent bajada, and the mountain blocks. These anthropogenic activities have remarkably induced strong wind erosion of the soil in severe arid conditions in the middle zone of Wadi Fatmah and Wadi Ash Shumaysi. Wind erosion has eventually produced a sufficient sand budget to be transported into the areas of sand accumulation. The primary consequence of the excess sand budget has been an increase in the spatial extents and dune migration rates of sand accumulations in the study area. However, this increase varies from one sand accumulation to another. In this study, we used multi-source remote sensing imagery and the state-of-the-art COSI-Corr technology to characterize sand accumulations in the study area and to determine the spatio-temporal changes in both the spatial extents and the dune migration rates. The mean annual migration rates of sand dunes in the three sand accumulations ranged from 5.5 and 7.2 to 8.6 m/yr. Analysis of the spatial extent and migration rates of sand accumulations indicates that the study area may have experienced desertification in response to changes in the anthropogenic regimes through the last few decades.
... Restricting the dis- cussion to quartz grains, eolian dunes composed of predominantly coarse sand have been described from several cold-climate settings such as Colorado in the United States (Ahlbrandt, 1979;, the east side of Hudson Bay in Canada ( Ruz and Allard, 1995), and the coasts of England and Denmark (Knight et al., 1998;Saye and Pye, 2006;Clemmensen et al., 2007). Eolian sand sheets and (or) wind ripples composed of coarse sand to granule size grains have been described from several cold-climate settings such as Colorado (Andrews, 1981), various locations in Canada (Cailleux, 1974;Good and Bryant, 1985;McKenna-Neuman and Gilbert, 1986;McKenna Neuman, 1990;Germain and Filion, 2002), Greenland (Willemse et al., 2003), Scotland (Ballantyne and Whittington, 1987), and Antarctica (Calkin and Rutford, 1974;Selby et al., 1974;Ackert, 1989;Gillies et al., 2012). ...
The Carolina Sandhills is a physiographic region of the Atlantic Coastal Plain province in the southeastern United States. In Chesterfield County (South Carolina), the surficial sand of this region is the Pinehurst Formation, which is interpreted as eolian sand derived from the underlying Cretaceous Middendorf Formation. This sand has yielded three clusters of optically stimulated luminescence ages: (1) 75 to 37 thousand years ago (ka), coincident with growth of the Laurentide Ice Sheet; (2) 28 to 18 ka, coincident with the last glacial maximum (LGM); and (3) 12 to 6 ka, mostly coincident with the Younger Dryas through final collapse of the Laurentide Ice Sheet. Relict dune morphologies are consistent with winds from the west or northwest, coincident with modern and inferred LGM January wind directions. Sand sheets are more common than dunes because of effects of coarse grain size (mean range: 0.35-0.59 mm) and vegetation. The coarse grain size would have required LGM wind velocities of at least 4-6 m/sec, accounting for effects of colder air temperatures on eolian sand transport. The eolian interpretation of the Carolina Sandhills is consistent with other evidence for eolian activity in the southeastern United States during the last glaciation. Published by Elsevier Inc. on behalf of University of Washington.
... This process has been followed by researchers to measure the migrations rates of sand dunes in many geographic regions over the world. The majority of these studies have been carried out on barchan dunes (e.g., Finkel, 1959;Merk, 1962;Long and Sharp, 1964;Calkin and Rutford, 1974;Wiegand, 1977;Maxwell and Vance Haynes, 2001;Aql, 2002;El-Banna, 2004;Mitasova et al., 2005;Bourke et al., 2009). Similar, but very limited studies have been carried out on the linear dunes in many regions of the world (Tsoar, 1978;El-Banna, 2004;Tsoar et al., 2004). ...
... The well-rounded sand grains found in Facies 4S are consistent with aeolian transport, as in the McMurdo Dry Valleys of Antarctica ( Fig. 3C; Calkin & Rutford, 1974;Hambrey & Fitzsimons, 2010). However, grains with a long history of aeolian transport can be finally deposited in aeolian, fluvial or lacustrine settings. ...
The Marinoan panglaciation (ca 650 to 635 Ma) is represented in north-east Svalbard by the 130 to 175 m thick Wilsonbreen Formation which contains syn-glacial carbonates in its upper 100 m. These sediments are now known to have been deposited under a CO2-rich atmosphere, late in the glaciation, and global climate models facilitate testing of proposed analogues. Precipitated carbonates occur in four of the seven facies associations identified: Fluvial Channel (including stromatolitic and intraclastic limestones in ephemeral stream deposits); Dolomitic Floodplain (dolomite-cemented sand and siltstones, and microbial dolomites); Calcareous Lake Margin (intraclastic dolomite and wave-rippled or aeolian siliciclastic facies); and Calcareous Lake (slump-folded and locally re-sedimented rhythmic/stromatolitic limestones and dolomites associated with ice-rafted sediment). There is no strong cyclicity, and modern analogues suggest that sudden changes in lake level may exert a strong control on facies geometry. Both calcite and dolomite in stromatolites and rhythmites display either primary or early diagenetic replacive growth. Oxygen isotope values (-12 to +15‰VPDB) broadly covary with δ13C. High δ13C values of +3·5 to +4·5‰ correspond to equilibration with an atmosphere dominated by volcanically degassed CO2 with δ13C of -6 to -7‰. Limestones have consistently negative δ18O values, while rhythmic and playa dolomites preserve intermediate compositions, and dolocretes possess slightly negative to strongly positive δ18O signatures, reflecting significant evaporation under hyperarid conditions. Inferred meltwater compositions (-8 to -15·5‰) could reflect smaller Rayleigh fractionation related to more limited cooling than in modern polar regions. A common pseudomorph morphology is interpreted as a replacement of ikaite (CaCO3·H2O), which may also have been the precursor for widespread replacive calcite mosaics. Local dolomitization of lacustrine facies is interpreted to reflect microenvironments with fluctuating redox conditions. Although differing in (palaeo)latitude and carbonate abundance, the Wilsonbreen carbonates provide strong parallels with the McMurdo Dry Valleys of Antarctica.
... In a study of Antarctic dunes, Calkin and Rutford (1974) determíned that a threshold of nearly twice that was needed for moist sand. ...
Describes density and stratification in lakes, distal glacier fed lakes and ice-contact lakes. The deposits are then described in terms of the sedimentary process, and dispersal mechanisms, stratification in lakes, the recognition of lake types, and spatial and temporal variations in sedimentation.-K.Clayton
... Dong et al. (2003) recognized cementation in large megadunes in the Badain-Jaran desert and argued that vegetation and cementation by calcium deposits promotes dune fixation. Subsurface ice-cemented layers in sand and snow Antarctic dunes may strongly influence the humidity balance between snowmelt and vapor transfer and fixate dunes temporarily (Calkin & Rutford 1974). ...
The current research presents ground penetrating radar images up to 30 m
in depth of two large desert dunes in California, USA— a
barchanoid ridge in the Dumont field and a linear dune in the Eureka
expanse. The radar images show a complicated structure of internal
layering with ascending cross-strata, cross-bedding and bounding
surfaces cutting through layers. Additional research using seismic
refraction surveys and sand sampling refine the image of the subsurface
(<5 m) structure. The sedimentary structure of the dune shows a
strong internal layering with a cemented structure that may immobilize
and influence migration of dune expanses. The subsurface features of the
sand dune fields in the Mojave Desert provide evidence of dune building,
wind regime and precipitation history.
... Where lee slope sand deposition was rapid, some of these slumped snow cornices were buried, at least temporarily, within the dune ( Steidtmann, 1973). Most denivation features and bedforms are ephemeral or annual in nature, but perennial niveo-aeolian deposits and snowrelated deformation structures in Victoria Valley, Antarctica, also have been described ( Calkin and Rutford, 1974;Bourke et al., 2009;Bristow et al., 2010). Koster (1988) suggested that denivation features are preserved in aeolian strata only under specific conditions, such as a unimodal wind regime and/or high migration rates. ...
We observed niveo-aeolian deposits, denivation features, and small meltwater-induced debris flows that had formed at the Great Kobuk Sand Dunes, northwestern interior Alaska in late March 2010. This high-latitude, cold-climate dune field is being studied as a planetary analog to improve our understanding of factors that may trigger debris flows on the lee slopes of martian aeolian dunes. Debris flows consisted of a sand and liquid water mixture that cascaded down the lee slopes of two barchanoid dunes on days when measured ground surface temperatures were below freezing. We hypothesize that relatively dark sand on snow caused local hot spots where solar radiation could be absorbed by the sand and conducted into the underlying snow, enabling meltwater to form and sand to be mobilized. This investigation provides insights into the interactions between niveo-aeolian deposition, slope aspect and insolation, thawing, and initiation of alluvial processes. These debris flows are morphologically similar to those associated with seasonal gullies or erosion tracks visible on the slopes of mid- to high-latitude dune fields in both martian hemispheres. Localized heating and thawing at scales too small for orbital sensors to identify may yield martian debris flows at current climate conditions.
... Evidence for aeolian processes is widespread throughout the Dry Valleys (Malin, 1991;Morris et al., 1972). Ventifacts are common and the Victoria Valley has extensive areas of sand dunes and sand sheets (Calkin and Rutford, 1974). Wind action is believed to be the main process redistributing organic matter to Dry Valleys soils (Moorhead et al., 1999). ...
Field experiments on boundary layer winds and sand transport in the Victoria Valley, Antarctica have provided information on the spatial and temporal variability of sand transport across coarse sand surfaces covered with isolated roughness elements (rock clusters). Five sand transport events, with a duration ranging between 9.6 and 22 h, were studied. Sand transport threshold velocity was determined using the time faction equivalence method and varied between 0.30 and 0.35 m s-1. Mean rates of sand transport ranged from 0.008 to 0.072 g cm s-1. Sand transport was variably intermittent, with continuous saltation (intermittency (gamma) = 1) occurring from 11% to as much as 31% of the time. For all events, there is a close temporal correspondence between intermittency values, shear velocity (u*, m s-1) and the ratio u*/u*t (u*t is threshold shear velocity), sand flux, and sand transport intensity as measured by piezoelectric saltation sensors. Although the roughness density of this site is low, partitioning of shear stress between the rock clusters and the intervening sand surface is important to the spatial pattern of sand transport and acts to increase the mean threshold wind shear velocity or shear stress for sediment transport by approximately 1.2 times compared to a bare sand surface. The effective local threshold wind shear velocity, however, varies by up to 6 times from the smoother sand areas to the most protected areas of the rock clusters. As a result, continuous and widespread sand transport will only occur at this site when the overall wind shear velocity exceeds 0.58 m s-1 (1.6 × u*t minimum).
... comm.). In the specific case of Victoria Valley, sand dunes are believed to be mostly inherited from sandstone units of the Beacon Supergroup (e.gCalkin and Rutford, 1974). Among samples from the IH group we selected only one sample collected from the top of Sequence Hills about 2635 m a.s.l., consisting of regolith developed on Ferrar dolerite, at a site characterized by evident tors and abundant sandy sediments. ...
... A instalação de condições de sedimentação desérticas, em trato de sistemas glaciais, é bastante comum. Regiões periglaciais apresentam condições ideais para o transporte eólico, como ausência de vegetação, ventos constantes e disponibilidade de sedimentos erodidos (Schultz & Frye 1968, Flint 1971 e Calkin & Rutford 1974). Os sistemas desérticos periglaciais produzem os mesmos tipos de depósitos e estruturas dos desertos de baixas latitudes. ...
STRATIGRAPHY AND SEDIMENTATION OF THE SANFRANCISCANA BASIN: A REVIEW This paper presents a stratigraphic and depositional systems review to the Phanerozoic cover of the São Francisco Craton, defined as the Sanfranciscana Basin. The Phanerozoic cover is composed mainly of sedimentary continental rocks and minor explosive volcanic rocks. The stratigraphy and sedimentology of the Phanerozoic successions are summarized as follows: Santa Fé Group (Carboniferous-Permian) -divided into Floresta and Tabuleiro formations. This glaciogenic sequence represents the gondwanan glaciation record in the Sanfranciscana Basin. These sediments are preserved in valleys excavated in the basement and crop out in most of the basin . Areado Group (Early Cretaceous) -constituted by the Abaeté, Quiricó and Três Barras formations, characterized by lateral and vertical interfingerings. The Abaeté Formation was deposited by braided stream and the in southern area by alluvial fans; the Quiricó Formation records a lacustrine sedimentation. and the Três Barras Formation, was deposited in the fluvial, fluviodeltaic and aeolian environments. The Areado Group is thick in southern portion of the basin (200 meters); it is less than 60 meters and discontinous in the central-northern areas. Mata da Corda Group (Late Cretaceous) -composed by the Patos and Capacete formations. The Patos Formation is composed by alkaline volcanic rocks. The Capacete Formation represents the distai epiclastic sediments with important aeolian sand contribution. It is present only in the southern sector of the basin. Urucuia Group (Late Cretaceous) -composed of sandstones, divided into Posse (with Facies l e 2) and Serra das Araras formations, respectively interpreted as dry field dune deposits, braided stream of channelized deposition and braided stream deposited by sheet flows. It is present in the entire basin. In the southern portion of the basin, it is recovered by volcaniclastic sediments, and in the northern area it becomes the most important unit. Chapadão Formation (Quaternary), represents the recent sandy, unconsolidated, covers of talus, residual or alluvium origin. Provenance studies show the following transportation vectors and source areas: Santa Fé Group -NE to S W transport, with source areas in Northern Espinhaço Range and in the Bambuí Group; Areado Group -transport from the adjacent elevated blocks, showing important axial flow; Urucuia Group -transport from NEE to SWW, with sources in the northest São Francisco Craton and the Capacete Formation -showing two directions of transport: volcanic rocks from South to North and aeolian sand from NE to SW.
... Therefore, in the periods of high obliquity, for example, sufficient warming on pole-facing slopes may melt near-surface ice deposits and increase pore pressure near the surface. Explanations for the origin of the near-surface ice include: (1) diffusion from the atmosphere [Mellon and Jakosky, 1995] (2) burial of precipitated snow and frost layers by rapidly aggrading sand layers [Calkin and Rutford, 1974;Bourke et al., 2004] (3) Blown snow transported simultaneously with sedimentary particles and deposited as niveo-aeolian deposits [McKenna Neuman, 1993;Bourke et al., 2004]. ...
Gullies that dissect sand dunes in Russell impact crater often display
debris flow-like deposits in their distal reaches. The possible range of
both the rheological properties and the flow rates are estimated using a
numerical simulation code of a Bingham plastic flow to help explain the
formation of these features. Our simulated results are best explained by
a rapid debris flow. For example, a debris flow with the viscosity of
102 Pa s and the yield strength of 102 Pa can form
the observed deposits with a flow rate of 0.5 m3/s sustained
over several minutes and total discharged water volume on the order of
hundreds of cubic meters, which may be produced by melting a surface
layer of interstitial ice within the dune deposits to several
centimeters depth.
... Another influence will be the presence of niveo-aeolian deposits. In polar deserts on Earth, sand dunes may have permafrost cores and/or contain sand layers interbedded with snow and ice [Calkin and Rutford, 1974;McKenna Neumann, 2004;Steidtmann, 1973]. We are investigating the potential for niveo-aeolian dune deposits on Mars in ongoing research [e.g., Bourke et al., 2004]. ...
Interaction between wind regimes and topography can give rise to complex
suites of aeolian landforms. This paper considers aeolian sediment
associated with troughs on Mars and identifies a wider range of deposit
types than has previously been documented. These include wind streaks,
falling dunes, ``lateral'' dunes, barchan dunes, linear dunes,
transverse ridges, sand ramps, climbing dunes, sand streamers, and sand
patches. The sediment incorporated into these deposits is supplied by
wind streaks and ambient Planitia sources as well as originating within
the trough itself, notably from the trough walls and floor. There is
also transmission of sediment between dunes. The flow dynamics which
account for the distribution of aeolian sediment have been modeled using
two-dimensional computational fluid dynamics. The model predicts flow
separation on the upwind side of the trough followed by reattachment and
acceleration at the downwind margin. The inferred patterns of sediment
transport compare well with the distribution of aeolian forms. Model
data indicate an increase of wind velocity by ~30% at the downwind
trough margin. This suggests that the threshold wind speed necessary for
sand mobilization on Mars will be more frequently met in these inclined
locations.
... Vegetation on terrestrial dunes can anchor the edges of barchan and transverse dunes, allowing them to flip in orientation and turn into parabolic dunes [McKee, 1979]; obviously, this process is not observed on Mars. Snow and ice can effectively freeze dunes during the winter in high latitude dune fields on Earth [e.g., Calkin and Rutford, 1974]. Similarly, the seasonal ice caps likely play a role in stabilizing dunes on Mars. ...
No sand transport pathways are visible in a study performed in Noachis Terra, a 60° x 35° region in the southern highlands of Mars known for its many intracrater dune fields. Detailed studies were performed of five areas in Noachis Terra, using Mars Orbiter Camera (MOC) wide-angle mosaics, Thermal Emission Imaging System (THEMIS) daytime and nighttime infrared mosaics, MOLA digital elevation and shaded relief maps, and MOC narrow-angle images. The lack of observable sand transport pathways suggests that such pathways are very short, ruling out a distant source of sand. Consistent dune morphology and dune slipface orientations across Noachis Terra suggest formative winds are regional rather than local (e.g., crater slope winds). A sequence of sedimentary units was found in a pit eroded into the floor of Rabe Crater, some of which appear to be shedding dark sand that feeds into the Rabe Crater dune field. The visible and thermal characteristics of these units are similar to other units found across Noachis Terra, leading to the hypothesis that a series of region-wide depositional events occurred at some point in the Martian past and that these deposits are currently exposed by erosion in pits on crater floors and possibly on the intercrater plains. Thus the dune sand sources may be both regional and local: sand may be eroding from a widespread source that only outcrops locally. Sand-bearing layers that extend across part or all of the intercrater plains of Noachis Terra are not likely to be dominated by loess or lacustrine deposits; glacial and/or volcanic origins are considered more plausible.
... Evidence for aeolian processes is widespread throughout the Dry Valleys (Malin, 1991;Morris et al., 1972). Ventifacts are common and the Victoria Valley has extensive areas of sand dunes and sand sheets (Calkin and Rutford, 1974). Wind action is believed to be the main process redistributing organic matter to Dry Valleys soils (Moorhead et al., 1999). ...
Studies of boundary-layer winds and surface roughness characteristics of unvegetated rocky desert surfaces provide new insights into the relations between aerodynamic roughness and surface roughness, as described by the roughness density (λ). The description of non-erodible roughness by the roughness density (λ) is shown to be valid for rocky surfaces as well as sparsely vegetated surfaces and simulated surfaces in a wind tunnel. There is a good relation (r2 = 0·71) between aerodynamic roughness and roughness density (λ), allowing use of the threshold friction velocity ratio to predict sediment transport rates on these surfaces. Copyright © 2004 John Wiley & Sons, Ltd.
... Sand wedges, however, may form not only in the permafrost but also in seasonally frozen ground (Murton et al., 2000). In their study of sand dunes in Victoria Valley, Antarctica, Calkin and Rutford (1974) documented that sand wedges can form when snow or ice are interbedded with gravely sediment. Sand wedges in Bass Lake pit are younger than 16 ka and because they appear as isolated bodies they were seasonal features which developed in cold winter weather rather than in continuous permafrost. ...
The Fair Oaks Dunes (FOD) of NW Indiana, USA is a large (~ 4500 km2) inland dune field associated with the late Wisconsin deglaciation of the Laurentide Ice Sheet. Meltwaters released by the Michigan, Saginaw, and Huron–Erie lobes transported fluvioglacial sediment through the Kankakee and Tippecanoe Valleys and their tributaries. The texture and composition of the sand in the FOD suggest a Saginaw Lobe origin of sediment with some Huron–Erie Lobe sediment. Sub-mature sand with sub-angular grains and a large feldspar content suggests relatively short distance of transport during two or possibly three dune-building and dune reworking events. We propose a model which explains the development of the dunes in three stages. Dune development began during the Bølling–Allerød (stage 1, ~ 15–13 ka) interval. During this stage anticyclonic easterly and north-easterly winds deflated the sand from outwash deposits and built transverse and barchanoid dunes on the western sides of the Tippecanoe Valley and paleo-channels. Further downwind, on the western and southwestern windward margins of the FOD, loess was deposited. During the early Younger Dryas (stage 2, ~ 12.5 ka) atmospheric circulation changed, and westerly winds reworked the original dunes to create a great variety of parabolic dunes. Simple, hemicyclic and lobate parabolic dunes developed in the western FOD, while further downwind, in the eastern and the southern FOD, more elongated hairpin and windrift dunes developed. On the upwind side of the dune field, loess deposits remained stable and were not remobilized during the second stage dune development. By the early Holocene the FOD dunes were stabilized until their minor remobilization during the Middle Holocene (stage 3). Minor disturbances caused by anthropogenic activities have occurred in last two centuries.
An abraded landscape forms predominantly by the mechanical wear of coherent material by saltating sand grains, with deflation removing particles and soils by wind shear. Abraded systems range from small wind-scoured areas to the vast landscape assemblages of the Sahara Desert and the planet Mars. Landforms include ventifacts, yardangs, deflation basins, and inverted terrain. Wind-abraded landscapes require strong and generally sustained winds, abrasive sediment, and sparse vegetation. These conditions occur in desert, cold (periglacial and paraglacial), and coastal environments, with the most extensive features on Earth formed in the hyperarid environments of Asia and Africa. Many of the same landforms occur on Mars.
Glacioaeolian processes, sediments, and landforms are a critical component of glacial and periglacial systems. Their forms range from extensive dune systems, cover samples, thick loess successions, to thin veneers of silts and sands that drape glacial and periglacial landforms, and erosion surfaces. Glacioaeolian processes may be found in environments more distal from the glacial settings such as in the loess deposits of the United States, Western Europe, South America, and Central Asia. The glacioaeolian system involves sediment production by chemical and physical weathering of rock and abrasion of rock and sediment by transporting agents, notably glaciers, wind, and water. This is followed by sediment transfer and deposition by aeolian processes. Sediment transfer and deposition are strongly controlled by climatic perturbations; e.g., rates of glacioaeolian sediment deposition, most notably glacial loess, occur during glaciation at its height.
The Carolina Sandhills is a physiographic region of the Atlantic Coastal Plain province in the southeastern United States. In Chesterfield County (South Carolina), the surficial sand of this region is the Pinehurst Formation, which is interpreted as eolian sand derived from the underlying Cretaceous Middendorf Formation. This sand has yielded three clusters of optically stimulated luminescence ages: (1) 75 to 37 thousand years ago (ka), coincident with growth of the Laurentide Ice Sheet; (2) 28 to 18 ka, coincident with the last glacial maximum (LGM); and (3) 12 to 6 ka, mostly coincident with the Younger Dryas through final collapse of the Laurentide Ice Sheet. Relict dune morphologies are consistent with winds from the west or northwest, coincident with modern and inferred LGM January wind directions. Sand sheets are more common than dunes because of effects of coarse grain size (mean range: 0.35–0.59 mm) and vegetation. The coarse grain size would have required LGM wind velocities of at least 4–6 m/sec, accounting for effects of colder air temperatures on eolian sand transport. The eolian interpretation of the Carolina Sandhills is consistent with other evidence for eolian activity in the southeastern United States during the last glaciation.
Quaternary dune fields are widespread throughout high-latitude regions of the Northern Hemisphere including Canada, Alaska, Europe, and Russia. Much of North America north of approximately 45� N latitude, and Europe north of 50� N latitude, was glaciated during the late Quaternary (Wisconsin and Weichselian glacial period, respectively). Most of these areas also presently experience seasonal cold climate conditions, though there are few large dune fields active today. Cold-climate eolian conditions presently occur in Antarctica, though the few dune fields there are small.
Dune activity is largely controlled by a combination of the three interacting factors of transport capacity (i.e., windiness), sediment supply, and sediment availability. Sediment supply represents the total amount of sandy source material, whereas sediment availability represents the proportion of unprotected, sandy material, i.e., that available for transport, and may be reduced by vegetation cover, moisture, snow, ice, surface lag deposits, and other factors. In high latitudes, sediment supply appears to be the limiting factor on the size of dune fields. Individual dune fields in high latitudes are rarely larger than a few 100km2, owing to the relatively
small amount of sediment. In comparison, sediment availability, as influenced by the amount of vegetation cover, appears to be a significant control on the degree of dune activity in high latitudes. Transport capacity is also a factor, as high-latitude continental areas may have been windier during late-glacial and early Holocene times than they are today.
An abraded landscape forms predominantly by the mechanical wear of coherent material by saltating sand grains, with deflation removing particles and soils by wind shear. Abraded systems range from small wind-scoured areas to the vast landscape assemblages of the Sahara Desert and the planet Mars. Landforms include ventifacts, yardangs, deflation basins, and inverted terrain. Wind-abraded landscapes require strong and generally sustained winds, abrasive sediment, and sparse vegetation. These conditions occur in desert, cold (periglacial and paraglacial), and coastal environments, with the most extensive features on Earth formed in the hyperarid environments of Asia and Africa. Many of the same landforms occur on Mars.
High-latitude dune fields are widespread throughout northern North America, Europe, and Russia. Although most dune fields are presently stabilized, many were active during the Late Glacial periods (Late Wisconsin of North America and Late Weichselian of Europe), soon after ice retreat and deposition of sandy source sediment, and continuing into the early Holocene. Sporadic mid-to-late Holocene dune activity has occurred as a result of changing climatic and geomorphic conditions, as well as localized disturbances by fire, animals, or human activity. High-latitude dune fields are small compared to more southerly dune fields, owing to the finite supplies of sandy source deposits derived mostly from glacigenic sediments. The most pervasive dune type in high latitudes is the parabolic dune, although transverse, longitudinal, and, more rarely, barchanoid dunes also occur. Blowouts are common where eolian activity is restricted to localized areas. High-latitude dunes are instructive with respect to paleoenvironments, as their morphology and stratigraphy may be used to determine past wind directions and regional circulation patterns. Episodes of past dune activity are also informative, as they may be linked to periods of low-vegetation cover or increased sediment input tied to abrupt changes in climate, sedimentary processes, or other disturbances.
An approximately 25-m thick sequence of dune and interdune strata exposed at Clear Creeek in south-central Wyoming records arid to semi-arid paleoclimatic fluctuations spanning approximately the last 7500 years. The Clear Creek strata are subdivided into six informal chronostratigraphic intervals that bracket climatically-distinctive episodes of dune and interdune sedimentation and are constrained chronologically by 14C dates. At least four episodes of enhanced eolian activity that reflect increased aridity are recorded in the Clear Creek strata. -from Author
DefinitionSedimentological and morphological features generated by the melting and/or sublimation of snow and ice incorporated into surface sediments, most commonly in aeolian bedforms.DescriptionCold-climate dune fields often contain interbedded sand, snow, and ice. These mixed deposits of wind-driven sand and snow are defined as niveo-aeolian deposits by Cailleux (1974, 1978) and were reviewed by Koster (1988) and Koster and Dijkmans (1988). As the snow and ice progressively ablate, these deposits are reworked and locally redeposited (French 2007). The lee slopes (or slip faces) of large aeolian dunes serve as a catchment for layers of wind-drifted niveo-aeolian deposits; such layers may be several meters thick. The sedimentological and morphological disturbances resulting from postdepositional temperature increases that cause the melting and/or sublimation of snow and ice are referred to as denivation features or bedforms (Cailleux 1974; Koster and Dijkmans 1988; French 2007). Simil ...
Extensive and thick sand accumulations, containing organic-rich horizons, at Blue Mountain, Falkland Islands, are most probably derived from weathering of local bedrock under late Pleistocene periglacial conditions. Weathering and subsequent deflation produced several shallow basins that are now occupied by lakes. Sand morphology, sedimentary structures and site characteristics indicate that the sand deposits are predominantly aeolian, although some alluvial sands are also present. Deflation occurred either before the lakes existed or at times of lower lake levels. Sixteen 14C dates from organic- rich horizons show that some sand accumulated in the early Holocene or late Pleistocene, but that most is of mid- to late Holocene age. Landscape stability/instability phases were not synchronous between sites and cannot be explained by the regional trends of Holocene climate change. A period of significantly lower lake levels and major aeolian erosion at c. 5000-4500 BP is proposed, but is not supported by regional evidence of greater warmth and/or aridity. More environmental data concerning periods of increased aridity and windiness are required before the relationship between landscape evolution and climatic change can be established.
At the global scale the largest coastal dunes formations are locatd on exposed windward coasts where large reserves of beach sand are well sorted by wave action. The physics of eolian sand transport is outlined, and the factors controlling dune morphology are reviewed. There is a section on the sediment with comments on weathering and diagenesis. The final section discusses the factors controlling dune stability and instability.-K.Clayton
Land surfaces in southern Victoria Land, Antarctica, totally devoid of vegetation, are actively sculptured by winds that often reach velocities of more than 100 km/h. Deflation and abrasion are thus key factors in the process of slope formation. Water erosion, active only during the short summer period, is limited to a few localities. Experiments in a wind tunnel proved that ventifacts in the Dry Valleys can be formed within a few decades or, at most, a few centuries. Yearly abrasion rates average a few millimeters. Considerable variability is caused by the different exposures of the ventifacts within the microrelief and by varying rock resistance. The importance of ice crystals (snow) as an abrasive agent should not be overestimated. (The translation is by William Ban of the University of Saskatchewan, Saskatoon.)
: The landscape in the vicinity of Scott Base is one of the most singular of landscapes in the already unique environment of the Ross Sea Region of Antarctica. A rich history of human endeavour together with a broad range of physical features such as volcanoes, various glacial landforms, polar beaches and the Dry Valleys with their own glaciers, sand dunes and patterned ground must make it one of the most fascinating areas on earth. This paper highlights some of the more notable of these landscape features.
Many studies have been carried out on coastal dunes of mid-latitude regions, but little is known about cold-climate coastal dunes. Coastal dunes that have developed in arctic and subarctic environments usually are described as minor aeolian accumulation features, but they occur widely along arctic and subarctic coastlines. In the Arctic, aeolian deflation is a common phenomenon and coastal dunes are less developed than in subarctic environments. Short open-water duration, coarse beach sediment, and sparse vegetation cover are factors explaining the limited coastal dune development of arctic regions. In subarctic settings, niveo-aeolian sedimentation is a major process contributing to coastal dune development. Quantitative and qualitative studies still are needed for a better understanding of the mechanisms of coastal-dune development in cold-climate environments. [Key words: coastal dunes, arctic, subarctic, coastal geomorphology].
The importance of glacigenic dust in the Earth's system during glacial periods is widely acknowledged. Under contemporary conditions, the world's largest dust sources are in low-lying, hot, arid regions and this is where most aeolian research is focused. However the processes of dust production and emissions are still operating in cold climate regions, particularly in proglacial areas. This paper assesses current understanding of the relationship between glacierised landscapes and dust emissions and inputs to the global dust cycle. It focuses on how elements in the glacial and aeolian geomorphic sub-systems interact to determine the magnitude, frequency and timing of aeolian dust emissions, and on feedback mechanisms between the systems. Where they have been measured, dust emission intensity and deposition rates in glacierised catchments are very high, in some cases far exceeding those in lower latitudes, however, few studies span long time scales. The impact of future glacier retreat on the balance between sediment supply, availability and aeolian transport capacity and implications for glacigenic dust emissions is also considered. This balance depends on relative spatial and temporal changes in meltwater suspended sediment concentration and wind strengths, which promote dust emissions, and patterns and rates of soil development and vegetation succession on recently-deglaciated terrain which protect sediments from deflation. Retreat of the Antarctic ice sheet could mean that in future glacigenic contributions to the dust cycle exceed those of non-glacigenic sources in the southern hemisphere. Copyright © 2012 John Wiley & Sons, Ltd.
During the 2011–2012 austral summer, we had the opportunity to verify a surficial geology map prepared nearly 50 years ago for the Victoria Valley system (VVS), the largest of the McMurdo Dry Valleys. We used high-resolution landsat images and a digital elevation model to identify landforms and prepare detailed maps of each of the five valleys in the VVS, including lateral and end moraines, rock glaciers, gelifluction sheets, gravel ripples, and hummocky and ice-cored drifts. Our mapping suggests that the Bull drift is less extensive than previously thought, attains a maximum elevation of ~ 750 m in Balham and Barwick Valleys and the upper Bull Pass region, and does not occur in McKelvey Valley. We found Insel drift to 850 m elevation in eastern McKelvey Valley and upper Bull Pass and were able to trace Insel drift down Bull Pass where it becomes Peleus drift in Wright Valley. The Victoria Lower Glacier likely responded to grounding of ice in the Ross Embayment and was out-of-phase with alpine glaciers elsewhere in the VVS. We amplified and quantified Calkin's relative chronology and provide here our multiple-parameter relative chronology for the McMurdo Dry Valleys that is based on surface-boulder weathering, soil weathering, salt stage, degree of development of the desert pavement, and form of patterned ground. Except for Victoria Lower Valley, we correlate Packard drift with Taylor II drift (ca., 120 ka), Vida drift with Taylor III drift (ca., 300 ka), Bull drift with Taylor IVb drift (2.7–3.5 Ma, and Insel drift with Peleus drift (> 3.7 Ma, < 5.4 Ma). The lack of a strong correlation between soil salt stage and depth of visible salts with elevation leads us to question whether a high-level lake (ca., 200 m deep) existed in the VVS during the early Holocene.
The present‐day periglacial zones of the polar regions in both hemispheres have many features in common, caused by the peculiarities of climate, glaciological and geocryological processes, and the geomorphology of the periglacial regions. On the other hand, there exist essential differences in the general appearance of the periglacial zones in the Northern and Southern hemispheres, related mainly to particular features of continental glaciation. An analysis of the literature and of data from the author's field observations have allowed him to reach some conclusions as to the major features of the geocryology of the polar regions: the thickness, distribution, temperature, and cryogenic structure of the permafrost and of seasonally frozen materials and the ground ice and cryogenic relief of these areas. This, in turn, made it possible to identify a geocryological zonation of the polar regions and to advance a new concept as to the present‐day periglacial zone.
Aeolian sand transport during winter and the snow-free season was assessed quantitatively by direct year-round field measurements along transects on the lee side of parabolic dunes in subarctic Québec. In 1987–1988, niveo-aeolian deposition was more important than aeolian sedimentation in three of the four study sites, and contributed > 75% of the total annual accumulation in exposed sites and < 25% in protected forest sites. The maximum depth of interstratified snow and sand deposits (3.5 m) was recorded in March. Semi-permanent snow lenses may persist longer than 2 years in the aeolian sediments. After dissipation of snow, 22 cm of sand (as a maximum) accumulated on the slipface of the most active dunes, whereas only minor sand accumulation occurred in distant areas from active sand erosion. Wind-driven sand was dispersed over 7.4 km2 in the Whapmagoostui-Kuujjuarapik area. The acumulation of snow and sand during the snow season, together with spring thaw and collapse of the niveo-aeolian deposit, caused different types of injuries to trees, especially in 1985 and 1987 when a maximum of torn branches was recorded over the last 10 year period.
The geomorphology, lithology and chronostratigraphy of extensive, late Pleistocene inland and river dune sands, aeolian sand sheets (‘cover sands’) and loess deposits of periglacial origin in northwestern Europe are well known. However, the idea that some of these aeolian sediments result from niveo-aeolian processes is still an open question, as no diagnostic sedimentary features have yet been reported. Moreover, actual niveo-aeolian sediments and related denivation forms, reported from various cold-climate regions, are not suitable analogues. Recent observations in active dune fields in northwestern Alaska indicate that interstratification of wind-driven snow and sand preferentially occurs on slip faces of transverse, barchanoid or parabolic dune ridges. Annual denivation forms develop: e.g. snow ramparts, sinkholes, snow hummocks, snow meltwater fans and tensional cracks. The surface consists of a cracked wet sand layer with a dimpled surface and spongy structure. Although the preservation potential of these features is low in this specific case, similar features may be observed in ancient sediments elsewhere and provide useful palaeoclimatic indicators. The niveo-aeolian concept should therefore not specifically be related to late Pleistocene cover sand deposition in northwestern Europe, as previously assumed.
Although partly active aeolian sand sheets and dunes cover large areas in the zones of (dis)continuous permafrost, little precise information is available about the influence of cold-climate conditions on modern aeolian processes. This means that palaeoenvironmental reconstructions in the stabilised, mainly Late Pleistocene dune fields and cover sand regions in the ‘sand belts’ of the European Lowlands and the Northern Great Plains of the USA and Canada, are necessarily still based on ancient evidence. Cold-climate wind deposits are typically derived from areas of abundant sediment supply like unvegetated flood plains, glacial outwash plains, till plains and lake shores. The common parabolic and transverse dune forms resemble those observed in temperate regions. Although a variety of periglacial features has been identified in Late Pleistocene dune and cover sands none of them indicate that permafrost is crucial to aeolian activity. Specific structures in aeolian strata permit tentative interpretation of the moisture content of depositional sand surfaces, the nature of annual sedimentation cycles and the processes by which strata were deposited and/or contorted. But surprisingly little is known about the role of vegetation in the process of sand accumulation. Dunes are most informative with respect to reconstructions of past wind regimes, which offer important data for verification of palaeoclimatic simulations.
The impact of modern cold glaciers on arid periglacial landscapes has received little attention compared with other glacial regimes, and there is a widely held assumption that cold glaciers are not effective geomorphological agents, despite recent studies to the contrary. This paper focuses on the processes operating at the margins of a number of glaciers in the Dry Valleys of Victoria Land, notably the Wright Lower Glacier. The glaciers are entraining primarily older drift deposits and highly weathered regolith which texturally are sandy gravels, as well as well-sorted sands of fluvial origin. Despite basal temperatures of the order of −16°C, frozen layers and blocks of sand and gravel are being incorporated into the base of the glaciers by folding and thrusting. The sedimentary products are ridges and aprons several metres high within which the principal lithofacies are sand, gravel, foliated glacier ice, lake ice and snow. These facies are glaciotectonized strongly. Draped over these landforms is a veneer of well-sorted aeolian sand up to half a metre thick. Supraglacial streams flowing off the glaciers incise these landforms and the sediment is redeposited as alluvial fans, lake deltas and lake-bottomset deposits. Overall the sediment/landform association differs markedly from those of other glacial regimes, with sand and gravel being the dominant facies, while the usual indicators of glacier working (such as facets and striations on clasts) are lacking. The preservation potential for these landforms on a thousand-year time scale is high, as modification in this arid regime by slope processes and running water is limited. Sublimation of buried ice is so slow that ridge features are likely to remain ice-cored almost indefinitely, modified only by wind transport and weathering.
Observations from Taylor Valley, Antarctica, suggest that the wedging effect of sand particles, packed by powerful winds into cracks in rocks, may act as a weathering mechanism. The strong winds and their accompanying solid material may cause stresses to the rock in three ways: the direct pressure of the wind and material, the hammering effect of the particles, and by preventing the closure of cracks opened by other forces. Although crude estimations of the forces involved have been calculated, actual field measurements are needed. This is a process which may operate in other dry environmentson our planet ond possibly on some of the hyper-dry inner planets of our solar system.
We have determined the source area from which dusts from the Last Glacial Maximum (LGM) section of the Dome C ice core were derived, by comparing their strontium and neodymium isotopic ratios with those of samples from potential source areas. The87Sr/86Sr and143Nd/144Nd isotope ratios of the dusts deposited ≈ 18 k.y. B.P. at the East Antarctic Dome C site were compared with potential Antarctic, Australian, southern African and South American sources. The isotope ratios clearly define the Patagonian provenance of the dust, with the other potential source areas being, at most, minor contributors. Contributions by volcanic ash and tephra to the dust sample were also determined to be minimal, based on the patterns of rare earth elements. Knowing the source of the dusts places constraints on the aeolian trajectory by which it was transported to Antarctica, and this serves as a test of the simulation of southern hemispheric circulation by atmospheric global circulation models during the LGM.
The Lower Victoria Valley is one of the McMurdo Dry Valleys, Antarctica, and has the largest concentration of aeolian sand dunes on the continent. Aeolian bedforms include elongate slipfaceless dunes which have been called ‘whaleback’ dunes. These dunes are composed of coarse sand and capped by granule ripples. Ground penetrating radar (GPR) profiles across one of these dunes reveal low-angle inclined sigmoid/tangential and convex reflections that are interpreted as strata within the dune. These dipping strata record the migration of the whaleback dune and show that they are not sand mantles as previously described but are actively migrating, long-wavelength, low-amplitude bedforms resembling zibar. An 800 m profile along the axis of the dune reveals low-angle dips from west to east showing that the dune has accreted towards the east. GPR profiles collected at 100 m intervals transverse to the dune axis reveal sets of cross-stratification dipping towards the south at the eastern end of the dune and towards the north at its western end. These apparent dips are resolved to show that the dune has migrated from west to east, driven by westerly foehn winds and katabatic winds blowing from the Polar ice cap, whilst at the same time it has been building obliquely towards the south. Accretion towards the north at the western end of the dune is attributed to reworking of the dune sand by easterly winds blowing inland from McMurdo Sound. An unconformity within the dune suggests that the wind regime has varied in the past. Beneath the unconformity the direction of dune migration was from west to east, and eastward extension of the dune continues at the present day. However, this is combined with accretion towards the north and west at the western end of the dune which is not recorded in the older sediments beneath the unconformity. Sand wedge structures that may have taken hundreds to thousands of years to form are found within the dune, and suggest that arid conditions suitable for dune construction have persisted in Victoria Valley for a considerable time.
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