Holocene, silty-sand loess downwind of dunes in Northern Michigan, USA

Schaetzl, Randall J.; Nyland, Kelsey E.; Kasmerchak, Chase; Breeze, Victoria; Kamoske, Aaron G.; Thomas, Sarah Ε.; Bomber, Michael; Grove, Leslie; Komoto, Kara; Miller, Bradley A.

doi:10.1080/02723646.2020.1734414

Cited by 4 publications

(6 citation statements)

References 68 publications

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“…Thus the distribution of loess is partly a function of topography and partly proximity to sand deposits and glaciofluvial sources. This situation is highly reminiscent of those in other areas of thin loess cover in association with sand, especially as recently documented by Schaetzl et al (2021) for Holocene dune‐proximal loess in northern Michigan. Here, too, loess was locally sourced and deposited on higher ground close to sand dunes at lower elevations, where it grades to finer grain sizes away from the dunes.…”

Section: Discussionsupporting

confidence: 56%

“…This observation perhaps implies sourcing of the loess sediments directly from tills or from material that has only been transported for a short distance by glaciofluvial processes, rather than far‐travelled glaciofluvial sediments or reworked material from the dunes themselves (e.g. Schaetzl et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…It is worth noting that at Gräshöjden especially, the relatively coarse size of the ‘loess’ sediments and geomorphic association with local sand dune ridges means these sediments are potentially better interpreted as a finer aeolian facies of sediments blown from nearby dune ridges, perhaps due to periodic dune destabilization (Figure 4) (e.g. Schaetzl et al, 2021). Indeed, at Finnhöjden, although the silt sediments are finer grained and closer to classic loess in texture (Figure 12), they also grade laterally into cover sands and ultimately dunes further downhill (Figure 4).…”

Section: Discussionmentioning

confidence: 99%

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Age, formation and significance of loess deposits in central Sweden

Stevens

Sechi

Tziavaras

et al. 2022

Earth Surf Processes Landf

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Loess deposits are common in the mid-latitudes and are excellent records of past climate, landscape change and dust. However, loess deposits are seldom reported from Fennoscandia. Here we investigate two former glaciofluvial areas in central Sweden, Brattforsheden and Bonäsheden, where post-glacial loess and sand dune activity have been documented previously. Based on detailed mapping, grain size, scanning electron microscopy and optically stimulated luminescence dating analyses, we confirm the presence of loess deposits at the sites and extend the known area of loess coverage. Our results suggest that loess deposits are more common than previously thought in Sweden. The results also demonstrate that basal parts of the loess are often mixed with underlying sediment, which may be a common feature of thin loess deposits close to former ice margins. Quartz luminescence is well suited for dating these deposits, but ages from the mixed basal loess layers are older than expected, while ages from undisturbed loess extend to c. 5 ka. The loess ages contrast with the timing of main dune activity in these areas, which is dominantly in the 1-3 kyr postdeglaciation (c. 10.9-10.5 cal kyr BP). We suggest that either sediment mixing during soil formation is responsible for the mid-Holocene loess ages, or that the loess deposits record periodic landscape destabilization into the mid-Holocene. Furthermore, there is a clear topographic control on aeolian sedimentary facies, with loess mantling high ground and dunes restricted to valleys. Loess deposits are also primarily found to the south and southwest of source areas, implying transport from the north and east. This pattern contrasts with evidence for NW winds inferred from associated sand dunes. At present, the reasons for this mismatch are unclear, although one possible explanation is that silts deposited at higher elevations were affected by Ekman flow deflection of NW surface winds.

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Section: Discussionsupporting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Age, formation and significance of loess deposits in central Sweden

Stevens

Sechi

Tziavaras

et al. 2022

Earth Surf Processes Landf

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“…The deposition of dust in periglacial environments contributes to the formation of loess deposits and loessic soils. Work on the source and distribution of such deposits has typically reported a decreasing depth of deposit comprising smaller particle sizes with distance from the sediment source that reflects the impact of atmospheric fallout and size‐dependent settling of dust as it is transported downwind (Hugenholtz & Wolfe, 2010; Muhs et al, 2004; Schaetzl et al, 2021). Dijkmans and Törnqvist (1991) examined modern periglacial aeolian deposits around Kangerlussuaq and reported a slight decrease in grain size over a 6 km transect with increasing distance from the Sandflugstdalen outwash plain.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, topography is known to result in different dust deposition rates on windward and leeward slopes (Comola et al, 2019; Goossens, 1996). Where the resultant direction of dust transport is consistent and unimodal this leads to distinctive spatial patterns of aeolian deposition (Muhs et al, 2004; Schaetzl et al, 2021); however, at the study sites used here sediment transporting winds are expected to be bimodal or multidirectional and to vary within and between seasons in reponse to local topographic and thermal drivers, and regional weather systems (Bullard & Austin, 2011; Bullard & Mockford, 2018; Heindel et al, 2015). The long trap exposure times used here mean that wind direction, and hence dust transport direction, is likely to be highly variable within each sampling period and the HDT trap most likely to capture highest rates of dust deposition will change from season to season.…”

Section: Methodsmentioning

confidence: 99%

Annual and seasonal variability in high latitude dust deposition, West Greenland

Soest

Bullard

Prater

et al. 2022

Earth Surf Processes Landf

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High latitude regions (≥ 50 N and ≥ 40 S) are thought to contribute substantially to contemporary global dust emissions which can influence biogeochemical cycling as well as geomorphic, cryospheric and atmospheric processes. However, there are few measurements of the emission or deposition of dust derived from these areas that extend beyond a single event or season. This article reports the deposition of locally-derived dust to an ice-free area of West Greenland over 2 years from 23 traps distributed across five sampling sites. Local dust sources include glacial outwash plains, glacially-derived delta deposits and the reworking of loessic soils. Annual dust deposition is estimated at 37.3 to 93.9 g m À2 for 2017-2018 and 9.74 to 28.4 g m À2 in 2018-2019. This annual variation is driven by high deposition rates observed in spring 2017 of 0.48 g m À2 d À1 compared to the range of 0.03 to 0.07 g m À2 d À1 during the rest of the monitoring period. The high deposition rates in spring 2017 were due to warmer than average conditions and high meltwater sediment supply that delivered large quantities of sediment to local outwash plains in 2016. For other seasons, dust deposition was lower over both autumn-winter periods (0.03 g m À2 d À1 ) than during the spring and summer (0.04-0.07 g m À2 d À1 ). When sediment availability is limited, dust deposition increases with increasing temperature and wind speed.Secondary data from dust-related weather type/observation codes and visibility records were found to be inconsistent with measured dust deposition during the period of study. One possible reason for this is the complex nature of the terrain between the observation and sample sites. The dust deposition rates measured here and the infidelity of the observed dust with secondary data sources reveal the importance of direct quantification of dust processes to accurately constrain the dust cycle at high latitudes.

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