Late Holocene debris cone evolution in Glen Feshie, western Cairngorm Mountains, Scotland

1989 ◽  
Vol 80 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Vanessa Brazier ◽  
Colin K. Ballantyne
Keyword(s):  
Debris Flow ◽  
Fifteenth Century ◽  
Late Holocene ◽  
Buried Soils ◽  
Lateral Migration ◽  
Flow Units ◽  
Vegetation Disturbance ◽  
River Erosion ◽  
Cone Development ◽  
Debris Cone

ABSTRACTRecent river erosion of three coalescing debris cones in Glen Feshie has exposed a complex sequence of debris flow units. Radiocarbon dating of organic matter from interbedded buried soils reveals that the soil at the base of the sequence was buried at c. 2000 yr BP, but that the bulk of the cones accumulated since the fifteenth century AD. The episodic nature of cone development is attributable to lateral migration of the River Feshie, with periods of cone accumulation when the river occupied the far side of its floodplain alternating with periods of erosion when the river impinged on the cones. There is no evidence to suggest that recent cone accumulation is related to anthropogenic vegetation disturbance, but phases of cone accumulation show a broad temporal correspondence with periods of Late Holocene climatic deterioration. The cones are essentially paraglacial in that their continuing accumulation depends on a supply of sediment derived from glacial and periglacial deposits upslope. The form of debris-flow units indicates that flows at this site were less viscous than most ‘hillslope’ flows, and cone volumes indicate an average annual accumulation of c. 50–60 m3 of sediment over the past c. 300years.

scholarly journals Topographic Thresholds and Soil Preservation along the Southern High Plains Eastern Escarpment, Northwest Texas, USA

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 476
Author(s):  
Travis Conley ◽  
Stance Hurst ◽  
Eileen Johnson
Keyword(s):  
Late Pleistocene ◽  
Late Holocene ◽  
High Plains ◽  
Buried Soils ◽  
Lateral Migration ◽  
South Fork ◽  
The South ◽  
Southern High Plains ◽  
Middle Holocene ◽  
Semi Arid

The eastern escarpment of the Southern High Plains (USA) is today a semi-arid erosional landscape delineated by canyon breaks and topographic relief. A series of buried soils were identified, described, and sampled at 19 soil profile localities exposed along terraces of the South Fork of the Double Mountain Fork of the Brazos River (South Fork) and two associated tributaries (Spring Creek and Macy 285 drainage). Radiocarbon dating revealed late-Pleistocene to early Holocene (~12,580–9100 14C B.P.), middle-Holocene (~6025–4600 14C B.P.), and late-Holocene (~2000–800 14C B.P.) buried soils. The late-Pleistocene to middle-Holocene soils were preserved only at higher elevations within the upper section of the South Fork and Spring Creek. A topographic position analysis was conducted using GIS to identify and examine the impacts of a soil topographic threshold on the preservation and distribution of buried soils within this geomorphic system. Above the identified ~810 m threshold, lateral migration of channels was constrained. Extensive channel migration below the threshold removed older terraces that were replaced with late-Holocene terraces and associated buried soils. Landscape topography constraints on geomorphic processes and soil formation impacted the preservation of archaeological sites in this semi-arid region.

scholarly journals Tidal Flat Depositional Response to Neotectonic Cyclic Uplift and Subsidence (1–2 m) as Superimposed on Latest-Holocene Net Sea Level Rise (1.0 m/ka) in a Large Shallow Mesotidal Wave-Dominated Estuary, Willapa Bay, Washington, USA

2018 ◽  
Vol 10 (1) ◽  
pp. 109 ◽  
Author(s):  
Curt D. Peterson ◽  
Sandy Vanderburgh
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Tidal Flat ◽  
Late Holocene ◽  
Columbia River ◽  
Small Rivers ◽  
Intertidal Flat ◽  
Sedimentation Rates ◽  
Lateral Migration ◽  
Willapa Bay

The late-Holocene record of tidal flat deposition in the large shallow Willapa Bay estuary (43 km in length), located in the Columbia River Littoral Cell (CRLC) system (160 km length), was investigated with new vibracores (n=30) and gouge cores (n=8), reaching 2–5 m depth subsurface. Reversing up-core trends of muddy sand to peaty mud deposits in marginal tidal flat settings demonstrate episodic submergence events resulting from cyclic tectonic uplift and subsidence (1–2 m) in the Cascadia subduction zone. These short-term reversals are superimposed on longer-term trends of overall sediment coarsening-up, which represent the transgression of higher-energy sandy tidal flats over pre-existing lower-energy tidal flat mud and peaty mud deposits in late-Holocene time. Fining-up trends associated with channel lateral migration and accretionary bank deposition occurred only infrequently in the broad intertidal flats of Willapa Bay. Vibracores and gouge cores were dated by 14C (n=16) and paleo-subsidence event contacts (n=17). Vibracore median probability 14C ages ranged from 0 to 6,992 yr BP and averaged 2,174 yr BP. Dated sample ages and corresponding depths of tidal flat deposits yield net sedimentation rates of 0.9–1.2 m ka-1, depending on the averaging methods used. Net sedimentation rates in the intertidal flat settings (~1.0 m ka-1) are comparable to the rate of net sea level rise (~1.0 m ka-1), as based on dated paleo-tidal marsh deposits in Willapa Bay. Reported modern inputs of river sand (total=1.77x104 m3 yr-1), from the three small rivers that flow into Willapa Bay, fall well short of the estimated increasing accommodation space (1.9x105 m3 yr-1) in the intertidal (MLLW-MHHW) setting (1.9x108 m2 surface area) during the last 3 ka, or 3.0 m of sea level rise. The under-supply of tributary sand permitted the influx of littoral sand (1.1x105 m3 yr-1) into Willapa Bay, as based on the net sedimentation rate (~1.0 m ka-1) and textural composition (average 60 % littoral sand) in analyzed core sections (n=179). The long-term littoral sand sink in Willapa Bay’s intertidal setting (55 % of total estuary area) is estimated to be about 5 % of the Columbia River supply of sand to the CRLC system, and about 30% relative to the littoral sand accumulated in barrier spits and beach plains during late-Holocene time. A 2.0 m rise in future sea level could yield a littoral sand sink of 2.2x108 m3 in the Willapa Bay intertidal setting, resulting in an equivalent shoreline retreat of 600 m along a 50 km distance of the barrier spit and beach plains that are located adjacent to the Willapa Bay tidal inlet. Willapa Bay serves as proxy for potential littoral sand sinks in other shallow mesotidal estuary-barrier-beach systems around the world following future global sea level rise.

Key Aspects of A Horizon Formation for Selected Buried Soils in Late Holocene Alluvium; Southern Prairies, USA

Soil Science ◽  
2009 ◽  
Vol 174 (7) ◽  
pp. 408-416 ◽  
Author(s):  
Brian J. Carter ◽  
J. Phillip Kelley ◽  
J. Byron Sudbury ◽  
Dale K. Splinter
Keyword(s):  
Late Holocene ◽  
Buried Soils ◽  
Key Aspects

scholarly journals Mid and Late Holocene flooding reconstruction based on fluvial archives of the East Carpathian rivers

2018 ◽  
Vol 20 (1) ◽  
pp. 17-33
Author(s):  
Maria RĂDOANE ◽  
Francisca CHIRILOAEI ◽  
Nicolae RĂDOANE ◽  
Constantin NECHITA
Keyword(s):  
Iron Age ◽  
Late Holocene ◽  
General Pattern ◽  
Geographical Area ◽  
Ice Age ◽  
Lateral Migration ◽  
Eastern Carpathians ◽  
Study Results ◽  
Floodplain Deposits ◽  
Fluvial Archives

This paper focused on the analysis of the interpretation potential given by fluvial archives, in order to decipher the Mid- to Late Holocene sedimentary history. The database discussed here refers to 65 dated ages (mostly radiocarbon), mappings of the most representative floodplain reaches of Suceava, Moldova and Siret rivers, and 23 outcrops analysed in floodplain deposits (river banks or gravel pits). The study results concentrated on (a) describing the regional features of Eastern Carpathian floodplains, (b) the floodplain morphology and its correlation with the structure of fluvial deposits and (c) identifying the paleoevents of fluvial activity on a centennial timescale. In this way, we were able to identify a general pattern of the dynamic geomorphology history for the rivers situated eastward of the Carpathians, which resulted from combining the Mid- to Late Holocene sedimentation phases, the avulsion and lateral migration processes that occurred during high fluvial activity intervals and the morphological adjustment of the rivers channels, from braiding to wandering and sinuously–meandering. The chronological overlay of the events revealed that the time intervals with the most extensive fluvial processes on the rivers draining the Eastern Carpathians occurred (in years before present) during 6200, 5300, 4100–4080, 3600, 2300–2200 (Iron Age), 1300 (Migrations Period), 950–970 (Medieval Climate Anomaly), 750–520 BP (Little Ice Age)and that these intervals generally overlap the high precipitation palaeoclimatic episodes documented in Romania. The fluvial activity of the rivers during the Mid- to Late Holocene has been compared as well with several records of paleo–climates variability over the geographical area of Romania. The result showed that many flooding episodes were coincident with the wet and cold intervals which were also identified in the variation of the other proxydata, especially after 4.7 kcal BP.

scholarly journals Late Holocene Geomorphology of the Columbia River Estuary, Oregon and Washington, USA

2014 ◽  
Vol 6 (2) ◽  
pp. 1 ◽  
Author(s):  
Curt Peterson ◽  
Sandy Vanderburgh ◽  
Michael C. Roberts
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Late Holocene ◽  
River Estuary ◽  
Columbia River ◽  
Sediment Supply ◽  
Sedimentation Rates ◽  
Lateral Migration ◽  
Columbia River Estuary ◽  
Apparent Paradox

Abundant river sediment supply and an open-water central bay area characterize the geomorphology of the large Columbia River estuary (~ 100 km in length). Lateral floodplains and marsh islands do constrict the uppermost reaches of the estuary, but the central axes of the lower estuary are dominated by shallow sand shoals (0–4 m water depth). A total of 58 vibracores are used to document the grain size and age (0–2,500 14CyrBP) of late Holocene deposits in the estuary. Sedimentation rates in stable floodplains (1.1 m ka-1) reflect rates of relative sea level rise (0.75 m ka-1). Sedimentation rates of muddy sand accretionary banks and prehistoric sand shoals (1.5–7 m ka-1) greatly exceed coeval rates of sea level rise, so they must represent short–term rates of vertical accretion resulting from channel lateral migration and associated cut and fill processes. The apparent paradox of unfilled accommodation space in the estuary is resolved by 1) winter wind–wave erosion of sand shoals to -3 m NAVD88 elevation and 2) asymmetric fluvial-tidal advection that results in net seaward transport of bed load in shallow tidal channels (> – 10 m NAVD88) and shallow subtidal shoals (> – 4 m NAVD88) during spring river flooding. 

Dominance of an ∼150-Year Cycle of Sand-Supply Change in Late Holocene Dune-Building along the Eastern Shore of Lake Michigan

2000 ◽  
Vol 54 (3) ◽  
pp. 414-422 ◽  
Author(s):  
Walter L. Loope ◽  
Alan F. Arbogast
Keyword(s):  
Lake Level ◽  
Late Holocene ◽  
Lake Michigan ◽  
Probability Distributions ◽  
Buried Soils ◽  
Lake Levels ◽  
Eastern Shore ◽  
Soil Burial ◽  
The Past ◽  
Sand Supply

Outcrops of buried soils on lake-plains and glacial headlands along Lake Michigan's eastern shore suggest that periodic dune-building has occurred there after relatively long (≥100 yr) periods of low sand supply. We located, described, and radiocarbon dated 75 such buried soils that crop out in 32 coastal dune fields beside the lake. We assume that peaks in probability distributions of calibrated 14C ages obtained from wood, charcoal, and other organic matter from buried A horizons approximate the time of soil burial by dunes. Plotted against a late Holocene lake-level curve for Lake Michigan, these peaks are closely associated with many ∼150-yr lake highstands previously inferred from beach ridge studies. Intervening periods of lower lake levels and relative sand starvation apparently permitted forestation and soil development at the sites we studied. While late Holocene lake-level change led to development and preservation of prominent foredunes along the southern and southwestern shores of Lake Michigan, the modern dune landscape of the eastern shore is dominated by perched dunes formed during ∼150-yr lake highstands over the past 1500 yr.

The Influence of Debris Flow Activity on the Sediment of the Lake Plansee over 3.6 ka (Tyrol, Austria)

2020 ◽  
Author(s):  
Carolin Kiefer ◽  
Michael Krautblatter ◽  
Christoph Mayr ◽  
Patrick Oswald ◽  
Michael Strasser
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Geophysical Methods ◽  
Fold Increase ◽  
Delivery Ratio ◽  
Sedimentation Rates ◽  
Autochthonous Organic Matter ◽  
Flow Activity ◽  
Debris Cone

<p>Debris flows represent a widespread geomorphological hazard in mountainous regions. Understanding the long-term dynamics of debris flow activity in view of climate change is crucial for the prevention and mitigation of future events. The activity of debris flows is evidently linked to the magnitude of rainstorms. Dietrich & Krautblatter (2017) found an increase in debris flow volumes after 1980 by a factor of 2 compared to the period 1947-1980 and by a factor of 3 compared to the mean Lateglacial/Holocene debris flow volumes by investigating aerial photos of the surroundings of lake Plansee (Reutte, Austria) and estimating debris flow cone volumes with geophysical methods.</p><p>In this study, the terrestrial observations of increasing debris flow volumes were compared with the subaquatic deposits from the deepest basin of the lake. The debris flow volume within a three-month period on a large debris cone was monitored by Terrestrial Laserscanning (TLS) and the debris flow activity over the last 3 600 years was reconstructed using sediment cores. Four short cores of up to 145 cm depth were recovered in a transect from the shallow subaquatic debris cone area to the deepest basin of the lake. The grain size, density, Magnetic Susceptibility as well as the d<sup>13</sup>-C, d<sup>15</sup>N- and C/N-ratios of the sediment were analyzed.</p><p>The Terrestrial Laserscans revealed a sediment delivery ratio of 30% for the steep debris cone bordering the lake. In the four correlated short cores, 52 debris flow events were differentiated within the last 3 600 years of sedimentation. The proportion of event layers in the cores ranges between 34% and 57% of the total section thickness. The sedimentation rates from a dated core confirm the increase of debris flow activity that was observed with terrestrial methods by Dietrich & Krautblatter (2017). The sedimentation rates show an 11-fold increase after 1930 compared to the rates before 1930 and a 5-fold to 12-fold increase compared to the average Holocene sedimentation rates in lake Plansee. Three types of event deposits were distinguished according to sedimentological criteria: flood-triggered debris flows, earthquake-induced subaquatic suspension flows and mega-events. The TOC/TN ratios of the sediment reveal a permanent influence of terrestrial carbon on the lake sediment and a mixed source of allochthonous and autochthonous organic matter. Large debris flow events can be distinguished from background sediments by increased d<sup>13</sup>C isotope ratios.</p><p>The results of this study reveal further scientific proof for the increase of debris flow activity in conjunction with increasing rainstorm activity. Here we show one of the first long-term archives of debris flow activity in the Northern Alps spanning the last 3 600 years and revealing cyclic shifts in debris-flow transport volumes by one order of magnitude.</p>

scholarly journals Comparisons and Interpretations of Charcoal and Organic Matter Radiocarbon Ages from Buried Soils in North-Central Colorado, USA

Radiocarbon ◽  
2008 ◽  
Vol 50 (3) ◽  
pp. 331-346 ◽  
Author(s):  
James H Mayer ◽  
George S Burr ◽  
Vance T Holliday
Keyword(s):  
Organic Matter ◽  
Land Surface ◽  
Late Holocene ◽  
Soil Formation ◽  
Colorado Front Range ◽  
Front Range ◽  
Buried Soils ◽  
North Central ◽  
Surface Stability ◽  
Combustion Residue

The reliability of radiocarbon ages based on soil organic matter (SOM) from Holocene buried soils in Middle Park, Colorado, is assessed by comparison with ages of charcoal. On average, 14C ages of SOM from buried surface horizons are 880 ± 230 14C yr younger than charcoal ages from the same horizon. Humic acid (HA) and low-temperature (400 °) combustion residue (LT) fractions are 390 ± 230 and 1290 ± 230 14C yr younger than charcoal ages, respectively, and HA ages are on average 860 ± 140 14C yr older than LT fractions. We interpret the offsets between 14C ages of charcoal and SOM fractions and the consistent offsets between the HA and LT fractions to reflect the duration of pedogenesis and different residence times of the SOM fractions examined here. The stratigraphic coherence of charcoal 14C ages suggests short residence time on the landscape, with little subsequent reworking. 14C ages of HA and LT fractions are complimentary to charcoal, and HA ages are interpreted to represent minimum ages for the onset of pedogenesis and LT ages are considered maximum ages for burial. The 14C chronology from buried soils indicates an episode of hillslope erosion in Middle Park during the early Holocene, followed by a long period of land surface stability and soil formation between 9000–4500 BP. Two episodes of late Holocene hillslope erosion between 3500–2500 and 1000–500 BP correspond with warming recognized in the Colorado Front Range, while surface stability and soil formation between 2500–1000 BP is contemporaneous with evidence for cooling at higher elevations.

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