Morphological Features of Seasonally Reduced Soils

Vepraskas, M. J.

doi:10.1201/9781420026238.ch7

Cited by 51 publications

(73 citation statements)

References 22 publications

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“…Based on color, composition and texture, we identify these indurated mud clasts and soft masses as redoximorphic features. Diagnostic of hydric (wetland) soils, the development of redoximorphic features requires saturation, respiring bacteria, and an adequate supply of decomposable organic carbon (Vepraskas, 2001). Redoximorphic features form by reduction, translocation, and oxidation of Fe and Mn oxides (Vepraskas, 1994; New England Hydric Soils Technical Committee (NEHSTC), 1998).…”

Section: Pockmark Field Paleogeography Since the Late Pleistocene Andmentioning

confidence: 99%

Shallow stratigraphic control on pockmark distribution in north temperate estuaries

et al. 2012

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Pockmark fields occur throughout northern North American temperate estuaries despite the absence of extensive thermogenic hydrocarbon deposits typically associated with pockmarks. In such settings, the origins of the gas and triggering mechanism(s) responsible for pockmark formation are not obvious. Nor is it known why pockmarks proliferate in this region but do not occur south of the glacial terminus in eastern North America. This paper tests two hypotheses addressing these knowledge gaps: 1) the region's unique sea-level history provided a terrestrial deposit that sourced the gas responsible for pockmark formation; and 2) the region's physiography controls pockmarks distribution. This study integrates over 2500 km of high-resolution swath bathymetry, Chirp seismic reflection profiles and vibracore data acquired in three estuarine pockmark fields in the Gulf of Maine and Bay of Fundy. Vibracores sampled a hydric paleosol lacking the organic-rich upper horizons, indicating that an organic-rich terrestrial deposit was eroded prior to pockmark formation. This observation suggests that the gas, which is presumably responsible for the formation of the pockmarks, originated in Holocene estuarine sediments (loss on ignition 3.5-10%), not terrestrial deposits that were subsequently drowned and buried by mud. The 7470 pockmarks identified in this study are non-randomly clustered. Pockmark size and distribution relate to Holocene sediment thickness (r 2 =0.60), basin morphology and glacial deposits. The irregular underlying topography that dictates Holocene sediment thickness may ultimately play a more important role in temperate estuarine pockmark distribution than drowned terrestrial deposits. These results give insight into the conditions necessary for pockmark formation in nearshore coastal environments.Published by Elsevier B.V.

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Section: Pockmark Field Paleogeography Since the Late Pleistocene Andmentioning

confidence: 99%

Shallow stratigraphic control on pockmark distribution in north temperate estuaries

et al. 2012

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“…The former has chromas of ≤2 and values of ≥4 with the assumption that they represent contemporaneous loss of iron from saturated and reduced conditions. These gray colors, however, can be inherited from the parent material or from a former soil moisture regime (Vepraskas, 2001). In contrast, gleyed colors, found on the gleyed Munsell color pages, are thought to reflect the contemporaneous accumulation of ferrous iron (Vepraskas, 2001).…”

Section: Setting and Methodsmentioning

confidence: 99%

“…This suggests that these redoximorphic features are relict and not actively forming today (Vepraskas, 2001). A few ped coats and pore linings deep in some profiles indicate periodic reduction and precipitation of iron manganese in localized settings.…”

Section: Iron Concentrationsmentioning

confidence: 98%

“…Features with clear and sharp boundaries are gradational over a distance of <2 mm whereas diffuse boundaries are gradational over a distance of >2 mm (Schoeneberger, 2002). Boundary is important because contemporaneous redoximorphic features in growth stages tend to have diffuse boundaries with relict features having nondiffuse boundaries (Vepraskas, 2001). Another point of clarification is that iron depletions have either gray or gleyed colors.…”

Section: Setting and Methodsmentioning

confidence: 99%

“…These gray colors, however, can be inherited from the parent material or from a former soil moisture regime (Vepraskas, 2001). In contrast, gleyed colors, found on the gleyed Munsell color pages, are thought to reflect the contemporaneous accumulation of ferrous iron (Vepraskas, 2001). If the redoximorphic field descriptions were incomplete, these horizons were eliminated from the data compilation.…”

Section: Setting and Methodsmentioning

confidence: 99%

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Hydropedological model of vertisol formation along the Gulf Coast Prairie land resource area of Texas

Nordt

Driese

2009

Hydrol. Earth Syst. Sci.

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Abstract. Vertisols are clayey soils containing slickensides and wedge-shaped aggregates formed by shrink-swell processes in seasonally wet climates. The dynamic distribution of macro-and microvoids as a by-product of this unique pedoturbation process, accompanied by microtopographic lows and highs (gilgai), mitigate our ability to make accurate and precise interpretations of aquic and hydric conditions in these problem soils. We studied Vertisols across a subhumid to humid climosequence to assess the formation of redoximorphic features on shallow, linear (nondepressional) landscape positions in response to varying levels of rainfall. Approximately 1000 mm of mean annual precipitation (MAP) is required to form soft iron masses that then increase in abundance, and to shallower depths, with increasing rainfall. Soft iron masses with diffuse boundaries become more abundant with higher rainfall in microlows, whereas masses with nondiffuse boundaries become more common in microhighs. Most soft iron masses form in oxygenated ped interiors as water first saturates and then reduces void walls where iron depletions form. In contrast, at least 1276 mm of MAP is needed to form iron pore linings in both microlow and microhigh topographic positions. Iron depletions do not correlate with rainfall in terms of abundance or depth of occurrence. The quantity of crayfish burrows co-varies with rainfall and first appears coincidentally with soft iron masses in microlows near 1000 mm of MAP; they do not appear until nearly 1400 mm of MAP in microhighs. Dithionite-citrate extractable and ammonium-oxalate extractable iron oxides increase systematically with rainfall indicating more frequent episodes of iron reduction and precipitation into pedogenic segregaCorrespondence to: L. C. Nordt (lee nordt@baylor.edu) tions. The sum of our data suggests that Vertisols forming in the Coast Prairie of Texas with MAP greater than 1276 mm should be classified as aquerts because of the presence of aquic conditions. These same soils may also meet the definition of hydric as one criterion for the identification of Federally-protected wetlands. However, there is a considerable disjunct between protracted periods of saturation and limited periods of reduction in these soils. Based on the distribution of redoximorphic features in the study area, regional water table data, and recent electrical resistivity data from a nearby upland Vertisol, non-Darcian bypass flow is the principle mechanism governing the flux of water through deep cracks where water first accumulates and then persists in microlow bowls at depths of 1 to 2 m.

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Indurated soil nodules: A vestige of ancient agricultural practices?

et al. 2022

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The identification of controlled fires in ancient agricultural systems is important for understanding how past societies managed the landscape. Although the use of fire in agriculture is documented in recent historical records, and combustion markers can persist in soils over a long time scale, this is a complex issue because combustion traits in general are ubiquitous. Archaeopedological surveys undertaken in an ancient forest in Burgundy (France) have led to the recovery of several red indurated nodules scattered in the soils. Gallo-Roman housing structures and parcels were recognized using light detection and ranging mapping, stimulating questions about the understanding of the nature of these nodules. Elemental and structural analyses by X-ray fluorescence and X-ray diffraction (XRD) confirmed the local origin of these features by comparing their composition with on-site sediments, and thermoluminescence dating placed the samples in the Medieval period. The results cast light on the nature of the nodules and how they can be related to controlled fires used in agricultural practices. Even though questions remain about which processes lead to the formation of the nodules, the firing temperature estimated via XRD analysis seems to be in agreement with that used in the "paring-and-burning" technique. The present study provides new information about medieval agriculture practices from the 10th to the 12th centuries CE and shows how past societies managed the opening and maintenance of agricultural fields using natural resources and "archaeological" remains from the antique period.

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Morphological Features of Seasonally Reduced Soils

Cited by 51 publications

References 22 publications

Shallow stratigraphic control on pockmark distribution in north temperate estuaries

Shallow stratigraphic control on pockmark distribution in north temperate estuaries

Hydropedological model of vertisol formation along the Gulf Coast Prairie land resource area of Texas

Indurated soil nodules: A vestige of ancient agricultural practices?

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