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

Abstract

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.

Biogeochemical characterization of a lithified paleosol: Implications for the interpretation of ancient Critical Zones

“…Dithionite-citrate exactable Fe-oxide values (Fe d ) (Table 3), as a measure of pedogenic segregations and coatings, are consistent with moderate accumulations in Vertisols formed in well drained and oxidizing conditions (Nordt and Driese, 2009). The Fe d concentration should represent quantities preserved from the time of paleosol burial, although it is possible that the Fe-oxide phases shifted within the lepidocrocite, goethite, hematite series from dewatering and redox reactions (Schwertmann and Taylor, 1989;Kraus and Hasiotis, 2006).…”

Ecosystem response to soil biogeochemical behavior during the Late Cretaceous and early Paleocene within the western interior of North America

“…Paleosols in the Black Peaks Formation formed in association with thermic-udic soil temperature and soil moisture regimes, respectively, inferred from reconstructed climate parameters (Nordt et al, 2003;Dworkin et al, 2005). These paleosols also have similarities in iron redoximorphic features and depth to carbonate with modern coastal plain Vertisols of similar climates (Nordt and Driese, 2009) (Table 4). The Study Butte soils are well drained Vertisols (Udert) with shrink-swell properties and Bk horizons, but with insufficient carbonate to classify as calcic subsurface diagnostic horizons (Hapludert).…”

“…Thermic-udic soils with similar iron redoximorphic and depth to carbonate patterns occur in modern-day subtropical coastal plain environments (Nordt and Driese, 2009). The Dawson soils were moderately well drained Vertisols with shrink-swell properties (Udert) forming on relatively stable floodplain surfaces (Hapludert) ( Table 4).…”

“…as doi:10.1130/B30365.1 Geological Society of America Bulletin, published online on 12 April 2011 Paleosols in the Javelina Formation probably formed in a taxonomically defined thermic soil temperature regime and ustic soil moisture regime, as inferred from reconstructed climate parameters (Nordt et al, 2003;Dworkin et al, 2005) and from iron redoximorphic features and shallower depth to carbonate in similar modern coastal plain Vertisols (Nordt and Driese, 2009) (Table 4). The Presidio is a moderately well drained Vertisol with a calcic subsurface diagnostic horizon that formed on stable landscapes (Calciustert) intergrading to aquic conditions because of gray colors at depth (Aquic Calciustert).…”

瀬戸内区中新統瀬戸陶土層の古土壌構成が示す古風化および古気候条件

“…1995, 1987TS-E Harland et al 1992 9 Ma 9-11 Ma Nikiforoff, 1959;Retallack, 20013 Retallack, 1988, 2001Retallack, 1988, 2001Soil Survey Staff, 2006 Figs. 2, 4, 5 1993, 1973Hurst, 1977Duchaufour, 1982, 1993;Kraus, 1999 soil structure illuviated clay cutan sepic plasmic microfabric , 2005 Brewer, 1976;Retallack, 1988Retallack, , 2001 illuviated clay Holzhey et al, 1974;Murphy, 1983;, 1988;Fitz Patrick, 1993 ultisol gilgai microrelief; Paton, 1974;Ahmad, 1996 mukkara subsurface horizon Paton, 1974;Pal et al, 2012Retallack, 2001Nordt and Driese, 2009F.A.O. 1977, 1978 , 1977, 19781971vertisol Soil Survey Staff, 2006Retallack, 2001Retallack, -u vertisol F.A.O., 1977Retallack, , 1978Retallack, 1971Retallack, vertisol F.A.O., 1977Retallack, 1971Retallack, vertisol F.A.O., 1978Retallack, vertisol -u 1963Retallack, 1972Retallack, 2001 Hatano and Yoshida, 2017 9-11 Ma …”