Soil Development Parameters in the Absence of a Chronosequence in a Glaciated Basin of the White Mountains, California-Nevada

1993 ◽  
Vol 39 (2) ◽  
pp. 186-200 ◽  
Author(s):  
Terry W. Swanson ◽  
Deborah L. Elliott-Fisk ◽  
Randel J. Southard
Keyword(s):  
Soil Formation ◽  
Soil Development ◽  
Second Order ◽  
Selection Strategy ◽  
Soil Parameters ◽  
Surface Erosion ◽  
Glacial Deposits ◽  
White Mountains ◽  
Soil Age ◽  
Exposure Ages

AbstractDetailed mapping and provisional numerical age determinations of glacial deposits in the South Chiatovich Creek Basin of the White Mountains provide an opportunity to evaluate the ability of conventional soil parameters to discriminate first- and second-order glacial events. Sampling and analytical procedures were designed to minimize variation in climate and lithology. When lithology and climate are similar among sites, age trends are more pronounced in both field and chemical soil properties. Profile development indices (PDIs), adjusted by removing melanization and pH, systematically increase with greater soil age, and discriminate first-order, but not second-order, glacial events. The best-fit curve for adjusted PDI data assumes an exponential form and suggests that the rate of soil formation in this region decreases over time, similar to the rate of weathering-rind development. Variation in eolian influx and surface erosion, which are dominant processes affecting soils of the basin, cause major uncertainties in establishing soil age and, hence, soil-development rates. Even on the youngest glacial deposits, soil age is probably significantly less than deposit age due to these geomorphic processes. Soil and weathering parameters imply that these field techniques can be inexpensively employed to define relative chronologies and to assess surface degradation and its impact on surface exposure ages. Results from this study indicate that site-selection strategy for establishing glacial chronologies should be reevaluated. Working with stable residual bedrock surfaces and associated low-relief outwash fans and terraces may prove more productive than focusing on relatively unstable moraine surfaces in tectonically active mountain systems.

Three soil chronosequences in recessional glacial deposits near the polar plateau, in the Central Transantarctic Mountains, Antarctica

2014 ◽  
Vol 26 (5) ◽  
pp. 573-583 ◽  
Author(s):  
Joshua W. Scarrow ◽  
Megan R. Balks ◽  
Peter C. Almond
Keyword(s):  
Soil Chemistry ◽  
Soil Formation ◽  
Soil Development ◽  
Soil Thickness ◽  
Glacial Retreat ◽  
Soil Material ◽  
Transantarctic Mountains ◽  
Study Sites ◽  
Landscape Units ◽  
Exposure Ages

AbstractSoil chronosequences in till deposits emplaced during glacial retreat in the Central Transantarctic Mountains are described. Discrepancies between the degree of soil development and reported cosmogenic surface exposure ages suggest slower, weaker soil development in this region than encountered in other areas of Antarctica. The study sites (Dominion Range, Mount Achernar and Ong Valley) were located between 83° and 85°S, at altitudes of 1600–2200 m, on the edge of the polar plateau. Soil landscape maps show a gradation of soil properties across landscape units that were designated as homogenous/single-event drifts in previous smaller-scale studies. Along transects away from the current ice edge, the depth to underlying ice thickened (from 2 cm to > 80 cm), soil became more weathered, saltier and less alkaline, and horizonation became more pronounced. Soil thickness, clast abundance and soil chemistry are all consistent with a two-layer mode of soil formation. We suggest that a thin, clast-rich surface horizon, originating from weathering of supraglacial debris, overlies a thick, clast-poor sublimation till. The supraglacial debris has a finite contribution to soil volume, whereas sublimation offers an ongoing source of soil material that thickens the soil from its base.

Comparison and Contrast of Processes of Soil Formation in the San Timoteo Badlands with Chronosequences in California

1996 ◽  
Vol 46 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Katherine J. Kendrick ◽  
Leslie D. McFadden
Keyword(s):  
Soil Formation ◽  
Soil Development ◽  
Oxide Content ◽  
Weighted Means ◽  
Wide Range ◽  
Soil Age ◽  
Climatic History ◽  
Higher Temperature ◽  
Geomorphic Surfaces ◽  
Age Estimates

The degree of soil development associated with geomorphic surfaces in the San Timoteo Badlands area (STB), California allows correlation of the surfaces. Soil development indices, based on field descriptions and laboratory analysis, provide a basis for comparison of these soils to each other and to dated soil chronosequences at Cajon Pass, Merced, and Anza, California. The soils in this study record a complex tectonic and climatic history, include preserved surfaces intermediate in soil development to those at Cajon Pass, and do not preserve a record of the major late Pleistocene to early Holocene aggradational event observed elsewhere in the region. Pedogenesis is similar to that of regional soils in southern California. With time, the profiles develop progressively thicker argillic horizons, and they increase in redness, clay, and secondary iron oxide content, and amount and thickness of clay films. With increasing soil age the ratio of dithionite-extractable Fe to total Fe increases, while the ratios of Fe2+to Fe3+and of oxalate- to dithionite-extractable Fe decrease. These trends are more subdued in the STB than elsewhere in the region, perhaps because the slightly higher temperature and lower precipitation of the STB may slow the rate of transformation of ferrihydrite to hematite. We use weighted means of soil development indices and rubification index values to compare the soils of this study to those at Cajon Pass, Merced, and Anza. Wide-range age estimates using the maximum limits of these values result in 27,500–305,000 yr for surface Q1, 43,000–570,000 yr for surface Q2, and 300,000–700,000 yr for surfaces Q3 and Q4. Weighing most heavily the nearest dated chronosequences, Anza and Cajon Pass, yields best estimates of age. This method constrains the time of formation of the Q1 surface to between 27,500 and 67,000 yr and the Q2 surface to 43,000–67,000 yr, and does not change the age estimates of the older surfaces.

scholarly journals Soil Development in Quaternary Glacial Deposits, Waterton Park Area, Southwestern Alberta

2007 ◽  
Vol 42 (2) ◽  
pp. 147-162 ◽  
Author(s):  
Eric T. Karlstrom
Keyword(s):  
Material Properties ◽  
Soil Development ◽  
Parent Material ◽  
Glacial Deposits ◽  
Soil Age ◽  
Late Wisconsinan ◽  
Park Area ◽  
Geomorphic Units ◽  
The U.S ◽  
Diagnostic Properties

ABSTRACTPedological investigations in the Waterton Park area provide a useful means of testing subdivisions of Quaternary glacial deposits based on geomorphic relations. Soils in the region, however, including Podzols, Brunisols, Luvisols, and Chernozemics, also reflect the influence of soil forming factors other than time. Nonetheless, a chronosequence can be established by comparing time-diagnostic properties of soils on different geomorphic units in areas with similar climate, vegetation, slope and parent material. Properties thought to be most diagnostic of relative soil age include thickness and degree of clay buildup in B horizons and two soil development indices which average degree of development of a number of properties. Pédologie and geomorphic data suggest surface deposits include mountain tills of three or four separate advances and continental tills of two separate advances. Mountain tills are tentatively correlated with the Late Wisconsinan (about 18 ka BP), Late and or Early Wisconsinan (about 100 to 65 ka BP). Late lllinoian (about 200 to 132 ka BP). and Early lllinoian and/or pre-lllinoian (about 400 to 700+ ka BP), whereas continental tills are tentatively correlated with the Late Wisconsinan and Late lllinoian deposits of the U.S. Midcontinent.

RATE OF PODZOLIC SOIL FORMATION NEAR HUDSON BAY, ONTARIO

1984 ◽  
Vol 64 (1) ◽  
pp. 31-49 ◽  
Author(s):  
R. PROTZ ◽  
I. P. MARTINI ◽  
G. J. ROSS ◽  
J. TERASMAE
Keyword(s):  
Key Words ◽  
Podzolic Soil ◽  
Soil Formation ◽  
Soil Development ◽  
Soil Profiles ◽  
Hudson Bay ◽  
Parent Materials ◽  
Carbon Dating ◽  
Soil Age ◽  
Carbonate Leaching

Six soil profiles on a transect orthogonal to the Hudson Bay coast of Ontario are shown to be of increasing age from approximately 100 yr near the coast to > 5000 yr 70 km inland. The stages of Podzolic soil development from calcareous parent materials are documented. The Ah horizons required at least 750 yr to develop. The Ae-Bh horizon sequence required at least 1893 yr to form. The Ae-Bf horizon sequence required at least 2300 yr to develop. The depth of carbonate leaching and vermiculite formation in the A horizons are very closely correlated to soil age. Key words: Vermiculite, Podzolic B horizon, carbon dating, carbonate leaching

scholarly journals Soils as proxies of the history of landscape and climate: Examples from eastern Bhutan

2013 ◽  
Vol 46 ◽  
Author(s):  
Karma Dema Dorji ◽  
Rupert Bliumler
Keyword(s):  
Soil Texture ◽  
Global Climate ◽  
Soil Formation ◽  
River System ◽  
Soil Development ◽  
Age Dating ◽  
Soil Parameters ◽  
Fluvial Deposits ◽  
Fluvial Terraces ◽  
History Of

The reconstruction of the landscape history and past environmental fluctuations is a major task with respect to forecasting man or naturally-induced changes. In this context the extent of soil development in fluvial deposits of the Chamkhar Chhu river system in Eastern Bhutan were studied for relative age dating. The deposits represent 25 fluvial terraces up to more than 260 m above the recent river level. We used a set of methods covering physical (soil texture, specific surface area) and chemical (pedogenic oxides, soil development indices) processes, and we calculated solum-weighted means of individual soil parameters to compare different sites, and to minimize problems caused by heterogeneity of the parent materials. The results were maintained by numerical age dating of fossil A horizons. Pedogenic oxides and soil development indices as well as soil texture indicate that soils can be used as proxies of the history of landscape and climate. Local as well as global climate fluctuations are well preserved in the soils despite slope processes inducing reverse-tended soil formation in fluvial deposits of Late Pleistocene origin and older, while soils on fluvial deposits of Holocene age indicate distinct chronosequences (Dorji et al. 2009).

scholarly journals Rates of biogeochemical phosphorus and copper redistribution in young floodplain soils

2009 ◽  
Vol 6 (12) ◽  
pp. 2949-2956 ◽  
Author(s):  
F. Zehetner ◽  
G. J. Lair ◽  
M. Graf ◽  
M. H. Gerzabek
Keyword(s):  
Anthropogenic Activities ◽  
Clay Mineralogy ◽  
Soil Formation ◽  
Climatic Conditions ◽  
Danube River ◽  
Tropical Environments ◽  
Order Of Magnitude ◽  
Soil Age ◽  
Marked Accumulation ◽  
Biogeochemical Transformations

Abstract. Nutrients and trace metals in river-floodplain systems may originate from anthropogenic activities and/or geogenic sources. Here, we analyze a soil chronosequence (2 to approximately 600 years) on a floodplain at the Danube River (Austria) to quantify the rates of P and Cu redistribution among biogeochemical pools during early soil formation under temperate continental climate. While bulk and clay mineralogy remained unchanged over the studied age gradient, we found considerable (mostly non-linear) redistribution of P and Cu among biogeochemical pools. The calcium-associated P and Cu fractions decreased rapidly during the initial decades of soil formation. The dissolution of calcium-associated P was mirrored by marked accumulation of organic P. Copper incorporated within resistant minerals showed a relative enrichment with soil age. The mean dissolution rates of calcium-associated (primary mineral) P decreased exponentially with increasing soil age from ~1.6 g m−2 yr−1 over ~15 years to ~0.04 g m−2 yr−1 over ~550 years, and were almost an order of magnitude higher than rates reported for tropical environments. Our study demonstrates that on riverine floodplains, rapid biogeochemical transformations can occur within the first centuries of soil formation under temperate climatic conditions.

Using Soil stratigraphic observations to constrain TCN depth profile ages of relict alluvial fan surfaces in the Sonoran Desert, USA

2020 ◽  
Author(s):  
Brad Sion ◽  
Eric McDonald ◽  
Janelle Bustarde
Keyword(s):  
Depth Profile ◽  
Sonoran Desert ◽  
Surface Modifications ◽  
Alluvial Fan ◽  
Soil Profiles ◽  
Surface Erosion ◽  
Soil Thickness ◽  
Erosion Rates ◽  
Comparison Results ◽  
Exposure Ages

<p>Interpretations of surface exposure ages derived from the accumulation of cosmogenic isotopes commonly are hampered by a lack of field documentation that is necessary to identify and constrain if any post-depositional surface modifications have occurred (e.g. surface erosion, burial) that will impact age interpretations. Previous authors have discussed these issues, but the community still has not fully adopted the practice of interpreting surface exposure ages in conjunction with detailed soil stratigraphic observations. We employ this “novel” approach by documenting a soil chronosequence from the Gould wash alluvial fan sequence near Cibola, AZ to demonstrate how soil stratigraphy can provide constraints for the relative stability of depositional surfaces and can influence interpretations of TCN ages.</p><p><br>The Cibola chronosequence represents a range of alluvial fan ages that extend well beyond those commonly observed in the desert southwestern US (typically <100 ka) and provides evidence for extended periods of surface stability. We identified seven different alluvial fan surfaces within the sequence, documented their soil morphological and chemical properties, and dated four of the fan surfaces with <sup>36</sup>Cl depth profiles. Fan deposits largely consist of volcaniclastic alluvium derived from the local Trigo Peaks and distal Castle Dome mountain blocks and show both a reduction of bar-and-swale surface topography and an increasing expression of desert pavement with relative surface age. The soil profiles consist of Av-Bk-BCky-Cky-Ck vertical horizon sequences (~125-cm thick) in the youngest fan units to Avk-Btky-Bkym-Bky-BCky-Cky-C (~400-cm thick) in the oldest fan unit that reflect systematic changes in soil thickness, structure, rubification of B horizons, and relative accumulations of eolian derived silt, clay, and salts as a function of relative surface age.</p><p><br>Chlorine-36 depth profile analysis yielded variable fan ages that are largely controlled by the magnitude of allowable erosion. Model results for which input data were parameterized to optimize unconstrained erosion rates indicate surface exposure ages of 46 (2A), 114 (2B), 268 (3A), and 386 (4A) ka. These are associated with best-fit erosion rates of 0-6 mm/kyr that indicate 0-136 cm net erosion. By comparison, results for which erosion rates were constrained to ~1 mm/kyr based on soil stratigraphic observations yielded exposure ages of 41 (2A), 114 (2B), 209 (3A), and 287 (4A) ka, resulting in differences of 10-25% of the unconstrained ages. The systematic morphological trends observed in the soil profiles do not support inferences of net erosion exceeding 30 cm and therefore cannot support the results from unconstrained parameter optimization. Although statistical optimization schemes provide better model fits to the data as indicated by chi-shared minimization routines, current models cannot account for field observations or for inferred constraints on surface modifications based on cosmogenic isotope concentrations alone. That task is better suited for and required by the sampling protocol to achieve more reliable surface exposure dates.</p>

Second-Order SMO Improves SVM Online and Active Learning

2008 ◽  
Vol 20 (2) ◽  
pp. 374-382 ◽  
Author(s):  
Tobias Glasmachers ◽  
Christian Igel
Keyword(s):  
Active Learning ◽  
Large Data ◽  
Single Step ◽  
Second Order ◽  
Selection Strategy ◽  
Support Vector ◽  
Data Sets ◽  
Working Set Selection ◽  
Working Set ◽  
Efficient Approximation

Iterative learning algorithms that approximate the solution of support vector machines (SVMs) have two potential advantages. First, they allow online and active learning. Second, for large data sets, computing the exact SVM solution may be too time-consuming, and an efficient approximation can be preferable. The powerful LASVM iteratively approaches the exact SVM solution using sequential minimal optimization (SMO). It allows efficient online and active learning. Here, this algorithm is considerably improved in speed and accuracy by replacing the working set selection in the SMO steps. A second-order working set selection strategy, which greedily aims at maximizing the progress in each single step, is incorporated.

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