Soil formation as an indication of relative age of glacial deposits in Eastern Greenland

1990 ◽  
Vol 90 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Bjarne Holm Jakobsen
Keyword(s):  
Soil Formation ◽  
Glacial Deposits ◽  
Relative Age

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.

Hornblende etching and quartz/feldspar ratios as weathering and soil development indicators in some Michigan soils

2004 ◽  
Vol 62 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Leslie R. Mikesell ◽  
Randall J. Schaetzl ◽  
Michael A. Velbel
Keyword(s):  
Climatic Factors ◽  
Soil Formation ◽  
Soil Development ◽  
Surficial Sediments ◽  
Time Duration ◽  
Development Indicators ◽  
Relative Age ◽  
Related Data ◽  
Weathered Soils ◽  
Outwash Plain

Weathering can be used as a highly effective relative age indicator. One such application involves etching of hornblende grains in soils. Etching increases with time (duration) and decreases with depth in soils and surficial sediments. Other variables, related to intensity of weathering and soil formation, are generally held as constant as possible so as to only minimally influence the time–etching relationship. Our study focuses on one of the variables usually held constant–climate–by examining hornblende etching and quartz/feldspar ratios in soils of similar age but varying degrees of development due to climatic factors. We examined the assumption that the degree of etching varies as a function of soil development, even in soils of similar age. The Spodosols we studied form a climate-mediated development sequence on a 13,000-yr-old outwash plain in Michigan. Their pedogenic development was compared to weathering-related data from the same soils. In general, soils data paralleled weathering data. Hornblende etching was most pronounced in the A and E horizons, and decreased rapidly with depth. Quartz/feldspar ratios showed similar but more variable trends. In the two most weakly developed soils, the Q/F ratio was nearly constant with depth, implying that this ratio may not be as effective a measure as are etching data for minimally weathered soils. Our data indicate that hornblende etching should not be used as a stand-alone relative age indicator, especially in young soils and in contexts where the degree of pedogenic variability on the geomorphic surface is large.

Mid-Holocene Erosion of Soil Catenas on Moraines near the Type Pinedale Till, Wind River Range, Wyoming

1994 ◽  
Vol 42 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Dennis E. Dahms
Keyword(s):  
Soil Formation ◽  
Soil Development ◽  
Type Locality ◽  
Buried Soils ◽  
Relative Age ◽  
Middle Holocene ◽  
Wind River Range ◽  
Age Studies

AbstractBuried soils are described from the floors of four kettles on Pinedale piedmont moraines of the southwestern Wind River Range, Wyoming, near the type locality of the Pinedale Till. The buried soils indicate that a previously unreported episode of slope erosion has occurred along adjacent catenas on some of the moraines in this region. Radiocarbon ages of the buried soils indicate that slope erosion occurred during the middle Holocene from 8540 ± 190 to 4800 ± 60 14C yr B.P. The presence of buried soils in moraine kettles indicates that profiles on the crests and backslopes of some of the moraines in this region are not the products of continuous post-Pinedale soil formation. Rather, the crest and backslope soils on Pinedale moraines result from two periods of soil development separated by an interval of erosion. Thus, soils on crests and backslopes are considered to be welded profiles. Relative-age studies that use soil data to estimate the age of moraines in this region must take into account the possibility that a mid-Holocene erosion episode affected the genesis and morphology of soils on the moraines. This study corroborates results of previous work that suggests that data from complete catenas are more useful for estimating the characteristic soil development on Quaternary moraines than are data derived from crests alone.

Glacial Sequence Near McCall, Idaho: Weathering Rinds, Soil Development, Morphology, and Other Relative-Age Criteria

1986 ◽  
Vol 25 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Steven M. Colman ◽  
Kenneth L. Pierce
Keyword(s):  
Rare Case ◽  
Soil Development ◽  
The Other ◽  
Rock Weathering ◽  
Glacial Deposits ◽  
Relative Age ◽  
Surface Rock ◽  
Ice Volume ◽  
Oxygen Isotope Record ◽  
Isotope Record

The sequence of glacial deposits near McCall, Idaho, previously assigned to the Pinedale and Bull Lake glaciations, contains deposits of four different ages. These ages are defined by multiple relative-age criteria, including weathering rinds, soil development, surface-rock weathering, morainal morphology, and loess stratigraphy. The thickness of weathering rinds on basaltic clasts is statistically representative and reproducible and can be used to estimate numerical ages. Following in order of decreasing relation to age are soil development, surface-rock weathering, and moraine morphology. The glacial deposits near McCall appear to correspond to times of high worldwide ice volume indicated by the marine oxygen-isotope record. Pilgrim Cove and McCall deposits, both assigned to the Pinedale glaciation, are late Wisconsin in age, perhaps 14,000 and 20,000 years, respectively. They represent a rare case in which deposits of Pinedale age can be separated by relative-age data. Timber Ridge deposits, assigned to the Bull Lake glaciation, have subdued, but well-preserved morainal morphology; relative-age data indicate that they are pre-Wisconsin in age, probably about 140,000–150,000 years old, although we cannot exclude an older age. Williams Creek deposits are clearly distinct from, and intermediate in age between, McCall and Timber Ridge deposits. Weathering rinds and the inferred ages of the other deposits suggest an early Wisconsin age for Williams Creek deposits.

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