Measurement and Calibration of Weathering Processes and Lichenometric Investigations on a Wave Washed Moraine, Bådamalen, on the Upper Norrland Coast, Sweden

Sjöberg, Rabbé

doi:10.1080/04353676.1990.11880326

Cited by 5 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These effects are usually identifiable in the field in terms of circular depressions and/or low ramparts. Previous research by Sjöberg (1987Sjöberg ( , 1988Sjöberg ( , 1990, and Broadbent (1990, 1991) on some of the beach sequences used here employed an R-value-age relationship to help date archaeological sites on the beaches. They reported a linear trend in R-value with altitude for beaches within the range 0-35 m a.s.l.…”

Section: Study Area: Background and Previous Workmentioning

confidence: 99%

The Schmidt hammer as a Holocene calibrated-age dating technique: Testing the form of the R-value-age relationship and defining the predicted-age errors

et al. 2011

View full text Add to dashboard Cite

Most recent developments of Schmidt-hammer exposure-age dating (SHD) as a calibrated-age dating tool have been limited by the use of locations at two age control points. This has necessitated: (1) making assumptions about a linear R-value—age relationship; and (2) basing predictions of age errors only on R-value variance at the two age control points. This paper analyses 9900 R-values obtained from multiple-age control points on a sequence of glacio-isostatically raised shorelines with well constrained ages (Skuleskogen High Coast World Heritage Site and environs, Gulf of Bothnia, northern Sweden) ranging from modern to 10.5 ka in age. The sampling design involved 30 measurements on granite beach boulders from 30 sites at 11 age control points. The R-value—age relationship is best described by a linear function (ordinary least squares, OLS) with an R2 of 0.89 ( p < 0.0001). Predicted-age errors are calculated using two approaches: (1) OLS regression, which takes account of the uncertainties associated with the regression line and the age control points; and (2) weighted total least squares (WTLS) regression which, in addition, takes account of possible shoreline age errors and the heteroscedasticity of R-value residuals with increasing age. With both approaches, 95% predicted-age errors are relatively modest: ±355—455 years and ±300—515 years, respectively, with larger R-value variance and hence uncertainty for older surfaces, and the possibility of further improvement from a more selective field sampling scheme that differentiates between age-related and non-age-related rock-surface variability. Our results also indicate that for certain lithologies and weathering environments, it is possible to construct reliable calibrated-age curves from relatively few age control points.

show abstract

Section: Study Area: Background and Previous Workmentioning

confidence: 99%

The Schmidt hammer as a Holocene calibrated-age dating technique: Testing the form of the R-value-age relationship and defining the predicted-age errors

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Relative dates have been obtained for Holocene surfaces, including various anthropogenic features, moraines, rock glaciers, rock-falls, avalanches, debris fl ow and deltaic deposits. SH has been used only sporadically to estimate the relative age of older features, for example, glacial landforms (Sumner et al, 2002), periglacial trimlines (Ballantyne, 1997;Anderson et al, 1998), rock glaciers (Humlum, 1998;Frauenfelder et al, 2005), raised beaches (Sjöberg, 1990) and lake shorelines (Matthews et al, 1986). Limitations of the method itself have been described (McCarroll, 1989;Goudie, 2006).…”

Section: Introductionmentioning

confidence: 96%

Surface and sub‐surface Schmidt hammer rebound value variation for a granite outcrop

Černá

Engel

2011

Earth Surf Processes Landf

View full text Add to dashboard Cite

This study presents rock strength variations at granite outcrops and in subsurface vertical profi les in the Jizerské hory Mountains, Czech Republic. Schmidt hammer rebound values in subsurface profi les change gradually from the bedrock surface downward. An exponential relation has been observed between the R-values and depth in rock outcrops to a depth of around 4·5 m. The exponential nature of the curve indicates that rock hardness increases more rapidly with depth in the uppermost 1 m section of the rock profi le. A detailed study of rebound values obtained from both intact and polished rock exposures reveal effects of surface grinding on results of the Schmidt hammer method. The range of data collected increases after grinding, allowing more precise discrimination of rock surfaces in respect of age and weathering. The Schmidt hammer method may be used effectively as a relative-age dating tool for rock surfaces that originated during the Late Pleistocene. It is concluded that this time limitation can be signifi cantly mitigated by surface grinding before measurement.

show abstract

“…It has been used to compare the surface hardness of different rock types (Barton & Choubey 1977;Day & Goudie 19771, and as a measure of degree of rock surface weathering (Day 1980;Whitlow & Shakesby 1988;Ballantyne et ul. 1989;McCarroll 1990;Sjoberg 1990Sjoberg , 1991Sjoberg & Broadbent 1991). It has also been used for recording degree of weathering as an indicator of surface age (Ballantyne 1986;Dawson et ul.…”

Section: Methodsmentioning

confidence: 99%

The vertical extent of ice sheets in Nordfjord, western Norway: measuring degree of rock surface weathering

McCarroll

Nesje

1993

Boreas

View full text Add to dashboard Cite

Degree of rock surface weathering was measured on sites in Oldedalen and Brigsdalen, where dates of deglaciation have been estimated. and on an altitudinal transect on the slopes of Skåla. representing one of the highest supra‐marine reliefs in western Norway. The Schmidt hammer is useful only for distinguishing sites deglaciated during the Little Ice Age from those deglaciated during the Lateglacial and early Holocene. Degree of roughness of granitic augen gneiss bedrock surfaces was quantified from profiles measured in situ using a micro‐roughness‐meter and profile gauge. There is a significant increase in surface roughness above a clear trimline at c. 1350 m a.s.I. but no significant increase above a higher trimline previously proposed as the vertical limit of the last ice sheet in this area (c. 1560 m a.s.I.). The roughness of boulder surfaces on the summit blockfield does not direr significantly from the roughness of bedrock surfaces downslope as far as the lower trimline. These unexpected results suggest that bedrock surfaces between the two trimlines were not glacially abraded during the Late Weichselian, so that the upper trimline is unlikely to represent the vertical limit of ice during either the Late Weichselian or a subsequent readvance. Preliminary results of 10Be dating of surface quartz samples from above the lower trimline support the proposal that the site was not abraded during the last glaciation. The results can be interpreted in two ways: (1) The upper trimline represents the vertical limit of a pre‐Late Weichselian advance. During the Late Weichselian the mountains were completely covered but surfaces down to the lower trimline were protected by cold‐based ice. (2) The lower trimline marks the vertical limit of the Late Weichselian ice and the upper limit an older and more extensive glaciation.

show abstract

Measurement and Calibration of Weathering Processes and Lichenometric Investigations on a Wave Washed Moraine, Bådamalen, on the Upper Norrland Coast, Sweden

Cited by 5 publications

References 7 publications

The Schmidt hammer as a Holocene calibrated-age dating technique: Testing the form of the R-value-age relationship and defining the predicted-age errors

The Schmidt hammer as a Holocene calibrated-age dating technique: Testing the form of the R-value-age relationship and defining the predicted-age errors

Surface and sub‐surface Schmidt hammer rebound value variation for a granite outcrop

The vertical extent of ice sheets in Nordfjord, western Norway: measuring degree of rock surface weathering

Contact Info

Product

Resources

About