The radar signatures and age of periglacial slope deposits, Central Highlands of Germany

Abstract

Determining the age of periglacial slope deposits (head) in the Central Highlands (Mittelgebirge) of Germany is a research challenge because of the lack of dateable organics and the contentious role of the Laacher See Tephra (LST) as a dating indicator. Ground penetrating radar (GPR) and cores were used to establish the subsurface stratigraphic relationships between the peat deposits of two bogs (Totenauer Moor, Bayerischer Wald and Schwarzes Moor, Rhön) and underlying head deposits in order to provide minimum ages for the head. Radiocarbon dates were obtained from peat bogs overlying the head in the Bavarian Forest, while in the Rhön (Schwarzes Moor) LST was found bedded in the peat above the head indicating that the latter therefore, is older than Alleröd. Radar profiles show that the head is a stratigraphically continuous, not interbedded, unit beneath the peat. The lowest peat at Totenauer Moor, immediately above the Upper Head, was dated at 11,550 ± 260 yr BP thus establishing the minimum age of the Upper Head as being older than Bölling and perhaps even Older Dryas, but not Younger Dryas. The LST shards were not deposited contemporaneously with the head but were incorporated by bioturbation and mass movements. This study demonstrated the utility of GPR as a tool for imaging head deposits. Copyright © 2001 John Wiley & Sons, Ltd.

GPR-based detection of Pleistocene periglacial slope deposits at a shallow-depth test site

“…Regarding the penetration depth, Völkel et al (2001) have stated that it cannot be ascertained whether GPR can be used to image PPSD, due to the increased attenuation in soils with large amounts of silt and clay. At the test site, we were able to prove that GPR is suitable for the detection of different layers patterned after PPSD within the range of 1 m, even beneath a loess-rich layer of 60 cm.…”

“…In the preceding phases of the Collaborative Research Centre (SFB 299), Schotte and Felix-Henningsen (1999), Sauer et al (2002) and Sauer and Felix-Henningsen (2004) focussed on the application of GPR to PPSD and described GPR field studies in the region. Other publications on the application of GPR to PPSD, such as Völkel et al (2001), who described radar signatures of PPSD, and Leopold and Völkel (2003), have concerned themselves with the possibility of tracing the upper boundary of PPSD buried under a peat bog. We focus on the detection of different PPSD layers by GPR.…”

Methods of surveying the thickness of humous horizons using ground penetrating radar (GPR): an example from the Garmisch-Partenkirchen area of the Northern Alps

“…Evaluations of specific diagnostic characteristics of mineral subsoils (Collins and Doolittle 1987;Collins et al 1989;Doolittle and Asmussen 1992;Doolittle and Collins 1995;Doolittle et al 2007;Truman et al 1988;Ziekur 2000) or root systems (Barton and Montagu 2004;Butnor et al 2001Butnor et al , 2003Cox et al 2005;Stover et al 2007) for pedoecological purposes, however, are rather rare. There exists a broad variety of studies concerning characterization and depth estimation of peat bogs and underlying sediments in northern and mid-latitude countries (Bjelm 1980;Hänninen 1992;Holden 2006;Holden et al 2002;Lapen et al 1996;Leopold and Völkel 2003;Lowry et al 2009;Rosa et al 2009;Ulriksen 1981;Völkel et al 2001;Warner et al 1990). However, in contrast to estimations of organic peat depths and subsurface features, the presented attempt of measuring the thickness of humous horizons in terrestrial forest soils is a completely novel approach in the field of GPR applications.…”

Applicability of ground‐penetrating radar as a tool for nondestructive soil‐depth mapping on Pleistocene periglacial slope deposits

“…Here, the GPR facies must be used to discriminate the different layers (Ékes and Hickin, 2001). Völkel et al (2001) as well as Leopold and Völkel (2003) mapped the border of PPSD to peat by using radar facies to distinguish both substrates. In our work, we mapped the different PPSD layers, where a reflection could be traced to the next soil profile, and thus increasing the certainty to correctly associate GPR facies with PPSD.…”

“…It can be used to detect the bedrock-soil interface (Mellet, 1995), to delineate the thawed and frozen layers in periglacial conditions (Hinkel et al, 2001;Moorman et al, 2003), to map soil variability (Collins and Doolittle, 1987;Schellentrager et al, 1988;Rebertus et al, 1989;Inman et al, 2002;Freeland et al, 2002) and many other applications in geosciences (Daniels, 2004). Only a few works discuss the application of GPR to map PPSD in Germany (Schotte and Felix-Henningsen, 1999;Völkel et al, 2001;Leopold and Völkel, 2003;Sauer and Felix-Henningsen, 2004;Gerber et al, 2007). The quality of the scans in such soils is limited due to the moderately unfavorable conditions for GPR in soils with a clay content of 18% to 35% (Doolittle et al, 2007).…”