Application of the Handysurf E-35B electronic profilometer for the study of weathering micro-relief in glacier forelands in SE Iceland

Abstract

ABSTRACT:Dąbski, M. 2015. Application of the Handysurf E-35B electronic profilometer for the study of weathering micro-relief in glacier forelands in SE Iceland. Acta Geologica Polonica, 65 (3), 389-401. Warszawa.This article presents the results of weathering micro-roughness measurements performed with the use of a Handysurf E-35B electronic profilometer, a new tool in geomorphological studies. Measurements were performed on glacially abraded basaltic surfaces within the Little Ice Age (LIA) glacial forelands of Hoffelsjökull, Fláajökull, Skálafellsjökull and Virkisjökull in Iceland. Results show a statistical increase in micro-roughness in a direction from the glacial termini to LIA moraines. However, a major change in the micro-roughness of basaltic surfaces only occurs during the first 80 to 100 years since the onset of subaerial weathering. Increase in rock surface micro-roughness is accompanied by an increase in weathering rind thickness and a decrease in Schmidt hammer R-values. Micro-roughness measurements with the use of the Handysurf E-35B can provide insights into initial rates of rock surface micro-relief development. The use of this instrument as a relative dating technique is limited to fine-grained rocks and decadal time-scales of weathering because of the limited range of measureable micro-relief amplitude.

Nanoscale Observations Support the Importance of Chemical Processes in Rock Decay and Rock Coating Development in Cold Climates

“…This discussion section links results presented in Figures 1-13 to prior scholarship on cold climate rock-surface processes. The results clearly confirm findings by Rapp [23], Hall [14,[24][25][26], Dixon [27][28][29][30][31][32][33][34][35], Thorn [36][37][38], their collaborators, and others [40][41][42][43][44][45][46][47][105][106][107] on the importance of chemical processes in cold climate geomorphic settings. However, Figures 1-13 also reveal new details of rock-surface chemical l processes at the nanoscale that, we hope, opens the eyes of cold-climate researchers who only perceive "minimal chemical weathering" [39] when they see bare rock (e.g., Figures 1, 11 and 13a).…”

“…Unfortunately, there still exists the assumption by some of "minimal chemical weathering" in cold climates like Antarctica [39]. However, most scholars no longer consider biochemical and chemical rock decay processes as unimportant or even a distant second to physical rock decay, as evidenced by recent research [40][41][42][43][44][45][46][47] and Ph.D. dissertations [48] on cold-climate rock decay not having fight against those prejudiced by the old paradigm.…”

Lichenometry and Schmidt hammer tests in the Kaunertal glacier foreland (Ötztal Alps) during the AMADEE-15 Mars Mission Simulation

“…This supports the previous finding of Dąbski (2009), who worked on post-LIA glacially abraded limestones in the Swiss Alps, as well as Dąbski (2014Dąbski ( , 2015, Evans et al (1999), and Dąbski and Tittenbrun (2013), who worked on freshly deglaciated basalts in Iceland. They showed that SHRT R-values decrease by 5 to 9% in a direction from the youngest to oldest moraines marking the LIA maxima of glaciers.…”

Rock Coating and Weathering-Rind Development at the Edge of Retreating Glaciers: An Initial Study

“…Paraglacial rock decay can progress rapidly in both periglacial and paraglacial settings (Dixon et al 1984;Ballantyne and Benn 1994;Thorn et al 2001;Dixon et al 2002;French and Guglielmin 2002;Dixon and Thorn 2005;Thorn et al 2006;Dixon 2013) by both abiotic decay processes (Anderson et al 2000) and microorganism-generated decay (Etienne 2002;Etienne and Dupont 2002;Guglielmin et al 2005;Borin et al 2010). Such rapid decay has been also documented physically through microrelief measurements (Dąbski 2015).…”