Weathering characteristics of arctic islands in northern Norway

Weathering processes and Quaternary origin of an alpine blockfield in Arctic Sweden

“…The major unit of the ruler in each photograph is centimetres. Fjellanger et al 2006;Paasche et al 2006;Andre´et al 2008), but, rather, a product of processes that have operated during the Quaternary. The chemical weathering of fine matrix in the Tarfalatj˚arro summit and saddle blockfield is significantly less advanced than has been reported for many tills, blockfields and saprolites in other formerly glaciated landscapes.…”

“…Many studies examining blockfield weathering and origins have incorporated data from pit excavations (Caine 1968;Rea et al 1996a;Ballantyne 1998;Marquette et al 2004;Paasche et al 2006 Clast weathering and assemblages of clay minerals may vary with depth beneath the ground surface because of soil horizon formation through illuviation and eluviation processes, diminishing biogenic influences from the surface downwards, reduced regolith mixing with depth, changes in the number, rapidity and magnitude of temperature fluctuations and/or changes in the volume of regolith water. The most advanced changes attributable to chemical weathering occur in the A and B horizons, which are therefore preferable sampling targets.…”

A Younger Dryas plateau icefield in the Monadhliath, Scotland, and implications for regional palaeoclimate

“…This was in part due to uncertainty as to what the lower boundaries of the blockfields and solifluction lobes on the plateau summits represent. Blockfields are relict features that are proposed to have formed as far back as the Neogene (Nesje, 1989;Rea et al, 1996;Whalley et al, 1997Whalley et al, , 2004Sumner and Meiklejohn, 2004;Fjellanger et al, 2006;Paasche et al, 2006), although recent work indicates they may have predominantly formed through physical weathering, such as frost wedging, under periglacial conditions during the Quaternary (Ballantyne, 1998(Ballantyne, , 2010aGoodfellow et al, 2009;Goodfellow, 2012;Hopkinson and Ballantyne, 2014). Irrespective of this debate, the extensive blockfields on many of the summits in the Monadhliath would not have formed on ice-free summits during the Younger Dryas alone (sensu.…”

Late Cenozoic deep weathering patterns on the Fennoscandian shield in northern Finland: A window on ice sheet bed conditions at the onset of Northern Hemisphere glaciation

“…Instead, the gruss-type weathering found in northern Finland is replicated in other formerly glaciated areas, including lowland shields. Remnant grusses are widely reported from within glacial limits in North America (Bouchard et al, 1995;Jansson and Lidmar-Bergstrom, 2004), the British Isles (Godard, 1961;Le Coeur, 1989;Coxon, 2005), Norway (Paasche et al, 2006;Fjellanger and Nystuen, 2007;Strømsøe and Paasche, 2011), Sweden (Lundqvist, 1985;Olvmo et al, 2005), Finland (Söderman, 1985;Peuraniemi and Pulkkinen, 1993) and northwestern Russia (Afanas'ev, 1977;Evzerov et al, 2007). In northern Finland and probably also widely across crystalline rocks in the Northern Hemisphere, gruss-type weathering developed under temperate to cool, humid climates through the Neogene and into the Early Pleistocene.…”

“…Saprolite characteristics and distribution indicate the manner in which differential chemical weathering has guided relief development over timescales of 10 6 -10 7 years (Hall et al, 1989;Lidmar-Bergström, 1995;Migoń, 1999). Saprolite geochemistry and clay mineralogy are pointers to the climatic conditions that prevailed during weathering and relief development in northern latitudes (Paasche et al, 2006;Strømsøe and Paasche, 2011). Isotope geochemistry of clay minerals may yield direct estimates of palaeotemperatures during weathering and indirect indications of the age of the weathered material (Gilg et al, 2013;Hall et al, 2015).…”