Results 71 to 80 of about 2,943 (230)
Boreas, EarlyView.We summarize the current state of knowledge on the age of the Middle Pleistocene ice advances into northern central Europe and provide 25 new single‐grain feldspar luminescence ages of Elsterian and Saalian glacigenic sediments to constrain the age of the ice advances and their tentative correlation with marine isotope stages/substages.
Niklas von Soest +10 more
wiley +1 more source
Linking bedrock discontinuities to glacial quarrying
Annals of Glaciology, 2019 Quarrying and abrasion are the two principal processes responsible for glacial erosion of bedrock. The morphologies of glacier hard beds depend on the relative effectiveness of these two processes, as abrasion tends to smooth bedrock surfaces and ...
J. B. Woodard +3 more
doaj +1 more source
Boreas, EarlyView.We present a 25‐stage reconstruction of the ice‐flow pattern evolution of the Scandinavian Ice Sheet based on mapping and analysis of ~240 000 subglacial lineations and lineation fields across Norway, Sweden, Finland, and parts of NW Russia. Our reconstruction uses a glacial geomorphological inversion approach, in which we generated 611 individual ...
Frances E. G. Butcher +9 more
wiley +1 more source
Boreas, EarlyView.Map of Lower sediment (LS) thickness is a surrogate for the distribution of Thorncliffe Formation (TF) and ~75% of TF thickness from the slope of Niagara Escarpment east to Brighton. Inset images show the LS sequence at the Don Valleys brickyards (DVBY) and undeformed TF sand and gravel (~15 m) below Newmarket Till (NT) at sites L and Co.
David R. Sharpe +3 more
wiley +1 more source
Journal of Glaciology, 2018 Over recent decades, Greenland ice sheet surface melt has shown an increase both in intensity and spatial extent. Part of this water probably reaches the bed and can enhance glacier speed, advecting a larger volume of ice into the ablation area.
OLIVIER GAGLIARDINI, MAURO A. WERDER
doaj +1 more source
Boreas, EarlyView.Effective and sustainable land use, conservation, and the use of geological resources (incl. raw materials, aggregates and groundwater) require a clear classification system of sedimentary units, with well‐defined vocabulary and unified mapping practices.
Jussi Hovikoski +6 more
wiley +1 more source
Geological and glacial-hydrologic controls on chemical weathering in the subglacial environment
Annals of Glaciology, 2022 A comparison of major ion chemistry of subglacial boreholes and discharging subglacial waters reveals three fundamentally different glacier hydrochemical regimes.
Joseph A. Graly, Soroush Rezvanbehbahani
doaj +1 more source
The Devil Lake pothole (Ontario): Evidence of subglacial fluvial processes [PDF]
Géographie physique et Quaternaire, 2002 A pothole 1.93 m deep and 1.3 m maximum diameter is located near the crest of a ridge that forms one arm of an eroded anticline in para-gneiss of the Precambrian Shield in southeastern Ontario. It's position on high ground in a region of more than 100 m relief on the bed rock precludes its formation by modern subaerial stream flow or by streams that ...
openaire +1 more source
Boreas, EarlyView.Rapid thaw of the Earth's cryosphere in response to anthropogenic warming highlights the need to identify and understand the contrasting signatures of past ice‐sheet stability and collapse. The Kvarken archipelago, western Finland, at the centre of the former Fennoscandian Ice Sheet (FIS), has been designated a UNESCO World Heritage site in recognition
Niko Putkinen +6 more
wiley +1 more source
Boreas, EarlyView.Glacially overdeepened valleys in the northern Alpine Foreland preserve Middle to Late Pleistocene sedimentary sequences that may serve as valuable archives for reconstructing past environmental changes in response to shifts in climate. This study presents a multidisciplinary analysis of two sediment cores from the overdeepened Wehntal Valley at ...
Johannes M. Miocic +8 more
wiley +1 more source