Specific erosional and depositional processes in a pleistocene subglacial tunnel in the wielkopolska region, poland

Pisarska‐Jamroży, Małgorzata; Zieliński, Tomasz

doi:10.1111/j.1468-0459.2012.00466.x

Cited by 23 publications

(10 citation statements)

References 75 publications

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“…The sediment intraclasts with well‐preserved internal laminations probably represent frozen sediment blocks that were eroded upstream and transported in a frozen state downstream before becoming embedded in the enclosing sediment (e.g. Pisarska‐Jamrozy & Zielinski ). The thermal erosion of frozen channel banks would be flow‐energy independent; however, their sizes up to 40 cm indicate substantial flow velocities for their traction transport before deposition.…”

Section: Resultsmentioning

confidence: 99%

A pre‐LGM sandur at Fiskarheden in NW Dalarna, central Sweden – sedimentology and glaciotectonic deformation

Flindt

Alexanderson

Benediktsson

et al. 2018

Boreas

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The Fiskarheden quarry, situated in NW Dalarna, central Sweden, reveals thick coarse‐grained sediments of Scott type facies association representing a sandur deposited in an ice‐proximal proglacial environment. Optically Stimulated Luminescence (OSL) dating of the sandur sediments suggests a pre‐Last Glacial Maximum (LGM) age. Most acquired ages are pre‐Saalian (>200 ka) and we regard each of these ages to represent non/poorly bleached sediment except for one small‐aliquot OSL age of 98±6 ka. This age comes from the top surface of an arguably well‐bleached sand bed deposited on the lee‐side of a braid‐bar, putting the sandur build‐up into the Early Weichselian. Large‐scale glaciotectonic structures show an imbricate thrust fan involving both ductile and brittle deformation. The deformation was from the WNW, which largely coincides with the formative trend of the predominating streamlined terrain and Rogen moraine tracts surrounding Fiskarheden. It is suggested that the deformation of the sandur sediments took place when the advancing glacier approached and pushed its own proglacial outwash sediment, during an ice‐marginal oscillation either at the inception of one of the Early Weichselian glaciations in the area, or during a general ice retreat amid a deglacial phase. The Fiskarheden sandur deposits are covered by a subglacial traction till deposited from the NE/NNE. This direction corresponds with younger streamlined terrain flowsets cross‐cutting the older NNW–SSE system and probably represents deglaciation in the area following the LGM. This study will add to the understanding of the formation and deformation of Pleistocene sandur successions and their relationship to past ice‐sheet behaviour.

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Section: Resultsmentioning

confidence: 99%

A pre‐LGM sandur at Fiskarheden in NW Dalarna, central Sweden – sedimentology and glaciotectonic deformation

Flindt

Alexanderson

Benediktsson

et al. 2018

Boreas

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“…Analogical records of such processes with the participation of fluvioglacial waters are documented mostly in eskers and sandurs e.g. : [2,3,5,9,12], but the outcrops reveal a record of different environmental features of their accumulation. In the Rzymsko esker, accumulation occurred during subglacial flows.…”

Section: Discussionmentioning

confidence: 99%

“…1). Sediments of high-energy glacifluvial flows in the area of Poland have been studied mainly within the extent of the Weichselian Ice Sheet [2,3,4,5] and they are considerably less recognised within the extent of the Saalian II Ice Sheet (Warta Stage). Although traces of glacial outburst floods in Wartanian sediments (compared to the jökulhlaup type of floods) were reported by Rdzany [6,7], they have not been the subject of more indepth research.…”

Section: Introductionmentioning

confidence: 99%

Sediments of High-Energy Meltwater Flows: Examples From Central Poland, Saalian Glaciation

Frydrych¹

2016

Geobalcanica 2016

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Outcrops of coarse grained fluvioglacial sediments, which originated in the conditions of high-energy flows, have been investigated within the extent of the Saalian II (Warta Stage) in Central Poland. They were accumulated during one of the recession phases of glaciation. The article presents examples of erosion and sedimentation in two zones of meltwater activity, which differ as regards their relation to the ice margin. In the area of the Rzymsko esker (Turek Upland Plain), record of high-energy flows, which occurred in a glacial tunnel, often under hydrostatic pressure, has been documented. High water speed and flow, allowed for boulders of considerable size (0.5-1 m) to be transported, which resulted in great erosional force. High-energy flows in subglacial tunnels shaped vast erosional forms, cut not only in older sediments of the Pleistocene, but also in Cretaceous marls and limestones. Some forms were filled with esker sediments. Typical lithofacies of the Rzymsko esker include massive gravels with boulders, and trough and tabular cross-bedded gravels and sands. A characteristic feature of these sediments is the presence of openwork texture. High-energy flows also occurred in the foreland of the Warta ice-sheet during glacial outburst floods. Sediments interpreted as an effect of such an event were analysed at the Siedlątków site (Łask Upland Plain). They form a vast stratum of massive boulders with sandy matrix. Analyses of textural and lithological features of the sediments at the studied sites revealed their close similarity. Coarse grained glacifluvial sediments were characterised by high content of local rocks and significant rounding, which indicates considerable erosional force during flows. The conducted research may imply a far greater impact of high-energy flows on the shaping of landscape and sediment composition within the extent of the Warta ice-sheet than it has been acknowledged so far.

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“…In some cases there is additional evidence for the action of bottom currents because the clasts show well‐developed imbrication (Fig. ) (Pisarska‐Jamrozy & Zielinski, , ). Such current activity also explains the (usually fairly slight) rounding of part of the clasts and implies that at least part of the breccias must have formed at the sedimentary surface.…”

Section: Genesis Of the Fabricmentioning

confidence: 99%

Origin of the vertically orientated clasts in brecciated shallow‐marine limestones of the Chaomidian Formation (Furongian, Shandong Province, China)

Loon

Han

2013

Sedimentology

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Numerous shallow-marine limestone layers of the Furongian (Late Cambrian) Chaomidian Formation in the Jiulongshan section (Shandong Province, China) are breccias. Some of these breccias show abundant vertical to subvertical clasts. Typically, these clasts end abruptly at the contact plane with the overlying deposit, either abutting the overlying sedimentary bed or via an erosional plane that truncates the clasts. A few exposures show concentrations of clasts that must have been uplifted to the extent that they transgressed the then sedimentary surface or (possibly) penetrated the overlying sediment which, in this case, consists of muds or marls. The clasts tend to show clusters with respect to the enclosing fabric. All clasts are parallel to each other in a specific cluster, while the various clusters may show different orientations of the clasts. It is deduced that both the exceptional position and the exceptional orientation of the clasts must be ascribed to the upward movement of the clasts under the influence of pore water escaping under high pressure through fluidized sediment.

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Specific erosional and depositional processes in a pleistocene subglacial tunnel in the wielkopolska region, poland

Cited by 23 publications

References 75 publications

A pre‐LGM sandur at Fiskarheden in NW Dalarna, central Sweden – sedimentology and glaciotectonic deformation

A pre‐LGM sandur at Fiskarheden in NW Dalarna, central Sweden – sedimentology and glaciotectonic deformation

Sediments of High-Energy Meltwater Flows: Examples From Central Poland, Saalian Glaciation

Origin of the vertically orientated clasts in brecciated shallow‐marine limestones of the Chaomidian Formation (Furongian, Shandong Province, China)

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