Sand veins and wedges in cold aeolian environments

Murton, Julian B.; Worsley, Peter; Goździk, Jan

doi:10.1016/s0277-3791(99)00045-1

Cited by 128 publications

(118 citation statements)

References 60 publications

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“…they have grown vertically with aggradation of the host sand sheet. The vertical lamination is very similar to that reported from other sand veins and wedges along the Beaufort Sea coast (Carter, 1983;Murton, 1996) and more generally within sand wedges of primary infilling (Murton et al, 2000).…”

Section: Sand Veins and Composite Veinssupporting

confidence: 84%

“…The chimney-like shape refers to the more or less uniform width of the structures with depth; because they lack the downward taper characteristic of wedges, they are termed veins (cf. Murton et al, 2000).…”

Section: Sand Veins and Composite Veinsmentioning

confidence: 99%

“…2000) -reveal downward-tapering or irregular structures, often with sand veins branching from theirs sides and toes (Murton, 1996, fig. 6; Murton et al, 2000). Syngenetic ice wedges tend to have a chevron or nested growth pattern (Yershov, 1998;Melnikov and Spesivtsev, 2000, fig.…”

Section: Thermal-contraction Cracking and Sand-wedge Growthmentioning

confidence: 99%

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Syngenetic sand veins and anti‐syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada

Murton

Bateman

2007

Permafrost & Periglacial

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Sand‐sheet deposits of full‐glacial age in the Tuktoyaktuk Coastlands, western Arctic Canada, contain syngenetic sand veins 1–21 cm wide and sometimes exceeding 9 m in height. Their tall and narrow, chimney‐like morphology differs from that of known syngenetic ice wedges and indicates an unusually close balance between the rate of sand‐sheet aggradation and the frequency of thermal‐contraction cracking. The sand sheets also contain rejuvenated (syngenetic) sand wedges that have grown upward from an erosion surface. By contrast, sand sheets of postglacial age contain few or sometimes no intraformational sand veins and wedges, suggesting that the climatic conditions were unfavourable for thermal‐contraction cracking. Beneath a postglacial sand sheet near Johnson Bay, sand wedges with unusually wide tops (≤3.9 m) extend down from a prominent erosion surface. The wedges grew vertically downward during deflation of the ground surface, and represent anti‐syngenetic wedges. The distribution of sand veins and wedges within the sand sheets indicates that the existence of continuous permafrost during sand‐sheet aggradation can be inferred confidently only during full‐glacial conditions. Copyright © 2007 John Wiley & Sons, Ltd.

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Section: Sand Veins and Composite Veinssupporting

confidence: 84%

Section: Sand Veins and Composite Veinsmentioning

confidence: 99%

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Syngenetic sand veins and anti‐syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada

Murton

Bateman

2007

Permafrost & Periglacial

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“…If ground ice was present, climate alternated between periods of freezing and some degree of surface thaw that would allow aeolian transport to occur or severely dry conditions in which little ice would have accumulated on the surface. The significance of the degree of deformation in sand wedges is not well understood, but the minimal deformation observed in the sandsheet and dune facies may relate to the packing of the sand and the amount of pore ice, where greater open pore space and less ice can accommodate wedge expansion without significant deformation (Murton et al, 2000). This could indicate an overall dryer climate than was present during the formation of the highly deformed sand wedges at the base of the mine, which likely formed under constant ice saturation or in the presence of water.…”

Section: Stuart Shelf Sand Wedgesmentioning

confidence: 99%

New constraints on equatorial temperatures during a Late Neoproterozoic snowball Earth glaciation

Ewing

Eisenman

Lamb

et al. 2014

Earth and Planetary Science Letters

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Intense glaciation during the end of Cryogenian time (∼635 million years ago) marks the coldest climate state in Earth history -a time when glacial deposits accumulated at low, tropical paleolatitudes. The leading idea to explain these deposits, the snowball Earth hypothesis, predicts globally frozen surface conditions and subfreezing temperatures, with global climate models placing surface temperatures in the tropics between −20 • C and −60 • C. However, precise paleosurface temperatures based upon geologic constraints have remained elusive and the global severity of the glaciation undetermined. Here we make new geologic observations of tropical periglacial, aeolian and fluvial sedimentary structures formed during the end-Cryogenian, Marinoan glaciation in South Australia; these observations allow us to constrain ancient surface temperatures. We find periglacial sand wedges and associated deformation suggest that ground temperatures were sufficiently warm to allow for ductile deformation of a sandy regolith. The wide range of deformation structures likely indicate the presence of a paleoactive layer that penetrated 2-4 m below the ground surface. These observations, paired with a model of ground temperature forced by solar insolation, constrain the local mean annual surface temperature to within a few degrees of freezing. This temperature constraint matches well with our observations of fluvial deposits, which require temperatures sufficiently warm for surface runoff. Although this estimate coincides with one of the coldest near sea-level tropical temperatures in Earth history, if these structures represent peak Marinaon glacial conditions, they do not support the persistent deep freeze of the snowball Earth hypothesis. Rather, surface temperatures near 0 • C allow for regions of seasonal surface melting, atmosphere-ocean coupling and possible tropical refugia for early metazoans. If instead these structures formed during glacial onset or deglaciation, then they have implications for the timescale and character for the transition into or out of a snowball state.

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“…These are: ventifacts in deflation pavements and aeolian cover sands and sand wedges (Goździk 1980(Goździk , 1992. They all commonly occur in central Poland and are linked to a polar desert environment (Goździk, 1973;Murton et al, 2000). A comparison of the three fluvial series excavated at Bełchatów leads to the conclusion that each of them formed under similarly severe climatic conditions.…”

Section: Comparison Of the Krzaki Series With Other Fluvial Series Atmentioning

confidence: 99%

Evolution of Early Pleistocene fluvial systems in central Poland prior to the first ice sheet advance – a case study from the Bełchatów lignite mine

Goździk

Zieliński

2017

Geologos

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Deposits formed between the Neogene/Pleistocene transition and into the Early Pleistocene have been studied, mainly on the basis of drillings and at rare, small outcrops in the lowland part of Polish territory. At the Bełchatów lignite mine (Kleszczów Graben, central Poland), one of the largest opencast pits in Europe, strata of this age have long been exposed in extensive outcrops. The present paper is based on our field studies and laboratory analyses, as well as on research data presented by other authors. For that reason, it can be seen as an overview of current knowledge of lowermost Pleistocene deposits at Bełchatów, where exploitation of the Quaternary overburden has just been completed. The results of cartographic work, sedimentological, mineralogical and palynological analyses as well as assessment of sand grain morphology have been considered. All of these studies have allowed the distinction of three Lower Pleistocene series, i.e., the Łękińsko, Faustynów and Krzaki series. These were laid down in fluvial environments between the end of the Pliocene up to the advance of the first Scandinavian ice sheet on central Poland. The following environmental features have been interpreted: phases of river incision and aggradation, changes of river channel patterns, source sediments for alluvia, rates of aeolian supply to rivers and roles of fluvial systems in morphological and geological development of the area. The two older series studied, i.e., Łękińsko and Faustynów, share common characteristics. They were formed by sinuous rivers in boreal forest and open forest environments. The Neogene substratum was the source of the alluvium. The younger series (Krzaki) formed mainly in a braided river setting, under conditions of progressive climatic cooling. Over time, a gradual increase of aeolian supply to the fluvial system can be noted; initially, silt and sand were laid down, followed by sand only during cold desert conditions. These fluvio-periglacial conditions are identified in the foreground of the advance of the oldest ice sheet into this part of central Poland. The series studied have been compared with other fluvial successions which accumulated in the Kleszczów Graben during subsequent glaciations so as to document general changes in fluvial systems as reactions to climatic evolution. Thus, a palaeoenvironmental scenario has emerged which could be considered to be characteristic of central Poland during the Early Pleistocene.

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Sand veins and wedges in cold aeolian environments

Cited by 128 publications

References 60 publications

Syngenetic sand veins and anti‐syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada

Syngenetic sand veins and anti‐syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada

New constraints on equatorial temperatures during a Late Neoproterozoic snowball Earth glaciation

Evolution of Early Pleistocene fluvial systems in central Poland prior to the first ice sheet advance – a case study from the Bełchatów lignite mine

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