Pleistocene epigenetic and syngenetic frost fissures, Belchatów, Poland

Abstract

Pseudomorphs of cryogenic fissures in stratified medium to fine silty sand and sand at Belchatów, Poland, indicate both epigenetic and syngenetic freezing of sediments at various times during the Pleistocene. Syngenetic fissures are more frequent. They are typically 0.5–2.0 m in vertical dimension, range in width from 5 to 20 cm, exhibit both upwarps and downwarps of enclosing sediments, and are offset from each other in the stratigraphic sequence. Epigenetic fissures are larger, generally increase in width upwards, and are related to an inferred ground surface. It is difficult to distinguish between syngenetic fissures that penetrate permafrost and soil (ground) veins or wedges that require only deep seasonal frost for their formation. Cold, continental environments characterized by rapid sedimentation and permafrost aggradation appear most conducive for formation of syngenetic fissures. Today, both large and small syngenetic fissures are known to exist in the permafrost regions of Siberia but are rarely reported from the western Arctic lowlands of North America.

Palaeoenvironmental Proxies for Permafrost Presence During the Younger Dryas, Central Poland

“…We argue that also deformation structures in Warta River valley have been caused by periglacial conditions rather than by tectonic activity for four reasons. First, finger‐like structures in the lower part of the frost fissures typically develop in periglacial environments (French and Goździk, ; Harry and Goździk, ). Second, the symmetrical arrangement of layers on both sides of the structures excludes faults, and the lack of characteristic fillings excludes tension wedges (van Vliet‐Lanoë et al, ).…”

Evidence for late‐Pleistocene permafrost in the New Jersey Pine Barrens (latitude 39°N), eastern USA

“…The wedges in the Pine Barrens also appear to be epigenetic rather than syngenetic (cf. French and Gozdzik, 1988). This is because all the wedges relate to the present ground surface.…”

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

“…Syngenetic ice wedges ≤26 m high and ≤2-3 m wide also occur in windblown silt (loess) in northern Alaska (Carter, 1988). French and Gozdzik (1988) suggested, however, that the majority of syngenetic frost fissures outside of central and northern Siberia are probably smaller than epigenetic ones, with heights of 0.5-2.0 m and maximum widths of 5-20 cm (cf. French et al, 1982).…”