Mots-clés
Delaware ; Delmarva Peninsula ; Etats-Unis ; Héritage géomorphologique ; Maryland ; New Jersey ; Pergélisol ; Plaine côtière ; Périglaciaire ; Quaternaire ; Sol figuré ; Virginia ; WisconsinienCoastal plain ; Delaware ; Inheritated geomorphological features ; Maryland ; New Jersey ; Patterned ground ; Periglacial features ; Permafrost ; Quaternary ; United States of America ; Virginia ; WisconsinanCuaternario ; Estados Unidos ; Herencia geomorfológica ; Nuevo Jersey ; Pergelisol ; Periglaciar ; Planicie litoral ; Suelo figurado ; WisconsinienseRelict thermal-contraction-crack polygons and past permafrost South of the Late Wisconsinan Glacial Limit in the Mid-Atlantic Coastal Plain, USA
Auteur(s) et Affiliation(s)
GAO, C.
Ontario Geological Survey, Sudbury, Canada
Description :
The paucity of reports on relict thermal contraction crack polygons in the mid-Atlantic Coastal Plain and many other areas in eastern North America has hampered our understanding of the extent and nature of past permafrost south of the Late Wisconsinan glacial limit. Examination of Google Earth™ imagery revealed orthogonal to hexagonal polygons, mostly 10–30 m in diameter, at more than 160 sites in sand and gravel deposits in southern New Jersey and the Delmarva Peninsula. The polygons are interpreted to indicate that continuous permafrost extended to 38.5°N in a zone more than 250 km wide to the south of the glacial limit under a mean annual air temperature of ≤ −6°C probably during the Late Wisconsinan.
Type de document :
Article de périodique
Source :
Permafrost and periglacial processes, issn : 1045-6740, 2014, vol. 25, n°. 2, p. 144-149, nombre de pages : 6, Références bibliographiques : 1 p.
Date :
2014
Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley
Langue :
Anglais
Anglais
Droits :
Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI)
Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI)