Advanced

The DeKalb mounds of northeastern Illinois as archives of deglacial history and postglacial environments

Curry, B. Brandon; Konen, Michael E.; Larson, Timothy H.; Yansa, Catherine H.; Hackley, Keith C.; Alexanderson, Helena LU and Lowell, Thomas V. (2010) In Quaternary Research 74(1). p.82-90
Abstract
The "type" DeKalb mounds of northeastern Illinois, USA (42.0 degrees N, -88.7 degrees W), are formed of basal sand and gravel overlain by rhythmically bedded fines, and weathered sand and gravel. Generally from 2 to 7 m thick, the fines include abundant fossils of ostracodes and uncommon leaves and stems of tundra plants. Rare chironomid head capsules, pillclam shells, and aquatic plant macrofossils also have been observed. Radiocarbon ages on the tundra plant fossils from the "type" region range from 20,420 to 18,560 cal yr BP. Comparison of radiocarbon ages of terrestrial plants from type area ice-walled lake plains and adjacent kettle basins indicate that the topographic inversion to ice-free conditions occurred from 18,560 and 16,650... (More)
The "type" DeKalb mounds of northeastern Illinois, USA (42.0 degrees N, -88.7 degrees W), are formed of basal sand and gravel overlain by rhythmically bedded fines, and weathered sand and gravel. Generally from 2 to 7 m thick, the fines include abundant fossils of ostracodes and uncommon leaves and stems of tundra plants. Rare chironomid head capsules, pillclam shells, and aquatic plant macrofossils also have been observed. Radiocarbon ages on the tundra plant fossils from the "type" region range from 20,420 to 18,560 cal yr BP. Comparison of radiocarbon ages of terrestrial plants from type area ice-walled lake plains and adjacent kettle basins indicate that the topographic inversion to ice-free conditions occurred from 18,560 and 16,650 cal yr BP. Outside the "type" area, the oldest reliable age of tundra plant fossils in DeKalb mound sediment is 21,680 cal yr BP; the mound occurs on the northern arm of the Ransom Moraine (-88.5436 degrees W, 41.5028 degrees N). The youngest age, 16,250 cal yr BP, is associated with a mound on the Deerfield Moraine (-87.9102 degrees W, 42.4260 degrees N) located about 9 km east of Lake Michigan. The chronology of individual successions indicates the lakes persisted on the periglacial landscape for about 300 to 1500 yr. (C) 2010 University of Washington. Published by Elsevier Inc. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Deglaciation, Ice-walled lake, Pingo, Ostracode, Plant macrofossil
in
Quaternary Research
volume
74
issue
1
pages
82 - 90
publisher
Academic Press
external identifiers
  • wos:000279758300011
  • scopus:77954029297
ISSN
0033-5894
DOI
10.1016/j.yqres.2010.04.009
language
English
LU publication?
no
id
482bc6e8-db2b-46ae-aad2-d4b4aee48f49 (old id 4449999)
date added to LUP
2014-05-26 09:25:39
date last changed
2018-05-29 10:03:06
@article{482bc6e8-db2b-46ae-aad2-d4b4aee48f49,
  abstract     = {The "type" DeKalb mounds of northeastern Illinois, USA (42.0 degrees N, -88.7 degrees W), are formed of basal sand and gravel overlain by rhythmically bedded fines, and weathered sand and gravel. Generally from 2 to 7 m thick, the fines include abundant fossils of ostracodes and uncommon leaves and stems of tundra plants. Rare chironomid head capsules, pillclam shells, and aquatic plant macrofossils also have been observed. Radiocarbon ages on the tundra plant fossils from the "type" region range from 20,420 to 18,560 cal yr BP. Comparison of radiocarbon ages of terrestrial plants from type area ice-walled lake plains and adjacent kettle basins indicate that the topographic inversion to ice-free conditions occurred from 18,560 and 16,650 cal yr BP. Outside the "type" area, the oldest reliable age of tundra plant fossils in DeKalb mound sediment is 21,680 cal yr BP; the mound occurs on the northern arm of the Ransom Moraine (-88.5436 degrees W, 41.5028 degrees N). The youngest age, 16,250 cal yr BP, is associated with a mound on the Deerfield Moraine (-87.9102 degrees W, 42.4260 degrees N) located about 9 km east of Lake Michigan. The chronology of individual successions indicates the lakes persisted on the periglacial landscape for about 300 to 1500 yr. (C) 2010 University of Washington. Published by Elsevier Inc. All rights reserved.},
  author       = {Curry, B. Brandon and Konen, Michael E. and Larson, Timothy H. and Yansa, Catherine H. and Hackley, Keith C. and Alexanderson, Helena and Lowell, Thomas V.},
  issn         = {0033-5894},
  keyword      = {Deglaciation,Ice-walled lake,Pingo,Ostracode,Plant macrofossil},
  language     = {eng},
  number       = {1},
  pages        = {82--90},
  publisher    = {Academic Press},
  series       = {Quaternary Research},
  title        = {The DeKalb mounds of northeastern Illinois as archives of deglacial history and postglacial environments},
  url          = {http://dx.doi.org/10.1016/j.yqres.2010.04.009},
  volume       = {74},
  year         = {2010},
}