Ghent University Academic Bibliography

Advanced

Environmental history of southern Patagonia unravelled by the seismic stratigraphy of Laguna Potrok Aike

Flavio Anselmetti, Daniel Ariztegui, Marc De Batist UGent, Catalina Gebhardt, Torsten Haberzettl, Frank Niessen, Christian Ohlendorf and Bernd Zolitschka (2009) Sedimentology. 56(4). p.873-892
abstract
Laguna Potrok Aike, located in southernmost Patagonia (Argentina, 52 degrees S) is a 100 m deep hydrologically closed lake that probably provides the only continental southern Patagonian archive covering a long and continuous interval of several glacial to interglacial cycles. In the context of the planned 'International Continental Scientific Drilling Program' initiative 'Potrok Aike Maar Lake Sediment Archive Drilling Project', several seismic site surveys that characterize in detail the sedimentary subsurface of the lake have been undertaken. Long sediment cores recovered the material to date and calibrate these seismic data. Laguna Potrok Aike is rimmed steeply, circular in shape with a diameter of similar to 3.5 km and is surrounded by a series of subaerial palaeoshorelines, reflecting varying lake-level highstands and lowstands. Seismic data indicate a basinwide erosional unconformity that occurs consistently on the shoulder of the lake down to a depth of -33 m (below 2003 ad lake level), marking the lowest lake level during Late Glacial to Holocene times. Cores that penetrate this unconformity comprise Marine Isotope Stage 3-dated sediments (45 kyr bp) similar to 3.5 m below, and post-6800 cal yr bp transgressional sediments above the unconformity. This Middle Holocene transgression following an unprecedented lake-level lowstand marks the onset of a stepwise change in moisture, as shown by a series of up to 11 buried palaeoshorelines that were formed during lake-level stillstands at depths between -30 and -12 m. Two series of regressive shorelines between similar to 5800 to 5400 and similar to 4700 to 4000 cal yr bpinterrupt the overall transgressional trend. In the basin, mound-like drift sediments occur after similar to 6000 cal yr bp, documenting the onset of lake currents triggered by a latitudinal shift or an increase in wind intensity of the Southern Hemispheric Westerlies over Laguna Potrok Aike at that time. Furthermore, several well-defined lateral slides can be recognized. The majority of these slides occurred during the mid-Holocene lake-level lowering when the slopes became rapidly sediment-charged because of erosion from the exposed shoulder sediments. Around 7800 and 4900 cal yr bp, several slides went down simultaneously, probably triggered by seismic shaking.
Please use this url to cite or link to this publication:
author
organization
year
type
journalArticle (original)
publication status
published
subject
keyword
Lake-level changes, lake sediments, maar lake, palaeoclimate, Patagonia, seismic stratigraphy, Westerlies
journal title
Sedimentology
volume
56
issue
4
pages
873 - 892
publisher
Wiley-Blackwell Publishing
place of publication
Malden USA
Web of Science type
Article
Web of Science id
000265983700002
JCR category
GEOLOGY
JCR impact factor
2.114 (2009)
JCR rank
5/49 (2009)
JCR quartile
1 (2009)
ISSN
0037-0746
DOI
10.1111/j.1365-3091.2008.01002.x
language
English
UGent publication?
yes
classification
A1
id
716966
handle
http://hdl.handle.net/1854/LU-716966
date created
2009-07-14 13:13:19
date last changed
2009-07-28 12:00:01
@article{716966,
  abstract     = {Laguna Potrok Aike, located in southernmost Patagonia (Argentina, 52 degrees S) is a 100 m deep hydrologically closed lake that probably provides the only continental southern Patagonian archive covering a long and continuous interval of several glacial to interglacial cycles. In the context of the planned 'International Continental Scientific Drilling Program' initiative 'Potrok Aike Maar Lake Sediment Archive Drilling Project', several seismic site surveys that characterize in detail the sedimentary subsurface of the lake have been undertaken. Long sediment cores recovered the material to date and calibrate these seismic data. Laguna Potrok Aike is rimmed steeply, circular in shape with a diameter of similar to 3.5 km and is surrounded by a series of subaerial palaeoshorelines, reflecting varying lake-level highstands and lowstands. Seismic data indicate a basinwide erosional unconformity that occurs consistently on the shoulder of the lake down to a depth of -33 m (below 2003 ad lake level), marking the lowest lake level during Late Glacial to Holocene times. Cores that penetrate this unconformity comprise Marine Isotope Stage 3-dated sediments (45 kyr bp) similar to 3.5 m below, and post-6800 cal yr bp transgressional sediments above the unconformity. This Middle Holocene transgression following an unprecedented lake-level lowstand marks the onset of a stepwise change in moisture, as shown by a series of up to 11 buried palaeoshorelines that were formed during lake-level stillstands at depths between -30 and -12 m. Two series of regressive shorelines between similar to 5800 to 5400 and similar to 4700 to 4000 cal yr bpinterrupt the overall transgressional trend. In the basin, mound-like drift sediments occur after similar to 6000 cal yr bp, documenting the onset of lake currents triggered by a latitudinal shift or an increase in wind intensity of the Southern Hemispheric Westerlies over Laguna Potrok Aike at that time. Furthermore, several well-defined lateral slides can be recognized. The majority of these slides occurred during the mid-Holocene lake-level lowering when the slopes became rapidly sediment-charged because of erosion from the exposed shoulder sediments. Around 7800 and 4900 cal yr bp, several slides went down simultaneously, probably triggered by seismic shaking.},
  author       = {Anselmetti, Flavio and Ariztegui, Daniel and De Batist, Marc and Gebhardt, Catalina and Haberzettl, Torsten and Niessen, Frank and Ohlendorf, Christian and Zolitschka, Bernd},
  issn         = {0037-0746},
  journal      = {Sedimentology},
  keyword      = {Lake-level changes,lake sediments,maar lake,palaeoclimate,Patagonia,seismic stratigraphy,Westerlies},
  language     = {eng},
  number       = {4},
  pages        = {873--892},
  publisher    = {Wiley-Blackwell Publishing},
  title        = {Environmental history of southern Patagonia unravelled by the seismic stratigraphy of Laguna Potrok Aike},
  url          = {http://dx.doi.org/10.1111/j.1365-3091.2008.01002.x},
  volume       = {56},
  year         = {2009},
}

Chicago
Anselmetti, Flavio, Daniel Ariztegui, Marc De Batist, Catalina Gebhardt, Torsten Haberzettl, Frank Niessen, Christian Ohlendorf, and Bernd Zolitschka. 2009. “Environmental History of Southern Patagonia Unravelled by the Seismic Stratigraphy of Laguna Potrok Aike.” Sedimentology 56 (4): 873–892.
APA
Anselmetti, F., Ariztegui, D., De Batist, M., Gebhardt, C., Haberzettl, T., Niessen, F., Ohlendorf, C., et al. (2009). Environmental history of southern Patagonia unravelled by the seismic stratigraphy of Laguna Potrok Aike. Sedimentology, 56(4), 873–892.
Vancouver
1.
Anselmetti F, Ariztegui D, De Batist M, Gebhardt C, Haberzettl T, Niessen F, et al. Environmental history of southern Patagonia unravelled by the seismic stratigraphy of Laguna Potrok Aike. Sedimentology. Malden USA: Wiley-Blackwell Publishing; 2009;56(4):873–92.
MLA
Anselmetti, Flavio, Daniel Ariztegui, Marc De Batist, et al. “Environmental History of Southern Patagonia Unravelled by the Seismic Stratigraphy of Laguna Potrok Aike.” Sedimentology 56.4 (2009): 873–892. Print.