Sign on

SAO/NASA ADS Physics Abstract Service

· Find Similar Abstracts (with default settings below)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Preliminary Chronostratigraphy of Pingualuit Impact Crater Lake Sediments (Nunavik, Canada): a Possible Arctic Terrestrial Record of Several Glacial/Interglacial Cycles
Authors:
St-Onge, G.; Guyard, H.; Pienitz, R.; Hausmann, S.; Salonen, V.; Luoto, T.; Francus, P.; Larocque, I.; Lavoie, M.; Lamothe, M.; Vincent, W. F.; Niederreiter, R.
Affiliation:
AA(ISMER and GEOTOP, Universite du Quebec a Rimouski 310 allee des Ursulines, Rimouski, QC G5L 3A1, Canada ; ), AB(ISMER and GEOTOP, Universite du Quebec a Rimouski 310 allee des Ursulines, Rimouski, QC G5L 3A1, Canada ; ), AC(Dept. of Geography and CEN, Universite Laval, Quebec, QC G1K 7P4, ; ), AD(Dept. of Geosciences, University of Arkansas, Fayetteville, AR 72701, United States ; ), AE(Dept. of Geology, University of Helsinki, Helsinki, FI-00014, Finland ; ), AF(Dept. of Geology, University of Helsinki, Helsinki, FI-00014, Finland ; ), AG(INRS-ETE and GEOTOP, 490 rue de la Couronne, Quebec, QC G1K 9A9, Canada ; ), AH(INRS-ETE and GEOTOP, 490 rue de la Couronne, Quebec, QC G1K 9A9, Canada ; ), AI(Dept. of Geography and CEN, Universite Laval, Quebec, QC G1K 7P4, ; ), AJ(Dept. of Earth and Atmospheric Sciences, Universite du Quebec a Montreal, Montreal, QC H3C 3P8, Canada ; ), AK(Dept. of Biology and CEN, Universite Laval, Quebec, QC G1K 7P4, Canada ; ), AL(UWITEC, Moosbachweg 10, Mondsee, A-5310, Austria ; )
Publication:
American Geophysical Union, Fall Meeting 2007, abstract #U13B-1150
Publication Date:
12/2007
Origin:
AGU
AGU Keywords:
1105 Quaternary geochronology, 1135 Correlative geochronology, 1165 Sedimentary geochronology, 1520 Magnetostratigraphy, 4914 Continental climate records
Abstract Copyright:
(c) 2007: American Geophysical Union
Bibliographic Code:
2007AGUFM.U13B1150S

Abstract

The Pingualuit Crater Lake is a 1.4 Ma perfectly circular depression. It is 3.4 km in diameter and hosts a lake with a maximum depth of 267 m with no surface connection to other surrounding water bodies. It is located in the northernmost part of the Ungava Peninsula in Nunavik, Canada (61°N, 73°W) and, due to its unique morphometry (shape, depth), the lake bottom may have escaped glacial erosion, possibly preserving a continuous Arctic terrestrial record of several glacial/interglacial cycles. Previous attempts to core the lake have resulted in the collection of only 14 cm of sediments that spanned about the last ~5000 years. Here, in order to test the possible accumulation of several glacial/interglacial cycles, we will present initial high resolution physical (CAT-scan, Multi Sensor Core Logger, color reflectance, high resolution digital images), magnetic (point source magnetic susceptibility) and sedimentological (detailed visual description, grain size) properties of about 10 m of sediments recently cored using a UWITEC piston percussion corer under harsh climatic conditions. The initial results revealed the presence of at least two decimetre-thick intervals composed of laminated, dark grey clayey silts characterized by a relatively low density and magnetic susceptibility that contrast sharply with the thicker and more abundant over- and underlying light grey, denser, sandy sediments. The sediment characteristics in the darker laminated intervals are also similar to the ones observed in the small surface gravity core sampled at the same site. Moreover, smear slides performed in these two intervals revealed the presence of diatoms and chrysophytes, suggesting that these two intervals represent ice-free conditions and thus possible interglacials, whereas the more abundant light grey and more sandy sediments likely reflect glacial intervals. This interpretation will be tested by ongoing paleomagnetic measurements (i.e., magnetostratigraphy), as well as radiocarbon and thermoluminescence dating.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints