thumbnail

Reconstruction of hydrological changes and response to effective moisture variations from North-Central USA lake sediments

Quaternary Science Reviews

By:
and
DOI: 10.1016/S0277-3791(01)00121-4

Links

Abstract

Ratios of the stable isotopes of oxygen and carbon in benthic ostracodes and marl from cores taken from two lakes in north-central Minnesota reflect Holocene hydrological and vegetation changes. Oxygen isotopes show that Williams and Shingobee Lakes, located in the same watershed but with different positions along a hydrologic gradient, were connected before 9.8 ka as part of a larger lake, Lake Willobee. From 9.8-7.7 ka, the level of Lake Willobee fell as a result of glacial retreat and increasing evaporation, leaving small separated basins. Further decreases in lake level after 7.7 ka due to increasing aridity triggered the inflow of ground water in Williams Lake at about 7 ka, and in Shingobee Lake at about 5 ka. After 4 ka effective moisture increased. The carbon-isotope record reflects changes in vegetation with higher ??13C values during the prairie period (7.7-4 ka) and lower values during preceding and succeeding forest periods. The differences in timing of hydrological events show that the biotic and geochemical response of the lakes to climate variations is mediated by their hydrologic systems. The response may be strongly spatially heterogeneous and can result in contrasting information from geochemical and biotic proxies from the same paleorecord. ?? 2002 Elsevier Science Ltd. All rights reserved.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Reconstruction of hydrological changes and response to effective moisture variations from North-Central USA lake sediments
Series title:
Quaternary Science Reviews
DOI:
10.1016/S0277-3791(01)00121-4
Volume
21
Issue:
12-13
Year Published:
2002
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Quaternary Science Reviews
First page:
1541
Last page:
1554