Abstract
The landscape of northeast Ontario, Canada, is dominated by glacial and postglacial landforms including numerous boreal lakes that formed following the retreat of the Laurentide Ice Sheet (LIS) and Glacial Lake Ojibway. This study uses micro-X-Ray Fluorescence elemental analysis to examine changes in sediment cores from two boreal lakes from northeast Ontario with the goal of inferring changes in terrestrial inputs and redox status of these lakes over the middle to late Holocene. These headwater lakes were selected as they have small watersheds that minimizes the complexity of hydrological responses, and as they are relatively proximal (∼130 km distance between lakes) to allow the detection of regional signals related to changes in climate over the Holocene. Strong correlations between Si, K, Ca, and Ti in Hogback Lake and Green Lake cores suggest that these elements represent proxies of terrestrial input. Standardized composite trends of these elements were very similar between the two lakes and were combined to represent a regional signal, with the highest terrestrial inputs between ∼6000 and ∼4000 cal yr BP, that subsequently declined through the Holocene. These results suggest that regional patterns in terrestrial input are linked to changes in hydroclimate and likely increased terrestrial stability over the middle to late Holocene. These composite trends are compared to similar geochemical composite trends from Iceland suggesting climate teleconnections between northeast North America and the North Atlantic. Cool conditions in the North Atlantic result in increased soil erosion in Iceland and correspond to cool and dry conditions in boreal northeast Ontario with corresponding low inputs of terrestrial material, and vice versa, over multidecadal time scales over the middle to late Holocene.
Original language | English (US) |
---|---|
Article number | 107056 |
Number of pages | 15 |
Journal | Quaternary Science Reviews |
Volume | 265 |
DOIs | |
State | Published - Aug 1 2021 |
Bibliographical note
Funding Information:The authors thank the Ontario Ministry of Natural Resources and Forestry for access to Green Lake within Greenwater Provincial Park. Additional thanks are given to Maya Grantier and Jessica Heck of LacCore, University of Minnesota, and Tom Brown of Lawrence Livermore National Laboratory for sample preparation and 14C AMS dating. Thanks are also given to Graham Mushet and Monica Fisher for their assistance with core collection. Special thanks are given to Dr. ? Geirsd?ttir for kindly providing the Iceland composite data presented in this manuscript. Funding for this project consisted of NSERC Discovery grants to EGR and BFC and an NSERC PGS-D scholarship to CACG with support from The W. Garfield Weston Foundation Fellowship Program, a program of the Wildlife Conservation Society Canada funded by The W. Garfield Weston Foundation. This research was based on samples collected from Canada's Treaty 9, the territory historically occupied and cared for by Ojibway and Oji-Cree peoples of the Anishinaabe nation.
Funding Information:
The authors thank the Ontario Ministry of Natural Resources and Forestry for access to Green Lake within Greenwater Provincial Park. Additional thanks are given to Maya Grantier and Jessica Heck of LacCore, University of Minnesota, and Tom Brown of Lawrence Livermore National Laboratory for sample preparation and 14 C AMS dating. Thanks are also given to Graham Mushet and Monica Fisher for their assistance with core collection. Special thanks are given to Dr. Á Geirsdóttir for kindly providing the Iceland composite data presented in this manuscript. Funding for this project consisted of NSERC Discovery grants to EGR and BFC and an NSERC PGS-D scholarship to CACG with support from The W. Garfield Weston Foundation Fellowship Program, a program of the Wildlife Conservation Society Canada funded by The W. Garfield Weston Foundation. This research was based on samples collected from Canada's Treaty 9, the territory historically occupied and cared for by Ojibway and Oji-Cree peoples of the Anishinaabe nation.
Publisher Copyright:
© 2021 Elsevier Ltd
Keywords
- Climate oscillations
- Generalized additive model (GAM)
- Itrax core scanning
- Micro-X-ray fluorescence (μXRF)
- Paleoclimate
- Sediment cores