Few records in the alpine landscape of western North America document the geomorphic and glaciologic response to climate change during the Pleistocene-Holocene transition. While moraines can provide snapshots of glacier extent, high-resolution records of environmental response to the end of the Last Glacial Maximum, Younger Dryas cooling, and subsequent warming into the stable Holocene are rare. We describe the transition from the late Pleistocene to the Holocene using a ~. 17,000-yr sediment record from Swiftcurrent Lake in eastern Glacier National Park, MT, with a focus on the period from ~. 17 to 11. ka. Total organic and inorganic carbon, grain size, and carbon/nitrogen data provide evidence for glacial retreat from the late Pleistocene into the Holocene, with the exception of a well-constrained advance during the Younger Dryas from 12.75 to 11.5. ka. Increased detrital carbonate concentration in Swiftcurrent Lake sediment reflects enhanced glacial erosion and sediment transport, likely a result of a more proximal ice terminus position and a reduction in the number of alpine lakes acting as sediment sinks in the valley.
|Original language||English (US)|
|Number of pages||11|
|Journal||Quaternary Research (United States)|
|State||Published - Jul 1 2015|
Bibliographical noteFunding Information:
We thank the Keck Foundation and NSF for supporting core collection as well as the Macalester College Wallace Faculty Research fund for providing financial support. We thank the LacCore facility ( NSF-EAR-0949962 ) and staff for their support in the field and lab. Thanks to the National Park Service and the Glacier Park Boat Company for logistical support, and Kevin Theissen, St. Thomas University, for use of his Elemental Analyzer. Special thanks to Lucy Andrews and Jason Addison for their input and laboratory work in the tephra identification process. We are grateful to Doug Clark and Eric Leonard for helpful comments that significantly improved the manuscript.
- Geomorphic change
- Glacial erosion
- Glacier National Park
- Grinnell Glacier
- Lake sediment core
- Last Glacial Maximum
- Late Pleistocene
- Total inorganic carbon
- Younger Dryas