Author(s)

Grayson W. Carlile

Graduation Year

2015

Date of Thesis Acceptance

Spring 5-13-2015

Major Department or Program

Geology

Advisor(s)

Nick Bader

Abstract

Glacier National Park in Montana is known for its spectacular landscape, carved by valley glaciers. Understanding the complex pattern of glacial advance and retreat may provide important insights into the relationship between climate and glacial cycles in alpine environments, and may help us to better predict the future of such landscapes. In the Grinnell Glacier valley, the remaining glacier sits atop a carbonate formation of the Belt Supergroup. Previous studies of lake sediment cores within the drainage system (MacGregor et al., 2011; Schachtman et al., in press) have found higher concentrations of carbonate sediments in parts of the core inferred to be deposited during times of glacial advance, suggesting that the concentration of carbonate in sediments may be used as a proxy for periods when the Grinnell Glacier advanced. In this study, we tested this hypothesis by measuring carbonate concentrations in sediments deposited during the Pleistocene and Holocene (a period of over 6,000 years) from a glacially fed lake closer to the Grinnell Glacier. Carbonate concentrations in sediments are higher during inferred periods of cooling, such as the Younger Dryas, when the Grinnell Glacier is expected to have been advancing. Conversely, carbonate concentrations decrease during warming periods, such as the Bølling-Allerød and early Holocene. This supports our hypothesis that carbonate concentration may be used as proxy for glacial extent within the Grinnell Glacier valley.

Page Count

22

Subject Headings

Montana -- Glacier -- Grinnell Glacier, Montana - Glacier -- Swiftcurrent Ridge Lake, Glaciers -- Montana -- Glacier National Park, Carbonate sediments, Landscapes -- Montana History, Lake sediments, Glaciers -- Measurement, Whitman College 2015 -- Dissertation collection -- Geology Department

Permanent URL

http://hdl.handle.net/10349/20151080

Document Type

Public Accessible Thesis

Terms of Use

If you have questions about permitted uses of this content, please contact the ARMINDA administrator

Included in

Geology Commons

Share

COinS
 

Rights Statement

Rights Statement

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).