Glacier project students and Amy Myrbo analyzing cores in the LacCore lab.

Submitted by Kelly MacGregor (Macalester College)

Kelly MacGregor (Macalester College) and Amy Myrbo (LacCore, University of Minnesota) and eight Gateway students collected water and sediment transport measurements as well as lake core samples in the Many Glacier region of Glacier National Park, Montana in summer 2018.  We spent two weeks in the field collecting data and sampling, and another two weeks at the LacCore laboratory conducting core descriptions and analysis.  Students determined that Fishercap Lake was shallow (~1 m deep), and is unlikely to be a significant sediment trap in the valley system.  They discovered a layer of gravel below ~50 cm of fine-grained sediment that may represent a period of lake dessication or possibly a major flooding event; radiocarbon dating (ongoing) will help constrain the timing of this event.  In addition, Swiftcurrent Lake cores sampled three volcanic ash units from the western U.S., including the Mazama ash (Crater Lake, OR; 7.6 ka) and the Mt. St. Helens J ash (~13.7 ka). Coring along a transect across an inlet delta in Swiftcurrent shows increasing deposition rates with distance from the inlet stream.The students presented their work to Park Rangers, and talked daily with Park visitors during the project.  They will be presenting the results of their research at two posters at the Geological Society of America meeting in November 2018.

GSA Abstracts:

  • Sediment Transport And Deposition In Fishercap Lake And The Swiftcurrent Valley, Glacier National Park, Montana, USA
  • Using Lake Cores To Analyze Sediment Transport And Environmental Change In Swiftcurrent Lake, Glacier National Park, Montana, USA