Physical Sciences and Mathematics Commons^™

A Continuous Late Holocene Record Of Paleoclimate Change From Grinnell Lake Sediment Cores, Glacier National Park, Montana, Jonathan G. Griffith

Honors Theses

Grinnell Lake is a glacially-fed alpine lake in the northern Rocky Mountains of Montana. Limnological parameters and radiocarbon ages from a ~1.17 -meter-long sediment core from Grinnell Lake provide a ~1,200 year-long climate record. The objective of this thesis is to develop a multi-proxy record of glaciation by distinguishing periods of positive and negative mass balance chronologically. Two overlapping sediment cores (1P-1B-1 and 1C-2B-1) were described, photographed, and sampled at 0.5 cm, 1 cm, and 5 cm intervals and analyzed for % organic carbon, % inorganic carbon, mineral composition, bulk density, biogenic silica, and clastic sediment flux. Glacial fluctuations were …