Geologic setting and stratigraphy of the Ziegler Reservoir fossil site, Snowmass Village, Colorado

Quaternary Research
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Abstract

The geologic setting of the Ziegler Reservoir fossil site is somewhat unusual – the sediments containing the Pleistocene fossils were deposited in a lake on top of a ridge. The lake basin was formed near the Town of Snowmass Village, Colorado when a glacier flowing down Snowmass Creek Valley became thick enough to overtop a low point in the eastern valley wall and entered the head of Brush Creek Valley. When the glacier retreated at the end of the marine isotope stage (MIS) 6, ~155-130 ka (thousands of years before present), the Brush Creek Valley lobe left behind a moraine that impounded a small alpine lake. The lake was initially ~10 m deep and was highly productive during most of its existence based on the abundant and exquisitely preserved organic material present in the sediments. Over time, the basin slowly filled with (mostly) eolian sediment such that by ~85 ka it contained more of a marsh or wetland than a true lake. Open water conditions returned briefly between ~75 and 55 ka before the impoundment was finally breached to the east, establishing ties with the Brush Creek drainage system and creating an alpine meadow that persisted until historic times.

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Publication type Article
Publication Subtype Journal Article
Title Geologic setting and stratigraphy of the Ziegler Reservoir fossil site, Snowmass Village, Colorado
Series title Quaternary Research
DOI 10.1016/j.yqres.2013.12.011
Year Published 2014
Publisher Elsevier
Contributing office(s) Geosciences and Environmental Change Science Center
Description 13 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Quaternary Research
Country United States
State Colorado
Other Geospatial Snowmass Village
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