A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA. Issue 3 (November 2014)

• Record Type: Journal Article
• Authors: Sharpe, Saxon E.; Bright, Jordon
• Is Part Of: Quaternary research. Volume 82:Issue 3(2014)
• Page Start: 604
• Page End: 617
• Publication Date: 2014-11
• Subjects: Snowmass, -- Colorado, -- Mollusk, -- Ostracode, -- late Pleistocene, -- Hydrology, -- MIS 5, -- Stable isotope, -- High-elevation; Geology, Stratigraphic -- Quaternary -- Periodicals; Glacial epoch -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; Époque glaciaire -- Périodiques; Geology, Stratigraphic; Glacial epoch; Quaternary Geologic Period; Electronic journals; Periodicals; 551.79
• DOI: 10.1016/j.yqres.2014.01.014
• Languages: English
• ISSNs: 0033-5894

Abstract

Abstract: Sediments containing terrestrial and aquatic mollusks and ostracodes from the Ziegler Reservoir fossil site (2705 m elevation) near Snowmass Village, Colorado, span ~130–87 ka (MIS 5e through 5b). The southeastern area of the site where taxa were recovered was a relatively fresh, shallow, well-vegetated wetland during MIS 5e through 5c time, approximately 2 m deep, with a total dissolved solids value of ~200–1000 mg L − 1 . The wetland was seasonally or annually variable and groundwater discharged along the margins of the bounding moraine. Groundwater likely contributed solutes to the system and may have contributed 18 O-enriched water. Based on stable isotopes from ostracode calcite (δ 18 OOST and δ 13 COST ), seasonal evaporation occurred and the dissolved inorganic carbon pool was unexpectedly enriched in 13 C. The mollusk and ostracode faunas changed little across the MIS 5e/5d/5c boundaries, whereas a distinct change in the ostracode fauna occurred between the deposition of Unit 11 and Unit 13, which corresponds in time to the MIS 5c/5b boundary, indicating some combination of increased surface and/or groundwater flow, a decrease in water temperature, and a freshening and a possible deepening of the wetland.