A Top-to-Bottom Luminescence-Based Chronology for the Post-LGM Regression of a Great Basin Pluvial Lake

• Published in: Quaternary
• Main Authors: Jeffrey S. Munroe, Caleb K. Walcott, William H. Amidon, Joshua D. Landis
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: pluvial lake; hydroclimate; Great Basin; luminescence dating; Nevada; Human evolution; GN281-289; Stratigraphy; QE640-699; Greenland
• Online Access: https://doi.org/10.3390/quat3020011; https://doaj.org/article/9d1bc978356849aba3eebf37f9779464

We applied luminescence dating to a suite of shorelines constructed by pluvial Lake Clover in northeastern Nevada, USA during the last glacial cycle. At its maximum extent, the lake covered 740 km 2 with a mean depth of 16 m and a water volume of 13 km 3 . In the north-central sector of the lake basin, 10 obvious beach ridges extend from the highstand to the lowest shoreline over a horizontal distance of ~1.5 km, representing a lake area decrease of 35%. These ridges are primarily composed of sandy gravel and rise ~1.0 m above the alluvial fan surface on which they are superposed. Single grain luminescence dating of K-feldspar using the pIRIR SAR (post-infrared infrared single-aliquot regenerative dose) protocol, corroborated by SAR dating of quartz, indicates that the highstand shoreline was constructed ca. 16–17 ka during Heinrich Stadial I (Greenland Stadial 2, GS-2), matching 14 C age control for this shoreline elsewhere in the basin. The lake regressed rapidly during the Bølling/Allerød (GI-1), before the rate of regression slowed during the Younger Dryas interval (GS-1). The lowest shoreline was constructed ca. 10 ka. Persistence of Lake Clover into the early Holocene may reflect enhanced monsoonal precipitation driven by the summer insolation maximum.