A late Wisconsin (32-10k cal a BP) history of pluvials, droughts and vegetation in the Pacific south-west United States (Lake Elsinore, CA)

作者：Kirby M E^*; Heusser L; Scholz C; Ramezan R; Anderson M A; Markle B; Rhodes E; Glover K C; Fantozzi J; Hiner C; Price B; Rangel H

来源：Journal of Quaternary Science, 2018, 33(2): 238-254.

DOI：10.1002/jqs.3018

• California
• drought
• glacial
• insolation
• lakes
• sediment

Continuous, sub-centennially resolved, paleo terrestrial records are rare from arid environments such as the Pacific south-west United States. Here, we present a multi-decadal to centennial resolution sediment core (Lake Elsinore, CA) to reconstruct late Wisconsin pluvials, droughts and vegetation. In general, the late Wisconsin is characterized by a wetter and colder climate than during the Holocene. Specifically, conditions between 32.3 and 24.9k cal a BP are characterized by large-amplitude hydrologic and ecologic variability. Highlighting this period is a approximate to 2000-year glacial mega-drought (27.6-25.7k cal a BP) during which the lake shallowed (3.2-4.5m depth). This period is approximately coeval with a Lake Manix regression and an increase in xeric vegetation in the San Bernardino Mountains (Baldwin Lake). The Local Last Glacial Maximum (LLGM) is bracketed between 23.3 and 19.7k cal a BP - a approximate to 3000-year interval characterized by reduced run-off (relative to the glacial), colder conditions and vegetative stability. Maximum sustained wetness follows the LLGM, beginning at 19.7 and peaking by 14.4k cal a BP. A two-step decrease in runoff characterizes the Lateglacial to Holocene transition; however, the vegetation change is more complex, particularly at the beginning of the Younger Dryas chronozone. By 12.6-12.4k cal a BP, the climate achieved near Holocene conditions.

• 出版日期2018-2