Ronald Amundson Carol Kendall Peter Wigand A. Hope Jahren 2001 <p><i>Celtis</i><span>&nbsp;sp. (commonly known as &ldquo;hackberry&rdquo;) fruits were collected from 101 North American sites located in 13 states and one Canadian province between the years of 1979&ndash;1994. The biomineralized carbonate endocarp of the hackberry, which is a common botanical fossil found throughout the Quaternary sediments of the Great Plains, was analyzed for its &delta;</span>¹⁸<span>O value and plotted against the &delta;</span>¹⁸<span>O value of site environmental water to demonstrate the potential of the hackberry as a paleoclimate indicator. This correlation was reinforced by intensive studies on extracted tissue-water &delta;</span>¹⁸<span>O value and hackberry endocarp carbonate &delta;</span>¹⁸<span>O value from three trees in Sterling, Colorado. The observed correlation in the large data set between hackberry endocarp carbonate &delta;</span>¹⁸<span>O value and environmental water is [endocarp &delta;</span>¹⁸<span>O=38.56+0.69&times;environmental water &delta;</span>¹⁸<span>O] (</span><i>R</i><span>=0.88;&nbsp;</span><i>R</i>²<span>=0.78;&nbsp;</span><i>p</i><span>&nbsp;value&lt;0.0001). The relation of the hackberry carbonate to temperature in the Great Plains was the following: (average daily-maximum growing season temperature [&deg;C])=6.33+0.67 (&delta;</span>¹⁸<span>O of endocarp carbonate) (</span><i>R</i><span>=0.73;&nbsp;</span><i>R</i>²<span>=0.54;&nbsp;</span><i>p</i><span>value=0.0133). The &delta;</span>¹⁸<span>O value of early Holocene fossil hackberry carbonate in the Pintwater Cave, southern Nevada, suggested precipitation &delta;</span>¹⁸<span>O values more positive than today (&sim;&minus;4&permil; early Holocene vs &sim;&minus;9 to &minus;10&permil; today). This shift, combined with paleobotanical data, suggests an influx of summer monsoonal moisture to this region in the early Holocene. Alternatively, the more positive &delta;</span>¹⁸<span>O values could be viewed as suggestive of warmer temperatures, although the direct use of Great Plains hackberry/temperature relationships to the Great Basin is of debatable value.</span></p> application/pdf 10.1006/qres.2001.2259 en Elsevier Paleoclimatic reconstruction using the correlation in δ¹⁸O of hackberry carbonate and environmental water, North America article