Climate variability in North America during the last 120,000 years 
revealed by carbon, oxygen and uranium isotopes in pedogenic carbonate

Reflected light photomicrographs of pedogenic carbonate rind (pedothem) from Wind River Basin, Wyoming: A) LA-ICPMS time transgressive analysis transect across pedogenic carbonate laminations; B) 230Th/U powder calibration sample taken from white oval; C) Magnified area of box in (B) showing arrangement of paired C and O analysis spots, vertically transects are along age axis, horizontal are synchronous along carbonate lamination; D) Magnified area of box in (C) showing spatial arrangement of C, O and U analysis spots.

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This work presents a continuous record of paleoclimate in mid-continent North America for the last 120,000 years based on micro-analyses of laminated pedogenic carbonate coatings (pedothems) formed on soil stones.  Modern micro-analytical techniques allow the carbonate layers to be dated and to be analyzed for stable O and C isotopes, which are related to the climatic conditions in which they formed.  The resulting dataset and paleoclimate record is the first of its kind, with a continuity and detail that rivals currently existing paleoclimate records and adds to our understanding of North America climate history during the most recent ice ages.

Press:
Nice article in Earth Magazine
​Berkeley news release
San Francisco public broadcasting story
Awesome example of robo-journalism gone awry
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