Todd E Lange

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Scholarly Contributions

Journals/Publications

• Jull, A. J., Miyake, F., Wacker, L., Salzer, M., Panyushkina, I. P., Lange, T. E., Cruz, R., Masada, K., & Nakamura, T. (2017). A large 14C excursion at 5480BC indicates an abnormal sun.. Proceedings of the National Academy of Sciences USA, 114(881-884), 4. doi:10.1073/pnas.1613144114
• Jull, A. J., Panyushkina, I. P., Lange, T. E., Kukarskih, V. V., Myglan, V. S., Clark, K. J., Salzer, M. W., Burr, G. S., & Leavitt, S. W. (2014). Excursions in the 14C record at AD 774-775 in tree rings from Russia and America. Geophysical Research Letters, doi: 10.1002/2014GL059874.
• Anchukaitis, K. J., Evans, M. N., Lange, T., Smith, D. R., Leavitt, S. W., & Schrag, D. P. (2008). Consequences of a rapid cellulose extraction technique for oxygen isotope and radiocarbon analyses. Analytical Chemistry, 80(6), 2035-2041.
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  PMID: 18293945;Abstract: We use infrared, radiocarbon, and stable isotope analyses to investigate the purity of cellulose extracted from wood using a rapid processing technique. Replicate laboratory standards processed using the standard Brendel method are not significantly different with respect to δ18O from those prepared using traditional techniques, although the process does result in a slight acetylation of the wood samples. Radiocarbon comparisons, however, show significant differences. We conclude mat the standard Brendel method is appropriate for developing stable isotope time series for high-resolution isotope dendroclimatology but must be used with caution for precision radiocarbon measurements. © 2008 American Chemical Society.
• Panyushkina, I. P., Leavitt, S. W., Thompson, T. A., Schneider, A. F., & Lange, T. (2008). Environment and paleoecology of a 12 ka mid-North American Younger Dryas forest chronicled in tree rings. Quaternary Research, 70(3), 433-441.
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  Abstract: Until now, availability of wood from the Younger Dryas abrupt cooling event (YDE) in N. America ca. 12.9 to 11.6 ka has been insufficient to develop high-resolution chronologies for refining our understanding of YDE conditions. Here we present a multi-proxy tree-ring chronology (ring widths, "events" evidenced by microanatomy and macro features, stable isotopes) from a buried black spruce forest in the Great Lakes area (Liverpool East site), spanning 116 yr at ca. 12,000 cal yr BP. During this largely cold and wet period, the proxies convey a coherent and precise forest history including frost events, tilting, drowning and burial in estuarine sands as the Laurentide Ice Sheet deteriorated. In the middle of the period, a short mild interval appears to have launched the final and largest episode of tree recruitment. Ultimately the tops of the trees were sheared off after death, perhaps by wind-driven ice floes, culminating an interval of rising water and sediment deposition around the base of the trees. Although relative influences of the continental ice sheet and local effects from ancestral Lake Michigan are indeterminate, the tree-ring proxies provide important insight into environment and ecology of a N. American YDE boreal forest stand. © 2008 University of Washington.
• Leavitt, S. W., Panyushkina, I. P., Lange, T., Cheng, L., Schneider, A. F., & Hughes, J. (2007). Radiocarbon "wiggles" in great lakes wood at about 10,000 to 12,000 bp. Radiocarbon, 49(2), 855-864.
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  Abstract: High-resolution radiocarbon calibration for the last 14,000 cal yr has been developed in large part using Euro- pean oaks and pines. Recent subfossil wood collections from the Great Lakes region provide an opportunity to measure 14C activity in decadal series of rings in North America prior to the White Mountains bristlecone record. We developed decadal 14C series from wood at the classic Two Creeks site (~11,850 BP) in east-central Wisconsin, the Liverpool East site (~10,250 BP) in northwestern Indiana, and the Gribben Basin site (~10,000 BP) in the Upper Peninsula of Michigan. Initial AMS dates on holocellulose produced younger-than-expected ages for most Two Creeks subsamples and for a few samples from the other sites, prompting a systematic comparison of chemical pretreatment using 2 samples from each site, and employing holocellulose, AAA-treated holocellulose, alpha-cellulose, and AAA-treated whole wood. The testing could not definitively reveal the source of error in the original analyses, but the "best" original ages together with new AAA-treated holocellulose and α-cellulose ages were visually fitted to the IntCal04 calibration curve at ages of 13,760-13,530 cal BP for the Two Creeks wood, 12,100-12,020 cal BP for Liverpool East, and 11,300-11,170 cal BP for Gribben Basin. The Liverpool East age falls squarely within the Younger Dryas (YD) period, whereas the Gribben Basin age appears to postdate the YD by ~300 yr, although high scatter in the decadal Gribben Basin results could accommodate an older age nearer the end of the YD. © 2007 by the Arizona Board of Regents on behalf of the University of Arizona.
• Leavitt, S. W., Panyushkina, I. P., Lange, T., Wiedenhoeft, A., Cheng, L., Hunter, R. D., Hughes, J., Pranschke, F., Schneider, A. F., Moran, J., & Stieglitz, R. (2006). Climate in the Great Lakes region between 14,000 and 4000 years ago from isotopic composition of conifer wood. Radiocarbon, 48(2), 205-217.
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  Abstract: The isotopic composition of ancient wood has the potential to provide information about past environments. We analyzed the Δ13C, Δ18O, and Δ2H of cellulose of conifer trees from several cross-sections at each of 9 sites around the Great Lakes region ranging from ~4000 to 14,000 cal BP. Isotopic values of Picea, Pinus, and Thuja species seem interchangeable for Δ18O and Δ2H comparisons, but Thuja appears distinctly different from the other 2 in its Δ13C composition. Isotopic results suggest that the 2 sites of near-Younger Dryas age experienced the coldest conditions, although the Gribben Basin site near the Laurentide ice sheet was relatively dry, whereas the Liverpool site 500 km south was moister. The spatial isotopic variability of 3 of the 4 sites of Two Creeks age shows evidence of an elevation effect, perhaps related to sites farther inland from the Lake Michigan shoreline experiencing warmer daytime growing season temperatures. Thus, despite floristic similarity across sites (wood samples at 7 of the sites being Picea), the isotopes appear to reflect environmental differences that might not be readily evident from a purely floristic interpretation of macrofossil or pollen identification. © 2006 by the Arizona Board of Regents on behalf of the University of Arizona.

Presentations

• Jull, A. J., Miyake, F., Panyushkina, I. P., Lange, T. E., Basin, C., Salter, M., & Masada, K. (2016, October). Search for cosmic-ray variations in the past from 14C and other radionuclides. Conference on the Application of Accelerators to Research and Industry. Fort Worth, Tx: CAARI/Sandia Labs/Univ of North Texas.

Poster Presentations

• Pearson, C. L., Brewer, P. W., Salzer, T. A., Hodgins, G. W., Jull, A. J., Lange, T. E., Cruz, R., Brown, D., Boswijk, G., Pearson, C. L., Brewer, P. W., Salzer, T. A., Hodgins, G. W., Jull, A. J., Lange, T. E., Cruz, R., Brown, D., & Boswijk, G. (2017, Spring). A 150 year record of annual Bristlecone Pine 14C from the second millennium BC. European Geosciences Union. Vienna.