Authored by: Dr. Adam Z. Csank / Department of Geography, University of Nevada-Reno Reno, NV 89557, USA

1. Introduction

In December of 2015 I was contacted by Dr John Gosse of Dalhousie University, acting on behalf Hal Butler and Devon Babineau. Hal and Devon were interested in determining the age of two hockey sticks one of which is believed to have the potential to be one of the oldest hockey sticks ever found.

In May of 2016, I met with Hal and Devon to have a look and see if it would be possible to use dendrochronologic methods to date their hockey sticks. After sanding the end grain of both sticks to better resolve the rings, I determined that the Jones stick only had 12 rings. The other stick had 16 rings. The number of rings is very small to allow for an accurate dendrochronlogical date. In addition the rings are what we term complacent, meaning that there is very little variability between rings. Both of these facts would make accurate dating using dendrochronology difficult (if not impossible) to do. Upon advising Hal and Devon of this I did mention that what I would be able to do would be to provide an identification of the type of wood that was used, results from that analysis were reported in an earlier report where one sample was identified as Maple and the other as American Elm. At the time I examined the sticks I collected samples of the sanding dust to analyze for stable isotopes in order to provenance the wood used to manufacture the hockey sticks. The results of the isotopic analysis are contained in this report.

2. Methods

Dust collected from the samples was first soaked in acetone for 24 hours to remove any traces of varnish that were on the original samples. Varnish would contaminate the isotopic results. The samples were subsequently processed to pure alpha-cellulose following a modified version of the Leavitt-Danzer method in standard use in my lab.

First a bleaching solution was prepared by mixing up a 14% solution of sodium chlorite. 10ml of glacial acetic acid were then added to this solution. Powdered wood samples were placed in 2ml microcentrifuge tubes, the tubes were filled ¾ full with the bleaching solution (~1.5ml) and were placed in aluminum heat blocks on a hot plate at 70º C for 4 hours. After 4 hours the bleaching solution was refreshed by pipetting out the used bleaching solution from the microcentrifuge tubes containing the samples and adding new solution. Samples were mixed and placed back in the heat blocks for 2 hours. The bleaching solution was refreshed at 2 hour intervals until the samples were white. Samples were then rinsed 3 times in deionized water and then ethanol was added to the microcentrifuge tubes to a level ¾ full. Samples were placed in the heat blocks on a hot plate at 70º C for 30 min. This step was to remove any remaining varnish. Samples were centrifuged and the ethanol was removed. Next a 17% solution of sodium hydroxide (NaOH) was added to the microcentrifuge tubes containing the samples. Samples were mixed and placed in heat blocks on a hot plate at 80º C for 1 hour. Samples were centrifuged and the NaOH was decanted. A 10% solution of hydrochloric acid was added to neutralize any remaining NaOH and samples were again centrifuged and decanted. Samples were then rinsed twice in  deionized water and once in ethanol. Finally samples were placed in a drying oven set to 50º C overnight.

Approximately 0.4mg of the purified alpha-cellulose from each sample was then weighed and placed into a silver capsule for stable oxygen isotope analysis. Oxygen isotope analysis was carried out using an IsoPRIME VisION Isotope Ratio Mass Spectrometer (IRMS) directly coupled to a Vario PyroCUBE set up in pyrolysis mode. In the PyroCUBE samples were pyrolized in an oxygen-free environment at a temperature of 1450º C, the resulting gas from the samples was run through a gas chromatograph and sent to the IRMS, where they were calibrated against a carbon monoxide reference gas and the benzoic acid standards IAEA-601 and IAEA-602, both obtained from the International Atomic Energy Agency.

3. Results

4. Discussion and Conclusion

The stable oxygen isotope values we found for these two samples are indicative of values that would place the origin of these samples in Northeastern North America. By using the mechanistic model of Roden et al. (2000) I can convert these cellulose isotope values into probable water values. When this is done the precipitation values fall between – 9 and -14 ‰. If we look at the map in figure 1 these values would place them away from the coast or further north (i.e. NS or NB).

Because a large number of Elms in eastern North America were killed by Dutch Elm disease very few isotopic studies have been carried out on elm. However, there was a study carried out by Buhay and Edwards (1995) who analyzed an elm from Southwestern Ontario who found values that were similar to ours (24.1 to 28.0 ‰). This would confirm that the Elm Hockey stick likely came from the Great Lakes region, possibly even from Ontario. There have been more Isotopic studies conducted using maple, in fact the Buhay and Edwards (1995) study also included a sample of maple from the same region of Southwestern Ontario with values ranging from 25.4 to 27.1 ‰. Again the maple hockey stick falls within this range, however, our value of 26.8 ‰ would seem to fall on the high end of that range. This may suggest the maple sample came from further south. However a study by Levesque et al. (2017) found isotopic values of 26.9 to 28.5 ‰ at a site in upstate New York, which are much higher than the values from the maple hockey stick. Also Richter et al. (2008) found maple from a site in Bucks county, Pennsylvania to have values of 29.2  0.27 ‰ which are much higher than our isotopic values. Isotopic values from trees in Michigan ranged from 22.6 to 24.1 ‰ (Powers et al. 2008), which are significantly lower than either of the two hockey sticks.

Based on the isotopic analysis I would conclude that the two samples likely came from the Great Lakes region, more specifically Ontario or upstate New York.

References.

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Buhay, W.M and T.W.D. Edwards (1995). Climate in Southwestern Ontario, Canada, between AD 1610 and 1885 inferred from oxygen and hydrogen isotopic measurements of wood cellulose from trees in different hydrologic settings. Quaternary Research, 44, 483-446.

Leavitt, S. W.; Danzer, S. R. Method for Batch Processing Small Wood Samples to Holocellulose for Stable-Carbon Isotope Analysis. Anal. Chem. 1993, 65, 87–89.

Powers, M.D., K.S. Pregitzer and B.J. Palik (2008). ¹³C and ¹⁸O trends across overstory environments in whole foliage and cellulose of three Pinus species. Journal of the American Society for Mass Specrometry, 19, 1330-1335.

Richter, S.L., A.H. Johnson, M.M. Dranoff and K.D. Taylor (2008). Continental-scale patterns in modern wood cellulose ¹⁸O: Implications for interpreting paleo-wood cellulose

¹⁸O. Geochimica et Cosmochimica Acta, 72, 2735-2743.

Roden, J.S., G. Lin and J.R. Ehleringer (2000). A mechanistic model for interpretation of hydrogen and oxygen isotope ratios in tree-ring cellulose. Geochimica et Cosmochimica Acta, 64, 21-35.