Archaeologia Islandica - 01.01.2009, Side 52

Richard E. Hughes and Gavin M. Lucas
150
125
100
E
-Q
oc
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25
0
0 20 40 60 80 100 120 140 160 180 200
Nb (ppm)
Figure 5. Rb vs. Nb Composition of Obsidian Artifacts from Hofstaðir. Dashed lines demarcate
the range of composition measured in geological samples. Open circles represent measurement
for single obsidian source standards. Filled triangles represent measurements for Hofstaðir arti-
facts from Table 2. Error bars are 2-sigma (95% confidence) error estimates for artifacts and
single obsidian source standards. The numbers of artifact plots do not correspond exactly to the
number of specimens in Table 2 because of data convergence at this scale.
Krafla

£
Katla
Torfajökull
Kerlingarfjöll
Hágöngur
i r
theless distinct from other sources.
Although Kerlingerfjöll and Katla over-
lap slightly in Rb/Nb composition (Figure
5) their Sr/Y concentrations are quite dif-
ferent (Figure 4). Based on these trace
element data, it is apparent that all four
artifacts were manufactured from obsidi-
an of the Krafla chemical type.
Conclusion, Future Studies, and
Related Research Issues
Results of this study show that, obsidian
from the Krafla area, located about 25
km northeast from Flofstaðir (see Figure
1) was used to manufacture all four arti-
facts analyzed from the site. Given the
proximity of Flofstaðir to the Krafla
obsidian source this result might have
been expected but, though we now know
something about local use, we have little
empirical information about how far
obsidian of this chemical type may have
traveled during different time periods. To
our knowledge, no other obsidian arti-
facts from different time periods in
Iceland have been subjected to trace ele-
ment analysis, so we do not know wheth-
er these Hofstaðir results are typical of-
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