Archaeologia Islandica - 01.01.2004, Page 67

Note on Organic Content of Turf Walls in Skagafjörður, Iceland
the guidelines for general Lol samples
(e.g., Oliver, Lotter and Lemcke 2001) in
which volumetric sub-samples were
place in weighed crucibles and weighed.
Weight loss was measured afiter heating
at 100° C ovemight to remove water, and
then after two hours at 550° C in a muf-
fle fumace which removed organic mat-
ter. After buming, the weighted crucible
was weighed again and the percentage of
the sample weight lost due to buming
was defined as the organic content of the
sample (Lol % in Figures 1-3).
In Skagafjörður, sample sequences
were taken at 2 archaeological sites
(Glaumbær & Stóra Seyla) in and one
bog deposit (Grófargil). An additional
sequence was taken and analyzed from
Hvanneyri (not discussed herein, see
Carter 2003 for a description). At the site
of Glaumbær, sequences were taken from
4 different locations and at Stóra Seyla 3
locations were sampled. Depths and
Lol's for these sites are presented in
Figure 1. At each of these locations a
sequence of samples was taken through
an exposed profile to assess change in
organic content with depth. A series of
double samples were also mn to make
sure that, within a sample, there was little
Lol variation. In those 8 cases, samples
from the same bag were bumed twice to
assess consistency. In those samples
Lol’s ranged from 3.3 to 24%, the maxi-
mum difference was 1.9%, and the aver-
age difference was 0.15% (SD =1.17%).
There was no trend in Lol differences.
Q.
QJ
Q
i 100
200
0 10 20 30 40 50
Lol %
Figure 2. Sample depth against Lolpercentage at Grófargil.
65