Beiner & Rabinovich, 2014: BONES AND SEDIMENTS
summer, but it is on the eastern bank of the
to prevent mold growth, and no paper bags
Jordan River and water wells up from the
were used in direct contact with the wet finds.
ground. Every morning, the excavation team
Each find was padded with a good amount of
bailed out water and continued doing so in
bubble wrap, in an open packaging which made
intervals throughout the day. Besides the
the padded product open enough to allow for
difficulty of distinguishing between the dark
air circulation.
brown bone finds and the surrounding dark
Salvaged material is currently being treated in
brown mud (Figure 3A), a main problem was
the lab, with damp and semi-dried mud being
that all exposed material began deteriorating
removed into plastic bags and surfaces cleaned
immediately. The condition of the bones
with acetone and saliva on swabs. It appears
seemed pristine, but they tended to fall apart
that the protection offered by the cover of the
easily when exposed. Valuable morphological
matrix and the slow-drying in the field lab
and taphonomical data was lost. After several
helped preserve many more features of the
seasons, it became clear that on site constant
bones (Figure 3c).
conservation was required.
Paraloid B72 does not work under such
conditions, and other more water-friendly
C
products such as Primal WS24 also have a
ASE
III:
RENEWED EXCAVATION
E
problem if they do not have the time to set
RQ
EL AHMAR (LOWER PLEISTOCENE)
before more water enters the system.
Communication
with
underwater
marine
The Erq el Ahmar (EEA) site was excavated by
archeologists in effort to search for solutions
the late Prof. Eitan Tchernov, following parts of
yielded that apparently, other than using
an elephant tusk found during survey. The
freshly prepared Plaster of Paris mixture inside
elephant skeleton parts exposed by the
plastic bags as a kind of cushion, there are not
Tchernov expedition had been preserved on a
many
possibilities
for
supporting
and
floodplain
with
active
soil
formation
consolidation
in
active
waterlogging
(pedogenesis) with small fluvial channels
conditions. Some of the ideas tested included
nearby, during a regressive phase of the lake
making a temporary jacket (over a barrier
(Feibel, 2004:24). Parts were extracted by the
layer) out of plumber's putty, or reinforcing
Tchernov expedition after coating, or partial
weak areas with cyclododecane (CDD) before
coating, in a heavy plaster of Paris jacketing
they became waterlogged. The putty proved
(Figure 4). The jacketed finds were kept in a
too weak and friable as a supportive jacket for
store until very recently, but had deteriorated
lifting bone. Experiments with CDD actually
very badly within the jackets, presumably due
worked, but between the hazards of using a
to a process of dehydration connected with the
portable burner in such conditions and the
presence of the plaster. Most of the skelet was
difficulty of creating an adequate CDD support
left in situ, with an unidentified applied to part
for actively cracking bone forced rejection of
of the bones and a cover of newspapers.
the method as a working option for this site,
Some of the bones had been plastered
especially since the conservator (GGB) could
over and marked with metal stakes. At the
only be there for consultation visits. The
end of that expedition, the site was covered
requirement was for something that could
over with nearby sediments, and further
work in the hands of a non-conservator. After
covering occurred as the area eroded out.
discussing issues such as which bones will
The previously exposed bones and new parts
need to undergo analysis, an agreement with
of the skeleton were uncovered by our team
the archeologist involved a trial use of gauze
in 2013. It was noticed that although the
combined with Primal WS24. This did work, as
metal stakes correctly marked out the location
long as the coated objects were not left
of the bones, the plaster had apparently caused
overnight to become completely covered by
serious
dehydration
and
powdering.
A
water. Therefore the final procedure consisted
conservator (GGB) was part of the 2013
of keeping all exposed bone damp along with
excavation team, so there was an opportunity
immediate consolidation of bones with diluted
to try different methods on site. Since the
Primal WS24 in water and then coating with
exposed bones were dry and very fragmented,
gauze (Figure 3b). By these means, bones
with tendency to powdering, the material of
were salvaged in their entire form.
choice was Paraloid B72 (with acetone as a
In this case, slow-drying and padded packing
solvent due to safety limitations). The team
proved to be of utmost importance. Care was
members were asked to drip or inject Paraloid
taken to slow down the drying of the bones by
B72 on exposed bone finds. Our first procedure
putting salvaged finds in containers covered
of choice involved coating large finds with
with polyethylene. The polythene layer was slit
gauze, as in the Revadim Quarry, in effort to
22
Journal of Paleontological Techniques