Dear Listers –
We have a series of soil cores from the bottom of a local
lake that have been stored in a freezer in our facility for a number of years.
We discovered today that the freezer they are in has malfunctioned, and
currently registers a tropical 85 F inside. There is standing water at the
bottom of the freezer and in the plastic core sleeves themselves; everything is
thoroughly defrosted and warm to the touch. The last time we checked the
freezer was at least a month ago, and it appeared to be functioning normally at
that point.
I am wondering whether there is any utility in attempting to
re-freeze the cores or whether they are beyond salvage at this point. They have
been curated primarily for their biological record (e.g. pollen) rather than
their geological or stratigraphic record, which is one of the reasons they were
frozen in the first place. Because this freezer is second hand, it is highly possible
that this kind of defrost may have happened before without our knowledge.
Any advice or resources would be helpful. Thanks in advance.
aloha
~Liz
Liz N. Clevenger, MA,
RPA
Curator of Archaeology
(415) 561-5086
Presidio Archaeology Lab | www.presidio.gov/history/archaeology
| (415) 561-ARCH info | (415) 561-5089 fax
The Presidio Trust | P.O. Box 29052, San
Francisco, CA 94129
Please
consider the environment before printing this e-mail.