Alaskan Archaeological Conservation at the University of Aberdeen

Think Alaska, flat open tundra contrasting with mountains and the sea – setting the background to an old frozen village buried for 500 years. Think climate change, melting permafrost, the Bering Sea and its storms eroding the coast – and artefacts leaching out onto the beach. Think Prehistoric times, grass turned into ropes and baskets, leather into garments and pouches, precious foods stored in vessels…

Julie Masson-MacLean, archaeological conservator, is working for the University of Aberdeen Archaeology Department on the grass, leather/fur and ceramic artefacts from the site of Nunalleq (XVe-XVIIe c), Southwest Alaska. The site represents the remains of a pre-contact Yup’ik Eskimo village of sod houses that collapsed quickly on themselves, sealing everything in situ. In 2009, after a severe storm local people from the nearby village of Quinhagak found large quantities of artefacts spilling from the site onto the beach. Concerned that part of their heritage was disappearing, they contacted archaeologist Dr. Rick Knecht, senior lecturer at the University of Aberdeen, who set up a rescue excavation. The loss of coastline due to erosion has been so severe, at an average rate of 1m/year, that the 2009 and 2010 excavation trenches have now gone.

The edge of the site with the eroding coast

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A view of the excavation

An astonishing collection of over 50000 artefacts has been unearthed including approximately 2000 pieces of grass basketry and 200 of leather/fur. The assemblage is in a remarkable state of preservation due to its burial in permafrost and waterlogged soils. Furthermore, the presence of sphagnum moss may also have contributed as it has recognised antimicrobial properties. Ivory, antler and wood artefacts are so well preserved that they resemble their ethnographic counterparts, while leather and grass artefacts require more care, though well-preserved features are observed such as boot sole pleating or basketry twining patterns. Pottery can be in poor condition comprising broken and crumbly, delaminated sherds; this is probably related to its manufacture as the coarse clay is low-fired and tempered with coarse sand, pebbles and hair/fur. However, the deeper the excavation goes the better the artefacts are preserved.

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Dr. Rick Knecht and Julie Masson-MacLean with a sample of the Nunalleq artefacts.

When Julie started working on the collection at the end of 2015, Nunalleq had already yielded an unexpected quantity of significant artefacts. This collection is unique coming from a region where little archaeological research has been conducted, and as a result, some artefacts are unidentified yet.

Wet and muddy, the finds need stabilisation by means of appropriate cleaning and drying. Typically, objects are cleaned with tweezers to remove dirt and pebbles, then washed on a support with distilled water. Grass artefacts are currently controlled-dried in fridges. It has been found that braided ropes made of roots are strong and dry easily while large flat baskets or long bundles made of grass leaves/strands are much trickier. The information available on wet archaeological grass is scarce so Julie is investigating polyethylene glycol (PEG) treatments as initial tests provided encouraging results. Large basketry is being packed in cut-to shape corefoam trays allowing for the safe handling of these fragile finds for cataloguing, study and adequate storage.

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A basket before conservation…

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… and after conservation, with a little braided fragment on its right side.

Leather artefacts are cleaned with a squeeze bottle, brushes and small tools, and an airbrush for well-preserved fragments. Their shape is recorded and then they are PEG-impregnated and atmospheric freeze-dried. Atmospheric freeze-drying is cost-effective but has a longer drying time – which is, in this case, feasible for the project as the leather collection is yet to be investigated.

An atmospheric freeze-dried leather boot showing two types of stitches: a running stitch with paired holes in the pleated front area and an overcast stitch along the sides.



A leather boot with a grass insole before cleaning…

…and after cleaning. It is currently undergoing atmospheric freeze-drying.

A fur clothing fragment showing possible decorative triangle pattern on the left

The fragment showing sewing on the right

With coarse arctic pottery, washing followed by quick air-drying can trigger further breakage as the cracks open and the clay splits following the large inclusions. To avoid this potential consolidation problem, the sherds were blocked-lifted when possible and then slow-dried, with gentle cleaning undertaken during the process. Several vessels were reconstructed and to quote R. Knecht it is like reconstructing a potato from … crisps! For one large pot (see photo below), missing areas were filled with Plaster of Paris and retouched for an aesthetic appearance while remaining distinguishable from the original sherds.

Large pot after restoration (left) from fragile sherds sensitive to splitting due to the use of coarse temper (right).

 

 

 

 

 

 

 

 

 

 

 

Slow-drying proved very successful and allowed for an excellent drying of two complete clay lamps, where previously, such finds would have crumbled away. The lamps and numerous sherds are being packed by prospective conservation student Sandra Toloczko in foam trays carved to shape and acid-free paper. Sandra is also being trained to clean sherds, small grass fragments and to treat wood.

Two complete lamps: after slow-drying…

…and in an acid-free paper nest inserted in a carved foam tray

This project interweaves archaeological conservation with actuality: on the one hand, the community in Quinhagak is committed to preserving its Heritage as it underpins Yupiit culture. On the other hand, the current work performed on the Nunalleq grass artefacts could help conservation at future well-preserved Arctic sites threatened by increased coastal erosion and melting permafrost due to global warming.

All the finds belong to the village and are due to return to Quinhagak in Spring 2018 to be stored and displayed at the Nunalleq Culture and Archaeology Center.

Julie graduated from Paris I University-Panthéon Sorbonne with a Master’s degree in Archaeological Conservation after completing her internships at The British Museum and the Canadian Conservation Institute where she worked on artefacts from the Canadian Arctic. She now works as a freelance conservator for the University of Aberdeen among other institutions.

 

 

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2 thoughts on “Alaskan Archaeological Conservation at the University of Aberdeen

  1. Pingback: A note from the conservation lab | Nunalleq 2017

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