Digitising and conserving fragile materials: the Australian Museum archaeology collection

We take a behind the scenes look at the process of digitising and conserving fragile objects in the First Nations Archaeology collection – an ongoing collaborative project with the AM's Collection Care and Conservation team.

A major digitisation project is currently underway in the First Nations Aboriginal and Torres Strait Islander archaeology collection, to enhance the collection and provide First Nations communities and the general public with access to objects usually held in storage. Digitisation of a museum object requires much more work than just taking a photo. Before beginning digitisation, an assessment of the object’s condition and housing (how the item is stored) is made. The First Nations archaeology collection is an extensive collection, comprised mostly of stone artefacts uncovered at various sites across NSW – these stone artefacts are relatively robust and generally easy to appropriately house. However, there are some larger items in the collection that are composed of composite materials including organic material and have been flagged as needing rehousing and conservation as part of their ongoing care. Every object within the collection is unique, and requirements are different for each artefact. Objects composed of composite materials often naturally degrade over time at a faster rate than stone artefacts. The digitisation project has provided collection staff with the time and resources to focus on these objects, allowing for a collaboration between the First Nations, archaeology and Collection Care and Conservation (CC&C) teams.

Conservation challenges with composite materials

Some of the objects from the First Nations archaeology collection which have proved the most challenging are latex moulds from stratigraphic sections. These are sediment samples from the original ‘wall’ of the archaeological site that contain shells, rocks and soil adhered to the latex. The Australian Museum currently has a latex mould from Balmoral Beach on Sydney harbour's north shore on display in the First Nations exhibition: Garrigarrang: Sea Country, which provides a good example of a stratigraphic section from a shell midden. Shell from the upper layer was radiocarbon dated to between circa 2750 BP (before present), and charcoal from the lower layer dated to circa 4000 BP. Within the matrix of the midden are fragments of shellfish and bones from fish, reptiles, and mammals.

While latex peels offer a visual educational perspective of the archaeological site, they also create conservation challenges due to their composite nature. Conserving composite materials found in a single object is challenging due to the accelerated chemical deterioration caused from different materials. Organic materials such as latex also have inherent instability and are highly susceptible to degradation when the material reacts with oxygen in the air. Heavily degraded latex results in the material becoming brittle due to loss of flexibility over time, which is challenging to conserve. Therefore, it is best to preserve the collection prior to the object reaching this stage by slowing down the degradation of materials. This is possible by controlling and maintaining a stable environmental condition such as the temperature and relative humidity. Providing appropriate housing using conservation grade storage materials and adequate physical support to the objects also reduces the risk of accelerated deterioration.

Conservation assessment and developing a conservation plan

To develop a conservation plan, Clare Kim (Conservator) and Rebecca Jones (Digitisation Officer) moved the items, including latex peels, from their location in storage into the CC&C lab – a complex task, as these items are located in different buildings within the Australian Museum. This movement was carefully planned to ensure any potential risks of damage from vibration and handling are minimised.

After slowly unwrapping the objects, the condition is assessed and detailed photos are taken to document the condition of the object. This step is essential to make sure the objects are in a stable condition to go through the digitisation process and to minimise any potential risk of damage that could occur during object handling. Also, if significant information about the object is obscured due to its condition, conservation treatment is provided to the relevant area, so this information can be captured.

The AM staff are frequently uncertain as to what is contained within the wrapping of older acquisitions as many were acquired decades before their time at the Museum and some early museum records are sparse on detail. Sometimes we can speak with the original excavators of the archaeological site who can remember invaluable information and share photos from the excavation to help understand and contextualise the object. This information significantly aids our decision-making process when developing a conservation plan.

These objects and their stories need to be preserved for future generations with great respect. Conserving this collection is a cross-cultural collaboration project between the First Nations archaeology collection, CC&C, relevant First Nations communities and archaeologists to gather as much information about the object as possible to help guide the treatment plan and decision-making process. The discussion often includes what are the most significant aspects that need to be preserved, which involves not only the physical part of an object, but also the intangible heritage that the object is carrying through stories, places, and practice.

Stay tuned! We hope to provide more updates on our progress for conservation treatment and re-housing in the near future.

Dr Rebecca Jones, Digitisation Officer First Nations Archaeology, Australian Museum.

Clare Kim, Collection Enhancement Conservator, Collection Care & Conservation, Australian Museum.