Detecting the origins of a 1,000-year-old trade mystery

Deep within a basement lecture theatre at Flinders University lies a treasure trove of 2,300 ceramic objects that could unlock lost cultural stories from the fabled maritime silk and spice trade route which flowed through Indonesia from at least the 9th century.

Assessing them is a major task facing Associate Professor Martin Polkinghorne and the Flinders archaeology team, because the idea of reconnecting these objects – from a major private collection donated to Flinders by Michael Abbott KC, supported by the Australian Research Council Linkage Program and a generous philanthropic donation from Alastair Hunter OAM – with the stories of their origin via reverse detective work has never been done before in archaeology.

“These are orphan objects, because we don’t know precisely where they came from. Commercial and unauthorised salvage teams have taken many of these from unidentified shipwrecks, and they have passed through art markets for decades. Now we have an opportunity, through using advanced technology, to investigate their origins,” says Associate Professor Polkinghorne.

“We have collections like this in museums and art galleries all around the world – orphaned items that we don’t know precisely how they were previously used, or what hands they have been passed through. Until now, there has only been aesthetic appreciation of these items as beautiful objects. Now, we aim to uncover the story of their provenance and underline the importance of their cultural value.”

Indonesia was at the epicentre of an extraordinary expansion period of global trade along South-East Asia’s Maritime Silk and Spice Route. The tradeware ceramics being examined were made in China, Vietnam and Thailand from as early as 830AD and imported to Indonesia and across the globe for domestic use, because the Indonesians had no tradition in high-temperature fired porcelain. These items were traded for spices, resins and aromatic woods.

“They were quite beautiful artisanal works that would have been used in people’s homes – very different to rare imperial porcelain,” explains Associate Professor Polkinghorne. “They tell us a lost story about how ordinary people lived in those times.”

The collection, which Mr Abbott amassed from the late 1960s to 2010 and is believed to be worth about $1.5 million, comprises items acquired from markets and dealers across Indonesia, some with shells and encrustaceans still attached, indicative of their shipwreck origins. However, the story of their trade journey is incomplete because the objects were salvaged without their location being accurately recorded.

It’s an intensive search for the Flinders team to find answers, with more than 700 recorded shipwrecks between the 9th and 20th centuries in Indonesia’s territorial waters (and many believe there could be thousands more), although the exact locations of only 170 wrecks have been surveyed, and only a handful have been studied with precise archaeological detail.

By reconnecting items from this collection to specific shipwrecks, the Reuniting Orphaned Cargoes project could unlock a new method for investigating other collections of orphan objects.

“This is a gateway project for archaeology,” says Associate Professor Polkinghorne. “We are working with the Indonesian Ministry of Marine Affairs and Fisheries, and they have a further 280,000 salvaged objects in storage, which remain unstudied. We will be working with them to establish new archaeological protocols and supply the interpretive tools that best protect them for the future. Our findings will address unprovenanced underwater cultural heritage, and open paths to implement and refine the operational guidelines of international heritage conventions that govern this area.”

The archaeological investigation team working at Flinders – which includes two Indonesian PhD students, acknowledged as that country’s best maritime archaeologists – will achieve their goals via several stages of investigation.

“Our first task will be reuniting the pieces with the ships they came from, and this will build a detailed narrative of the maritime silk trade route, which was the greatest trade route in the world at that time,” says Associate Professor Polkinghorne. “We will be working with the Indonesian ministry that monitors shipwrecks and be comparing ceramics they have from the sea floor with our collection.”

The researchers will use machine learning to examine the decorations on ceramics and compare them to form relationships between matched items across the different collections. They will then use methods of archaeological science that will reveal the elemental fingerprints of each object, to identify their composition and help trace their origin – right back to specific kilns they were fired in.

“We can compare glazes, clays, firing techniques – each of which were distinctive to specific locations. Actually, identifying where the objects were made is not so difficult, because ceramic art history is very well catalogued. The hard part is tracking them from the kiln to the shipwreck. It’s going to be much harder for us to identify exactly what shipwreck on the sea floor they came from.”

Incredibly, the encrustaceans attached to some objects that were salvaged from the sea floor will help the archaeologists to unravel this mystery, as they provide extra biological data to help pinpoint their salvage location.

“This is blue sky thinking by us to use marine encrustaceans as a means of locating specific regions on the sea floor, but we will be working with a network of Indonesian biologists who have already classified the ecosystems around shipwreck sites,” says Associate Professor Polkinghorne. “Analysis of the encrustaceans could lead to further examination of microfauna and microflora that provide even more detailed information.

“It's especially fascinating, because all this is all on our doorstep. The further we delve into this examination, the more we may also learn about the earliest international trading with Australia.”

The Reuniting Orphaned Cargoes project is expended to take up to five years, and beyond identifying the origins of specific items, other successful outcomes will include supplying archaeological interpretive tools that can help protect underwater cultural heritage.

“We are hoping it can help efforts to stop random private salvage operations in Indonesia, because reports of additional ceramic collections being sold recently on art markets suggests this practice of removing items from historic shipwrecks without adhering to archaeological protocols is continuing,” says Associate Professor Polkinghorne. “We want to protect underwater cultural heritage, now and into the future, so this work will hopefully provide a framework that can help the Indonesian authorities to solve that problem.”