Audio News for March 10 to March 16, 2013

Welcome to the Audio News from Archaeologica!  I'm Laura Pettigrew and these are the headlines in archaeological and historical news from March 10th to March 16th, 2013.


Coral tool chemistry measures migrations across early Polynesia

Original Headline: Coral Clocks


In our first story, researchers have learned to read the dates of Polynesia’s early tools made of coral.  Some 3,000 years ago, inhabitants of New Guinea set their sights east and headed out to sea, generating a migration of thousands of miles to islands across the South Pacific.  Archaeologists have been able to track the migration of these pioneers, a group called the Lapita, by the finds of their distinctive pottery.  Now researchers are using advanced chemistry involving coral tools used by the earliest migrants to accurately reconstruct their maritime travels.

According to David Burley, a professor of archaeology at Simon Fraser University in Canada, the first stop the Lapita made in Polynesia was the settlement of Nukuleka in the Kingdom of Tonga, but many debates about the details remain.  In particular, the date that the Lapita made landfall on different islands has proved impossible to nail down.

Potsherds found around the midden pile and burial ground at Nukuleka are of an early variant not found elsewhere in Tonga.  The pottery contains temper—an additive such as sand to strengthen the clay—that did not originate on the island.  Wherever the temper came from, researchers think it’s some distance.  This element of the exotic points to Nukuleka as the founding settlement on Tonga, but without any precise date for when the settlement began.

Recently, Burley aged a charred nut buried deep within the site using radiocarbon dating, and found that it was between 2,769 and 2,947 years old.  Given that radiocarbon dating has a relatively big range of error, Burley and colleagues at the University of Queensland in Australia looked to tools made of coral to confirm and refine a more exact date.

Members of the Lapita culture used chunks of staghorn coral as files to smooth and sculpt wood and shell.  Living corals, in building their calcium carbonate skeletons, incorporate uranium from seawater, and that uranium decays to become thorium at a traceable rate.  The ratio of the two elements provides a precise estimate of how long ago the coral died.  Patrick Kirch at the University of California, Berkeley, has had success using dating of coral offerings placed at temples in Hawaii.  Previous radiocarbon data from wood charcoal at the temples had suggested a gradual development of temples over the span of a couple hundred years, but more precise coral dating showed that the temples were actually built during just several decades.  

Following this lead, Burley carried out uranium-thorium dating on 13 coral files from different strata within the Nukuleka site.  This nailed down the founding of Nukuleka to 2,838 years ago, plus or minus 8 years, a preciseness rarely seen in archaeology.

To work successfully, of course, coral tool dating must also observe some limitations.  According to Burley, the technique can only work if archaeologists have the right material in the right context.  They must show that the coral died at the time it was used.  At Nukuleka, for instance, the coral must have been plucked fresh from the ocean for it to be useful as a file.

According to Matthew Spriggs, an archaeology professor at Australian National University, the several-hundred-year range of a radiocarbon date can’t resolve whether an artifact is, say, 3,000 years old or 3,200 years old, making it difficult to plot the initial movements of the Lapita out of New Guinea, or which island was settled first, or the particular sequence of settlements across an archipelago.  Coral tool dating can provide the more accurate calendar needed to answer these questions.

Chinese coin on East African island shows early long-range trade

Original Headline:  Ancient Chinese coin found on Kenyan island by Field Museum expedition


Next we travel to Kenya, where a joint expedition of scientists led by Chapurukha M. Kusimba of The Field Museum and Sloan R. Williams of the University of Illinois at Chicago has unearthed a 600-year-old Chinese coin on the island of Manda off the northern Kenyan coast.  The coin is evidence of trade with China long before European explorers set sail and changed the map of the world.

The coin, known as a yongle tongbao, is a small disk of copper and silver with a square hole in the center to be worn on a belt.  These coins were issued by Emperor Yongle, who reigned from AD 1403 to 1425, during the Ming Dynasty.  The emperor's name is written on the coin, making it easy to date.  Emperor Yongle, who started construction of China's Forbidden City, was interested in political and trade missions to the lands that ring the Indian Ocean and sent Admiral Zheng He, also known as Cheng Ho, to explore those shores.  Zheng He led 7 naval expeditions into the Indian Ocean between 1405 and 1433.   On his fourth voyage, he visited Malindi, Kenya, in 1414, just south of Manda, and stopped there again on his fifth voyage between 1416 and 1419.

According to Dr. Kusimba, curator of African Anthropology at The Field Museum, Zheng He was, in many ways, the Christopher Columbus of China.  The find of the coin may ultimately provide physical proof that Zheng He came to Kenya.  Beyond that, the finding is significant for its proof of links between east Africa and Asia.  It has long been known that Africa had multiple relationships to the rest of the world, but this coin renews a discussion about the relationship between China and Indian Ocean nations.

That relationship stopped soon after Emperor Yongle's death, when later Chinese rulers banned foreign expeditions, allowing European explorers to dominate the Age of Discovery and expand their countries' empires.  The Portuguese explorer Vasco da Gama arrived in 1498 on the Kenyan coast at Malindi to sign a trade agreement and hire a guide for his voyage to India.

The island of Manda was home to an advanced civilization from about AD 200 to 1430, when it was abandoned and never inhabited again.  Trade played an important role in the development of Manda, and this coin may show how trade played a role not only in the rise of the island, but also even in its fall.  For the greater east African region as a whole, the coin is solid evidence of a farflung Asian trade connection that was forgotten for a long time.

Ancient German reindeer hunters developed first fishhooks

Original Headline: Ancient Reindeer Hunters Fished Ice Age Lakes


In Germany, archaeologists have unearthed six fishhooks, the oldest of which was carved from a 19,000-year-old mammoth tusk.  

Hunters of ice age reindeer around 12,300 years ago likely left the fishhooks, along with mammal and fish bones, in an open field in what is now Wustermark, Germany.  The fishhooks, the oldest found in Europe, suggest humans developed fishing tools earlier than previously thought, probably to catch fast-moving fish that appeared in lakes as the climate warmed.

According to Robert Sommer, a paleoecologist at the University of Kiel in Germany, these people came up with new ideas to use the newly available resources of their changing environment.  The eel, perch and pike that entered lakes are too fast to snag with a harpoon or a spear, so innovations like fishhooks were required.

Most archaeological evidence for ancient seafood consumption has washed away with rising sea levels.  In 2011, scientists discovered the world's oldest fishhooks in coastal caves in East Timor, formerly part of Indonesia.  However, because the hooks were not complete, they relied heavily on nearby fish bones to infer the nature and use of the fragmentary tools.

Archaeologists in Europe thought hunter-gatherers around 12,000 years ago speared slow-moving fish like salmon in shallow streams, and did not use hooks until much later.

Sommer and his colleagues unearthed several Paleolithic finds during a routine environmental assessment prior to the construction of a shopping mall 20 kilometers west of Berlin.

The site, which was once an open field near an ancient lake, revealed six fishhooks, along with animal and fish remains.  One of the fishhooks is carved from ivory from a mammoth tusk, while the rest were made of bone from reindeer or elk, which were common in these hunters’ diet.  Because mammoths went extinct long before the anglers lived, Sommer inferred that the people at this site probably found a whole tusk that could still be used for its ivory, millennia after the mammoth’s death.

According to Sue O'Connor, an archaeologist at the Australian National University, who found the East Timor fishhooks, but was not involved in this study, the German fishhooks are impressive because they show the sophistication of ancient hunters.  Sommer’s research is detailed in the May 2013 issue of the Journal of Archaeological Science.

Early estate in D.C. area produces new evidence of slavery in the colonial era

Original Headline: Archaeological Dig Unearths Slave History at Georgetown Estate


For our final story, we travel to the United States, where archaeologists working at Tudor Place in the District of Columbia, an historic Georgetown estate with ties to George Washington, have unearthed artifacts that suggest the former existence of a dwelling for both enslaved and free workers on the site.

A team of archaeologists spent several days in the past week meticulously digging and sifting through layers of soil in the Tudor Place garden, in an area called the tennis lot.

In a 2011 study, they uncovered similar artifacts pointing to domestic life and correlated with an 1863 map suggesting the location of an outbuilding in the area.  And so the team, from the Dovetail Cultural Research Group, began digging a half-dozen pits, 3-foot-by-3-foot square, in areas chosen to expand on the possibilities suggested by the previous finds and the documentary research.

Last week they discovered a pit that was full of domestic artifacts, such as oyster shells, ceramics and pieces of brick.  All of these suggest the former presence of some sort of structure there, according to Jessica Zullinger, director of preservation at Tudor Place.  Looking at the items found so far, Zullinger estimated that they date back to the early 19th century.

The archaeologists then uncovered one of the more exciting finds so far, a large piece of Colonoware.  Colonoware is a type of rough ceramic made by African-Americans from the end of the 17th century through the Civil War, and found from the Chesapeake region into the southern states along the East Coast.  This is an extremely rare find in the district, and even highly unusual on this side of the Potomac.

According to Zullinger, it is unlikely they will uncover intact pieces of whatever structure may have been there, but it is not outside the realm of possibility.

Although the space currently  is part of the gardens that adorn the historic home, that could change, depending on what they find.  The new findings help inform and could change how they interpret the home and its grounds for the public.  If the archaeologists determine that this is a building and that the evidence for it probably is there, the Preservation Society will have to talk about excavation and further exploration.  For now, the dig is still a research activity that will help inform the interpretation of the site.

That wraps up the news for this week!
For more stories and daily news updates, visit Archaeologica on the World Wide Web at, where all the news is history!
I'm Laura Pettigrew and I'll see you next week!