Fishy finds in 660-year-old archaelogy dig

Moa-bone fishhooks and fossilised dog poos are amongst the treasures unearthed by archaeologists combing the remains of one of the oldest human settlements ever uncovered in New Zealand.

But the researchers warn that rising sea levels and accelerating coastal erosion mean the sites will soon be lost forever.

A team of researchers from the University of Auckland and Auckland Museum have found evidence of a small fishing settlement on Great Mercury Island - the private island owned by controversial richlisters Michael Fay and David Richwhite.

The village, in Coralie Bay is thought to have been inhabited by Maori as early as 1350AD, just 30 years after some estimates of the first Polynesian landfall in Aotearoa.

Auckland Museum archaeology curator Louise Furey said the discovery helped build a picture of how early Maori settlers lived and worked.

"It's filling in the picture of how those early Maoris and Polynesians were using the coast."

The fish hooks were likely made from the bones of the smallest, and most common, moa species. While moa grew up to 2 metres in height, these birds were thought to be slightly larger than a turkey.

The birds were brought over from the mainland on canoes, where the fishermen would have eaten them then made use of their bones as well.

The last of New Zealand's moa species are believed to have been driven to extinction within 100 years of human arrival. Furey said sites like this were becoming increasingly rare and this one was one of the oldest Maori settlements uncovered. She said there was no evidence to suggest people were in New Zealand before 1320AD.

University of Auckland archaeologist Simon Holdaway said finds such as fish hooks and fossilised dog poo were small, but significant.

The dog poo helps paint a clearer picture of the relationship between early Maori and the dogs they brought with them on their Pacific voyages. Early settlers ate dogs, a meat saved for high-status Maori. They also used dog hair in cloaks and fed the dogs leftover fish carcasses. 

Holdaway said discovering moa-bone fishhooks was not unusual in a coastal areas, but the Great Mercury Island sites were better preserved than many other areas, thanks to a lack of development and intensive farming.

However, the site would not be there forever, Holdaway said.

Rising sea levels, bigger storms and other forms of coastal erosion meant the sites would only be around for about another 10 years.

'It's really, really important that we analyse the material that's left."

The team's most recent visit to the island was in June, and it will return in summer, when it hopes to find more traces of the lives of those who occupied the island.

Furey said she hoped to find kumara pits and houses. There were very few examples of early Maori houses and things such as the direction the house was facing or the location of the cooking area would help build a better picture of how Maori lived and how these habits have changed over time.

Holdaway said he hoped to find a waka.

"It's like the crown jewels."
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Reference:

Walters, Laura. 2015. “Fishy finds in 660-year-old archaelogy dig”. Stuff. Posted: July 19, 2015. Available online: http://www.stuff.co.nz/auckland/local-news/70325586/fishy-finds-in-660yearold-archaelogy-dig.html

Light cast on lifestyle and diet of first New Zealanders

A University of Otago-led multidisciplinary team of scientists have shed new light on the diet, lifestyles and movements of the first New Zealanders by analysing isotopes from their bones and teeth.

In research published this week in the prestigious international journal PLOS ONE, the team are able to identify what is likely to be the first group of people to colonise Marlborough's Wairau Bar possibly from Polynesia around 700 years ago. They also present evidence suggesting that individuals from two other groups buried at the site had likely lived in different regions of New Zealand before being buried at Wairau Bar.

The researchers, co-ordinated by the Department of Anatomy's Associate Professor Hallie Buckley, undertook isotopic analyses of samples recovered from the koiwi tangata (human remains) of the Rangitane iwi tupuna (ancestors) prior to their reburial at Wairau Bar in 2009.

The Wairau Bar Koiwi Project is part of a larger archaeological project being conducted in collaboration with the Rangitane iwi, the Canterbury Museum and the University of Otago. The interpretation of these new data was strengthened by collaboration with colleagues from SPAR, the University of Otago archaeologists who undertook the more recent archaeological excavations at the site.

"By examining ratios of carbon and nitrogen isotopes present in bone collagen we were able to estimate individuals' broad dietary makeup over a 10-20 year period prior to death. Our analysis of strontium isotopes in teeth allowed us to distinguish between people growing up in geologically different landscapes," says Dr Rebecca Kinaston, who conducted the isotope analyses on the bones and teeth.

The tupuna were originally buried in three separate groups in a large village at the Wairau site. First excavated over 70 years ago, this ancient settlement is one of the most important archaeological sites in New Zealand because of its age and the range of east Polynesian type artefacts found there.

Previous research found that one of the burial groups displayed distinct cultural differences to the two other burial groups at the site. These included the positions in which they were interred and the presence of more numerous and rich grave offerings, including whale bone ornaments and moa eggs generally not found with the other two groups.

The new isotopic analysis of bone collagen and teeth suggests that members of this first group shared similar diets and childhood origins, while individuals in Groups 2 and 3 displayed highly variable diets and spent their childhood in geologically different areas to Group 1.

"Interestingly, Group 1 individuals showed a dietary trend similar to that identified in prehistoric individuals from a site in the Marquesas Islands in French Polynesia, with both sets of people sharing a low diversity in protein sources," Dr Kinaston says.

In contrast, dietary patterns in Groups 2 and 3 were found to be in line with individuals who spent most of their lives eating from a wide range of protein sources, such as would be available through New Zealand's then bountiful seal, moa and other bird populations.

The large range found in Group 2 and 3's strontium isotope ratios could reflect that they grew up in regions outside of Wairau Bar—but not where Group 1 did—and also that they were hunting and gathering across a wide geographical range, says Associate Professor Hallie Buckley.

"This is consistent with other archaeological evidence that the first settlers in New Zealand were highly mobile. That members of Groups 2 and 3 were still buried back at Wairau suggests that this village may have fulfilled both a ceremonial and home base function."

If this is the case, this may represent the roots of the tangihanga ritual, in which Maori are buried in their ancestral lands, developing among these first New Zealanders, Associate Professor Buckley says.
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References:

EurekAlert. 2013. “Light cast on lifestyle and diet of first New Zealanders”. EurekAlert. Posted: May 15, 2013. Available online: http://www.eurekalert.org/pub_releases/2013-05/uoo-lco051513.php

Maori ovens to provide missing data on Earth’s magnetic field

Deep beneath our feet lies a mass of molten iron rich rock, stirred into complex patterns by heat and the Earth’s rotation, this is the geodynamo – the source of Earth’s magnetic field.

Filling the palaeomagnetic gap

As our planet’s magnetic field is constantly changing, it is difficult to know how the field behaved at any given point in the past. However, there is one way to examine the more recent palaeomagnetic history; through our ancestors’ love of fire.

Palaeomagnetism has had an incredibly important role in the history of geology, but palaeomagnetic data can also be crucial as a dating tool for human settlement sites.

To establish an accurate palaeomagnetic chronology, researchers often rely on human pottery-making or metalwork furnaces for example.

It does however require activities that involve firing minerals to temperatures exceeding the Curie Temperature; the point above which objects become demagnetized. When the objects cool, the finished pot remagnetizes, locking in a record of the direction and strength of the magnetic field in the region at that specific point in time and space.

“We have very good palaeomagnetic data from across the world recording field strength and direction – especially in the Northern Hemisphere,” said Gillian Turner from Victoria University, Wellington, New Zealand.

“The southwest Pacific is the gap, and in order to complete global models, we’re rather desperate for good, high-resolved data from our part of the world,” she told BBC News.

Dr Turner was speaking at the recent American Geophysical Union (AGU) Fall meeting, the world’s largest annual gathering of Earth scientists.

Finding palaeomagnetic data

The Maori, who first settled New Zealand around 1200 CE, are one such example of a culture that left behind no pottery and this may suggest that there is no palaeomagnetic data to gather.

However the Maori are famous for hāngi, large steam pit ovens using heated rocks.

The Maori legends tell how the stones would glow white hot and by placing thermocouples into a test firing of a hāngi the team was able to show temperatures as high as 1,100 C were achieved.

Hāngi stones were carefully chosen and the Maori preferred andesite rocks found in Central North Island as they were less likely to shatter in the fire; fortunately for the team, they also contain a high concentration of magnetite.

Dr. Turner and her fellow researchers experimented with modern hāngi to confirm that the rocks did indeed exceed the Curie Temperature, which means that all rocks from ancient hāngi sites potentially hold a wealth of information on Earth’s magnetic fields. By radiocarbon dating charcoal recovered at the hāngi sites, Dr. Turner can identify exactly when the rocks were first fired and thus match magnetic data with timescales.

Understanding current climatic systems

Dr Turner and her team propose to gather data recorded by magnetic particles deposited in lake and marine sediments in New Zealand and archaeological artefacts such as fired pottery from the Lapita culture for example, will be part of the study too. The outcome will be a detailed history of the southwest Pacific’s magnetic field over the last 10,000 years.

This history will enable a high-resolution tool for dating recent events, such as early settlement of New Zealand and climate change, to be developed. And, by combining their measurements with similar observations from the Northern Hemisphere it is hoped to provide a globally consistent model of Earth’s dynamic magnetic field.

Global earth and climate systems have recently dominated national and international forums. They are beginning to impact on the way we live, and we need to understand how they work. New Zealand’s unique geological evolution offers important insight into these natural earth and climate systems, providing some of the most significant archives – both long and short-term.

The challenge facing geologists is to interpret these records in a time scale that means something to us – and to work out which intervals of the archive are most relevant to the specific problems we face.
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References:

Past Horizons. 2013. “Maori ovens to provide missing data on Earth’s magnetic field”. Past Horizons. Posted: December 22, 2012. Available online: http://www.pasthorizonspr.com/index.php/archives/12/2012/maori-ovens-to-provide-missing-data-on-earths-magnetic-field