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Wednesday, June 9, 2010

Hand Axes on Crete

Hand axes excavated on Crete suggest hominids made sea crossings to go ‘out of Africa’
January 14, 2010 by Ray

By Bruce Bower

Human ancestors that left Africa hundreds of thousands of years ago to see the rest of the world were no landlubbers. Stone hand axes unearthed on the Mediterranean island of Crete indicate that an ancient Homo species — perhaps Homo erectus — had used rafts or other seagoing vessels to cross from northern Africa to Europe via at least some of the larger islands in between, says archaeologist Thomas Strasser of Providence College in Rhode Island.

Several hundred double-edged cutting implements discovered at nine sites in southwestern Crete date to at least 130,000 years ago and probably much earlier, Strasser reported January 7 at the annual meeting of the American Institute of Archaeology. Many of these finds closely resemble hand axes fashioned in Africa about 800,000 years ago by H. erectus, he says. H. erectus had spread from Africa to parts of Asia and Europe by at least that time.

Until now, the oldest known human settlements on Crete dated to around 9,000 years ago. Traditional theories hold that early farming groups in southern Europe and the Middle East first navigated vessels to Crete and other Mediterranean islands at that time.

“We’re just going to have to accept that, as soon as hominids left Africa, they were long-distance seafarers and rapidly spread all over the place,” Strasser says. The traditional view has been that hominids (specifically, H. erectus) left Africa via land routes that ran from the Middle East to Europe and Asia. Other researchers have controversially suggested that H. erectus navigated rafts across short stretches of sea in Indonesia around 800,000 years ago and that Neandertals crossed the Strait of Gibraltar perhaps 60,000 years ago.

Questions remain about whether African hominids used Crete as a stepping stone to reach Europe or, in a Stone Age Gilligan’s Island scenario, accidentally ended up on Crete from time to time when close-to-shore rafts were blown out to sea, remarks archaeologist Robert Tykot of the University of South Florida in Tampa. Only in the past decade have researchers established that people reached Crete before 6,000 years ago, Tykot says.

Strasser’s team cannot yet say precisely when or for what reason hominids traveled to Crete. Large sets of hand axes found on the island suggest a fairly substantial population size, downplaying the possibility of a Gilligan Island’s scenario, in Strasser’s view.

In excavations conducted near Crete’s southwestern coast during 2008 and 2009, Strasser’s team unearthed hand axes at caves and rock shelters. Most of these sites were situated in an area called Preveli Gorge, where a river has gouged through many layers of rocky sediment.

At Preveli Gorge, Stone Age artifacts were excavated from four terraces along a rocky outcrop that overlooks the Mediterranean Sea. Tectonic activity has pushed older sediment above younger sediment on Crete, so 130,000-year-old artifacts emerged from the uppermost terrace. Other terraces received age estimates of 110,000 years, 80,000 years and 45,000 years.

These minimum age estimates relied on comparisons of artifact-bearing sediment to sediment from sea cores with known ages. Geologists are now assessing whether absolute dating techniques can be applied to Crete’s Stone Age sites, Strasser says.

Intriguingly, he notes, hand axes found on Crete were made from local quartz but display a style typical of ancient African artifacts.

“Hominids adapted to whatever material was available on the island for tool making,” Strasser proposes. “There could be tools made from different types of stone in other parts of Crete.”

Strasser has conducted excavations on Crete for the past 20 years. He had been searching for relatively small implements that would have been made from chunks of chert no more than 11,000 years ago. But a current team member, archaeologist Curtis Runnels of Boston University, pointed out that Stone Age folk would likely have favored quartz for their larger implements. “Once we started looking for quartz tools, everything changed,” Strasser says.
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Monday, June 7, 2010

Stone Age Color, Glue 'Factory' Found

Stone Age Color, Glue 'Factory' Found
The color and glue trade could have been a blossoming industry some
58,000 years ago.


By Jennifer Viegas | Thu Jun 3, 2010 07:00 AM ET


The Stone Age version of successful businessmen like Steve Jobs and
Bill Gates might have been involved in the color and glue trade.


A once-thriving 58,000-year-old ochre powder production site has just
been discovered in South Africa. The discovery offers a glimpse of
what early humans valued and used in their everyday lives.


The finding, which will be described in the Journal of Archaeological
Science, also marks the first time that any Stone Age site has yielded
evidence for ochre powder processing on cemented hearths -- an
innovation for the period. A clever caveman must have figured out that
white ash from hearths can cement and become rock hard, providing a
sturdy work surface.


"Ochre occurs in a range of colors that includes orange, red, yellow,
brown and shades of these colors," project leader Lyn Wadley told
Discovery News. "Yellow and brown ochre can be transformed to red by
heating them at temperatures as low as 250 degrees Celsius (482
degrees Fahrenheit)."


Wadley, who authored the study, is a professor in the School of
Geography, Archaeology and Environmental Studies and in the Institute
for Human Evolution at the University of the Witwatersrand. She said
ochre has been found on bone awl tools probably used for working
leather, so it is possible that the ancients sported colorful leather
clothing and other leather goods.


Red-hot leather clothing is still found in stores today, but the
probable wearers then were a far cry from today's fashion elite.


Ochre is derived from naturally tinted clay that contains mineral
oxides. In addition to coloring objects, it makes a compound adhesive
when mixed with other ingredients, such as plant gum and animal fat.


"This glue would have attached stone spear or arrowheads to hafts, or
blades to handles for cutting tools," Wadley explained.


Ochre can also be used as body paint and makeup, as a preservative and
as a medicinal component, so it could have served many different
functions during the Stone Age.


Wadley analyzed the ochre "factory" at the large Sibudu rock shelter
north of Durban in KwaZulu-Natal, South Africa. The site consisted of
four cemented hearths containing the ochre powder. The cement
workstations could have held grindstones and/or served as storage
receptacles for the powder, according to Wadley, who also excavated
about 8,000 pieces of ochre in the area.


She believes the natural material was collected just over a half a
mile away from the site, where it would have been heated and ground or
just ground directly onto coarse rocks.


Francesco d'Errico, director of research at the National Center of
Scientific Research at the University of Bordeaux, said pigment
material is found in bits and pieces at various early sites. However,
not much was known in detail before about how it was processed and
used.


Based on the nature of the cemented ash and the geology of the Sibudu
site, d'Errico believes that people 58,000 years ago intended to
produce large quantities of red pigment in a short time frame.


He now thinks ochre pigment was a "fundamental constitute of Middle
Stone Age culture, and that its production likely involved the work of
several members of the group."

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Bird rock art could be world's oldest

Bird rock art could be world's oldest
By: Emma Young | June-3-2010


*


A ROCK PAINTING THAT appears to be of a bird that went extinct about
40,000 years ago has been discovered in northern Australia. If
confirmed, this would be the oldest rock art anywhere in the world,
pre-dating the famous Chauvet cave in southern France by some 7,000
years.


The red ochre painting was found in southwest Arnhem Land by a member
of the Jawoyn Association, which represents the local traditional
owners of the land. When Robert Gunn, an archaeologist brought in to
document rock art in the area, saw the painting he immediately thought
it looked like Genyornis, an emu-like, big-beaked, thick-legged bird
that went extinct along with other Australian megafauna between 40,000
and 50,000 years ago.


"But I bit my tongue, and sent it off to a recognised authority,
palaeontologist Peter Murray in Darwin, to see what he thought. When
he confirmed that it probably was Genyornis, it was pretty exciting,"
Robert says.


Robert thinks there are two possible interpretations: either this is
among the oldest rock paintings in the world, or Genyornis went
extinct later than anybody thinks.


Age old question


But there's no good archaeological or palaeontological evidence that
Genyornis survived longer than about 40,000 years ago, says Bruno
David, an archaeologist and rock art specialist at Monash University
in Melbourne, who has seen photos of the painting and who has worked
in the region. "If this is Genyornis, then it has to be more than
40,000 years old," he says.


Robert is now planning to record the site in much more detail, and
next year Bruno and his team will excavate the area thoroughly. A rock
fall created the exposed face on which the painting was made. By
studying buried samples from beneath the fallen rock, the team should
be able to work out the age of the rock face. If it is older than
40,000 years, this won't prove that the painting is that old, but it
will support the idea that it could be.


Some rock art specialists strongly suspect that the painting is
younger. The oldest pigment found on a rock anywhere in Australia is
28,000 years old, but the image is so covered with dust and other
rocky accretions, it's impossible to know what it looked like.


The Genyornis site is a shallow shelter and most such paintings in
Australia are thought to be less than about 5,000 years old; older
ones are thought to have been eroded away by weather. The Chauvet
artworks, in contrast, are deep inside a cave that was sealed for more
than 20,000 years. However, some of the sandstone in Arnhem Land does
have the advantage of being extremely hard and durable.


Cautious optimism


Bruno says it's important to be cautious. The features of the painted
bird match the features of the extinct Genyornis very closely, but
this might be a coincidence, he says. "It's possible that at some time
in the past, people were painting animals that didn't necessarily
match living species - or that the bird wasn't a physical bird, but an
animal that was part of the local, ancestral Jawoyn Dreaming beliefs,"
he says. And if this is the case, the painting could have been made at
any time in the past.


But either way it's exciting, he says. "If it's Genyornis, then it's
of extreme significance. If not, it's very significant because it
tells us something about the way people understood their landscapes."


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