Point of Origin
Discovery of prehistoric quarries in Peruvian highlands could be key
to understanding how humans first settled South America
About the Photo: Last
summer, University of Maine under-graduates (left to right) Louis
Fortin and Benjamin Morris, and graduate student Kurt Rademaker
(right) joined UMaine archaeologist Daniel Sandweiss on the
excavation of a 3,700-year-old site in the Peruvian highlands,
researching links between prehistoric inland and coastal habitation.
Following the 12-day excavation, Rademaker and Morris headed higher
to 16,400 feet, where they discovered prehistoric quarries and large
deposits of obsidian eroding out of the mountainsides.
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High in the remote, arid mountains of
southern Peru, University of Maine graduate student Kurt Rademaker
struck anthropological gold last summer. He went there hoping to locate
large deposits of obsidian, a volcanic glass used for millennia to make
weapons and tools. He not only found entire hillsides of obsidian, but
also several prehistoric extraction pits — complete with the sticks used
to pry obsidian out of the ground — and places he describes as workshop
These discoveries could be quite significant — in fact, they could be
huge — if follow-up research helps to answer questions such as how the
first inhabitants of South America got there, how they lived and how
people in different parts of the continent interacted. Rademaker thinks
important answers are to be found by following the obsidian.
Nearly a decade ago, UMaine Professor of Anthropology and Quaternary
Studies Daniel Sandweiss found pieces of obsidian among the artifacts at
an ancient fishing site on the Peruvian coast. That site, Quebrada
Jaguay (Jaguay Canyon), was discovered in the 1970s, but Sandweiss was
the first to excavate it extensively. First settled around 13,000 years
ago, it is the earliest confirmed fishing site in the New World.
Richard Burger of Yale University chemically traced the obsidian that
Sandweiss discovered at Quebrada Jaguay to a highland valley about 100
miles inland. That finding raised questions about the relationship
between the two areas and the people who inhabited them.
"To find out if there was a connection, we needed both the site at the
coast and specific sites (not just a general area) from the same time
period in the mountains," says Sandweiss, an international authority on
maritime adaptation and the influence of climate on cultural development
in South America. "The idea was to go to the highland area where the
obsidian was known to come from and look for sites that might be of the
Last summer, University of
Maine under-graduates (left to right) Louis Fortin and Benjamin
Morris, and graduate student Kurt Rademaker (right) joined UMaine
archaeologist Daniel Sandweiss on the excavation of a 3,700-year-old
site in the Peruvian highlands, researching links between
prehistoric inland and coastal habitation. Following the 12-day
excavation, Rademaker and Morris headed higher to 16,400 feet, where
they discovered prehistoric quarries and large deposits of obsidian
eroding out of the mountain-sides.
Hammer stones used to
break obsidian into small pieces, as well as wooden digging sticks
for prying the volcanic glass out of the earth, were found at 15,800
feet above sea level in the remote Chumpullu Valley. Near the
prehistoric extraction pits were thousands of tailings or chips,
indicating where tools of obsidian had been made. Kurt Rademaker,
undergraduate Benjamin Morris and two Peruvian colleagues mapped the
boundaries of the obsidian source that spanned hundreds of acres.
They also collected more than 100 rock samples for geochemical
Early inhabitants of Peru
sought out naturally occurring outcrops of obsidian in order to
extract the volcanic glass for tools and weapons.
Photos courtesy of Kurt Rademaker and Daniel Sandweiss
That's what took him and several researchers, including Rademaker, to
Peru last year. After helping Sandweiss and his team excavate a site at
about 12,000 feet, Rademaker and some of the others rented two horses
and a burro, and went higher.
"As we were walking up the river valley, we started seeing pieces of
obsidian at our feet," Rademaker says. "The higher we went, the more
incredible it became."
At 16,400 feet, they stopped and settled in for two weeks of
geoarchaeological surveying. The obsidian source they discovered in
Quebrada Pulhuay spans hundreds of acres.
"It's a world of obsidian up there, literally mountains of it," says
Rademaker, a native of Kentucky who came to UMaine in 2003 to conduct
research with Sandweiss. "For years, archaeologists had been desperately
searching for the source of this material, and we came to a place where
we were falling all over it. We knew we were in the right spot."
Based on Burger's chemical analysis of obsidian tools and other objects
found throughout Peru from various periods, the researchers knew that a
large obsidian quarry area must exist. But on the only two previous
scientific expeditions, in the 1980s and '90s, archaeologists focusing
their searches in more accessible, lower elevations found only small
outcrops of obsidian, with little evidence of serious mining.
"Kurt went up higher and to a different area of the source, and really
found the mother lode," Sandweiss says. "He found where the obsidian
came from and all the evidence needed to show that people were there
working it. That is the exciting thing about what he has done. It
explains why one of the two most important sources of obsidian
throughout 13,000 years of Peruvian history had previously appeared to
be a fairly minor source. Now we know exactly where to focus future
Obsidian was made into weapons, tools and jewelry. Most obsidian is
black, but it also can be gray, red or nearly clear. When it is sliced,
the surface is smooth and shiny; it is, after all, volcanic glass.
Surgeons sometimes use obsidian scalpels because they are sharper than
Rademaker says it was evident at several sites in the high mountains
that obsidian had been extensively mined. "We found the actual digging
sticks, pieces of wood that people had cut and used to pry out the
rocks," he says.
Because these sites are well above the timberline, the wooden sticks had
to have been brought there. Preserved by the cold, dry climate, they
might have lain there for hundreds or thousands of years.
Also at the extraction pits, Rademaker and his team found hammer stones
used to break the obsidian into smaller pieces so it could be carried
away. Not far from the extraction pits were found thousands of obsidian
chips, indicating where tools were made. The researchers also found
tools, broken and intact.
The most common type of tool used by people in prehistory was the biface.
Sharp on two edges, it could be used as either a knife or projectile
point. Rademaker calls it "the Swiss Army knife of prehistoric tools"
because of its versatility. Also common were long, thin blades used for
Obsidian chips found scattered around the workshop sites in the
mountains varied in size, up to 10 inches. Those found at the coastal
Quebrada Jaguay site were mostly tiny slivers. Sandweiss theorizes that
some tools might have been made in rough form in the mountains, then
taken to the coast for final shaping and sharpening.
Now that obsidian artifacts have been found in both places, the next
step is to determine whether they are from the same period. Rademaker,
who plans to pursue his doctoral degree at UMaine, is eager to return to
Peru and continue his fieldwork.
"I want to do more thorough mapping and find out more about those sites,
possibly through some excavations," he says. "If it turns out that we
have found very old sites that are contemporary with Dan's site at the
coast, then it would be worthwhile to do a complete highland-to-coast
survey. We would try to trace a route between those two points to
identify other sites that might fit into the early settlement system."
Such a survey could shed light on the seasonal migration patterns of the
prehistoric people and what they were doing in different places at
different times. It also could help settle the argument over when and
how South America was settled.
"The traditional view is that the first people came down the interior,
the spine of the Andes, hunting mammoths and other big animals,"
Sandweiss says. "Then, when the animals went extinct 11,000 or 12,000
years ago, people turned to other things like fish, small animals and
"But this view has been falling apart over the last two decades," he
says, "in part because it didn't make sense that they would just go
after big animals. Also, we have been finding sites where people were
clearly doing something else, like Quebrada Jaguay, where they were
fishing. It seems they were very adaptable, able to make a living in
Perhaps people were coming down the coast at the same time others were
moving through the interior of the continent, or — turning traditional
belief on its head — maybe coastal settlers came first and then moved
inland. Sandweiss says it is too early to speculate because so few sites
have been found and researched. However, evidence of an obsidian
connection between the mountains and the coast might prove to be an
important clue, bringing scientists a step closer to definitive answers.
It certainly raises a lot of questions.
"Already, we know so much more than we did before last summer,"
Sandweiss says. "We have the first real evidence of a material link
between coast and highlands at the very beginning of occupation. This
has the potential to be a very exciting and significant piece of the big
picture of New World archaeology."
By Dick Broom
for more stories from this issue of UMaine Today Magazine.