Category Archives: NORTH AMERICA

Controversial cave discoveries suggest humans reached the Americas much earlier than thought

Controversial cave discoveries suggest humans reached the Americas much earlier than thought

Stone tools unearthed in a cave in Mexico indicate that humans could have lived in the area as early as about 33,000 years ago, researchers reported. That’s more than 10,000 years before humans are generally thought to have settled North America.

Archaeologists have unearthed what appear to be stone tools, including this one, in a cave in central Mexico that date as early as about 33,000 years ago.

This controversial discovery enters a new piece of evidence into the fierce debate about when and how the Americas were first populated.

“A paper like this one is really stirring up the pot,” says co-author Eske Willerslev, an evolutionary biologist at the University of Cambridge. It “will no doubt get a lot of arguments going.”

For decades, archaeologists thought the Americas’ first residents were the Clovis people — big game hunters known for their well-crafted spearpoints who crossed a land bridge from Asia to Alaska about 13,000 years ago. Recent, well-accepted archaeological discoveries suggest that North America’s first settlers actually arrived a few thousand years before the rise of the Clovis culture, by about 16,000 years ago, says Vance Holliday, an archaeologist at the University of Arizona in Tucson not involved in the new work.

If the new finds really are human tools, Holliday says, this would be the oldest evidence for a human-inhabited site anywhere in the Americas.

At Chiquihuite Cave in central Mexico, archaeologists unearthed what appear to be over 1,900 stone tools.

Using radiocarbon dating to determine the ages of charcoal, bone and other detritus surrounding the artefacts, the researchers determined that more than 200 of the tools were embedded in a layer of the earth as old as 33,150 to 31,400 years. Other artefacts were found in a layer as fresh as about 13,000 years old.

The tools, excavated from 2016 to 2017, do not resemble Clovis technology or any other stone tools found in the Americas, the researchers say.

This haul “has a lot of small blades and small flakes that were used for cutting,” says archaeologist Ciprian Ardelean of the Autonomous University of Zacatecas in Mexico.

His team also dug up squarish stone fragments that he suspects were used to make composite tools of some sort, assembled from pieces of rock stuck into wooden or bone shafts.

“People are going to disagree about whether this qualifies as evidence” of human activity, says Loren Davis, an archaeologist at Oregon State University in Corvallis not involved in the work. “These are rocks that were broken, but … people don’t have a monopoly on the physics involved with breaking rocks,” Davis says that a closer examination of the artefacts in person or via 3-D models could convince him that they are indeed relics of human craftsmanship.

Ben Potter, an archaeologist in Fairbanks, Alaska, affiliated with the Arctic Studies Center at Liaocheng University in China, is similarly “intrigued but unconvinced” that Chiquihuite Cave was an ancient human abode. He notes the crude shape of many of the artefacts, as well as the absence of other evidence — such as butchered animal remains or human DNA — that would peg the site as a human residence.

Humans may have arrived in North America way earlier than archaeologists thought
Researchers looking for ancient DNA take samples in Chiquihuite Cave, Mexico.

Neither the tools’ shape nor the apparent lack of other human-made remains disqualifies Chiquihuite Cave as an ancient dwelling, Ardelean says. He argues that archaeologists’ expectations of what North American stone tools should look like are overly influenced by the perfection of Clovis points, which were neatly chipped from brittle stone such as jasper. The limestone used by the Chiquihuite Cave dwellers was more difficult to work with, he says, so it makes sense that these implements would be more rugged.

As for corroborating evidence of human activity, Ardelean expects human DNA to turn up only in specific areas of the cave, like where people ate or relieved themselves. He and his colleagues may not have excavated those spots yet, he says. The swath of ground investigated in this dig was also far from the mouth of the cave, where ancient people would more likely have cooked, eaten, thrown out garbage and performed other daily activities, he says.

Anthropologist Ruth Gruhn of the University of Alberta in Edmonton “wasn’t a bit surprised” at the authors’ claim of 30,000-year-old human handiwork in Mexico.

This cave joins a handful of sites in Brazil that have shown evidence of human occupation more than 20,000 years ago — although those reports remain controversial. To convince many archaeologists that humans really were in the Americas so early, “what you need is an accumulation of sites of that antiquity,” says Gruhn, whose commentary on the new study appears in Nature.

If there were humans in Mexico more than 30,000 years ago, that would affect what route they could have taken south from Alaska, says geologist Alia Lesnek of the University of New Hampshire in Durham. Archaeologists have thought that if humans arrived about 16,000 years ago, they may have plodded south along the Pacific Coast.

That’s because a narrow, inland ice-free corridor between two ice sheets covering Canada would not have had enough plants or animals to sustain human travellers. But more than 30,000 years ago, those ice sheets had not yet reached their full extent, Lesnek says, opening up the possibility of inland migration.

Long Lost Early Colonial Fort Discovered in Maryland

Long Lost Early Colonial Fort Discovered in Maryland

According to a Washington Post report, archaeologist Travis Parno, archaeological geophysicist Tim Horsley, and their colleagues at Historic St. Mary’s City announced the discovery of the undisturbed outline of the palisaded fort at St. Mary’s, which was erected in southern Maryland by English colonists in 1634.  Maryland archaeologist Travis Parno was at a board game convention in Philadelphia, sitting at a table surrounded by thousands of other enthusiasts when he got a text message. He was supposed to be on vacation, taking a break from his search for the legendary fort at St. Mary’s, the first permanent English settlement in Maryland and one of the earliest in what would become the United States.

Back at St. Mary’s, archaeological geophysicist Tim Horsley had been scanning a site a half-mile from St. Mary’s River with ground-penetrating radar that could detect the outlines of ancient buildings. The text message interrupting Parno’s vacation was from Horsley. It said: “I think we found it.”

On Monday, Historic St. Mary’s City announced that Parno, director of research for the organization, and Horsley had indeed found the outlines of the palisaded fort that was erected in Southern Maryland by white settlers in 1634. Horsley’s scans had revealed the imprint of post holes that formed a large rectangle with a semicircular bastion at one corner. The scans also showed evidence of what appeared to be dwellings inside the fort, including several that may have been Native American. Excavation later turned up evidence of the brick cellar of a guardhouse or storehouse, the trigger guard for a musket, and a quartzite arrowhead that was 4,500 years old.

Dig on the site of the original fort at St. Mary’s.
Recreation of a 17th century building at Historic St. Mary’s City.

“This is our moment,” Parno said. “This is the earliest colonial archaeological site in Maryland. This is it.”

William M. Kelso, the archaeologist who in 1994 discovered the lost fort at Jamestown, Va., said the discovery is “extremely significant because St. Mary’s is sort of a sister colony … [and] it’s another page to the story, to chapter one.”

Archaeologists had been seeking the St. Mary’s fort since the 1930s. The site today is in an empty meadow where the wind blows off the river and the shadows of soaring turkey buzzards drift over the landscape. It is owned by Historic St. Mary’s City and is about the size of a football field. Much like the famous Jamestown fort, which marked the first permanent English settlement in what would become the United States, its exact location had been lost. The original 150 colonists, including many English Catholics fleeing Protestant persecution back home, had arrived at St. Mary’s on two ships, the Ark and the Dove, in late March 1634, Parno said.

Modern recreation of the Dove.

They were preceded by the English settlers at such places as Jamestown in 1607, Plymouth in 1620, and Massachusetts Bay in 1630. The Maryland group included a Jesuit priest, Father Andrew White; the colony’s first governor, Leonard Calvert; and Mathias de Sousa, an indentured servant of African and Portuguese descent who later served in the legislative assembly of freemen.

“I found a most convenient harbor, and the pleasant country lying on each side of it,” Calvert wrote to his business partner, Richard Lechford, on May 30, 1634.

“On the east side of it we have seated ourselves, within one-half mile of the river,” he wrote. They had erected “a pallizado of one hundred and twenty yards square” with four bastions equipped with small artillery pieces.

The palisade was probably 12- to 14-feet high.

White reported: “Our Towne we call St. Maries … [It] abounds not alone with profit but also with pleasure.”

But like Jamestown, the settlement at St. Mary’s was later abandoned. The capital moved to Annapolis in the 1690s, and the site was left undisturbed and ripe for archaeology. St. Mary’s has produced stunning archaeological finds in the past. It was Maryland’s first capital and home to the first State House. In 1990, experts exhumed three lead-lined coffins containing the remains of Maryland colonial governor Philip Calvert, who died in 1683, his first wife, Anne, and Calvert’s 6-month-old son. Anne’s coffin contained sprigs of the memorial herb rosemary, bits of a silk ribbon that may have been used to bind her wrists for burial — and much of her hair. The baby had suffered from the childhood disease rickets and probably scurvy.

Calvert family coffins discovered in 1990.

The search for the fort had continued through the 1980s and ’90s with inconclusive results. The quest was put on hold for many years as St. Mary’s focused on other projects. Parno resumed the hunt in 2017, and his find was deemed conclusive in late 2019. The plan had been to announce the discovery last year, but the coronavirus pandemic brought that to a halt. Last summer, though, using coronavirus safety protocols, Parno was able to return to the site and uncover the top of what may be the cellar of a building inside the fort.

Parno noted that the site marks not only a turning point in Maryland’s colonial history. It also marked a massive moment of change for the native peoples of this region,” he said.

“Archaeology in this area shows us people have been here for at least 10,000 years. White wrote that the colonists, “to avoid all occasion of dislike, and colour of wrong,” purchased from the local Yaocomaco Indians the land for 30 miles around, paying with axes, hoes, cloth, and hatchets. The Yaocomaco Indians tolerated the newcomers, he wrote, because the Indians had enemies: The “Sasquasahannockes … [who] come sometimes upon them, and waste and spoile them and their country.”

And the archaeology hinted that the fort may have been built around several existing native dwellings, Parno said.

The Yaocomaco people lived on both sides of the St. Mary’s River. The arrangement was that they would be allowed to stay on the east side with the colonists until the Indians’ crops there were harvested. Then they would move to the west side.

“Some few Indians are here to stay by us till next yeare,” Father White wrote. “Then the land is wholy to be ours alone.”

It’s not clear if, for a time, the colonists and the Yaocomaco lived together in the fort, according to the Historic St. Mary’s City website. “But it is likely that their residences were … in relative proximity to one another.” And an Indian dwelling that had been vacated would have provided good shelter for weary colonists.

“You come off this ship after months, and you need a place to lay your head, and you want something that’s covered and warm,” Parno said.

One day this month, tiny pink flags marking the outline of the fort fluttered in the breeze as Parno’s team methodically scraped away soil at the site. After Horsley’s scan found the fort’s outline in 2018, Parno said he verified it with excavation in 2019. He found that there had been a three-foot-deep trench where the colonists had stood the timbers for the palisade. Inside the trench, the wood had left telltale stains in the soil. “It was clear as day,” Parno said.

Long Lost Early Colonial Fort Discovered in Maryland
A conjectural drawing of the 1634 fort at the St. Mary’s settlement in Maryland.

But he had been surprised when the work revealed that the outline of the fort didn’t match Calvert’s 1634 description of it. Instead of the large square palisade with bastions at the four corners that Calvert described, the team found a smaller, rectangular fort with one bastion. The discrepancy may be because Calvert was describing plans for the fort before it was completed, according to Historic St. Mary’s.

As Parno walked the site this month, fellow archaeologist Stephanie Stevens paused with her shovel. She had done archaeology at the site in 2017. “We had always heard about: ‘There’s this fort somewhere, but we don’t know where it is.’ All these different things,” she said.

Then one-day Parno summoned the team, showed the scan of the fort’s outline, and said, “We found it.”

Archaeologist Travis Parno at his dig on the site of the original fort at St. Mary’s.

“That was amazing,” she said.

Giant Face of Ucanha: Huge Sculpted Mayan Mask Found in Mexico

Giant Face of Ucanha: Huge Sculpted Mayan Mask Found in Mexico

A giant Mayan mask as tall as a person has been revealed at an archaeological site in the Mexican state of Yucatán. 

Giant Face of Ucanha: Huge Sculpted Mayan Mask Found in Mexico
The stucco mask of Ucanha being worked on by archaeologists

The mask, which depicts the face of an unknown deity or elite person, was sculpted from the building material stucco and dates back to a period in Maya history known as the Late Preclassic (about 300 B.C. — A.D. 250), according to the news outlet Novedades Yucatán.

The discovery was made in 2017 at the archaeological site of Ucanha, near the modern-day city of Motul, and since then researchers with Mexico’s National Institute of Anthropology and History (INAH) have worked painstakingly to restore it.

View of the giant stucco face, or Mayan mask, in situ. The face was discovered in the Yucatán Peninsula near the village of Ucanha

Stucco masks like this one “represent the faces of individuals with particular features that can be associated with deities or with characters of prominent social status,” INAH said in a statement.  

The mask is a stucco relief, a type of brightly-colored painted sculpture carved from a background of stucco. The Maya typically placed these masks around stairways with pyramidal bases, according to the statement.

Archaeologists have found similar reliefs in Acanceh and Izamal, but this is the first in Ucanha. The discovery is part of ongoing research into Mayan mounds found at the site. 

The mask was temporarily reburied after its discovery so that the structure was protected until it could be properly studied and preserved.

Samples taken from the structure revealed deterioration and it was re-excavated in 2018 so that archaeologists could restore it. 

During the restoration and conservation process, archaeologists reinforced fragile parts of the mask.

They also moved sections that had been displaced overtime back to their original positions. They also cleaned the surfaces to highlight the mask’s patterns and colors. 

The archaeologists completed the work in 2019, before reburying the mask for a final time. INAH said the goal of these efforts is to ensure the long-term preservation of the mask at the site, which does not have legal protection.

Ship Found 20 Feet Below World Trade Center Site Traced to Colonial-Era Philadelphia

Ship Found 20 Feet Below World Trade Center Site Traced to Colonial-Era Philadelphia

Researchers long stumped by the mysterious history of an 18th-century ship uncovered at the World Trade Center have finally discovered its origins — thanks to tree rings, according to a new study.

Ship Found 20 Feet Below World Trade Center Site Traced to Colonial-Era Philadelphia
The ship was uncovered in 2010, while workers were excavating the World Trade Center site.

The massive wooden ship — the skeleton of which was unexpectedly discovered 25 feet below street level in the muddy excavation of the World Trade Center site in 2010 — has now been traced to Colonial-era Philadelphia, with a history linked to Independence Hall, according to a new report from scientists at Columbia University’s Lamont-Doherty Earth Observatory.

Scientists say the wood from the vessel was chopped in 1773 from a forest of white oak trees in Philadelphia, the same type of trees used to build Independence Hall, where the Constitution and Declaration of Independence were signed.

Columbia scientists were able to link the growth rings found in the old wood of the ship with a previously taken sample of wood from Independence Hall, researchers said.

Tree rings are like “barcodes” that create unique patterns, allowing for dating, said Neil Pederson, Columbia tree ring scientist and co-author of the study.

Archaeologists dismantle the remains of an 18th-century ship at the World Trade Center construction site.

While the majority of the boat was made from white oak, a sample from the keel of the ship was the key to narrowing down its history.

“The keel was actually made from hickory, which was only found in the Eastern United States or Eastern Asia, which meant we could really narrow down our search — East Asia wasn’t really a possibility,” Pederson said. “That discovery really put me in a good mood — and put us in a good geographic zone.”

The ship’s 32-foot hull was carefully dug out of the muck in July 2010, exhaustively documented, disassembled, and sent off for preservation at the Maryland Archaeological Conservation Laboratory. Some timber samples, however, were sent to Columbia for analysis.

Historians believe the vessel was likely a merchant ship, in the Dutch style of a Hudson River sloop. It likely traveled along the Atlantic, bringing wood and food down to the West Indies and returning with sugar, salt, molasses, and rum.

The ship suffered an infestation of Teredo worms while in the Caribbean, which likely ate away at its wood and led to its demise after about 20 to 30 years on the water. It’s believed that by 1797, the boat was buried in the landfill used to extend Manhattan’s shoreline westward.

Hundreds of artifacts were found in and around the boat, including ceramics, musket balls, a buckle, a British button, a coin, animal bones, dozens of shoes, and a human hair with a single louse on it.

The ship remains at the Maryland Archaeological Conservation Laboratory, and researchers say it’s possible it may eventually be reassembled.

Guatemalan family uncovers ancient Mayan murals on their kitchen walls during a home renovation

Guatemalan family uncovers ancient Mayan murals on their kitchen walls during a home renovation

Home renovations in a Guatemalan mountain village in 2003 unearthed “unparalleled” Maya murals, according to researchers. Now, reports broadcast network RT, a new analysis published in the journal Antiquity has revealed additional insights on the wall paintings, which date to the 17th or 18th century and blend Spanish colonial influences with local indigenous culture.

Lucas Asicona Ramirez, right, discovered the centuries-old paintings after he started chipping away at the plaster in the kitchen of his house.

Local historian and study co-author Lucas Asicona Ramírez found the murals while renovating his kitchen in Chajul, a rural town in Guatemala’s highlands, reported Mike McDonald for Reuters in 2012.

Several houses in Chajul, including Asicona’s, date to the colonial era (1524 to 1821); other locals have discovered similarly historic artworks behind the plaster in their homes.

The Ramirez home is located in the impoverished town of Chajul, Guatemala.
Researchers work to preserve the Maya wall paintings inside the Chajul home.

The majority of Guatemala’s colonial-era murals are found in houses of worship. Centered on Christian themes, these religious artworks were used by the Spanish to assert their dominance over the Maya people, writes Tom Fish for Express. In contrast, the Chajul wall paintings appear inside private homes—and, most tellingly, contain distinct flourishes of indigenous culture.

“We consider these murals to be very unique,” Ivonne Putzeys, an archaeologist at the University of Guatemala in San Carlos, told Reuters. “It’s a tangible heritage that represents [s] real scenes from history.”

In 2015, an international team of researchers started preserving and studying the murals in collaboration with a Maya community indigenous to Guatemala: the Ixil. This group formed the bulk of the roughly 200,000 people killed during the Guatemalan Civil War, which lasted from 1960 to 1996.

As the experts write in the paper, conducting interviews and consultations with the Ixil was essential to understanding the art’s cultural context.

Many of the friezes feature dancers and musicians. Jaroslaw Źrałka, an archaeologist at Jagiellonian University and first author of the new study, tells Ancient Origins’ Ed Whelan that dance played an important role in the Maya civilization, both recording and relaying history and cultural practices. The dance was so important to the Maya that Spanish missionaries used it as a conversion tool, says Źrałka.

Through interviews with the Chajul Ixil community, the researchers were able to identify specific murals as depictions of known dances from the colonial era.

A mural of ancient vessels adorns the wall next to the family’s stove.

One mural shows tall, bearded conquistadors playing drums as they encounter a dancer dressed in a traditional feathered costume. This scene may illustrate the Dance of the Conquest, which details Spain’s invasion and attempts to convert the Maya to Christianity.

Another mural may show the Dance of the Moors and the Christians. Introduced by the Spaniards, this performance tells the story of Spain’s seizure of lands occupied by Muslim kingdoms, according to Express.

The researchers note that the wall art may also feature dances now lost to history. Many were forgotten when the government prohibited the performance of indigenous dances in the 19th and 20th centuries.

Chemical analysis of the paintings revealed the use of natural clay pigments typical in Maya art, suggesting the murals were indeed created by indigenous artists, reports Ancient Origins. The artworks’ style hews closely to local traditions, showing few signs of foreign influences.

The researchers suggest that the houses in which the murals were found once belonged to key community members—perhaps members of what was known as the cofradías, or brotherhood.

These groups organized religious events connected to both Christian and pre-Hispanic Maya traditions. The houses featuring the friezes may have served as meeting places or venues for rituals and dances.

Per the paper, the murals’ blending of Maya and European imagery could mean that local culture, as revived by the cofradías, was making a defiant comeback as Spain’s influence and control over the region faded.

The Arctic Could Turn Green and Free of Ice Like it was 125,000 Years Ago

The Arctic Could Turn Green and Free of Ice Like it was 125,000 Years Ago

Researchers analyzed plant DNA more than 100,000 years old retrieved from lake sediment in the Arctic (the oldest DNA in lake sediment analyzed in a publication to date) and found evidence of a shrub native to northern Canadian ecosystems 250 miles (400 km) farther north than its current range.

As the Arctic warms much faster than everywhere else on the planet in response to climate change, the findings, published this week in the Proceedings of the National Academy of Sciences, may not only be a glimpse of the past but a snapshot of our potential future.

“We have this really rare view into a particularly warm period in the past that was arguably the most recent time that it was warmer than present in the Arctic. That makes it a really useful analogue for what we might expect in the future,” said Sarah Crump, who conducted the work as a Ph.D. student in geological sciences and then a postdoctoral researcher with the Institute of Arctic and Alpine Research (INSTAAR).

To gain this glimpse back in time, the researchers not only analyzed DNA samples, they first had to journey to a remote region of the Arctic by ATV and snowmobile to gather them and bring them back.

Dwarf birch is a key species of the low Arctic tundra, where slightly taller shrubs (reaching a person’s knees) can grow in an otherwise cold and inhospitable environment. But dwarf birch doesn’t currently survive past the southern part of Baffin Island in the Canadian Arctic. Yet researchers found DNA of this plant in the ancient lake sediment showing it used to grow much farther north.

“It’s a pretty significant difference from the distribution of tundra plants today,” said Crump, currently a postdoctoral fellow in the Paleogenomics Lab at the University of California Santa Cruz.

Tundra Plants

While there are many potential ecological effects of the dwarf birch creeping farther north, Crump and her colleagues examined the climate feedbacks related to these shrubs covering more of the Arctic. Many climate models don’t include these kinds of changes in vegetation, yet these taller shrubs can stick out above snow in the spring and fall, making the Earth’s surface dark green instead of white — causing it to absorb more heat from the sun.

“It’s a temperature feedback similar to sea ice loss,” said Crump. During the last interglacial period, between 116,000 and 125,000 years ago, these plants had thousands of years to adjust and move in response to warmer temperatures. With today’s rapid rate of warming, the vegetation is likely not keeping pace, but that doesn’t mean it won’t play an important role in impacting everything from thawing permafrost to melting glaciers and sea-level rise.

“As we think about how landscapes will equilibrate to current warming, it’s really important that we account for how these plant ranges are going to change,” said Crump.

As the Arctic could easily see an increase of 9 degrees Fahrenheit (5 degrees Celsius) above pre-industrial levels by 2100, the same temperature it was in the last interglacial period, these findings can help us better understand how our landscapes might change as the Arctic is on track to again reach these ancient temperatures by the end of the century.

Mud as a microscope

To get the ancient DNA they wanted, the researchers couldn’t look to the ocean or to the land — they had to look in a lake. Baffin Island is located on the northeastern side of Arctic Canada, kitty-corner to Greenland, in the territory of Nunavut and the lands of the Qikiqtaani Inuit. It’s the largest island in Canada and the fifth-largest island in the world, with a mountain range that runs along its northeastern edge. But these scientists were interested in a small lake, past the mountains and near the coast.

Above the Arctic Circle, the area around this lake is typical of a high Arctic tundra, with average annual temperatures below 15 °F (?9.5 °C). In this inhospitable climate, the soil is thin and not much of anything grows.

But DNA stored in the lake beds below tells a much different story. To reach this valuable resource, Crump and her fellow researchers carefully balanced on cheap inflatable boats in the summer — the only vessels light enough to carry with them — and watched out for polar bears from the lake ice in winter. They pierced the thick mud up to 30 feet (10 meters) below its surface with long, cylindrical pipes, hammering them deep into the sediment.

The goal of this precarious feat? To carefully withdraw a vertical history of ancient plant material to then travel back out with and take back to the lab. While some of the mud was analyzed at a state-of-the-art organic geochemistry lab in the Sustainability, Energy and Environment Community (SEEC) at CU Boulder, it also needed to reach a special lab dedicated to decoding ancient DNA, at Curtin University in Perth.

To share their secrets, these mud cores had to travel halfway across the world from the Arctic to Australia.

A local snapshot

Once in the lab, the scientists had to suit up like astronauts and examine the mud in an ultra-clean space to ensure that their own DNA didn’t contaminate that any of their hard-earned samples.

It was a race against the clock.

“Your best shot is getting fresh mud,” said Crump. “Once it’s out of the lake, the DNA is going to start to degrade.”

This is why older lake bed samples in cold storage don’t quite do the trick. While other researchers have also collected and analyzed much older DNA samples from permafrost in the Arctic (which acts as a natural freezer underground), lake sediments are kept cool, but not frozen. With fresher mud and more intact DNA, scientists can get a clearer and more detailed picture of the vegetation which once grew in that immediate area.

Reconstructing historic vegetation has most commonly been done using fossil pollen records, which preserve well in sediment. But pollen is prone to only showing the big picture, as it is easily blown about by the wind and doesn’t stay in one place. The new technique used by Crump and her colleagues allowed them to extract plant DNA directly from the sediment, sequence the DNA, and infer what plant species were living there at the time. Instead of a regional picture, sedimentary DNA analysis gives researchers a local snapshot of the plant species living there at the time. Now that they have shown it’s possible to extract DNA that’s over 100,000 years old, future possibilities abound.

“This tool is going to be really useful on these longer timescales,” said Crump. This research has also planted the seed to study more than just plants. In the DNA samples from their lake sediment, there are signals from a whole range of organisms that lived in and around the lake.

“We’re just starting to scratch the surface of what we’re able to see in these past ecosystems,” said Crump. “We can see the past presence of everything from microbes to mammals, and we can start to get much broader pictures of how past ecosystems looked and how they functioned.”

Scientists stunned to discover plants beneath mile-deep Greenland ice

Scientists stunned to discover plants beneath mile-deep Greenland ice

In northwestern Greenland in 1966, US Army scientists drilled through nearly a mile of ice and pulled up a fifteen-foot-long tube of dirt from the bottom. Then this frozen sediment was lost in a freezer for decades. It was accidentally rediscovered in 2017.

Engineers with the Cold Regions Research and Engineering Laboratory capture part of an ice core at Camp Century, Greenland, circa 1966.

In 2019, University of Vermont scientist Andrew Christ looked at it through his microscope — and couldn’t believe what he was seeing: twigs and leaves instead of just sand and rock. That suggested that the ice was gone in the recent geologic past — and that a vegetated landscape, perhaps a boreal forest, stood where a mile-deep ice sheet as big as Alaska stands today.

Over the last year, Christ and an international team of scientists — led by Paul Bierman at UVM, Joerg Schaefer at Columbia University, and Dorthe Dahl-Jensen at the University of Copenhagen — have studied these one-of-a-kind fossil plants and sediment from the bottom of Greenland. Their results show that most, or all, of Greenland, must have been ice-free within the last million years, perhaps even the last few hundred thousand years.


“Ice sheets typically pulverize and destroy everything in their path,” says Christ, “but what we discovered was delicate plant structures — perfectly preserved. They’re fossils, but they look like they died yesterday. It’s a time capsule of what used to live on Greenland that we wouldn’t be able to find anywhere else.”

The discovery helps confirm a new and troubling understanding that the Greenland ice has melted off entirely during recent warm periods in Earth’s history — periods like the one we are now creating with human-caused climate change.

Understanding the Greenland Ice Sheet in the past is critical for predicting how it will respond to climate warming in the future and how quickly it will melt. Since some twenty feet of sea-level rise is tied up in Greenland’s ice, every coastal city in the world is at risk. The new study provides the strongest evidence yet that Greenland is more fragile and sensitive to climate change than previously understood — and at grave risk of irreversibly melting off.

“This is not a twenty-generation problem,” says Paul Bierman, a geoscientist at UVM in the College of Arts & Sciences, Rubenstein School of Environment & Natural Resources, and fellow in the Gund Institute for Environment. “This is an urgent problem for the next 50 years.”

The new research was published March 15 in the Proceedings of the National Academy of Sciences.

Beneath the Ice

The material for the new PNAS study came from Camp Century, a Cold War military base dug inside the ice sheet far above the Arctic Circle in the 1960s. The real purpose of the camp was a super-secret effort, called Project Iceworm, to hide 600 nuclear missiles under the ice close to the Soviet Union. As a cover, the Army presented the camp as a polar science station.

A sediment sample from the Camp Century core site.

The military mission failed, but the science team did complete important research, including drilling a 4560-foot-deep ice core. The Camp Century scientists were focused on the ice itself — part of the burgeoning effort at the time to understand the deep history of Earth’s ice ages. They, apparently, took less interest in a bit of dirt gathered from beneath the ice core. Then, in a truly cinematic set of strange plot twists, the ice core was moved from an Army freezer to the University of Buffalo in the 1970s, to another freezer in Copenhagen, Denmark, in the 1990s, where it languished for decades — until it surfaced when the cores were being moved to a new freezer.

For much of the Pleistocene — the icy period covering the last 2.6 million years — portions of the ice on Greenland persisted even during warmer spells called “interglacials.” But most of this general story has been pieced together from indirect evidence in mud and rock that washed off the island and was gathered by offshore ocean drilling. The extent of Greenland’s ice sheet and what kinds of ecosystems existed there before the last interglacial warm period — that ended about 120,000 years ago — have been hotly debated and poorly understood.

The new study makes clear that the deep ice at Camp Century — some 75 miles inland from the coast and only 800 miles from the North Pole — entirely melted at least once within the last million years and was covered with vegetation, including moss and perhaps trees. The new research, supported by the National Science Foundation, lines up with data from two other ice cores from the center of Greenland, collected in the 1990s. Sediment from the bottom of these cores also indicates that the ice sheet was gone for some time in the recent geologic past.

Scientists stunned to discover plants beneath mile-deep Greenland ice
Most of Greenland is covered with ice today. But a new study shows that the deep ice at a site called Camp Century in northwestern Greenland entirely melted at least once within the last million years. The research suggests that the landscape may have instead been covered with green tundra, perhaps like this view of eastern Greenland, near the ocean.

The combination of these cores from the center of Greenland with the new insight from Camp Century in the far northwest gives researchers an unprecedented view of the shifting fate of the entire Greenland ice sheet.

The team of scientists used a series of advanced analytical techniques — none of which were available to researchers fifty years ago — to probe the sediment, fossils, and the waxy coating of leaves found at the bottom of the Camp Century ice core. For example, they measured ratios of rare forms — isotopes — of both aluminum and the element beryllium that form in quartz only when the ground is exposed to the sky and can be hit by cosmic rays. These ratios gave the scientists a window into how long rocks at the surface were exposed vs. buried under layers of ice. This analysis gives the scientists a kind of clock for measuring what was happening in Greenland in the past.

Another test used rare forms of oxygen, found in the ice within the sediment, to reveal that precipitation must have fallen at much lower elevations than the height of the current ice sheet, “demonstrating ice sheet absence,” the team writes.

Combining these techniques with studies of luminescence that estimate the amount of time since sediment was exposed to light, radiocarbon-dating of bits of wood in the ice, and analysis of how layers of ice and debris were arranged — allowed the team to be clear that most, if not all, of Greenland, melted at least once during the past million years — making Greenland green with moss and lichen, and perhaps with spruce and fir trees.

And the new study shows that ecosystems of the past were not scoured into oblivion by ages of glaciers and ice sheets bulldozing overtop. Instead, the story of these living landscapes remains captured under the relatively young ice that formed on top of the ground, frozen in place, and holds them still.

In a 1960’s movie about Camp Century created by the Army, the narrator notes that “more than ninety percent of Greenland is permanently frozen under a polar ice cap.” This new study makes clear that it’s not as permanent as we once thought. “Our study shows that Greenland is much more sensitive to natural climate warming than we used to think — and we already know that humanity’s out-of-control warming of the planet hugely exceeds the natural rate,” says Christ.

“Greenland may seem far away,” says UVM’s Paul Bierman, “but it can quickly melt, pouring enough into the oceans that New York, Miami, Dhaka — pick your city — will go underwater.”

Hundreds of Artifacts Returned to Mexico by Arizona Homeland Security

Hundreds of Artifacts Returned to Mexico by Arizona Homeland Security

Homeland Security Investigations (HSI) returned 277 pre-Columbian artefacts to Mexican officials Tuesday during a repatriation ceremony in the Mexican Consulate in Nogales.

Hundreds of Artifacts Returned to Mexico by Arizona Homeland Security

The pieces were recovered after two separate investigations by HSI special agents assigned to Phoenix and Nogales, Arizona. Scott Brown, special agent in charge of HSI Phoenix, presented the relics to Mexican Consul General Ambassador Ricardo Santana and Jose Luis Perea, director of the Mexican Institute for Anthropology and History (INAH) in Sonora, Mexico. The Mexican officials accepted the relics on behalf of the people of Mexico.

“The cultural significance of artefacts from regions around the world extends beyond any monetary value,” said SAC Brown. “The pieces, like those discovered, are fragments of history; and it is an honour to return them to their rightful home country. HSI fully supports the importance of antiquities and cultural property, and it is through these repatriations that new generations are able to experience a part of their nation’s story.”

HSI Arizona returns hundreds of pre-Columbian artifacts to Mexico

The HSI Phoenix case began Oct. 8, 2013, when special agents were contacted by a representative of the Chandler Historical Society regarding multiple suspected pre-Columbian Chinesco-Western pottery figures with origins as far back as 100 B.C., which were in the possession of the City of Chandler Museum.

HSI special agents promptly met with the museum’s director who turned over 10 Shaft Tomb artefacts for further review and investigation. Through archaeological expert analysis, the authenticity of these artefacts was confirmed as being more than 1,500 years old and originating from Mexico.

HSI Arizona returns hundreds of pre-Columbian artefacts to Mexico

HSI special agents met with the Mexican consulate general of Nogales, director of archaeology in Sonora, Mexico, chief archaeologist for the Cerro de Trincheras zone to view the artefacts, which were authenticated as historically significant artefacts originating from Mexico.

Results of this meeting confirmed the 10 ceramic figurines to be Shaft Tomb artefacts believed to accompany deceased individuals during the last rite of passage circa 100 B.C. to 500 A.D. from the geographic regions of Nayarit, Jalisco, and Colima, Mexico. The archaeological experts estimated the value of the artefacts between $26,100 and $45,700.

The HSI Nogales case began in October 2012, after HSI special agents were contacted by U.S. Customs and Border Protection (CBP) regarding numerous suspected Pre-Columbian artefacts that were declared by two Mexican citizens who presented themselves for entry into the United States from Mexico via the Mariposa Port of Entry in Nogales.

HSI Nogales took custody of 267 artefacts. The items detained included arrowheads, axe heads, hammerheads, spearheads, and small stone carvings. Archaeological expert analysis subsequently confirmed the authenticity of the artefacts as being between 1,000 and 5,000 years old and of significant cultural value.

In March 2013, HSI Hermosillo representatives contacted INAH in Sonora to arrange a meeting with HSI Nogales at the CBP Nogales administrative offices to conduct a thorough examination of the detained artefacts.

The three INAH research professor archaeologists viewed the artefacts and concluded that the 267 individual pieces were pre-Hispanic (aka pre-Columbian) cultural artefacts of Mexican origin from Northwest Mexico. INAH appraised the artefacts at over $124,000.

HSI concluded that all the seized pieces were imported into the United States contrary to law pursuant to the United Nations Educational, Scientific and Cultural Organization (UNESCO) Convention of 1970 and the Cultural Property Implementation Act, and therefore were to be returned to their proper home of Mexico.

U.S. Consul General in Nogales Laura Biedebach underscored, “The United States government is committed to combating the theft and trafficking of cultural heritage and to preserving and protecting it where it is found. We will continue to cooperate across agencies and borders to ensure that our citizens can enjoy their cultural heritage. We have much work to do to preserve our history for the next generation, but we are in this together and proud to be your partners.”

“This repatriation comes at an opportune time, in the year of a very significant commemoration for Mexico, the 500th anniversary of the taking of Tenochtitlan, which was a heartrending encounter between the cultural universes of Western Europe and America, said INAH Director Jose Luis Perea. “This event allows us to deeply recognize the pre-Hispanic cultures of Mexico, as well as the resistance and presence of its contemporary indigenous peoples.”

HSI is the investigative arm for the U.S. Department of Homeland Security and plays a leading role in criminal investigations that involve the illicit distribution of cultural property, as well as the illegal trafficking of artwork, specializing in recovering works that have been reported lost or stolen. HSI’s International Operations, through its 80 offices in 53 countries, works closely with foreign governments to conduct joint investigations.

Despite increasingly aggressive enforcement efforts to prevent the theft of cultural heritage and other antiquities, the illicit movement of such items across international borders continues to challenge global law enforcement efforts to reduce the trafficking of such property. Trafficking in antiquities is estimated to be a multi-billion dollar transnational criminal enterprise.

HSI is committed to pursuing a strategy to combat transnational organized crime related to the illicit trafficking of cultural artefacts by targeting high priority organizations and strengthening international law enforcement partnerships.

The public, government and private institutions often aid HSI in identifying, investigating and prosecuting illicitly trafficked cultural property. If you have information about the illicit trade of cultural property or art, call the ICE Tip Line at 1-866-DHS-2-ICE or report tips online.