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ProfessorF Great Old One Joined: 09 Aug 2005 Total posts: 331 Location: Ulan Bator - inside my head looking out Gender: Unknown |
 Posted: 10-01-2009 20:03 Post subject: |
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‘Stonehenge’ At The Bottom Of Lake Michigan
| Quote: | STONEHENGE BENEATH THE WATERS OF LAKE MICHIGAN
[Image: Standing stones beneath Lake Michigan? View larger].
In a surprisingly under-reported story from 2007, Mark Holley, a professor of underwater archaeology at Northwestern Michigan University College, discovered a series of stones – some of them arranged in a circle and one of which seemed to show carvings of a mastodon – 40-feet beneath the surface waters of Lake Michigan.
If verified, the carvings could be as much as 10,000 years old – coincident with the post-Ice Age presence of both humans and mastodons in the upper midwest.
[Image: The stones beneath Lake Michigan; view larger].
In a PDF assembled by Holley and Brian Abbott to document the expedition, we learn that the archaeologists had been hired to survey a series of old boatwrecks using a slightly repurposed "sector scan sonar" device. You can read about the actual equipment – a Kongsberg-Mesotech MS 1000 – here.
The circular images this thing produces are unreal; like some strange new art-historical branch of landscape representation, they form cryptic dioramas of long-lost wreckage on the lakebed. Shipwrecks (like the Tramp, which went down in 1974); a "junk pile" of old boats and cars; a Civil War-era pier; and even an old buggy are just some of the topographic features the divers discovered.
These are anthropological remains that will soon be part of the lake's geology; they are our future trace fossils.
But down amongst those otherwise mundane human remains were the stones.
[Image: The "junk pile" of old cars and boat skeletons; view larger].
While there is obviously some doubt as to whether or not that really is a mastodon carved on a rock – let alone if it really was human activity that arranged some of the rocks into a Stonehenge-like circle – it's worth pointing out that Michigan does already have petroglyph sites and even standing stones.
A representative of the University of Michigan Museum of Paleontology has even commented that, although he's skeptical, he's interested in learning more, hoping to see better photographs of the so-called "glyph stone."
[Image: The stones; view larger].
So is there a North American version of Stonehenge just sitting up there beneath the glacial waters of a small northern bay in Lake Michigan? If so, are there other submerged prehistoric megaliths waiting to be discovered by some rogue archaeologist armed with a sonar scanner?
Whatever the answer might be, the very suggestion is interesting enough to think about – where underwater archaeology, prehistoric remains, and lost shipwrecks collide to form a midwestern mystery: National Treasure 3 or Da Vinci Code 2. Even Ghostbusters: The Return.
But only future scuba expeditions will be able to tell for sure. |
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| ramonmercado AKA Dora Kaplan Joined: 19 Aug 2003 Total posts: 7414 Location: Dublin Gender: Male |
| Posted: 28-01-2009 19:33 Post subject: |
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| Quote: | Comet Impact Theory Disproved
http://www.spacedaily.com/reports/Comet_Impact_Theory_Disproved_999.html
Understanding whether rapid changes in climate have caused wild fires in the past will help understand whether current changes in global temperatures will cause more frequent fires at the present time. Such fires have a major impact on the economy and health of the population, as well as feeding into the increase in global warming.
by Staff Writers
Bristol, UK (SPX) Jan 28, 2009
New data disproves the recent theory that a large comet exploded over North America 12,900 years ago, causing a shock wave that travelled across North America at hundreds of kilometres per hour and triggering continent-wide wildfires.
Dr Sandy Harrison from the University of Bristol and colleagues tested the theory by examining charcoal and pollen records to assess how fire regimes in North America changed between 15 and 10,000 years ago, a time of large and rapid climate changes.
Their results provide no evidence for continental-scale fires, but support the fact that the increase in large-scale wildfires in all regions of the world during the past decade is related to an increase in global warming.
Fire is the most ubiquitous form of landscape disturbance and has important effects on climate through the global carbon cycle and changing atmospheric chemistry. This has triggered an interest in knowing how fire has changed in the past, and particularly how fire regimes respond to periods of major warming.
The end of the Younger Dryas, about 11,700 years ago, was an interval when the temperature of Greenland warmed by over 5 degrees C in less than a few decades. The team used 35 records of charcoal accumulation in lake sediments from sites across North America to see whether fire regimes across the continent showed any response to such rapid warming.
They found clear changes in biomass burning and fire frequency whenever climate changed abruptly, and most particularly when temperatures increased at the end of the Younger Dryas cold phase. The results published, January 26, in the Proceedings of the National Academy of Science.
Understanding whether rapid changes in climate have caused wild fires in the past will help understand whether current changes in global temperatures will cause more frequent fires at the present time. Such fires have a major impact on the economy and health of the population, as well as feeding into the increase in global warming. |
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| ProfessorF Great Old One Joined: 09 Aug 2005 Total posts: 331 Location: Ulan Bator - inside my head looking out Gender: Unknown |
| Posted: 17-06-2009 14:48 Post subject: |
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| Quote: | Local site rewrites history of early humans in America
6/12/2009 12:30 AM
By DR. TOM MACK
Columnist
Since 1998, archaeologists at a site in Allendale County have been making discoveries that have the potential to rewrite the history - or more precisely, the prehistory - of our state.
The Topper site, named for a local resident who first found ancient artifacts at this location that borders the eastern shore of the Savannah River, has been the subject of major media attention because of the unearthing of evidence that human habitation in North America predates traditional estimates.
One of the staple beliefs of paleoamerican research - the term "paleo" is derived from the Greek word for "ancient" - holds that the first Americans appeared no earlier than 13,000 years ago; these early humans, it is thought, originated in Northeast Asia and crossed over to our continent after the last Ice Age.
Labeled the Clovis culture by scientists because the first evidence of these ancestors of the indigenous people of North America was found in the 1930s near present-day Clovis, N.M., these prehistoric humans were noted for their creation of distinctly shaped stone spear points used in the hunting of bison and mastodon and other early mammals.
The Topper site offers rich evidence of Clovis occupation in the Central Savannah River Area; in fact, the team responsible for excavating the site, members of the South Carolina Institute of Archaeology and Anthropology, think that they have discovered at Topper an early quarry used by the Clovis people to gather the materials - in this case, a type of rock known as chert - for fashioning their stone tools.
Just its identification as a Clovis site would have been enough to make Topper an archaeological location of intense scientific interest, but a decision made by Dr. Albert Goodyear, the founder and director of the Allendale Paleoindian Expedition, to dig deeper than is generally the case at most such sites led to hypotheses that have made headlines.
In 2004, Goodyear and his team dug four meters below the surface and found artifacts in a layer of burnt plant remains that were subsequently tested via radiocarbon dating. The finding that this charcoal deposit is as old as 50,000 years may lend credence to the theory that human habitation on this continent dates much, much earlier than anyone supposed. Goodyear himself asserts that "Topper is the oldest radiocarbon-dated site in North America."
The verdict is still out, however, as to whether this evidence alone contradicts the long-held belief that early humans first arrived in America from Asia 13,000 years ago.
Many scientists argue that there is still not sufficient proof - incontrovertible material evidence - to support that contention.
Still, this pre-Clovis claim is tantalizing - and the search for further proof is under way, thanks to the ongoing work of the S.C. Institute of Archaeology and Anthropology at USC. Excavation continues unabated, with the active encouragement of the Clariant Corporation, which owns 2,000 acres in Allendale County, including the Topper site.
This Swiss-based company not only decided to provide camping facilities for the staff of the Southeastern Paleoamerican Survey but also made a significant financial contribution to the construction of a pavilion that shelters some of the most critical area of excavation - a viewing deck was added at this spot for the convenience of visitors in 2007.
Anyone can take part in this history-making effort to rewrite our state's prehistorical past.
Each summer, members of the public can join the "expedition" and participate in the dig by paying a largely tax-deductible fee; in return, they get to "work" the site and learn more about excavation techniques and artifact identification. For more information, visit www.allendale-expedition.net.
Dr. Mack is a Carolina Trustee Professor at USC Aiken.
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| ramonmercado AKA Dora Kaplan Joined: 19 Aug 2003 Total posts: 7414 Location: Dublin Gender: Male |
| Posted: 03-09-2009 18:00 Post subject: |
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| Quote: | Underwater Expedition Delivers Key Findings In Search For Evidence Of Early Americans
http://www.sciencedaily.com/releases/2009/08/090831131402.htm
ScienceDaily (Sep. 1, 2009) — In one of the more dramatic moments of an underwater archaeological survey co-led by Mercyhurst College archaeologist James Adovasio along Florida’s Gulf Coast this summer, Andy Hemmings stood on an inundated river’s edge where man hasn't set foot in more than 13,000 years.
Donning full scuba gear, Hemmings stood in 130 feet of water on a peninsula at the intersection of two ancient rivers nearly 100 miles offshore from Tampa. The last time humans could have stood in that spot, mammoth and mastodon roamed the terrain.
“The successful tracking of the St. Marks-Aucilla River and the Suwannee River, between 50 and 150 kilometers respectively, represents what we believe to be the most extensive delineation of submerged prehistoric river systems ever done anywhere in the world,” Adovasio said.
Another pivotal find is the identification of chert at three dive sites along the river systems; chert is a superior quality fine-grained stone used by prehistoric peoples to make tools.
“There is no doubt,” Adovasio said, “that we have found the haystacks and are one step closer to uncovering the archaeological needles;” in effect, narrowing the search for evidence of early Americans in the now submerged Inner Continental Shelf in the Gulf of Mexico off the Florida coast.
Hemmings, one of the leading Paleoindian underwater archaeologists in North America, agreed. “My feeling is, given a little time to probe the sediments with a dredge, we will quickly find human artifacts.”
The signature expedition of the National Oceanic and Atmospheric Administration (NOAA) Office of Ocean Exploration and Research began in the summer of 2008 when a distinguished group of scientists led by Mercyhurst’s Adovasio and Hemmings identified and mapped buried river channels that could potentially help document the late Pleistocene landscape. This year’s mission, undertaken July 23 to Aug. 5, further traced the river systems along whose beaches prehistoric people may have populated and identified raw materials that they may have used in tool making.
The mission also has advanced underwater understanding and research methodology exponentially, Adovasio said.
“We have developed protocols for exploring deep water, which is both time and labor intensive, as well as expensive, unlike anything done before,” he said.
From the Weatherbird II, flagship of the Florida Institute of Oceanography in St. Petersburg, researchers electronically mapped the modern sea floor with a side scan sonar device and created images of the layered sediments below the seafloor surface with a sub-bottom profiler. Using GPS technology, the team selected dive locations based on an understanding of what the surface should look like, and what was hidden below that surface adjacent to the old river channels.
On the peninsula where the relict Suwannee River intersects another ancient system, divers were able to collect a 1m sediment core but were unable to complete a lengthier search for human artifacts because the water neared 130 feet, the maximum depth level for this year’s dive. The team plans to return to this spot next year, increasing the divers’ depth level certification to 165 feet and using a dredge to lift the silt away and see if there is an archaeological site at this confluence.
“Proof of past human habitation here would reinforce the disintegration of the once prevalent hypothesis about who the first Americans were, how they got here and when they arrived,” said Adovasio, who rose to fame 30 years ago while excavating the Meadowcroft Rockshelter near Pittsburgh, Pa. Besides primary funding from NOAA, this summer’s work was supported by the Mercyhurst Archaeological Institute, Gault School of Archaeological Research, Florida Bureau of Archaeological Research, Florida Institute of Oceanography, and the University of Illinois at Chicago, among others. Students from Mercyhurst, Harvard, the University of Michigan and Texas A & M were also part of the research group.
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Adapted from materials provided by Mercyhurst College. |
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| ramonmercado AKA Dora Kaplan Joined: 19 Aug 2003 Total posts: 7414 Location: Dublin Gender: Male |
| Posted: 13-10-2009 18:15 Post subject: |
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| Quote: | North America comet theory questioned
http://www.nature.com/news/2009/091012/full/news.2009.997.html
No evidence of an extraterrestrial impact 13,000 years ago, studies say.
Rex Dalton
An independent study has cast more doubt on a controversial theory that a comet exploded over icy North America nearly 13,000 years ago, wiping out the Clovis people and many of the continent's large animals.
Sediments at the San Jon site, in eastern New Mexico, contained very low abundances of magnetic spherules said to be evidence of an impact.Vance HollidayArchaeologists have examined sediments at seven Clovis-age sites across the United States, and did not find enough magnetic cosmic debris to confirm that an extraterrestrial impact happened at that time, says the report in the Proceedings of the National Academy of Sciences (PNAS)1. It is the latest of several studies unable to support aspects of the impact hypothesis.
In 2007, a team led by Californian researchers announced a theory2 that a comet or asteroid had exploded over the North American ice sheet, creating widespread fire and an atmospheric soot burst followed by a cooling period known as the Younger Dryas. Sometime after this, the Clovis people, sophisticated large-animal hunters known for their spear points, mysteriously disappeared; the team linked their vanishing to the environmental effects of the proposed impact.
Key evidence came in the form of magnetic microspherules discovered in sediments at 25 locations, including eight Clovis-age sites. Richard Firestone, of Lawrence Berkeley National Laboratory in California, and his colleagues argued that the microspherules were remnants of cosmic debris from an explosion.
But in more than 18 months of sedimentary analysis, a team led by Todd Surovell, an archaeologist at the University of Wyoming in Laramie, was unable to detect microspherule peaks. Two of the seven sites the group studied were places where Firestone's team identified spherule peaks.
"I spent hundreds of hours at the microscope examining sediment samples," says Surovell, "and I didn't find any physical evidence to support their theory."
Standing firm
The other team isn't backing down. "Their study doesn't negate our hypothesis," says James Kennett, a palaeoceanographer at the University of California at Santa Barbara and one of Firestone's co-authors. Another co-author, avocational geophysicist Allen West of Prescott, Arizona, says that Surovell's group didn't use the correct technique to extract, identify and quantify the microspherules.
Several other groups have been unable to support important aspects of the comet theory.
In a PNAS article published in February3, Jennifer Marlon, a doctoral geography student at the University of Oregon in Eugene, and her colleagues found no systematic burning of biomass — as would have occurred if continent-wide fires had happened — at the time of the Younger Dryas in pollen and charcoal records at 35 sites. And at the Ecological Society of America meeting in Albuquerque, New Mexico, in August, Jacquelyn Gill, a palaeoecology doctoral student at the University of Wisconsin-Madison, reported finding no evidence of massive burning in sediment cores taken from lake beds in Ohio and Indiana.
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Kennett, however, calls these studies "flawed". In August, his team published a report4 saying they had found nanometre-sized diamonds, purportedly created during an impact, and soot in sediments dated to the Younger Dryas on Santa Rosa Island, off the coast of California.
More studies of the theory — both critical and supportive — are in the publishing pipelines at other journals.
Surovell's co-author Vance Holliday, an archaeologist at the University of Arizona in Tucson, and his colleagues have an article in press at Current Anthropology that says the archaeological and geochronological records don't support a collapse of Clovis people at the time of the purported impact.
References
Surovell, T. A. et al. Proc. Natl Acad. Sci. USA advance online publication doi:10.1073/pnas.0907857106 (2009).
Firestone, R. B. et al. Proc. Natl Acad. Sci. USA 104, 16016-16021 (2007). | Article | PubMed
Marlon, J. R. et al. Proc. Natl Acad. Sci. USA 106, 2519-2524 (2009). | Article | PubMed
Kennett, D. J. et al. Proc. Natl Acad. Sci. USA 106, 12623-12628 (2009). | Article | PubMed |
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| ramonmercado AKA Dora Kaplan Joined: 19 Aug 2003 Total posts: 7414 Location: Dublin Gender: Male |
| Posted: 21-10-2009 18:34 Post subject: |
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| Quote: | Pre-Columbian Societies Knew a Thing About Extracting Gold
http://sciencenow.sciencemag.org/cgi/content/full/2009/1020/2
By Charles C. Mann
ScienceNOW Daily News
20 October 2009
When Spanish conquistadors seized the Inka emperor Atawalpa in 1532, they demanded an enormous ransom of silver and gold. For weeks, llama trains carried tons of gold and silver statues, cups, and other objects to the Europeans, who then ordered them melted down to ingots for transport back to Spain. Such an enormous stash suggests that the Andean people knew sophisticated metallurgy, but there has been little evidence to support this. Now a team of geologists and archaeologists have found clues that these indigenous people refined gold with mercury amalgamation, an important metallurgical technique that is still in use today.
To extract precious metals from ore, workers mix liquid mercury with finely ground gold or silver ore, creating an amalgam or alloy. They then separate out the heavier amalgam and heat it to boil away the mercury, arriving at almost-pure silver or gold. The Romans knew of mercury amalgamation in the 1st century, but it was not widespread in Europe until the 12th century. Polish engineer-archaeologist Arthur Posnansky insisted as far back as 1945 that amalgamation was used near the famed Incan site of Machu Picchu, but archaeologists have always vigorously disputed these claims, noting that much of Posnansky's work was overly credulous. Instead, experts believed that the process was nonexistent in the Americas until colonist Bartolomé de Medina developed a variant in Mexico in 1557.
But William Brooks, a geologist based in Reston, Virginia, couldn't believe that societies, which produced large quantities of gold, lacked techniques to recover it from placer gold, the minute gold flakes in stream beds found along coastal Peru. So Brooks and colleagues in Peru and Colombia analyzed residual mercury levels in seven samples of pre-European-contact gold foil--three from the Sicàn culture, which existed between 750 C.E. and 1375 C.E. in Peru, and four from Colombia. The team found signs of amalgamation similar to those seen in contemporary gold foil in southeastern Peru, it reports today at the Geological Society of America's annual meeting in Portland, Oregon. "We think this technique was used throughout the Andes, probably centuries before it was commonly used in Europe," Brooks says.
The researchers' work has not escaped criticism, however. Almost all known Sicàn gold artifacts were looted from elite burial sites, which makes their context uncertain, says Izumi Shimada of Southern Illinois University in Carbondale, director of the Sicàn Archaeological Project. Moreover, he says, both artifacts and bodies in the tombs were often "painted from head to foot in cinnabar," a brilliant vermillion pigment made from a mercury-sulfur compound, which could have contaminated the scientists' measurements. To confirm mercury amalgamation, Shimada says, "would require an independent testing of items recovered from a nonfunerary context."
Brooks agrees that contamination is a potential issue and says that the museums preparing their samples carefully removed the cinnabar deposits. If there were still cinnabar contamination, however, Brooks says he would have expected random variations between samples instead of the consistent measurements his team observed. Also, amalgamation, he says, just makes sense: "They had to have some way to produce all that gold, and an obvious candidate is the metallurgical technique used everywhere else in the world." |
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| PeniG Proud children's writer Joined: 31 Dec 2003 Total posts: 2352 Location: San Antonio, Texas Age: 48 Gender: Female |
| Posted: 06-11-2009 17:48 Post subject: |
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The headline here is in error, and should say "oldest directly datable" artifact, and should reference North America. There's a layer under Monte Verde that Dillehay has tentatively dated to 30,000 YBP, and certain stone artifacts at Gault, Topper, and Meadowcroft may well turn out to be older than this one; but dating bone is a much more straightforward business than dating stone.
| Quote: |
Oldest American artefact unearthed
Oregon caves yield evidence of continent's first inhabitants.
Rex Dalton
An Oregon cave has yielded the oldest artefact ever found in the Americas.
Tom StaffordArchaeologists claim to have found the oldest known artefact in the Americas, a scraper-like tool in an Oregon cave that dates back 14,230 years.
The tool shows that people were living in North America well before the widespread Clovis culture of 12,900 to 12,400 years ago, says archaeologist Dennis Jenkins of the University of Oregon in Eugene.
Studies of sediment and radiocarbon dating showed the bone's age. Jenkins presented the finding late last month in a lecture at the University of Oregon.
His team found the tool in a rock shelter overlooking a lake in south-central Oregon, one of a series of caves near the town of Paisley.
Kevin Smith, the team member who uncovered the artefact, remembers the discovery. "We had bumped into a lot of extinct horse, bison and camel bone – then I heard and felt the familiar ring and feel when trowel hits bone," says Smith, now a master's student at California State University, Los Angeles. "I switched to a brush. Soon this huge bone emerged, then I saw the serrated edge. I stepped back and said: 'Hey everybody — we got something here.'"
Coprolite controversy
Whether the cave dwellers were Clovis people or belonged to an earlier culture is uncertain. None of the Clovis people's distinct fluted spear and arrow points have been found in the cave.
"They can't yet rule out the Paisley Cave people weren't Clovis," says Jon Erlandson, an archaeologist at the University of Oregon who wasn't involved in the research.
The only other American archaeological site older than Clovis is at Monte Verde in Chile, which is about 13,900 years old.
Last year, Jenkins and colleagues reported that Paisley Cave coprolites, or fossilized human excrement, dated to 14,000 to 14,270 years ago1. That report established the Paisley Caves as a key site for American archaeology.
Analysis of ancient DNA marked the coprolites as human. But in July, another group argued that the coprolites might be younger than the sediments that contained them2.
This team, led by Hendrik Poinar of McMaster University in Hamilton, Ontario, also questioned the 2008 report because no artefacts had been found in the crucial sediments. The Oregon team strongly disputed the criticisms3.
Laid to rest?
The dating of the bone tool, and the finding that the sediments encasing it range from 11,930 to 14,480 years old, might put these questions to rest. "You couldn't ask for better dated stratigraphy," Jenkins told the Oregon meeting.
"They have definitely made their argument even stronger," says Todd Surovell, an archaeologist at the University of Wyoming in Laramie who was not involved in the research.
Other researchers questioned whether the cave's inhabitants would have been mainly vegetarian, as the coprolites suggested4. In his recent lecture Jenkins noted other evidence reflecting a diet short on meat but including edible plants such as the fernleaf biscuitroot Lomatium dissectum.
In late September, a group of archaeologists who study the peopling of the Americas met with federal officials and a representative of the local Klamath tribe to review the evidence at Paisley Caves. The specialists spent two days examining sediments, checking the tool, and assessing other plant and animal evidence.
"It was an impressive presentation," says David Meltzer, an archaeologist at Southern Methodist University in Dallas, Texas, who attended the meeting. "This is clearly an important site, but there are some tests that need to be done to seal the deal." One key, he says, is to better understand how the specimens got to the cave.
References
1.Gilbert, W.T.P. et al. Science 320, 786-789 (2008).
2.Poinar, H. et al. Science 325, 148 (2009).
3.Rasmussen, M. et al. Science 325, 148 (2009).
4.Goldberg, P., Berna, F. & Macphail, R.I. Science 325, 5937, 148 (2009).
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