carbon dated

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A representation of the age span carbon dating is able to accurately predict.

Carbon dating works by understanding the properties of two isotopes of carbon, carbon 12 and carbon 14. Carbon 12 does not decay and remains constant in a sample, whereas carbon 14 decays at a very even, constant rate.

By measuring the ratio of carbon 12 to carbon 14, we can understand how long a sample has been around for.

The half life of carbon 14 is around 5,730 years. As seen by the second graph, this means that if a sample has half of the carbon 14 it should usually have, it has been around for 5,730 years. A quarter of the amount, double that time, one eight of the original amount, more still.

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Welwitschia mirabilis (commonly known as Welwitschia or tree tumbo) is a monotypic gymnosperm native to the Namib desert in Namibia and Angola. An adult welwitschia consists of roots, a stem base, and only two leaves (the same two leaves from when the plant was a seedling). The two leaves, which can grow to over 26 feet in diameter, lie on the ground becoming torn to ribbons and tattered with age. Their estimated lifespan, using carbon dating, is 400-1500 years with the oldest being over 2000 years.

nature.com
Skeleton plundered from Mexican cave was one of the Americas’ oldest
Rock-encased bone shard left behind by thieves allowed researchers to determine that the remains are probably more than 13,000 years old.

A human skeleton that was stolen from an underwater cave in Mexico in 2012 may be one of the oldest ever found in the Americas. Scientists have now put the age of the skeleton at more than 13,000 years old after analysing a shard of hip bone — left behind by the thieves because it was embedded in a stalagmite.

Cave divers discovered the remains in February 2012 in a submerged cave called Chan Hol near Tulúm on Mexico’s Yucatán peninsula, and posted photos of a nearly complete skull and other whole bones to social media. The posts caught the attention of archaeologists Arturo González González at the Desert Museum in Saltillo, Mexico, and Jerónimo Avilés Olguín at the Institute of American Prehistory in Cancún.

By the time researchers visited the cave in late March, the remains were gone — except for about 150 bone fragments and a pelvic bone that had been subsumed by a stalagmite growing up from the cave floor. On the basis of these bones, the researchers think that the skeleton belonged to a young man who died when sea levels were much lower and the cave was above ground.

Dating techniques

To determine the age of human remains, researchers often measure levels of a radioactive isotope of carbon in collagen protein within bones. But in this case, most of the collagen had been leached out by water while the bones were submerged, making this method unreliable, says Wolfgang Stinnesbeck, a palaeontologist and geoscientist at the University of Heidelberg, Germany, who led the efforts to date the remains.

Instead, Stinnesbeck’s team collected a fleck of the pelvis bone and surrounding stalagmite, which contains a mineral called calcite. The team then dated the rock using the relative levels of uranium and thorium isotopes in the calcite. The deeper into the stalagmite the researchers sampled, the older the dates turned out to be; stone just 2 centimetres from the bone was 11,300 years old. Calcite closer to the bone gave conflicting results, Stinnesbeck says.

The team determined that the skeleton was older than 13,000 years by analysing the rate at which calcite had formed around the bone, and by matching the shifts in stalagmite isotope levels to those in other caves. The findings were published on 30 August in PLoS ONE1.

A diver collects a portion of a cave stalagmite found in cave that contains ancient human bones.

Alistair Pike, an archaeological scientist at the University of Southampton, UK, notes that the stalagmite set over the bone during a time of profound climate change, which could have altered the stalagmite’s rate of growth. He says he is therefore more comfortable considering the bones to be a minimum of 11,300 years old — still “very significant”, he notes.

Ancient company

Few other human remains from the Americas are older than 13,000 years. The skeleton of a teenage girl recovered from a different Yucatán cave was carbon-dated to more than 12,000 years old, and a skeleton found in another submerged cave near Tulúm was deemed to be around 13,500 years old, also using radiocarbon dating.

“They’ve done a really nice job determining the age of this thing,” says David Meltzer, an archaeologist at Southern Methodist University in Dallas, Texas. There is convincing archaeological proof that humans colonized the Americas before 14,000 years ago, but very old remains are precious. “These sites are rare as hen’s teeth,” Meltzer says.

Apart from the Yucatán finds, the next-oldest skeleton from the Americas is that of a 12,600-year-old boy found in Montana, whose sequenced genome places him on a lineage leading to present-day Native American groups. Researchers have sequenced only a few other human skeletons from the Americas that are older than 10,000 years, hindering efforts to unravel the region’s ancient population history.

A stalagmite had grown around a shard of ancient pelvic bone (bottom portion).

Getting DNA from what remains of the Chan Hol skeleton will be hard. A sample sent to one of the world’s leading ancient-DNA labs, the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, did not contain enough DNA, Stinnesbeck says. He hopes to find DNA in the few teeth not taken by the thieves.

The theft still boggles Stinnesbeck, whose team is continuing to study the cave and its remains. The researchers recently reported the discovery of fossils in the cave that are of a new species of peccary2 — a hoofed mammal related to pigs — as well as evidence that the cave’s human inhabitants made fires.

“What would you want with a skeleton? Would you take it home?” Stinnesbeck asks. “If they had known it was very old, maybe just to have a souvenir, to have something special.”

“We went to the police and they did some inquiries,” he adds. “They never came up with anything substantial.”

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Bonus:

“Jesus Tony, how old is this guy?”
“I don’t know, I didn’t carbon date him! He’s on the young side.”

The Sealand Skull, according to individuals who have examined it say it could have belonged to an extraterrestrial being. The skull does not match any known species on planet Earth. It is one of the most controversial artifacts discovered in recent years. The Sealand Skull has raised numerous questions that science cannot find an answer to.

The Sealand skull was discovered in 2007 in Olstykke, Denmark by workers who were replacing sewer pipes. Until recently, nobody seemed interested in this finding. It was in 2010 that the skull was first examined at the College of Veterinary Medicine in Denmark. The researchers concluded that they were not able to solve the mystery nor provide anything that would explain to what species it belonged to. The skull was later sent to the Niels Bohr Institute in Copenhagen. Carbon dating revealed that this mysterious being lived between 1200 and 1280 BC.

When compared to a normal human skull, the Sealand skull has several differences. For example, the eye sockets of the skull of Sealand are not only quite large but are also much deeper and more rounded. The eyes sockets of the Sealand skull seem to extend further to the sides. Examinations of this scull indicate that this being was most likely adapted to colder weather, the relative eye size also suggest it was a nocturnal creature, conditions that are found in space.

The images are really interesting and prove just how unusual the skull of Sealand really is. Even though the skull is similar to that of a human, there are still several differences that make it unique. More researches are leading towards the possibility that the Sealand skull belonged to an extraterrestrial being that lived on Earth. Other researchers suggest that it belonged to a lost and forgotten species of ancient humans, who were very different when compared to modern humans

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The Irish Deer or Giant Deer was a species of Megaloceros and one of the largest deer that ever lived. Its range extended across Eurasia, from Ireland to east of Lake Baikal, during the Late Pleistocene. The latest known remains of the species have been carbon dated to about 7,700 years ago. (Source)

World's largest hoard of carbon dates goes global

Radiocarbon dating has long been used to reveal the age of organic materials — from ancient bones to wooden artefacts. Scientists are now using the amassed dates for wider applications, such as spotting patterns in human migration. And a Canadian database is poised to help researchers around the world to organize this trove of archaeological and palaeontological data, and to address problems that have plagued carbon dating for years.

Set up in the 1980s, the Canadian Archaeological Radiocarbon Database (CARD) is undergoing an expansion that began in 2014. The database currently holds 70,000 radiocarbon records from 70 countries. The latest effort aims to make the software behind the site open source, making it easier for other research groups to set up their own version of CARD while still contributing core information to the main database. The first such site should come online within the year. Read more.

I foresee my valentine humour getting worse and worse each year…. much love to the archaeology lovers on tumblr from moi :)