A long lost piece of Stonehenge The ones captured by a man doing restoration work on the monument were traced back 60 years later, giving scientists a chance to look inside one of the monument’s pillars for the first time.
In 1958, Robert Phillips, a representative of the drilling company that helps restore Stonehenge, took the cylindrical core after it had been drilled from one of Stonehenge’s pillars – Stone 58. Later, when he immigrated to the United States, Phillips took the core with him.
Due to Stonehenge’s protected condition, samples of the stones can no longer be extracted. but with return heart In 2018, researchers had the opportunity to conduct unprecedented geochemical analyzes of the Stonehenge plumes, which they describe in a new study.
They found that the towering stones of Stonehenge, or sarsenes, were made of rocks containing sediments formed when dinosaurs walked on the ground. Other grains in the rock date back 1.6 billion years.
“we’ve got Computed tomography examination The rock, go with it X ray“He looked at it under various microscopes and analyzed its sedimentation and chemistry,” said study lead author David Nash, professor of physical geography at the University of Brighton in England.
“Except for the thin-section analyzes and two chemical methods, all of the techniques we used in the study were new to both Stonehenge and the UK’s Sarcinian gem study,” Nash told Live Science in an email.
The central circle of Stonehenge columns was erected during the Neolithic period, about 2,500 years ago, According to the English heritageIt is a non-profit organization that manages the historical monuments of England.
The Sarcens were erected in two concentric versions – an inner horseshoe and an outer circle – and blue stones [smaller monument stones] between them in a double arc,” English Heritage said on its website.
When scientists looked through a microscope at thin slices of sarcoin rock from Stone 58, they were surprised to discover that the stone was 99.7 percent quartz. Nash said that quartz “cement” holds fine to medium grains of quartz and forms an “interlocking mosaic of crystals.”
This made the rock more durable, and perhaps the reason the builders chose this type of rock to create their massive monument thousands of years ago.
“This cement is incredibly strong. I wondered if the builders of Stonehenge could tell something about the properties of the stone, and they chose not only the largest and closest rocks, but also those that were most likely to stand the test of time,” said Nash.
Above: A micrograph from a sarcin sample showing the tightly interlocking mosaic of quartz crystals holding the rocks together. The outlines of quartz sand grains are indicated by arrows.
Older than dinosaurs
In the email, Nash said the researchers’ analysis also revealed clues about the ages of the sediments in the rocks.
“The sand sediments in which the stone originated were deposited during the Paleogene, 66 [million] 23 million years ago, so the Sarcens couldn’t be older than that.”
However, when scientists compared the ratios of isotopes of neodymium – or atoms For the element with a different number of neutrons in the nucleus – in the samples, they found that some sediments in the garde stone were older.
Some grains of sand formed as long ago as 1 billion to 1.6 billion years ago, Nash said.
While this analysis answered some questions about Stonehenge, there are still other unresolved mysteries, among them the whereabouts of two other cores excavated from stone 58 during the 1958 restoration, which also disappeared from the record.
Researchers report that workers at the Salisbury Museum in England discovered part of one of those cores in their collection in 2019. Museum director Adrian Green contacted a representative at English Heritage, who reported the discovery of part of a 58″ stone core in a box marked ‘3x Stonehenge Stones’. of ‘Treasure Box’,” according to the study.
Scientists investigated the Salisbury segment along with the Phillips core, and recorded its data in their study. However, the authors wrote: “How and when it was in the museum is unknown.”
The scientists said the location of the third core (and the rest of the core found in the Salisbury Museum) “is similarly unknown”.
The results were published August 4 in the journal PLUS ONE.