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MYSTERY SOLVED! 
We FINALLY (almost certainly...) know where Stonehenge's giant sarsen stones come from!
THREAD
We FINALLY (almost certainly...) know where Stonehenge's giant sarsen stones come from!
THREAD
Weighing up to 30 tonnes and standing up to 7 metres tall, the sarsens form all 15 stones of Stonehenge's central horseshoe.
They also form the uprights and lintels of the outer circle, and outlying stones like the Heel Stone and the Slaughter Stone.
They also form the uprights and lintels of the outer circle, and outlying stones like the Heel Stone and the Slaughter Stone.
We've known for a long time that the smaller bluestones were brought from the Preseli Hills in Wales 
but the source of the sarsens has been a mystery... until now! 
but the source of the sarsens has been a mystery... until now!
A team of geologists have managed to develop a method of analysing sarsen stone by looking at minute traces of elements within the stones, a technique first tested in Botswana. 
The breakthrough came when a core, drilled from Stone 58 during repair work, was unexpectedly returned home. 
(A man called Robert Phillips kept the core after it was removed in the 1950s!
For years it had pride of place in his office before he took it with him to the USA – first to New York, then Illinois, California and finally Florida.
)
For years it had pride of place in his office before he took it with him to the USA – first to New York, then Illinois, California and finally Florida.
)
When Robert decided to return the core last year, experts started piecing together a puzzle.
They compared the core's chemical composition to that of sarsen outcrops from across England and the other sarsens at Stonehenge.
They compared the core's chemical composition to that of sarsen outcrops from across England and the other sarsens at Stonehenge.
The results showed a best match with one particular location, *finally* revealing where the giant sarsen stones probably come from...
West Woods, just south of Marlborough, about 40 minutes' drive from Stonehenge.
West Woods, just south of Marlborough, about 40 minutes' drive from Stonehenge.
This fascinating discovery also gives us a clue about what our Neolithic ancestors were looking for when sourcing stones for Stonehenge.
It seems likely they wanted the biggest, most substantial rocks they could find, and it made sense to get them from as nearby as possible.
This might be very different to the source of the smaller bluestones, where another reason for selecting those stones – perhaps a sacred connection to the mountains – was at play. 
