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Researchers accurately dating a 7k-year-old settlement using cosmic rays

phys.org

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Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays

#3

Post by senkora »

This is very cool. The article is worth a read, but the TL;DR is that a high cosmic ray event left a mark in a specific growth ring on trees, and so it is possible to 1) loosely date a piece of wood used in a building to within a few decades using carbon dating and then 2) precisely date when it was cut down by counting how far the marked growth ring is to the edge of the tree.

Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays

#4

Post by [deleted] »

senkora wrote: post #3

This is very cool. The article is worth a read, but the TL;DR is that a high cosmic ray event left a mark in a specific growth ring on trees, and so it is possible to 1) loosely date a piece of wood used in a building to within a few decades using carbon dating and then 2) precisely date when it was cut down by counting how far the marked growth ring is to the edge of the tree.

[deleted]

Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays

#6

Post by hinkley »

senkora wrote: post #3

This is very cool. The article is worth a read, but the TL;DR is that a high cosmic ray event left a mark in a specific growth ring on trees, and so it is possible to 1) loosely date a piece of wood used in a building to within a few decades using carbon dating and then 2) precisely date when it was cut down by counting how far the marked growth ring is to the edge of the tree.

I remember a while back someone managed to build a many hundred year sequence of growth rings by analyzing all of the incremental construction in one town and aligning tree rings from one piece of wood with the same rings in newer or older pieces, using software not unlike reassembling DNA fragments, but with growth rings.

Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays

#7

Post by apercu »

hinkley wrote: post #6
senkora wrote: post #3

This is very cool. The article is worth a read, but the TL;DR is that a high cosmic ray event left a mark in a specific growth ring on trees, and so it is possible to 1) loosely date a piece of wood used in a building to within a few decades using carbon dating and then 2) precisely date when it was cut down by counting how far the marked growth ring is to the edge of the tree.

I remember a while back someone managed to build a many hundred year sequence of growth rings by analyzing all of the incremental construction in one town and aligning tree rings from one piece of wood with the same rings in newer or older pieces, using software not unlike reassembling DNA fragments, but with growth rings.

I don't know about the rest of the world, but in the UK dendrochronology is widely used for dating wood structures. In England they have a database that can date (some) trees back basically to any time of human existence in England. In Ireland their data goes back before 5000 BCE.

Thanks Time Team. :)

Re: Researchers accurately dating a 7k-year-old settlement using cosmic rays

#8

Post by Archelaos »

hinkley wrote: post #6
senkora wrote: post #3

This is very cool. The article is worth a read, but the TL;DR is that a high cosmic ray event left a mark in a specific growth ring on trees, and so it is possible to 1) loosely date a piece of wood used in a building to within a few decades using carbon dating and then 2) precisely date when it was cut down by counting how far the marked growth ring is to the edge of the tree.

I remember a while back someone managed to build a many hundred year sequence of growth rings by analyzing all of the incremental construction in one town and aligning tree rings from one piece of wood with the same rings in newer or older pieces, using software not unlike reassembling DNA fragments, but with growth rings.

The maximum is not just many hundred years. The Hohenheimer Jahrringkalender based on pine trees of central Europe goes back 12,460 years and people are working on extending it backwards another 2,000 years.[1]

Such calendars are anchored in the present and require an unbroken backward chain of quality wood samples from the same region and the same tree species.

The advantage of the new method based on Miyake events is that such events are so rare that they can be used to determine an anchor point in the past, provided that external evidence for a piece of wood can be used to make plausible a time period for it in which there was only one such event whose date is known from external evidence, such as ice core drills.[2] From this single Miyake event tree ring one can then work one's way forwards and backwards to establish a tree ring chronology that does not need to be anchored in the present.

One can even imagine that in the future it might be possible to create such chronologies without a good time frame for a single Miyake event, if two Miyake events are found at a certain distance from each other in an otherwise unanchored tree ring chronology.

[1] https://journals.uair.arizona.edu/index.php/radiocarbon/arti... (PDF)

[2] Confirmed Miyake events took place in 7176 BCE, 5259 BCE, 660 BCE, 774 CE and 993 CE. Other candidates for Miyake events are 12,350 BCE, 5410 BCE, 1052 CE and 1279 CE. See: https://en.wikipedia.org/wiki/Miyake_event

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