Researchers discover Japan's oldest rock dating back 2.5 billion years in Shimane

So, serious question.

How is it that there is only a single rock?! I mean, how did it get there? What about the rocks around it?!

Its very strange.

Under intense tectonic. heat and pressure, granites are transformed into gneiss. or anatectic rocks, I suppose rocks around are not from the same age formation, or if from the same age have been transformed too much so dating will be different

If rocks deposited around/over the granite are sedimentary rocks, they will be younger and possibly eroded.

The article does not mention the importance of this granite but it is possible only a small part has been well preserved.

And it was possibly part of the Asian continent before separating to become part of Japan

zones2surf:

How is it that there is only a single rock?! I mean, how did it get there? What about the rocks around it?!

He did not find "a single rock." He found an area where solidified magma surfaced above the ground. He simply collected samples to investigate and made a discovery.

https://headlines.yahoo.co.jp/hl?a=20190325-00010002-doshin-sctch.view-000

This is an educated guess.

Wish I had time to spend looking for small old rocks. Gold yes, but little old rocks?

Hoorah!

Site of the oldest rock in Japan? Do I hear another UNESCO world heritage site listing?

zichi - The Great Oxygenation Event was starting. Free oxygen released.

Thanks to stromatolites.

@socrateos,

He did not find "a single rock." He found an area where solidified magma surfaced above the ground. He simply collected samples to investigate and made a discovery.

https://headlines.yahoo.co.jp/hl?a=20190325-00010002-doshin-sctch.view-000

Thanks. I knew there was probably more to it, but just found the way the article here described it as strange. But that was due to the underlying Kyodo article, I suppose.

"Many rocks of the same age exist in North Korea and northeastern China, and analysis of the latest specimen is likely to provide insight into the formation of the Japanese archipelago, which was originally connected to the Asian continent."

Don't tell the nationalists their oldest rock derives from the mainland, which they were once part of.

Many rocks of the same age exist in North Korea and northeastern China, and analysis of the latest specimen is likely to provide insight into the formation of the Japanese archipelago, which was originally connected to the Asian continent.

"We will study the chemical composition of the rock and make clear from which part of the continent it came," said Yasutaka Hayasaka, an associate professor at Hiroshima University.

if it is found to be originally connected to NE China or North Korea, they will be making claims for the return of the land.