Sunabara Site – Japan’s oldest stone tools are 110,000 to 120,000 years old

07 Jun

It was recently announced that the 36 stone tools found in 2009 at the Sunabara site (砂原遺跡) in Izumo city, Shimane prefecture have been dated to 110,000-120,000 years old, making them Japan’s oldest. Since their discovery almost five years ago, there had been some debate over their age (at one point, their age was broadened to between 70,000 and 120,000 years old). This latest announcement, however, generally agrees with that originally presented at the time of discovery. Researchers were able to determine their age after recognizing Sambe Kisuki tephra (三瓶木次火山灰: 110-115ka) in the same soil layer that the tools had been found in.


Picture source

For an article written in 2010 by one of the archaeologists involved, see here.

Article source

島根・砂原遺跡の石器、再び「国内最古」に 2013/6/6 21:35

島根県出雲市の砂原遺跡の学術発掘調査団(団長・松藤和人同志社大教授)は6日までに、出土した石器36点について見解を再修正し、11万~12万年前の「国内最古」と結論づけた報告書にまとめた。2009年の発表では、12万7千年前ごろにできた地層と、約11万年前の三瓶木次火山灰でできた地層に挟まれた地層から石器が出土したとして、石器の年代は約12万年前の国内最古と発表した。 その後、火山灰の地層は三瓶木次層でなく、約7万年前の三瓶雲南層と判明。翌年、石器の年代を7万~12万年前と幅を持たせて修正した。岩手県遠野市の金取遺跡でも5万~9万年前の石器が出土していたことから、砂原遺跡の石器も最古から最古級と見解を変更した。 松藤教授によると、石器を含む地層の成分を詳しく調べたところ、層の中に三瓶木次火山灰が含まれていることが分かり、約11万年前と判明、石器を含む層は11万~12万年前と結論付けた。 松藤教授は「考古学の研究であまり試みられなかった地質学の手法も組み合わせて、年代を特定できた。遺跡調査の手法を飛躍的に高める先例になるのではないか」としている。〔共同〕

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Posted by on June 7, 2013 in Uncategorized


2 responses to “Sunabara Site – Japan’s oldest stone tools are 110,000 to 120,000 years old

  1. Corey Noxon

    June 8, 2013 at 2:46 am

    Wow, quite a discovery. Did they happen to mention in the article wht they were basing their age estimate on? Considering previous dating issues regarding the Japese paleolithic, I would imagine they’d be careful about making claims going back that far without solid evidence.

    • Joseph Ryan

      June 8, 2013 at 4:00 am


      Thanks for your comment and also for reminding me to finish the post — I have included the rationale for the dating in the final sentence above the (unfortunately tiny) picture.


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