They said a Japanese oil exploration company, not that it was near Japan. It could have been anywhere in the pacific, and it was as gifted to researchers in Aus

They said a Japanese oil exploration company, not that it was near Japan. It could have been anywhere in the pacific, and it was as gifted to researchers in Australia not Japan. Radionucleotide contamination is an issue though. Apparently carbon dating will be useless to date anything since the 1950s in the future due to carbon isotope emissions from nuclear testing. So they must have taken care to ensure they were examining clean samples.