Editing Manuport (section)

=== Barrow Island chert ===
In 2014, a [[chert]] manuport was discovered embedded in an ancient reef on [[Barrow Island (Western Australia)|Barrow Island]], [[Western Australia]]. The island has no natural chert deposits and so the stone must have been carried from mainland Australia.<ref name=":4">{{Cite journal |last1=Ward |first1=I. |last2=Salvemini |first2=F. |last3=Veth |first3=P. |date=2016 |title=3D visualisation and dating of an embedded chert artefact from Barrow Island |journal=Journal of Archaeological Science: Reports |volume=7 |pages=431–436|doi=10.1016/j.jasrep.2016.05.023 |bibcode=2016JArSR...7..432W }}</ref> Chert is a traditional toolstone and other chert artifacts found on Barrow Island have been modified to be used as a blade.<ref name=":4" /> The closest sources of chert are several kilometers away by boat in the [[Pilbara]] and [[Carnarvon Basin]].<ref name=":4" /> The stone is believed to have been transported during the [[Last Glacial Period|last Ice Age]] when the coastlines of Barrow Island and Australia would have been much closer and more easily traversable.<ref name=":4" /> The manuport notably displays no signs of fracture, despite being carried for the intended later use as a tool.<ref name=":4" /> This implies that the chert stone must have been lost at some point during transport.<ref name=":4" />

The manuport was found lodged in [[Caliche|calcrete]], a kind of [[sedimentary rock]] typical of sand dunes and reefs that have dried out.<ref name=":4" /> The exposed portion of the chert measures 40mm wide by 35mm high.<ref name=":4" /> Chemical analysis has determined the calcrete’s age to be 41,000 years old, indicating the earliest possible date that the manuport was deposited.<ref name=":4" /> This supports other archeological discoveries on the island suggesting humans occupied Barrow Island as early as 53,000 years ago.<ref name=":4" /> Collectively these artifacts present one of the oldest examples of [[Fishing|maritime resource exploitation]] [[Recent African origin of modern humans|outside of Africa]].<ref name=":4" />

Australian archeologists have noted that calcrete is an ideal medium for preservation and the finding of the Barrow Island manuport is a strong indication further artifacts are likely to be located along Western Australia’s limestone shelf.<ref name=":4" /><ref>{{Cite journal |last1=Dortch |first1=C. E. |last2=Morse |first2=K. |date=December 1984 |title=Prehistoric Stone Artefacts on Some Offshore Islands in Western Australia |journal=Australian Archaeology |volume=19 |pages=31–47|doi=10.1080/03122417.1984.12092954 }}</ref>