Characterization of an archaeological decorated bark cloth from Agakauitai Island, Gambier archipelago, French Polynesia

In this work, we present results of the analysis of a bark cloth bundle discovered at the Te Ana o te Tetea cave on Agakauitai in the Gambier Archipelago. The bundle was made up of large and small strips of thin tapa, with some watermarks left by the beaters. Associated with the tapa, were a piece of wood and cordage. A few of the bark cloth samples showed symmetrical black lines along some of the folds. This paper presents the results of a number of analyses performed on the bark cloth bundle from this island with the aim of determining its age, if the decorations were man-made and the plant species used for its manufacture. Samples were dated by Accelerator Mass Spectrometry (AMS) and the designs were analyzed by portable X-ray fluorescence (XRF) and Scanning Electron Microscopy - Energy Dispersive X-ray spectroscopy (SEM-EDX) for elemental characterization. Raman spectroscopy was also performed in order to assess the chemical nature of pigments. These analyses allow us to conclude that the finds date to the pre-European contact period for this island group and that these lines can be attributed to man-made designs. In addition, genetic analysis of the ribosomal region were performed to identify the species used in its manufacture, which indicate that the plant used to make the tapa cloth was Broussonetia papyrifera or paper mulberry. The availability of new genetic sequencing techniques allow for new and very sensitive analyses of archaeological material that require careful handling from the beginning in order to avoid sample contamination.