Topography and morphology surveys will be conducted close to the areas of archaeological excavations along two transects perpendicular to the shoreline. Levelling will be undertaken using a conventional automatic level. Along the transects, each reference points will be positioned using DGPS coordinates. Reef-rim elevations will be defined by reference to present mean sea level, assuming a conservative error of ±0.10 m. Vertical excavations will be dug in both transect from top surface to the level related to the adjacent reef flat or to the underlying conglomerate surfaces if present. A number of 2 to 3 excavations could be dug along each transect in order to reconstruct island subsurface stratigraphy. Visual field mean grain-size analysis of coarser detrital material will be performed using the Udden- Wentworth classification as measured along the longest axis from photographed square-metre quadrats. Coral pebbles and coarse-grained sands will be collected for radiometric dating at all excavated sites. Taxonomic identification of dated coral specimens was made at the generic level. In addition to the excavated sections investigated close to the archaeological areas, if possible, a total of 6 other excavations (3 per transect) could be made along 2 transects, respectively selected from Motu Tiaraunu (leeward rim side) and Motu Oroatera (windward rim side). This will allow the timing and mode of motu accretion to be reconstructed.

Approved