Seismic stratigraphy of the High Plateau, Mahiniki Plateau, as seen in seismic reflection data measured during cruise SO224
The Manihiki Plateau, located in the Equatorial Pacific, is a Large Igneous Province (LIP) formed during the Cretaceous. Previous studies point out multiple phases of volcanic activity with a complex geodynamic evolution but the setting of formation as well as its role in the ocean palaeocirculation remain unclear. Here, high resolution seismic data are presented that were gathered during cruise SO224 to study the plateau’s development following the initial phase of creation and the sedimentary distribution. First results of seismic stratigraphy for profile AWI-20120001 show six reflectors below seafloor in the sedimentary column, which match well the sedimentary structures presented by Shipboard Scientific Party, 1976 for campain DSDP Leg 33 Site 317. Comparing our data to the lithology of their borehole data the six horizons in four units can be identified ranging from age older than Aptian-Barremian to Quaternary, comprising basalt, limestone and volcaniclastic, cherts and chalks and calcareous ooze.