STRATIGRAPHY AND PALEONTOLOGY OF PLEISTOCENE SUBMARINE VOLCANIC-SEDIMENTARY SEQUENCES AT THE NORTHERN KERMADEC ISLANDS

Early Pleistocene marine volcanic/sedimentary sequences on Raoul Islan d and adjacent islets of the northern Kermadec Islands, southwest paci fic, are included in the Herald Group (new) and constituent Boat Cove Formation, Chanter Formation (new) and Dayrell Formation (new). They a re the oldest known shallow-marine deposits in the Kermadec Islands re gion. The following history is inferred from their stratigraphy, struc tural relationships and paleontology. (1) Development of a large strat ivolcano formed of basaltic andesite lava flows, hyaloclastite breccia and sandstone and epiclastic deposits (Boat Cove Formation). Shallow marine biotas colonised lava, boulder and sandy gravel substrata on th e flanks of the volcano, and hermatypic coral patchreefs formed locall y. (2) Removal of parts of the upper flanks of the volcano by marine e rosion, caldera formation or flank collapse, followed by further erupt ions of submarine basaltic andesite lava and tephra from parasitic ven ts (Chanter Formation). (3) Local cessation of volcanism followed by s ubsidence of the volcano, and accumulation of an upwards deepening cor al patchreef and epiclastic volcaniclastic to detrital bioclastic and coralline algal-dominated sedimentary sequence (Dayrell Formation).