Open AccessIntraplate volcanism of the western Pacific: New insights from geological and geophysical observations in the Pigafetta Basin
Author(s) -
Stadler Timothy J.,
Tominaga Masako
Publication year - 2015
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2015gc005873
Subject(s) - intraplate earthquake , geology , volcanism , volcano , cretaceous , paleontology , basement , oceanic basin , structural basin , pacific plate , earth science , geophysics , tectonics , subduction , civil engineering , engineering
Understanding intraplate volcanism is a key to deciphering the Earth's magmatic history. One of the largest intraplate volcanic events occurred during the mid‐Cretaceous, roughly 75–125 Ma in the western Pacific. To investigate the origin of this volcanism we present the first comprehensive study of volcanism in the Pigafetta Basin using seismic surveys, magnetic and gravity modeling, and Ocean Drilling Program (ODP) drill core and well log data from Site 801. Our results show that intraplate volcanism in the Pigafetta Basin coincides with the rest of the western Pacific seamount provinces, supporting the previously suggested plumelets scenario for the origin of intraplate volcanism during the mid‐Cretaceous volcanic events. Our magnetic modeling suggests that the late‐stage volcanism does not overprint the remanant magnetization acquired by the Jurassic ocean crust in the Pigafetta Basin, and hence, marine magnetic anomalies recorded in the Jurassic basement are preserved. Also, the formerly identified Rough‐Smooth Boundary (RSB) is indistinguishable from any other rough‐smooth topographic boundaries throughout the survey area suggesting that the RSB is unlikely to be a Cretaceous sill‐Jurassic basement boundary. Lastly, the apparent ages and spatial distribution of volcanic features suggests a dynamic history of hydrothermal circulation in the Pigafetta Basin, indicating that hydrothermal circulation was ongoing well past 100 Ma.