Collaborative Research: Investigation of the Origin of Non-Hotspot, Intraplate, Volcanic Ridges and Cross-Grain Gravity Lineations

Oregon State University, Corvallis OR

Investigators

Abstract

This project addresses the origin of intraplate volcanic ridges - often called cross-grain anomalies - located on the Pacific plate. Suggestions for the origin of these ridges include small-scale confection rolls, lithospheric boudinage, and small plumes resembling mini-hotspots that originate in the upper mantle. Two neighboring intraplate ridges will be studied. Measurements will include ocean-bottom seismometer observations of mantle structure, a seismic refraction/reflection profile of crustal structure, micro- earthquake recordings, extensive geochemical probing of the melting conditions and composition of the mantle, radiometric dating of the timing of volcanc activity, and mapping of bathymetry, seafloor sidescan reflectivity, sediment thickness, and gravity and magnetic anomalies.