Paleomagnetic Constraints on the Origin and Evolution of the Musicians and South Hawaiian Seamounts, Central Pacific Ocean

摘要

This reprint presents geologic and tectonic implications of 22 new paleomagnetic poles, 24 paleoinclinations, and 14 new radiometric ages determined for seamounts and ridges in the Musicians Seamounts and the South Hawaiian Seamounts. Paleolatitudes show that the seamounts were formed astride the equator and are consistent with coeval volcanism over a range of 10 deg 20 deg of latitude. Although the data show no clear evidence for the origin of any of the seamounts at fixed-latitude hotspots, a progression of ages in the NW-SE trending chain in the Musicians implies hotspot formation. Two mean paleomagnetic poles defining the Pacific plate Cretaceous apparent polar wander path at 80 and 87 Ma of age were calculated. Results imply volcanism over a period from before 90 Ma to after 70 Ma, in both seamounts provinces. Paleomagnetic results in each of the two provinces are interpreted to indicate a possible 15 deg 26 deg counterclockwise rotation of two small crustal blocks. (edc)