Young source for Hawaiian plume

摘要

Highly radiogenic strontium in melt inclusions from lavas of the Mauna Loa shield volcano in Hawaii have been found to have an isotopic composition that matches that of seawater 200 million to 650 million years old. These waters must have contaminated the Mauna Loa source rock before subduction, imparting a unique 'time stamp' consistent with mantle circulation at an average speed of 2 centimetres per year, which is more rapid than previously thought.