About this issue
This issue of Geochemical Perspectives aims to take the mystery out of mantle metasomatism, reviewing the evidence for the essential role of hydrous ultramafic dykes in the upper mantle as sources for a wide variety of igneous rocks. It explores the historical development of concepts about the upper mantle and melts produced from it, discussing why certain types of investigations and experiments occurred when they did and what lies ahead in the study of hydrous mantle rocks.
