text: Hattori and De Hoog, after considering the debate surrounding the cause of varying oxidation conditions in igneous rocks at shallow crustal levels, documented that highly oxidized conditions of rocks are an intrinsic character of the source magma in the mantle. They emphasized the capability of oxidized magmas to transport large quantities of sulfur and metals as well.
  In her 1995 work, Hattori provided the initial documentation of oxidized arsenic in the overall reduced mantle, as arsenic is present by replacing Si. One of her PhD students, Jian Wangm, evaluated the redox state of mantle rocks and discovered that carbon is the primary control for the oxidation conditions of the mantle in subduction zones.