Heinrich Dieter ‘Dick’ Holland
Heinrich D. Holland was a leading light in geochemistry for almost six decades. His early work was in seawater geochemistry and economic geology, particularly the formation of hydrothermal ore deposits. But his studies of ore deposits also led him to consider the history of the atmosphere and the rise of atmospheric oxygen. It is in this latter area that he made his greatest mark. He wrote two books and dozens of papers and book chapters on this topic. Holland did more than anyone to solidify the notion that atmospheric O2 increased dramatically about halfway through Earth’s history—an event now termed the “Great Oxidation Event,” or GOE.