George Patrick Leonard Walker (2 March 1926 – 17 January 2005) was a British geologist who began his career studying mineralogy and later made significant contributions to volcanology. He was widely regarded as one of the pioneers of modern quantitative volcanology. Biography Walker was born in Harlesden, London in 1926. He was the only child of Leonard Walker, an insurance salesman, and Evelyn Frances (nee McConkey), a nurse. He went to school at Acton Lane Elementary School, and won a scholarship to Willesden County School in 1937. In 1939, Walker and his mother were in Ballinderry, County Antrim, when World War II broke out. They stayed in Ballindery, and Walker completed his schooling at Wallace High School, Lisburn. Walker went to Queen's University, Belfast to study geology and graduated with a BSc in 1948, and an MSc in 1949. He then went on to study for a PhD at the University of Leeds, under the supervision of W Q Kennedy. His dissertation focussed on the secondary (alteration) minerals in the igneous rocks of Northern Ireland. In the summers of 1952 and 1953, Walker joined Kennedy on geological expeditions to the Ruwenzori Mountains and the Belgian Congo. Career and research In 1952 Walker took up an assistant lectureship in mineralogy at Imperial College, London. He was promoted to lecturer in 1954 and finished his PhD in 1956. For the next ten years, Walker turned his attention to the study of alteration minerals in lavas of eastern Iceland, spending each summer from 1955 to 1966 mapping in Iceland. This work earned him an international reputation as a meticulous mineralogist, and provided the first evidence for how the crust grows at oceanic ridges. In 1964, Walker was promoted to Reader at Imperial college. Following the eruption of Surtsey from 1963-1967, Walker began to take an interest in active volcanism. This led to some of his pioneering studies, first of basaltic volcanism and lava flows on Mount Etna; and later, on pyroclastic rocks and the products of explosive volcanic eruptions, in Italy, the Azores and Tenerife. In 1977, Walker was awarded a Captain James Cook Fellowship of the Royal Society of New Zealand, which he took up at the University of Auckland. Although this began as a visiting position, in 1978 Walker resigned from Imperial College, and moved to New Zealand with his family. In 1981, he moved to the newly created Gordon Macdonald