Leslie Moore died in Edgbaston, Birmingham, on 13th November 2003 at the age of 91. He was born in Somerset, the son of a miner, spending the early part of his life in the small market and mining town of Midsomer Norton before winning a scholarship to the University of Bristol. There he chose to read geology for his BSc, subsequently carrying out research for his PhD on the structure, stratigraphy and economic geology of the eastern part of the Bristol - Somerset Coalfield, under the supervision of Professor A. E. Trueman. He was later awarded a DSc by the same University.

On completion of his PhD, Leslie spent a short time teaching in Ipswich, Suffolk, before being appointed to an Assistant Lectureship in the Department of Geology, University College Cardiff. There he extended his interest in the Coal Measures to the eastern part of the South Wales Coalfield. He spent a short time in more senior positions at the University of Glasgow and again at Bristol before accepting the invitation to become Sorby Professor of Geology at the University of Sheffield in 1949. On accepting the appointment, Leslie was charged with the task of promoting the growth of the science in Sheffield. The task was to occupy most of his working life in Sheffield, during which he saw the honours school grow from single figures in the 1950s to one of the largest in the country, with an annual intake of more than 40, by the early 1970s.

An excellent teacher, he always taught the major part of the first year course, frequently lecturing to classes of more than 100, arousing interest and enthusiasm for geology among many students studying the subject for the first time. Within the University, he served for many years as Dean of the Faculty of Pure Science and the Staff Student Treasurer of the Students Union, and he was the first Warden of Earnshaw Hall of Residence.

Outside the University, Leslie belonged to many geological societies. He joined the Yorkshire Geological Society in 1949, and served on Council before becoming President in 1971-1972. He was elected an Honorary Member of the Society in 1992. He was also a founding member of the Palaeontological Association and was instrumental in the establishment of the British Micropalaeontological Society and the Association of Teachers of Geology. He extended a warm welcome to all these societies whenever they met in Sheffield.

The administrative burden of running an expanding department limited the time available to Leslie for personal research. His early work had been concerned with the coalfield geology of SW Britain, and he was later to be called as a specialist witness in the Government Enquiry following the Aberfan disaster in 1966. In 1946, he published a landmark paper on the development of spores within the fructifications of Coal Measure plants, which had far reaching implications in the development of palynology as a separate branch of palaeontology. The pioneering significance of this work was recognized with the award of the Lyell Fund by the Geological Society in 1947 and led to the establishment of an internationally important research school in palynology and micropalaeontology in Sheffield. Leslie successfully encouraged and supervised the PhD research of several students who were later to be responsible for the academic and industrial development of the science. In the later part of his career in Sheffield, he turned his interests to micro-palaeobiology with particular reference to seeking evidence of fungal and bacterial attack on organic matter in sedimentary rocks. Unfortunately little of this work was completed and published before his retirement, but his account of these phenomena in the Precambrian Nonesuch Shale from the USA, published in the Society's Proceedings in 1969, provided a vital stimulus for other research elsewhere.

In 1977, after 28 years as Sorby Professor and Head of the Department of Geology at Sheffield, Leslie retired with his wife Peggy to the village of Curbar in the Peak District, some miles to the west of the city, where they enjoyed their garden, set in beautiful Millstone Grit scenery. Visitors were always welcome and if the weather was inclement, he would delight in entertaining his guests with jazz renditions on the organ. Unfortunately, Peggy developed a terminal illness and died shortly afterwards. Deeply hurt by his loss, and with increasing mobility problems, Leslie decided to leave Curbar to be nearer his son John, in Birmingham. He suffered a fall in the early part of 2003 that required surgery to the hip, and although he came through the operation well, he never regained his mobility. He died peacefully on 13th November 2003.

Following the death of Peggy, a number of former students expressed a wish to acknowledge formally the influence that Leslie and Peggy had had during their student days and career development. After much discussion, it was agreed that an award in the form of a medal should be developed. Because of Leslie Moore's long association with the Yorkshire Geological Society, it was agreed that the administration of the medal should be entrusted to the Society. It was most pleasing for Leslie to be able to make the first presentation of the Moore Medal in 1988 to Stephen Vincent for his final year undergraduate mapping project in the Mendip Hills, an area where Leslie worked himself as a student in earlier days.