Stephen Stokes, luminescence chronologist and Quaternary scientist, passed away on Monday 24 March 2014 after a long illness at the age of 50: Stephen had been diagnosed with amyotrophic lateral sclerosis, also known as motor neurone disease.

Stephen was born in Liverpool, England, on March 17th, 1964. When he was 6, his family moved to New Zealand where he surfed through school and college, undertaking his BSc and Masters under the guidance of Professor David Lowe at Waikato. His first paper, Stokes and Lowe 'Discriminant function analysis of late Quaternary tephras from five volcanoes in New Zealand using glass shard major element chemistry' was published in Quaternary Research in 1988. Stephen returned to his birth land on securing a scholarship to study at Oxford where, under the tutelage of Martin Aitken, luminescence dating pioneer, and Andrew Goudie, desert geomorphologist, he gained his DPhil in 1994, having worked on the application of OSL to secure new chronologies of aeolian sedimentation in the southwest USA. Crucially, he showed the evolution of US sand seas to be more complex, and spread over more accumulation phases, than had previously been widely acknowledged. His thesis also pioneered technical advances in optical dating. His love of travel, fieldwork and technical challenges meant that he often got drawn into other projects while a doctoral student. This, and his wit, is captured in his thesis acknowledgement:

"Mandela is free, Nixon is dead, Thatcher is out of office, the Soviet Union has split, England are not in the World Cup, all my friends are marrying, Cliff Richard has (finally) stopped making records, and I have two grey hairs- it must be time to finish up!"

With his abundant talent and supreme ability to inspire students, it was no surprise that he continued in the School of Geography at Oxford, first as a Departmental Demonstrator then as a University Lecturer and Fellow of St Catherine's College. He was a true scholar and academician, equally at home with the most inexperienced undergraduates and senior academics alike, never afraid to challenge established theory and the establishment, to explore ideas, and to constantly push boundaries, especially in terms of the application of luminescence dating. Stephen was the first to apply OSL to marine sediments, and the first to take its application into various desert realms, including parts of the Sahara and Sahel, Kalahari, and Arabia. He loved to talk science- his doctoral viva was over six hours long, not because there was a problem, but because he wanted to talk. He had extremely fruitful working relationships with established academics including Gary Haynes, Ashok Singhvi and Warren Wood, but most notably with students. His outstanding lectures inspired undergraduates such as Simon Armitage, Sallie Burrough, Sarah Feakins and Abi Stone, who went on to doctorates with other supervisors and then to their own academic careers. He directly or jointly supervised the doctorates of several now-established academics, such as Lee Arnold, Zhongping Lai, Julie Rich and Tom Stevens, while taking on others such as Richard Bailey and Chantal Tribolo in postdoctoral positions. All owe something, and often a lot, to the catalyst that was Stephen Stokes.

In the midst of his career, Stephen Stokes envisioned a somewhat different perspective in what could be his contribution to society. He was awarded an MBA in his mid-forties and joined the private sector. He brought a refreshing new angle to the issues of environmental assessment in a world shifting from dire exploitation to sustainable development. In 2007, he joined AMR Research (Gartner) in Boston as a business analyst. As an Oxford academic and down-to-earth thinker, he helped redefine sustainability in the whole supply chain.

Stephen authored almost 80 papers in his short academic career. Many are landmark papers in luminescence dating and its application to dune and lake sediments, to major archaeological questions, and even to dating fault movements. His last paper (to date), Singhvi, Stokes et al. 'Changes in natural OSL sensitivity during single aliquot regeneration procedure and their implications for equivalent dose determination', was published in Geochronometria in 2011.

In 2003, Stephen's life changed irreversibly when a woman from Montreal happened to visit Oxford. Stephen and Marie-Josée Duquette embarked on an always-surprising adventure together that included the birth of a daughter, Laurence, now 9 years old. This small family brought Stephen immeasurable joy. He is also survived by family in New Zealand and London. Stephen's life was lived to the full, it burned bright and short, and his death leaves a gap that it will not be possible to fill.

David Thomas, University of Oxford
Michel Lamothe, Université du Québec à Montréal