A Symposium in Honour of Gerard V. Middleton: GeoConvention, Calgary, June 21, 2022

Gerard Middleton, Emeritus Professor at McMaster University, passed away on 2nd November 2021 at the age of 90. Gerry, as he was happy to be called, was one of the first geologists in Canada to “self-identify” as a sedimentologist, although he started his career as a paleontologist working on Devonian carbonate sediments. He arrived at McMaster University in 1955, and soon switched to sedimentary geochemistry, and then to the study of clastic sedimentary processes, a field that, at that time, could be said to have not even reached the stage of infancy. In the 1960s and 1970s Gerry made fundamental advances in our understanding of sediment transport and the identification, classification and interpretation of hydrodynamic sedimentary structures and sediment gravity flows (a term Gerry coined). Gerry retired in 1996, and a special issue of this journal (v. 24, #1, 1997), under the editorship of then editor Roger Macqueen, was dedicated to his lifetime contributions as researcher, author and editor. Gerard’s career and his substantial contributions to the progress of the geosciences in Canada are also expertly summarized in the obituary Bob Dalrymple and Janok Bhattacharya (2021) published in Geoscience Canada. We now have a certain perspective with which to look back on Gerry’s contributions to the science of sedimentology and assess their significance, and it is fair to say that he was at the centre of several of the most fundamental breakthroughs in our understanding of clastic sedimentary processes. The GeoConvention 2022 symposium was designed to focus on these developments, and the advances that have been made, based on his research, by his former students and associates, and by others who have benefited intellectually from his long-lasting influence. His many other contributions to the life and work of Canadian geoscience are ably summarized by Dalrymple and Bhattacharya (2021). John Southard, of MIT, was invited to present some opening remarks to the symposium from his office, via Zoom. His personal reminiscences of working with Gerry, and the research they initiated in the field of sediment hydraulics helped to put the history and development of the field into perspective, and we enjoyed some of the personal stories of two productive researchers working together to essentially create an entire new field of sedimentology. A truly successful research professor is one who can inspire students, and several of the speakers at this symposium (Dalrymple, Bhattacharya, Plint, Leckie and Arnott) were privileged to have been part of the large body of students who passed through the McMaster “school” of sedimentology in the 1970s, led by Gerry and his colleague, Roger Walker. Dalrymple was supervised by Gerry; Bhattacharya and Leckie by Walker; Plint was a post-doctoral fellow working with Roger Walker, and Arnott an undergraduate. For at least two decades, the 1970s and 1980s, the Middleton-Walker school was arguably one of the top two truly “world class” (a much overused term) places to do sedimentary geology; its only real rival, Oxford University, was led by Harold Reading. Readers of this journal will not need to be reminded of the amazing success of the famous “Facies Models” volume produced as a result of the collaborative work of Middleton and Walker. Gerry used to like to remind audiences that although Walker was the founder and editor of the “Facies Models” project, it was he, Gerry, who wrote the first ever textbook summary of facies models that appeared in the first edition of the Blatt, Middleton and Murray textbook, published in 1972. It is not necessary to be a formal member of a research group to benefit from its influence. In my case, I became aware of the importance of McMaster University from the distance of Calgary, as a research scientist with the Geological Survey of Canada and made my first visit there as a seminar speaker in 1975. Later, I worked as Program Chair for the Sedimentology Congress that Gerry organized and chaired at McMaster University in 1982 on behalf of the International Association of Sedimentologists. I served as graduate advisor or examiner on several of the McMaster doctoral committees through this period, and always valued my involvement with the team. The two additional speakers, Bell and Englert, represent that huge body of researchers whose science ultimately stemmed from the advances initiated by Gerry, through the body of work carried out by his successors and colleagues world-wide. The study of sediment gravity flows and submarine fans, and turbidites systems in general, exploded in the 1980s, largely as a result of the widespread use of submarine sonar methods and advanced seafloor coring, and the growing importance of deep-water sediments as petroleum reservoirs. But Middleton’s major contributions, in particular his original Volume 49 2022 227