LAUSR

This Special Issue comprises a selection of the papers pre‐ sented at the fifth Granulites and Granulites meeting, held in July 2018 in Ullapool, northwest Scotland. The meeting was in large part a celebration of the outstanding career contribution of Michael (Mike) Brown, who delivered the 51st Hallimond Lecture of the Mineralogical Society of Great Britain and Ireland, “Time's arrow, time's cycle: Granulite metamor‐ phism and geodynamics” (Brown & Johnson, 2019a). At the time, he was halfway through his tenure as President of the Mineralogical Society of America. Mike has published more than 150 peer‐reviewed articles and book chapters, and has edited several books, mostly on topics relating to high‐grade metamorphism and crustal melting, combining petrology, structural geology, geochemistry and geochronology, to bet‐ ter understand orogenic processes and global geodynamics. In the past decade or so, while pursuing several other ave‐ nues of investigation, his research has focussed on identi‐ fying and interpreting secular change in the metamorphic record within the context of evolving global geodynamics. Of course, the metrics related to Mike's published scientific con‐ tributions are readily accessible. Less easy to quantify, but no less impactful, are his other contributions to metamorphic geology. These constitute a very long list, which includes the organization of numerous scientific meetings, confer‐ ences, symposia, short courses and workshops, time served on the boards and councils of various societies and journals, and the establishment (in 1981) of the Metamorphic Studies Group, a specialist group of the Geological Society and the Mineralogical Society of Great Britain and Ireland. However, among his most important contributions was founding (in 1982, the first volume was published in 1983) the Journal of Metamorphic Geology, and serving as an Editor for the next three‐and‐a‐half decades. While doing all of this, he spent more than six years as a Head of School at Kingston University in the UK, and was Chair of Department at the University of Maryland in the USA for 21 years! It is difficult to think of anybody who has done quite so much to promote and sustain metamorphic geology over the past half century. The papers in this Special Issue cover a range of topics that relate to Mike's interests and expertise. It is our hope that, on reading these contributions, the reader will be stimulated to consider and question their findings, in order to better understand metamorphic processes within the broader con‐ text of Earth's geodynamic evolution.