Charles Lapworth’s mylonites

Abstract

When I left Imperial College to take up a postdoctoral fellowship at the University of Birmingham, the late Professor John Sutton pointed out that although Lapworth had introduced the term mylonite and the process of mylonitization (Lapworth 1885, 1886), he had given few petrographical details and no illustration of his specimens. John Sutton suggested that the material might still be in Lapworth’s Birmingham collections, and that it would be interesting if these type specimens could be unearthed. Subsequently, Dr Isles Strachan, then at Birmingham, and with some familiarity with Lapworth’s collections, kindly located a slide case containing thin sections, some labelled ‘Mylonite’ in Lapworth’s hand. An accompanying notebook contained Lapworth’s listing of his specimens. With every intention of investigating these, I carried them to Edinburgh, but those countless diversions that beset the academic environment have delayed this task and it is with no passing apology that I assemble this brief account. Following his classical work on the zonation of the Moffat shales in southern Scotland, Lapworth set out from his base at the Mason College in Birmingham (the forerunner of the University of Birmingham) to join in the effort of resolving questions of stratigraphy in rocks of supposedly similar age near Durness and Eriboll, in NW Scotland. The historical background to the development of conflicting interpretations there is well recounted by David Oldroyd (1990). One of Lapworth's principal contributions was to harness the recently published ideas of Heim regarding Alpine tectonics, coupled with his own careful fieldwork, to supply convincing demonstration . . . For welcoming regards, Jon Clatworthy, Lapworth Curator; for studio photography, the front cover, Yvonne Cooper; for assistance with photomicrography, Ian Parsons; for delving into Lapworth's collections, Isles Strachan; for stimulating this quest, and to the memory of John Sutton. This item is published with the permission of the Lapworth Museum of Geology, The University of Birmingham.