| Popis: |
I fondly remember a graduate class in the early 1980s on Archean geology at Queen’s University in Kingston, Canada, run by Herb Helmsteadt, Dugald Carmichael, Ed Ferrar, and John Haynes, with most other members of staff chipping in with talks and discussions. It was a very holistic, integrated way of teaching students about greenstone belts and shear zone-hosted gold deposits, komatiites, stromatolites, and so forth. This cross-disciplinary teaching was a “trademark” of the earth sciences at Queen’s, then way ahead of its time. The class had interesting and enthusiastic students, many eager to map and analyze Archean rocks of the Canadian Shield and, in particular, the Slave craton and the Superior province. Some are now leaders in Archean studies (and authors of chapters in this book; the principal editor of this book, too, completed his Ph.D. in this department). The most interesting aspect of the geology graduates from Queen’s University (and from others throughout Canada) is the sustained collegiate manner in which they set about their tasks to study the ancient real estate of Canada, including the Acasta gneisses, now recognized as the oldest preserved rocks on our planet (described in chapter 3.1). Their systematic collaboration has yielded the most comprehensive “open source” inventory of ancient lithosphere available anywhere in the world. Field-mapping has remained a prime objective, well supported today by a number of excellent geochronology laboratories that have sprung up all over the place, rooted in the superb high-precision work at the Ontario Museum and the mentorship of Tom Krogh. In the mid-1980s, the geologists also joined forces with an emerging geophysics consortium, culminating in the Lithoprobe program that systematically paved geotransects across Canada, producing seismic images of its crust (www.lithoprobe.ca). Other geophysical methods such as teleseismic and magnetotelluric probing joined in to look deeper into the lithosphere … |
