Basement Tectonics 8

The 8th International Conference on Basement Tectonics was held in Butte, Montana, August 8-12,1988. Historically, basement tectonics conferences have focused on such topics as reactivation of faults, the influence of basement faults on metallogeny and hyrocarbon accumulation, and the use of geophysical and remote sensing techniques to interpret subsurface and surface geology. The 8th Conference diverged from past conferences in that a unifying theme was selected. Because ancient major terrane or cratonic boundaries are often postulated to be fault zones which are subsequently reactivated, the conference was organized to examine all aspects of ancient continental margins and terrane boundaries and to compare younger (Mesozoic) ones, about which more is known, with older (Paleozoic and Precambrian) ones. Moreover, because the 8th Conference was held in the northwestern United States, a greater emphasis was placed on the Mesozoic margin of western North America and the North American shield. The seven oral sessions and four poster sessions all dealt with aspects of the conference theme: characterization and comparison of ancient continental margins. The organizers extend their thanks to those individuals who graciously consented to serve as moderators for the oral sessions: John M. Bartley, Mark S. Gettings, M. Charles Gilbert, John M. Guilbert, Donald W. Hyndman, William P. Leeman, Robert Mason, and A. Krishna Sinha. The program with abstracts volume was prepared by S. E. Lewis and M. J. Bartholomew.

The 10th International Basement Tectonics Conference was conducted on the campus of the University of Minnesota, Duluth, in Duluth, Minnesota, USA, from August I through August 11, 1992. A total of 78 individuals were in attendance, 47 of which represented the host country, with the remaining 31 traveling from 11 different foreign countries. The four days of presentations were divided into three technical sessions, namely "Shear Zones", "Basement Control On Younger Structures", and "Rifting Midcontinent Rift System". This tripartite conference theme was also employed in the field trip agenda with three excursions being offered, all ably organized by Field Trip Chairman John C. Green. The pre-conference trip set the stage through a two day review of the "Archean and Early Proterozoic Rocks of Northeastern Minnesota". Under beautiful summer skies, 16 sites were visited within the Vermilion district of Minnesota, considered to be the best example of an Archean greenstone belt in the United States. All registrants participated in the mid-conference trip conducted along the gabbroic and volcanic terrain of the "Midcontinent Rift, Northeastern Minnesota".

The Ninth International Conference on Basement Tectonics was held at the Australian National University in Canberra 2-6 July 1990. The opening keynote address was given by Prof. R.W.R. Rutland, Director of the Bureau of Mineral Resources. Other keynote speakers were E.S.T. O'Driscoll, an Australian consultant, and Prof P. Bankwitz, Central Institute for Physics of the Earth, Potsdam, GDR. Technical sessions were arranged by session conveners on the following five topic- i) The structure of the Australian craton and cover basins; ii) Basement structure of continental regions; iii) Structural patterns and mineral deposits; iv) Techniques for analysing basement structures; v) Structural patterns in oceanic crust. The arrangement of papers for this Proceedings Volume has been simplified. Part 1 deals with Australia, Part 2 with other areas and Part 3 lists the titles of all the papers read at the conference. Abstracts of these papers are available in Geological Society of Australia Abstracts No 26 and may be purchased for $AI0 from the Geological Society of Australia Office, ANA House, 301 George Street, Sydney NSW 2000. Field trips to view aspects of the Lachlan Fold Belt and the Sydney Basin were assisted by H.J. Harrington, D. Branagan, D. Wyborn, B. Drummond and M.J. Rick~d. A longer field trip, aborted through low enrolments, was organized by H.J. Harrington with assistance from W. Preiss, N. Cook, R. Glenn, A. Grady, and P. James; this assistance is gratefully acknowledged.

The Eleventh International Conference on Basement Tectonics was held at the GeoForschungsZentrum Potsdam in Germany 25-29 July 1994. It was the first time that a meeting of this series took place in the centre of Europe and the first such meeting in this area after the recent political changes in eastern Europe. Consequently, the main theme of the meeting focussed on the structure and history of the entire European continent. Further themes were grouped around topics of current interest. Keynote lectures on these topics were given by A. Berthelsen, St. Mueller, A. Green, and D. Fountain. The technical sessions were arranged with support of the Scientific Committee on the following topics: 1. Continental scale features of basement rocks of phanerozoic cratons - with emphasis on Europe 2. Extrapolation and correlation of geological and geophysical data from basement rocks: an assessment 3. Mechanisms of basement exhumation in the evolution of orogenic belts 4. Structure and intraplate deformation of the North-American craton Papers submitted to this volume have however all been collected in one part since all of them deal with different aspects of deformation of the continental basement. A second part contains a complete list of all papers and posters presented at the meeting. Field trips to study some of the above mentioned aspects in the Harz mountains, the Granulite Massif, and the Erzgebirge were organized by P. Bankwitz, P. Frischbutter, 1. Rotzler, K. Rotzler, and B. Mingram. Their assistance is gratefully acknowledged.

Proceedings of the Seventh International Conference on Basement Tectonics, held in Kingston, Ontario, Canada, August 1987