Basement Tectonics 13: Proceedings of the Thirteenth International Confenrence on Basement Tectonics, held in Blacksburg, Virginia, U.S.A., June 1997 ... Conferences on Basement Tectonics, 7)

The Thirteenth International Conference on Basement Tectonics was held on the campus of Virginia Polytechnic Institute and State University in Blacksburg, Virginia from June 2 -6, 1997. The oral presentations and discussions over three days covered a wide range of topics, and provided the international audience with a perspective on scientific efforts underway around the world. The conference participants were able to attend two separate field trips: (I) a pre-conference trip guided by Professor Robert Hatcher of the University of Tennessee, Knoxville, examined the Basement rocks in the North Carolina -Tennessee region of the Appalachian Mountains, and (2) a mid-conference field trip guided by A.K. Sinha, convener of the conference, allowed participants to examine the complex rock associations and structures of the> 1000 m.y. old basement rocks in Virginia. Both the field trip guidebooks and abstract volumes were published for the conference. The meeting brought together scientists from more than 14 countries. Their participation, and the fiscal success of the meeting would not have been possible without the support of the Department of Geological Sciences, the College of Arts and Sciences (VPI&SU) and the Basement Tectonics Association. Their support is gratefully acknowledged. As Chairman of the Organizing Committee, I would like to thank Margie Sentelle, Jay Thomas, Peter Welch, and Barry Robinson for the smooth operation of the conference. Front Matter....Pages i-ix Geotectonics and Characteristic Features of Fertile and Non-Fertile Younger Granites, Eastern Desert, Egypt....Pages 1-24 Structural Associations of the Basement and Sedimentary Cover of the Georgian Part of the Caucasus....Pages 25-32 The Eastern Edge of the Rio De La Plata Craton: A History of Tangential Collisions....Pages 33-48 New Data and Interpretations for the Precambrian, Midcontinent USA....Pages 49-63 Allochthonous Units in the Variscan Belt of NW Iberia: Terranes and Accretionary History....Pages 65-84 Early Compression and Late Dextral Transpression Within the Grenvillian Event of the Hudson Highlands, NY, USA....Pages 85-98 Crust-Forming Process: Basement and Basements in the Southern Appalachian Orogen....Pages 99-118 Petrogenesis of Pan-African Granitoids, Gabal Hamra Area, Southwestern Sinai, Egypt....Pages 119-138 Geology of the Blue River Gneiss, Eastern Arbuckle Mountains, Oklahoma....Pages 139-153 Zircon Ages of Basement Orthogneisses from the Northern Segment of the Araguaia Belt, Brazil....Pages 155-178 Damodar Graben: A Centre of Contrasting Magmatism in the Eastern Indian Shield Margin....Pages 179-202 A New Tectonic Belt in the Baltic Sea Region - Farther Interpretation of the Deep Seismic Results from the “Baltic Sea” and “Babel-B” Profiles....Pages 203-216 A Geochemical Reconnaissance of the Roseland Anorthosite Complex, Virginia, and Comparisons with Andesine Anorthosites from the Grenville Province, Quebec....Pages 217-232 Basement Tectonic Structures Delineated from Aeromagnetic Survey Data South Eastern Desert, Egypt....Pages 233-256 Appalachians in the Time Interval between the Grenville Orogeny and Variscan Collision....Pages 257-275 Geodynamics of the Early Precambrian: Evidence for the Baltic Shield....Pages 277-295 Lead Isotope Mapping of Crustal Reservoirs within the Grenville Superterrane: II. Adirondack Massif, New York....Pages 297-312 Paleomagnetism of the Boot-Phantom Pluton and the Amalgamation of the Juvenile Domains in the Paleoproterozoic Trans-Hudson Orogen, Canada....Pages 313-331 Dengying Formation Gas System of the Sichuan Basin, Southwest China: Model for Precambrian Indigenous Hydrocarbon Accumulation....Pages 333-344 Morphology and Isotopic Age of Zircons from Shear-Zones within Granitoids of the Belomorian Tectonic Zone, Baltic Shield, Russia....Pages 345-364 Back Matter....Pages 364-364 The proceedings of the Thirteenth International Basement Tectonics Conference follows in the footsteps of earlier symposia in highlighting the current status of geological and geophysical investigations in basement-dominated regions of the world. A significant number of papers deal with the tectonics of terranes - their transport, accretionary history and recognition. New petrologic, structural geochemical and geochronologic data from nine countries on four continents provide the framework for the interpretation of processes associated with basement tectonics. Topics range from structural, petrologic and isotopic interpretation of Grenville events to magmatism associated with rifting. Broader keynote papers deal with topics ranging from the geodynamics of the Early Precambrian to the identification of new tectonic belts in the Baltic Sea Region