Deformation of the Earth’s crust happens at a multitude of scales, ranging from submicroscopic to planetary. Tectonics explores structures and processes from regional to global, differentiating itself from the material covered in most structural geology textbooks. Moores and Twiss emphasize basic principles and methodologies of tectonics, embracing the time-honored perspective of using present processes to understand the past. Comprehensive in scope and detail, coverage includes the effects of plate motions and reconstructions and the resultant structures associated with active rift, transform, and subduction boundaries as well as triple junctions and collision zones; deformations of both the ocean basins and the continents; and orogenic belts. Moores and Twiss present tectonics as an open-ended field of study in which assumptions can be challenged and interpretations changed. The authors emphasize the use of models as a means of understanding observations and putting them in context to maintain a distinction between what we know from observing the Earth and what we infer from interpretation.

The essays in this collection are attempts to understand medieval aesthetic principles and products, not to champion the numerical approach. All the essays share a confidence that when Chaucer, for example, wrote alle thynges been ordeyned and nombred, he was enunciating a philosophical and aesthetic principle of fundamental importance to medieval thought.

The ihsan Ketin NATO Advanced Study Institute on the Tectonic Evolution of the Tethyan Region was conceived in 1982 in Veszprem, Hungary, when three of the organizers (B. C. B. , L. H. R. and A. M. C. 9. ) had come together for a meeting on the tectonics of the Pannonian basin. All three of us had experience in the Tethyan belt and all three of us had been for some time deploring the lack of communication among workers of this immense orogenic belt. Much new work had been completed in such previously little-known areas as Turkey, Iran, Afghanistan, the People's Republic of China, the entire Himalayan region, as well as new work in the European parts of the chain. Also, ironically, parts of the belt had just been closed to field work for political reasons, so it seemed as if the time was right to sit back and consider what had been done so far. Because the Istanbul group had had an interest in the whole of the Tethyan belt and because that ancient city was more centrally locElted with excellent opportunities to see both Palaeo- and Neo-Tethyan rocks in a weekend excursion, we thought that Istanbul was a natural place for such a meeting, not mentioning its own considerable attractions for the would-be contributors. A happy coincidence was that Prof.