Granitic Systems

This special volume stems from a symposium 'Granitic Systems - State of the Art and Future Avenues' that was held at the Department of Geology, University of Helsinki to mark the retirement of Professor Ilmari Haapala. The twenty articles in the volume cover a wide range of granite-related topics and focus on three general themes: tectonics and source regions, petrologic processes, and fractionated granites and pegmatites. Both original papers and reviews are included, and the volume will be acknowledged by anyone with a background in Earth Sciences ad a flavor for granitoid rocks. * Comprehensive account of the current status of granite-oriented research * Topics ranging from mineralogy, petrology, and geochemistry to tectonics and crustal evolution

There are several books emphasizing the mineralogical and petrological aspects of granites, but this book is the only one emphasizing the experimental aspects.

Granites (sensu lato) represent the dominant rock-type forming the upper–middle continental crust but their origin remains a matter of long-standing controversy. The granites may result from fractionation of mantle-derived basaltic magmas, or partial melting of different crustal protoliths at contrasting P–T conditions, either water-fluxed or fluid-absent. Consequently, many different mechanisms have been proposed to explain the compositional variability of granites ranging from whole igneous suites down to mineral scale. This book presents an overview of the state of the art, and envisages future avenues towards a better understanding of granite petrogenesis. Particular emphasis of this Volume is on the following topics: Compositional variability of granitic rocks generated in contrasting geodynamic settings during Proterozoic to Phanerozoic Periods, Main permissible mechanisms producing subduction-related granites, Crustal anatexis of different protoliths, and the role of water in granite petrogenesis, New theoretical and analytical tools available for modelling whole-rock geochemistry, in order to decipher the sources and evolution of granitic suites.

Granite is exposed over more than 15% of the continents, implying that its significance to the Earth’s surface is comparable to that of the carbonates. Landforms and Geology of Granite Terrains is devoted to this phenomenon and provides a comprehensive explanation of the landforms and landscapes developed on granitic rocks and forms. Whereas existing literature in the field predominantly deals with karst landscapes, this book is specifically focussed on granitic terrains. Landforms and Geology of Granite Terrains provides detailed considerations of the forms, major and minor, well-known and not so familiar granitic terrains, developed over large areas of the continents. It comprises interpretations which are of general significance in the analysis and understanding of the landscape and includes many theories in the context of granite landforms. The importance of structure, including crystal stresses, and the value of etching of subsurface initiation, multi-stages or two-stages development, neotectonic forms, solution forms is emphasized as well as the antiquity of some forms and surfaces (inherited forms). Morphogenetic forms are placed in perspective and comparison is made with similar forms in other rock types. This work is intended for geologists, geomorphologists, geographers and mining engineers and can serve both as a practical guide for professionals and as a textbook for university courses. Author, location and subject indices are included.

viii debate of those earlier days has been beautifully summarized by H. H. Read in his famous "Granite Controversy" (1957). Read's formulation of the controversy occurred at the time when geochemistry was as a new and powerful tool. The new techniques opened era during which emerging an granites were considered mainly from this new viewpoint. Geochemical signatures have shown that mantle and crustal origins for granites were both possible, but the debate on how and why granites are emplaced did not progress much. Meanwhile, structural geology was essentially geometrical and mechanistic. In the early 70's, the structural approach began to widen to include solid state physics and fluid dynamics. Detailed structural maps of granitic bodies were again published, mainly in France, and analysed in terms of magmatic and plastic flow. The senior editor of this volume and his students deserve much of the credit for this new development. Via microstructural and petrofabric studies, they were able to discriminate between strain in the presence of residual melt or in the solid-state, and, by systematically measuring magnetic fabrics (AMS), they have been able to map magmatic foliations and lineations in ever finer detail, using the internal markers within granites coming from different tectonic environments. The traditional debate has been shifted anew. The burning question now seems to be how the necessary, large-scale or local, crustal extension required for granite emplacement can be obtained.