Granulites and Crustal Evolution

Granulites are, by definition, rocks that crystallized at high temperatures. It is generally agreed that they were formed in regions where the geothermal gradient exceeded normal continental values. These rocks commonly display coronitic mineral fabrics which may be used to trace the thermal and geodynamic history of the continental crust. In the same way that eclogites provide information on the earliest stages of some orogenic episodes, granulites usually tell us about later events, including thermal anomalies, thermal reequilibration, CO streaming, crustal melting, and 2 differentiation of the continental crust. Their study is particularly important if we are to under stand the nature of the middle and lower continental crust. Consistent with the contributions I received, the contents of this volume fall into four general areas: Crustal Evolution, Regional Syntheses, F1uids and Petrological Equilibria, Geochemistry and Geophysics. These represent an up-to-date reflection of the centres of interest in the field of granulites. The first manuscripts arrived in September 1988 while the conference was held, the last contribution arrived in November 1989, more than a year later. I apologize to those who were prompt and took deadlines seriously, but I believe that it was worth waiting to secure a product covering most of the important aspects concerning granulite genesis. All papers were vetted by at least two reviewers. I would like to thank RJ. Arculus, N.T. Arndt, P. Barbey, SR. Bohlen, AM. Boullier, M. Brown, T. Chacko, 1.D. Clemens, K.C. Condie, J.C. Duchesne, C. Dupuy, w.G.

Klappentext

Proceedings of the NATO Advanced Research Workshop on Petrology and Geochemistry of Granulites, Clermont-Ferrand, France, September 5-9, 1988

Inhalt
The NATO ARW granulite conference: a report.- Crustal Evolution.- Genesis of continental crust: evidence from island arcs, granulites, and exospheric processes.- The granulite granite connexion.- Heat, fluids, and melting in the granulite facies.- Granites, granulites, and crustal differentiation.- Regional Syntheses.- Europe.- Evolution of the lower crust in the Ivrea zone: a model based on isotopic and geochemical data.- The granulite belt of Lapland.- North and South America.- A model for the granulite-migmatite association in the Archean basement of southwestern Montana.- Multi stage late Archaean granulite facies metamorphism in Northern Labrador, Canada.- Archean tectonic setting of granulite terranes of the Superior Province, Canada, a view from the bottom.- The granulites of the Jequié complex and Atlantic Coast mobile belt, Southern Bahia, Brazil An expression of Archean/Early Proterozoic plate convergence.- From Africa to India.- Pressure-Temperature-Time paths of granulite metamorphism and uplift, Zambesi belt, N.E. Zimbabwe.- Thermal history and tectonic setting of the Namaqualand granulites, Southern Africa: clues to Proterozoic crustal development.- The granulite-facies rocks of the Limpopo belt, Southern Africa.- Crustal evolution of the granulites of Madagascar.- Nature and scale of fluid-rock exchange in granulite grade rocks of Sri Lanka: a stable isotope study.- The granulite terrane of the Nilgiri Hills (Southern India): characterization of high-grade metamorphism.- Fluids and Petrological Equilibria.- Granulites of Satnuru and Madras: A study in different behaviour of fluids.- Scapolite phase equilibria: additional constraints on the role of CO2 in granulite genesis.- Synmetamorphic fluid inclusions in granulites.- Fluid inclusions ingranulites: peak vs. retrograde formation.- Thermometry and barometry of mafic granulites based on garnet clinopyroxene plagioclase quartz assemblages.- Geochemistry and Geophysics.- Geochronology in Granulites.- Origin of granulites: geochemical constraints from Archean granulite facies rocks of the Sino-Korean craton, China.- The oxygen isotope composition of lower crustal granulite xenoliths.- Ionprobe investigation of rare earth element distributions and partial melting of metasedimentary granulites.- Geochemistry of intermediate/- to high-pressure granulites.- Thermal data and crustal structure. Role of granites and the depleted lower crust.- Some thermal aspects of granulite history.- Key word/subject index.