The Cooma granodiorite and migmatites in southeastern Australia are formed by replacement of metapelites and metapsammites. Evidence to support this hypothesis include: (1) zoned plagioclase and myrmekite in high-grade gneisses, migmatites, and granod . . .

South of Little Raft Lake in the Chief Lake granitic complex, south of Sudbury, Canada, Na-rich, felsic magma locally commingled with a Na-rich mafic magma. In addition, subhedral quartz and large sodic plagioclase phenocrysts floated-off from the fel . . .

The following illustrations in this presentation show four photomicrographs of cathodoluminescent images, two black-and-white scanning electron microscope images, and six photomicrographs of thin sections in which various stages of replacement of prim . . .

Most geologists believe that plutonic bodies, including granites, have been emplaced as magma, even though the majority of granites contain mineral assemblages that are stable in the temperature range of 400-600º C − well below melting conditions for . . .

Higgins (1999) proposed that microcline megacrysts in the Cathedral Peak granodiorite resulted from Ostwald ripening in which textural coarsening of earlier formed small K-feldspar crystals were sacrificed to feed the growth of a select few larger cry . . .

Examples of how silicate minerals in plutonic igneous rocks are modified by mobilized K and Si in the temperature range of about 350-550ºC have not been described elsewhere, whereas modifications above and below this range have been thoroughly documen . . .

There is no doubt that the Donegal intrusions (Fig. 1) were originally magmatic in origin. The magmatic style, petrologic history, age, and structure of the Donegal granites have been thoroughly studied (e.g., Pitcher and Berger, 1972; Holder, 1979; B . . .

During K- and Si-metasomatism of deformed, relatively-mafic parent rocks to form more felsic, granitic rocks containing myrmekite, Ca, Mg, and Fe must leave the system as the modified rock is enriched in K, Na, and/or Si. When this kind of metasomatis . . .

In this presentation questions are raised about a melt-restite unmixing model proposed by Barton and Sidle (1994) for the myrmekite-bearing Waldoboro granite complex along the southeastern coast of Maine (USA). This complex consists mostly of granite/ . . .

The following discussions and interpretations are based on an analysis of 58 thin sections of samples collected during the EuroGranites '97 field trip, Sept. 4-10, 1997, in which 32 participants examined several predominantly I-type granites in easter . . .