Plagioclase twinning laws in the Hidaka metamorphic rocks.

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks

Shock Compression of Crustal Rocks: Data for Quartz, Calcite, and Plagioclase Rocks

ttugoniot data in the 4to 250-kb stress range were obtained for quartzite and novaculite, sandstones of varying porosity, single-crystal calcite, marble, porous and nonporous limestone, several plagioclases of varying composition, and a basalt. Conventional plane-wave, in-contact explosive assemblies were used; the shock state was computed from measured shock velocities; particle velocities are...

Slow oxygen diffusion rates in igneous zircons from metamorphic rocks

Empirical tests of oxygen exchange rate in zircon crystals from amphiboliteand granulite-facies metamorphic rocks of the Grenville Province demonstrate preservation of igneous dO through protracted igneous and metamorphic histories, forming the basis of quantitative estimates of diffusion rate. Granitic orthogneisses, which cooled slowly after granulite-facies metamorphism, show no consistent r...

Two types of tourmaline with igneous and metamorphic origin in metamorphic rocks of north Golpayegan, Isfahan province

The Muteh-Golpayegan metamorphic complex consist of different metamorphic rocks including pelitic, semi-pelitic, carbonate, quartz-feldspathic and basic metamorphosed rocks. The metapelitic rocks include chlorite schist, biotite schist, garnet schist, staurolite schist, kyanite schist, sillimanite schist and andalusite schist. The semi-pelitic rocks contain higher amounts of quartz and lower am...

The Phyllosilicates in Diagenetic-metamorphic Rocks of the South Portuguese Zone, Southwestern Portugal

Devonian and Carboniferous metasedimentary sequences in the southernmost sector of the Iberian Massif, part of the Hercynian Orogen in southwestern Portugal, contain shales and slates of low but variable metamorphic grade. These rocks have been studied by optical microscopy and XRD to obtain basic data on their clay mineralogy and crystal-chemical parameters (IC, the index of “crystallinity”, b...