Porphyritic granite


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Related to Porphyritic granite: Porphyritic Texture
granite containing feldspar in distinct crystals.

See also: Granite

References in periodicals archive ?
For many people passing through Fitchburg, the most striking feature of the city is the Rollstone Boulder, an enormous 100-ton chunk of porphyritic granite that once crowned Rollstone Hill.
Porphyritic granite mined from a series of quarries near the picturesque hamlet of Vermilion Bay has made its way around the world for uses ranging from small grave markers to entire building facades for structures in Japan, China, Singapore, the United Arab Emirates, Russia and its biggest market, the U.
1) consists of five granite types: wiborgite, pyterlite, even-grained granite, porphyry aplite, and porphyritic granite, of which wiborgite is the most common granite type (see also Simonen 1987) (Fig.
The Nelson batholith near the property consists mainly of porphyritic granite, with lesser amounts of granodiorite, quartz diorite, quartz monzonite, diorite, monzonite and syenite.
G1 and G2 are samples from the Megacrystic Granite which is a distinctive porphyritic granite comprising large (15-80 mm) pink megacrysts of K-feldspar (~15-20%) set in a coarse-grained (2 5 mm) groundmass of plagioclase (-44%), quartz (~22%), K-feldspar (~3 8%), biotite (~7-10%), and hornblende (~1-5%) with accessory titanite, allanite, apatite, zircon, and opaque minerals.
24 square kilometres): This permit area hosts structurally controlled gold mineralization associated with felsic dykes and altered porphyritic granite, which occur within a regional intermediate volcanic and volcanoclastic terrain associated with a major tectonic structure.
In the first case study the material was porphyritic granite and the study area was located in the eastern part of the Central Finland Granitoid Complex (CFGC) in southeastern Finland (Fig.
Samples collected from a small outcrop of highly porphyritic granite showed pervasive hematisation, magnetite veining and disseminations, malachite staining ((+/-) chalcocite) and gold mineralization grading up to 1.
Mineralization at the Mitchell North Zone is hosted by a distinctive, reddish-purple K-spar-quartz porphyritic granite, which is conspicuously lacking in ferromagnesian minerals.
4 metres), intersected anomalous gold along its entire length, cutting porphyritic granite with quartz, quartz-calcite and quartz-pyrite-arsenopyrite veins.
4 metres) intersected anomalous gold along its entire length, cutting porphyritic granite with quartz, quartz-calcite and quartz-pyrite-arsenopyrite veins.
Prospecting work indicates that these anomalies can be linked to porphyritic granites that have higher U and Th contents than the surrounding units (Quirion 1999).