Virtual Vista: Photomicrographs of Metamorphic Rocks

The Virtual Vistas on this page are photomicrographs of thin-sections of metamorphic rocks linked to the website Dr. Allen Glazner at the University of North Carolina in Chapel Hill, North Carolina, USA.

Each photomicrograph shows a representative texture and mineral composition of a common metamorphic rock type that you learned about in Chapter 7 of your text.

<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::Slate::http://www.geolab.unc.edu/Petunia/IgMetAtlas/meta-micro/slate.UX.jpg','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif">Slate (937.8K)</a>Slate

The image of slate above illustrates the very fine-grained nature of this low grade metamorphic rock.

<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::Phyllite::http://www.geolab.unc.edu/Petunia/IgMetAtlas/meta-micro/phyllite.X.jpg','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif">Phyllite (969.2K)</a>Phyllite

Note in this image of phyllite above that the size of individual crystals is somewhat larger than in the preceding image of slate.

<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::Schist::http://www.geolab.unc.edu/Petunia/IgMetAtlas/meta-micro/crenulation.X.jpg','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif">Schist (105.5K)</a>Schist

Foliation is evident in this photomicrograph of a muscovite-biotite garnet schist.

<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::Gneiss::http://www.geolab.unc.edu/Petunia/IgMetAtlas/meta-micro/gneiss.X.jpg','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif">Gneiss (563.4K)</a>Gneiss

The photomicrograph above shows the coarse grain size and texture of a gneiss. Note that the interlocking crystals composing this rock are reminiscent of the interlocking texture of crystals in an igneous rock. Why might this be so?