A Geoscience Digital Image Library

TitleThin section of alkalic granite
DescriptionThis is the cross polarized thin section of alkalic granite. It consists of K-feldspar which is the dark gray in the upper right corner. The quartz is the lighter gray crossing right through the middle of the photo. The amphiboles are the black (opaque) area. The pyroxene (aegirine) is the darker gray shown in the upper left corner. The brown area is the original mafic mineral.
ChronostratigraphyCarboniferous (Probably Mississippian)
Geologic provinceQuincy Granite
LocationUSA ▹ Massachusetts ▹ Norfolk. Near Quincy.
PhotographerDarla Sondrol. 1899-12-30.
CollectionWard’s Collection of Classic North American Rocks #4.
Key wordsgranite, intrusive, igneous, Massachusetts
Tech details1.35 MB. Thin section. Nikon FDX-35.
GeoDIL number1524