A Geoscience Digital Image Library

TitleThin section of diorite
DescriptionThis is a plain polarized thin section of diorite. Green hornblende, the dominant species, contributes to a moderately well-developed gneissoid foliation in subparallel subhedra, partly replaced by biotite, in both anhedral patches and euhedral tablets. The medium plagioclase in anhedral, slightly zoned gradationally and locally has central parts sericitized. Large sphene euhedra from a conspicuous accessory. Others are epidote, rare allanite, apatite and magnetite.
ChronostratigraphyCretaceous (?)
LocationUSA ▹ California ▹ Los Angeles. Near Azusa.
PhotographerDarla Sondrol. 2002-04-09.
CollectionWard’s Collection of Classic North American Rocks #25.
Key wordsdiorite, California, thin section
Tech details948 KB. Thin section. Nikon FDX-35.
GeoDIL number2629