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A Geoscience Digital Image Library

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TitleLamprophyre, Spanish Peaks, Colorado
DescriptionThis lamprophyre is a dark gray uniformly fine-grained rock. Lamprophyres are dark colored igneous rocks, often having the general appearance of basalt. Lamprophyres, however, are closer to andesite in composition and typically contain biotite (phlogopite). Although not identifiabled in this photograph, the fine mineral grains consist of olivine, magnetite, augite, plagioclase and biotite. This specimen is 8 cm across. Lamprophyres may also contain amphibole, melilites, Kfeldspar, feldpathoids and a number of other minerals.
ChronostratigraphyPost-Upper Cretaceous (Post Pierre)
LocationUSA ▹ Colorado. Spanish Peaks.
PhotographerMike Davis. 2001-03-20.
CollectionWard’s Collection of Classic North American Rocks #39.
Key wordslamprophyre, Colorado
Tech details691 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number203