State by State
- Specimen Number
Cut and polished block of dimension stone composed of coarse-grained pink granite. State survey staff identifies this as Pikes Peak granite, a syenogogranite composed of pink microcline, quartz, hornblende, and biotite.
Igneous. Plutonic. Granitic. Syenogranite.
- Location & Occurrence
Potassic pluton from anorogenic Pikes Peak batholith, almost certainly the Pikes Peak Formation. The coarse grain texture and uniformity indicate slow stable cooling at significant depth.
- Geologic Age
Proterozoic, ~ 1 billion years old (Ga).
Highest peak in the Mountain State. Massive granite batholiths float high in the crust, especially after Cenozoic de-lamination of lithosphere. Being deeply rooted and low-density, they float high. Closeup shows classic granitic texture.
Credit State Survey.