A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Corderite hornfels, near Helena, Montana |
|---|---|
| Description | This is a fine grained rock, so individual minerals are difficult to see. Dark grains of altered cordierite (up to 0.5 cm across) are in a sea of biotite, quartz and muscovite. The specimen is 8 cm across. |
| Chronostratigraphy | Precambrian Belt Sediment metamorphosed during the early Laramide (Late Cretaceous) |
| Lithostratigraphy | Belt Series |
| Location | USA ▹ Montana. Near Helena. |
| Photographer | Nessa Eull. 2001-04-10. |
| Collection | Ward’s Collection of Classic North American Rocks #71. |
| Key words | hornfels, Montana, cordierite |
| Tech details | 882 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 322 |
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