A Geoscience Digital Image Library
A Geoscience Digital Image Library
| Title | Diabase porphyry, Cape Ann, Massachusetts |
|---|---|
| Description | In this porphyritic extrusive igneous rock, the blocky greenish-gray crystals are plagioclase phenocrysts. The gray-green finer grained material surrounding them is a matrix of plagioclase, pyroxene, hornblende and biotite. This specimen is 9 cm across. |
| Chronostratigraphy | Triassic (?) |
| Location | USA ▹ Massachusetts ▹ Essex. Near Cape Ann. |
| Photographer | Mike Davis. 2001-03-20. |
| Collection | Ward’s Collection of Classic North American Rocks #38. |
| Key words | diabase, porphyry, Massachusetts |
| Tech details | 728 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. |
| GeoDIL number | 202 |
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