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Diorite Porphyrite
Rock type:
Age:
50 millions years
Submitted 4 years 3 months ago by rock.
Dyke diorite porphyrite. Sikhote-Alin series of Eocene subintrusions. Eocene. The thickness of the dikes varies from 1 to 20 m, sometimes reaching 70 m, the length rarely exceeds 500 m. The studied contacts of the dikes have steep angles (70-80 degrees) of incidence, and contact alteration are expressed in weak keratinization of rocks to a width of 5-10 cm. Consist: phenocrysts 20-25% - plagioclase, hornblende; the bulk 75-80% - plagioclase 30-35%, dark-colored mineral (hornblende?) 15-20%, quartz up to 1%. Accessory: apatite, sphene. δπ₽2
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