Answer :
Final answer:
D. Diorite is intermediate with a phaneritic texture; rhyolite is felsic with an aphanitic texture; basalt porphyry is mafic with a porphyritic texture.
The correct classification of diorite, rhyolite, and basalt porphyry according to composition and texture would be: diorite as intermediate with a phaneritic texture, rhyolite as felsic with an aphanitic texture, and basalt porphyry as mafic with a porphyritic texture.
Explanation:
Classification of Rocks by Composition and Texture
The composition and texture of rocks are crucial in their classification. Let's examine the rocks listed in the question:
- Diorite: This is an intermediate igneous rock with a phaneritic texture, meaning it has visible crystals and is characterized by a mix of light and dark minerals.
- Rhyolite: Rhyolite is a felsic, extrusive igneous rock. It is equivalent to granite in mineral composition but has an aphanitic texture with very fine crystals, usually smaller than 1 mm, due to the quick cooling of lava.
- Basalt porphyry: It is a mafic rock with a porphyritic texture, which means it contains larger crystals, known as phenocrysts, within a finer-grained groundmass.
Therefore, the correct answer to the classification of these rocks based on their composition and texture is:
Diorite is intermediate with a phaneritic texture; rhyolite is felsic with an aphanitic texture; basalt porphyry is mafic with a porphyritic texture.
