Answer:
Step-by-step explanation:
Porphyry is a term that is used for the igneous rock. It consists of large grained sized crystals like quartz, feldspar and fine grained size silicates for example aphanitic matrix or groundmass. The porphyry deposits can be seen deposited in the case of volcanic eruption or volcanic arcs.
The porphyry deposits are formed from the rising magma is cooled. The magma is cooled slowly deep below the earth crust. This results in formation of large crystal grains that have a diameter of 2mm. But when the magma get cooled this results in formation of shallow depth and eruption of the volcano this results in the creation of the small grains that are invisible to the unaided eye.