Texture, composition and formed of igneous rocks?

A igneous rock has an aphanitic matrix (groundmass) of (Na rich) Plagioclase Feldspar with large Pyroxene crystals (about 20% of rock) in it.





a) How would you classify this rock in terms of texture?





b) How would you classify this rock in terms of composition?





c) How could this rock be formed?Texture, composition and formed of igneous rocks?
I would refer to the texture as Prophyritic (Aphanitic texture with larger inclusions).





I would refer to the composition as you described - plagioclase with pyroxene inclusions





This rock would be formed, probably in a volcanic vent or tube (the pyroxene portion) which would allow crystal growth. Some follow on volcanic activity would then expell the rock into an environment in which it would cool more quickly (the aphanitic plagioclase portion). Also, if you look at Bowens Reaction Series you see that Pyroxene precipitates at fairly high temperatures, whereas the feldspars are relatively low temperature rocks.