1. The answer is; buried deep within
The deeper you go into the earth’s crust, the higher the pressure. This is due to the weight of the overlying layers of rock. Due to this pressure, there is also great heat. This heat and pressure cause the molecules of the rocks to realign themselves and the crystals of the room change causing the rock to metamorphose into a different rock.
2. The answer is; magma
Apart from the heat that is associated with the enormous pressure in the great depths of the earth crust due to the weight of overlying rock layers, magma in magma chambers in the crust also part of the intense heat in these regions. This heat changes rocks into metamorphic rocks.
3. The answer is; foliated
The pressure and temperatures in the earth's crust are not uniform. A part of rock may be subjected to a slightly higher temperature and pressure compared to another region of the rocks. This unevenness causes different crystal structures and orientations at different points in the rocks making the rock appear layered or banded.