Question

briefly describe the roles of heat, pressure, and water in the origin of magma. ( in your own word)

Answer 1

So as the temperature and pressure rises with the depth,and eventually reaching to an level wherein the strongest rock has melted turning it into magma. As the magma hits the water it starts to instantly turns into rock and the interior color as well 

I hope this helps, have a great day ;)

Answer 2

The semifluid or hot fluid substance within or below the crust of the Earth from which lava and other igneous rock are produced by cooling is known as magma.  

The temperature and pressure elevate with depth, finally reaching to a level wherein the strongest rock is melted, transforming into magma. When the magma comes into contact with water, it instantly gets transformed into a rock, that is, the outside solidifies briskly, and the inside of it gets cold.