As magma cools and crystallizes minerals form is predictable patterns in a process known as

As magma cools and crystallizes minerals form is predictable patterns in a process known as 'Bowen reaction series'.

Explanation:

The sequence in which minerals crystallize out from the magma is Bowen's reaction series. The top most layer of the magma will crystallize first and slowly successive layers will cool down to form crystals.

The newly formed mineral from the cooling magma reacts again with the remaining magma further to form another series of minerals.

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.