Bowen's Reaction Series

This diagram of Bowen's Reaction Series shows how the common silicate minerals crystalize at different temperatures. Click on image for full size (21K JPG ) Windows Original Image

As magma cools slowly, elements within it become chemically bonded forming crystals of minerals. However, not all minerals form at the same time during the cooling process. Some minerals crystallize when magma is at a higher temperature, while others only crystallize when magma is at a lower temperature. Bowen's Reaction Series describes when the eight most common silicate minerals form during the cooling process.

In the Bowen's Reaction Series diagram to the left, minerals that form at high temperatures are listed at the top and minerals that form at lower temperatures are listed at the bottom.

Rocks that form from magma or lava cooled from high temperatures tend to contain a lot of iron and magnesium but little silica. These rocks are called mafic and tend to be dominated by dark colored minerals such as amphibole and pyroxene.

When magma cools slowly, minerals that form at cooler temperatures dominate the resulting rock. These rocks are called felsic and tend to be light colored with minerals such as feldspar and quartz.