Bowen's Reaction Series

Definition

Bowen's Reaction Series is a conceptual model that illustrates the order of mineral crystallization from magma as it cools, showing how different minerals form at different temperatures and conditions. This series helps to understand the relationships between various igneous rocks and their mineral compositions, linking it to the classification of Earth materials, the behavior of specific silicate structures, and principles of mineral associations.

5 Must Know Facts For Your Next Test

1. Bowen's Reaction Series is divided into two branches: the discontinuous series, which shows the formation of ferromagnesian minerals like olivine and pyroxene, and the continuous series, which illustrates the evolution of plagioclase feldspar from calcium-rich to sodium-rich forms.
2. The series emphasizes that as magma cools, earlier formed minerals can influence the crystallization of later ones, impacting the mineral assemblages in igneous rocks.
3. The temperature range for crystallization in Bowen's Reaction Series typically spans from about 1,200°C to below 600°C, illustrating how mineral stability changes with temperature.
4. Understanding Bowen's Reaction Series is crucial for identifying the potential mineral content in igneous rocks and predicting their behavior during geological processes such as melting and metamorphism.
5. This series also highlights the role of pressure and volatile content in magma evolution, further influencing which minerals will crystallize and when.

Review Questions

• How does Bowen's Reaction Series illustrate the relationship between temperature and mineral formation?
  • Bowen's Reaction Series clearly demonstrates that different minerals crystallize from magma at varying temperatures. As magma cools, specific minerals like olivine form first at higher temperatures, while others like quartz appear later at lower temperatures. This sequential crystallization helps geologists predict which minerals are likely present in igneous rocks based on their cooling history.
• Discuss how Bowen's Reaction Series can be applied to understand mineral associations within igneous rocks.
  • Bowen's Reaction Series provides insight into mineral associations by detailing how certain minerals crystallize together or influence one another's formation as magma cools. For example, early-forming ferromagnesian minerals may react with remaining magma to produce later-forming minerals like feldspar. This interconnectedness allows geologists to interpret the conditions under which specific igneous rocks formed and understand their mineralogical compositions.
• Evaluate the impact of fractional crystallization on the diversity of mineral compositions in igneous rocks as explained by Bowen's Reaction Series.
  • Fractional crystallization plays a significant role in shaping the diversity of mineral compositions found in igneous rocks as highlighted by Bowen's Reaction Series. As certain minerals crystallize out of cooling magma, they remove elements from the liquid phase, altering its chemistry. This process leads to a variety of rock types with differing mineral contents, such as the transition from mafic to felsic compositions, illustrating how Bowen's model can explain both magmatic differentiation and resultant rock diversity.

Related terms

Igneous Rocks:

Rocks formed from the solidification of molten material called magma or lava, classified into intrusive and extrusive types based on their formation process.

Felsic and Mafic: Two primary categories of igneous rocks based on their mineral composition; felsic rocks are rich in silica and lighter-colored minerals, while mafic rocks are richer in iron and magnesium, resulting in darker colors.

Fractional Crystallization: The process by which different minerals crystallize from cooling magma at different temperatures, leading to changes in the composition of the remaining liquid and affecting the types of igneous rocks that form.