This is a simple essay explaining the Bowen Reaction Series.

Essay by charmed_power_threeCollege, Undergraduate February 2004

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Works Cited: Chernicoff & Fox Essentials of Geology, Ghaly Basic Geosciences

Illustrations For all Levels

The Bowen Reaction Series

In 1922, Norman Levi Bowen and his colleagues

determined the sequence in which silicate minerals

crystallize as magma cools (Chernicoff 56). This work made

it possible to summarize a complex set of geochemical

relationships, called Bowen's Reaction Series.

This series shows that silicate mineralscancrystallize

from mafic magmas in two

ways, in a discontinuous series or a continuous series.

Iron and magnesium rich silicates(ferromagnesian)

crystallize one after another in a specific sequence

(Chernicoff 56).

Because each successive type of this mineral

crystallized differs from the one that came

before it, this progression is called the discontinuous

series. In the discontinuous series the first

ferromagnesian mineral to crystallize is olivine. Olivine

has a low silica content and a relatively simple structure

of independent tetrahedra (Chernicoff 56).

At the same temperatures as the olivine and the

pyroxenes crystallize, so does the

calcium feldspar.

As these crystals continue to interact

with the remaining liquid, sodiumions from the liquid magma

replace the calcium ions in the calcium feldspar (Chernicoff

57). Eventually the crystals are completely converted to

sodium feldspar. Because one type of ion is being replaced

by a similar ion; the internal structure does not change.

This progression is called the continuous series

(Chernicoff 57).

After both minerals from the discontinuous series

and the continuous series have crystallized completely from

an initially mafic magma, less than 10% of the original

liquid remains (Chernicoff 57). Depending on its

composition, this liquid may now contain higher

concentrations of silica, potassium, and aluminum. In such

a case, potassium feldspar, potassium-aluminum mica, and

quartz are the last minerals to crystallize (Cherincoff 57).

Higher Temperature: Basic Magma

Olivine Anorthite




Amphiboles Andesine


Biotite Albite




Low Temp: Acidic Magma (Ghaly 21).