Bowen s reaction series

Bowen s reaction series representing the relationship of igneous silicate mineral composition to crystallization temperature. The plagioclase feldspars represent a continuous series grading from the calcium-rich to sodium-rich to potassium-rich forms. The rest of the minerals constitute a discontinuous series in which distinct crystal structures are characteristic of a particular temperature range under which the magma solidified. 

Mineral composition and structure are the primary intrinsic factors controlling weathering rates. Based on early weathering studies, Goldich (1938) observed that the weathering sequence for common igneous rocks in the field was the reverse of Bowen s reaction series that ranked minerals in the order of crystalhzation from magma. Amphi-boles and pyroxenes are expected to weather faster than feldspars which weather faster than... 

Fig. 4.14 Common silicate minerals ranked in Bowen s reaction series. Note that minerals formed under high temperatures with more ionic bonding are more susceptible to weathering. Ferromagnesian—minerals which contain essential iron and magnesium. Felsic—a rock containing feldspars and quartz.

The specific mineral crystallizing from magma depends both on the composition and temperature of the magma. The order of crystallization of the main silicate minerals is given by Bowen s reaction series, which is shown in... 

The primary minerals crystallize from high-temperature melts (magma), often under conditions of high pressure beneath the earth s crust. The sequence of crystallization of the common minerals in forming igneous rocks is called the Bowen reaction series. As diagrammed in Figure 6.1, it is seen that there are actually two reaction series ... 

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