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        <h1 class="subHeadings">Theory</h1>
        <h2 class="theoryHeadings" id="bowensreactionseries">Bowen's Reaction Series</h2>
        <p>
	Bowen's Reaction Series arranges the silicate minerals in the order that they crystallise from a magma. The minerals at the top of the series crystallise from the melt at higher temperature than those 
	lower down. It contains a continuous series, (right hand limb), discontinuous series (left hand limb), and the residual phases that describe the reaction pathway of different silicate minerals. 
	The discontinuous series crystallises different minerals, with abrupt changes separating the different minerals due to a mineral reacting with the melt to form a different mineral (eg. Olivine reacting to crystallise pyroxene). 
	The continuous series always crystallises plagioclase,  but the composition of the plagioclase varies from more calcic at higher temperatures and more sodic as the temperature decreases. 
	with the minerals at the bottom of the series being more stable, and less susceptible to weathering. 
	The residual phases are the minerals at the bottom and crystallise last. Bowen's reaction series also predicts the stability of minerals in the low pressure conditions at the Earth's surface, 
	<br /><br />
	It should be noted that all reactions do not start crystallising olivine/anorthite-rich plagioclase and continue through until they crystallise quartz. 
	The actual reactions depend on many factors, such as the chemical composition of the melt, temperature, pressure, and amount of fractional crystallisation. 
	For example, basalts form from the crystallisation of olivine, pyroxene and calcic plagioclase meaning that crystallisation stopped without the series progressing. 
	If more fractional crystallisation were to occur, more intermediate and felsic minerals can crystallise.
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