Which one of the following is a control on magma viscosity?
A magma’s viscosity is largely controlled by its temperature, composition, and gas content (see downloadable programs at the bottom of this page). The effect of temperature on viscosity is intuitive. Like most liquids, the higher the temperature, the more fluid a substance becomes, thus lowering its viscosity.
What happens to the silica content of minerals as the magma cools Does it increase or decrease?
As it cools, it crystallizes, new bonds form between ions, and tiny crystals begin to appear. As cooling progresses, different minerals crystallize out of the magma at different temperatures. Composition again changes as each crystallized mineral is removed from the magma.
What factors determine which minerals crystallize and solidify out of magma first?
When magma cools, the cooling process is the reverse of the process of partial melting. Chemicals in magma combine to form minerals, and each mineral has a different freezing point. Minerals that have the highest freezing points crystallize first.
What are the main factors that affect the melting of magma?
The factors that mainly affect in the formation of magma can be summarized into three: Temperature, Pressure and composition. Temperature plays a role in the formation of the melts in the magma.
Which minerals are the first to crystallize from cooling magma?
The sequence in which minerals crystallize from a magma is known as the Bowen reaction series (Figure 3.10 and Who was Bowen). Of the common silicate minerals, olivine normally crystallizes first, at between 1200° and 1300°C.
What minerals that crystallize at higher temperature as a result of contact?
Minerals near the top of the diagram, such as olivine and anorthite (a type of plagioclase), crystallize at higher temperatures. Minerals near the bottom, such as quartz and muscovite, crystalize at lower temperatures.
Which of these are the three ways in which rock may melt?
Which of these are the three ways in which rock may melt? Lowering the pressure; Increasing the temperature; Addition of water.