Granite is an intrusive, felsic rock, which may be produced by partial melting or fractional crystallization. Explain how these processes can produce felsix magmas from more mafic parent magmas.
Since this is not my area of expertise, I searched Google under the key words "fractional crystallization granite" to get these possible sources:
http://en.wikipedia.org/wiki/Fractional_crystallization_(geology)
http://en.wikipedia.org/wiki/Igneous_differentiation
http://64.233.167.104/search?q=cache:OdaBGZxKD9sJ:ocw.mit.edu/NR/rdonlyres/Earth--Atmospheric--and-Planetary-Sciences/12-109Fall-2005/612BAB6C-E1B0-46F5-895C-D6C7B54CC0A0/0/Nov3notes.pdf+fractional+crystallization+granite&hl=en&ct=clnk&cd=7&gl=us&client=safari
I hope this helps. If not, you can try your own searches using other key words in your question. Thanks for asking.
Thank you
Both partial melting and fractional crystallization are processes that can produce felsic magmas from more mafic parent magmas.
Partial melting occurs when a portion of a rock undergoes melting while the rest remains solid. In the case of mafic parent magmas, which are rich in iron and magnesium, the partial melting process can lead to the production of felsic magmas. This is because the minerals that are rich in silica, such as quartz and feldspar, have lower melting temperatures compared to the minerals rich in iron and magnesium. As a result, during partial melting, these minerals are the first to melt and separate from the rest of the magma, enriching the remaining melt with silica and other felsic components.
Fractional crystallization, on the other hand, involves the removal of minerals from a magma as it cools and solidifies. In the case of mafic parent magmas, the minerals that crystallize first are rich in iron and magnesium, such as olivine and pyroxene. As these minerals crystallize and separate from the remaining melt, the composition of the magma gradually becomes more felsic. This is because the minerals that are rich in silica, such as quartz and feldspar, have higher melting temperatures and therefore take longer to crystallize.
Both partial melting and fractional crystallization can occur in different geological settings, such as in the Earth's mantle or during the formation of igneous rocks in volcanic or plutonic environments. These processes contribute to the diversification of magma compositions and the formation of different rock types, including felsic rocks like granite.