Earth Science Flashcards
what iron ore is classified as a Direct shipping ore
Hematite
To be classified as a BIF or banded iron formation what percentage of iron must atleast be contained in the rocks
15%
The two modes of magmatic differentiation are:
Discontinuous Magmatic Differentiation and Continuous Magmatic Differentiation
When magma cold, chemical reactions occur that create a series of different minerals. This process of differentiation occurs along two branches:
The Discontinuous Branch and The Continuous Branch
Minerals that form in the discontinuous branch are all ___________.
Ferromagnesian
If minerals formed by magmatic differentiation contain high percentages of iron and magnesium, then they are _____________.
Ferromagnesian
The discontinuous branch is called discontinuous because:
The minerals form at discrete temperatures and not continuously during cooling.
The first four minerals to crystallize as a result of discontinuous magmatic differentiation are:
Olivine, pyroxene, amphibole, and biotite.
The continuous branch us made up of the ___________.
Plagioclase feldspars
The _________ to ___________ ratio in plagioclase feldspars changes continuously as as the magma cools.
Calcium to Sodium
The first feldspars to form during continuous magmatic differentiation contain the highest amounts of _________.
Calcium.
In continuous magmatic differentiation, subsequently formed feldspars progressively have less _________ and more _________.
Less calcium and more sodium.
What colors are plagioclase feldspars typically?
Pink, tan, brown, or whitish
Any magma left over after all the reactions of magmatic differentiation have been completely crystallized at the ________ ________ as ________.
Lowest temperature as Quartz.
The two theories of magmatic differentiation were first proven in the laboratory by who?
N.L. Bowen
