IGNEOUS PETROLOGY (CHEMISTRY OF IGNEOUS ROCKS) Flashcards
Elements with conc. >1wt%
Major Elements
how much of the Earth’s crust is SiO2 by wt%?
75%
how much of the earth’s crust is SiO2 by vol%?
94.70%
Only anion listed among the eight most common crustal elements
Oxygen (nonmetal)
This is the primary bearer of Aluminum Oxide in the silicate Minerals (Al2O3)
Feldspar Mineral group
As SiO2 increases what oxides decreases?
Fe, Mg, Ti, and Ca
What oxides increases when SiO2 Increases?
Na and K
These are elements which occur in concentration of 0.1-1.0% by wt
Minor Elements
What minor elements are associated with basic rocks?
Cr, Ni and Cu
What minor elements are associated with felsic rocks?
Li, Be, and Ba
This occur in <1000ppm or <0.1% by wt and consiered as DNA of Magmas
Trace elements
This is the measure of the ease with w/c an element fits into a crystal structure
Compatibility
These are elements which form long lasting bond and are incorporated in the crystal structures due to their immobility
Compatible Elements
These are very mobile elements which readily migrate into the melt since they do not fit easily into the crystal strucure and thus weakly bonded
Incompatible Elements
What would be the composition of the residual rock or restite after melt removal?
enriched in compatible elements and depleted in incompatble elment
Rocks produced by cooling of partial melts are enriched in?
Incompatible Elements
a relatively flat REE Conc pattern
Chrondite-normalized pattern
What are the atomic numbers of REEs
57-71, 21 and 39
How many REEs are considered by IUPAC?
17
what distinguishes LREEs from HREEs?
LREEs are more incompatible
Elements characterized by having relatively high ionic charge and a small ionic radius
HFSEs
What are the use of HFSEs and HREEs?
tracing mantle-related processes
since they are immobile
These are elements with large ionic radius but small charge and usally have a ratio of >0.2
LILEs
Large Ion Lithophiel elements
What are the uses of LILEs since they are mobile?
They are used in magma genesis studies and role of hydrous fluid interaction
