Please enable JavaScript.
Coggle requires JavaScript to display documents.
METAMORPHIC-LECTURE 1 - Coggle Diagram
METAMORPHIC-LECTURE 1
Thompson AFM projection
-
Treat Fe and Mg as separate components, thus taking into account variations in the Mg/(Mg+Fe) ratios
Muscovite common, so all compositions are projected from muscovite onto Al2O3-FeO-MgO
-
-
Kfs projects away from front face of diagram (AFM), so kfs would plot at -ve infinity
At high grade metamorphism, musc is unstable, replaced by kfs+qtz+Al2O3 mineral. New projection
-
-
AKF diagram
-
-
4 AKF phases, musc+bt+and+crd+qtz
-
Tetrahedron, Thompson AFM projection for 2D
Reactions
Discontinuous
Crossing tie-line
-
'Non-terminal', all phases are still stable individually
-
-
Inclusion type
-
-
-
Mineral Q not involved, XYQ persists in some rocks
-
Continuos
-
Within PT fields, bounded by discontinuous equilibra
-
Minerals become richer in M, modal abundances of A and B decrease, lose one of A or B, end up w/ A+C or B+C
-
-