Amphibolitic Migmatite, Welcome Springs, Utah
Migmatites have under gone metamorphosis resulting in the complete melting in one or more mineral component (usually feldspar and quartz, where present) forming the leucosome curly whitish bands. The remaining minerals are still in a ductile semi-solid state. In this case, a 1700 Ma metasediment was pushed down into an oceanic trench resulting in a typical banding pattern.
This is an amphibolitic migmatite. Common in this are also migmatites based on gneiss.Size: about 100cm across across.
Amphibolitic Migmatite, Welcome Springs, Utah
Migmatites have under gone metamorphosis resulting in the complete melting in one or more mineral component (usually feldspar and quartz, where present) forming the leucosome curly whitish bands. The remaining minerals are still in a ductile semi-solid state. In this case, a 1700 Ma metasediment was pushed down into an oceanic trench resulting in a typical banding pattern.
This is an amphibolitic migmatite. Common in this are also migmatites based on gneiss.Size: about 100cm across across.