Melting Point
- (denser) mafic rocks crystalize at higher temperatures
- (lighter) felsic rocks crystalize at lower temperaturers
Bowen’s Reaction Series
Since different minerals melt at different tempreatures (as in above), we have a…
Partial Melting
Partial Melting! This results in the felsic runoff first, and then mafic runoff.
Spreeading centers are ultramafic, which emans that this process mostyl contirbutes a dyversity of tho utputs.
“will it flow or will it blow?”
flow
Mafic magmas is low in sillica and hot; this results in low viscocity, runny magma, low gass content (gas rises faster than magma).
blow
Felsic magma high in silloca, colder, higher viscoicty—need force to move; this means that gas is trapped and then more explosive power.
bi-modal volcanism
Contintal rift, crust thins over time, and thus th v olcano has mafc and felsic components *
straddling Magmatic Plumb
- big plumb (rising blumb + head)
- “flood basults”: rising hot spot creates a bunch of channels of magma that they join together to form a (a large blob); massive xetension
- island volcanism: small dragging along, small islands, once the plate pass the large plumb