Page 25 n FACTORS THAT INFLUENCE MELTING OF ROCKS&#13; n &#13; n 1) Temperature - usually between 800-1200 O C &#13; n 2) Rock Composition - granite melts ~ 800 O C and basalt ~12000C (reflects silica content - BRS)&#13; n 3) Pressure at Melting - a drop in pressure will cause hot rock to melt resulting in &quot;pressure relief melting&quot; without need for increased temperature - most important at spreading centers &#13; n 4) Water Content of Rock - water lowers the melting point of magmas - dry granite melts at 700 O C while wet granite (10-15% water) melts at 600 O C&#13; n 25
(n 4) Water Content of Rock - water; lowers; the melting point of magmas - dry granite melts) Context(n 4 ) Water Content of Rock - water lowers,List([427, 468))):(pressure relief; melting; )
n 4 ) Water Content of Rock - water lowers,List([427, 468))
n 4) Water Content of Rock - water pressure relief
lowers melting
the melting point of magmas - dry granite melts