Figure 7. Diagram of FeO+Fe2O3/FeO+Fe2O3 +MgO
versus TiO2 averages reflecting the differentiation
trend of basaltic magma (see the text for the regions included). The solid
circles are oceanic basalts and basalts containing xenoliths, open squares are
gabbros from the ocean floor and xenoliths, and solid triangles are Patynskii
intrusive rocks ranging from primary nonmagnetic olivine gabbros to highly
magnetic ferrogabbros. The broken line bounds the region of primary nonmagnetic
gabbros. Points close to (FeO+Fe2O3/FeO+Fe2O3 +MgO
0.57, TiO2
1.5 )
correspond to the original
basaltic magma. The crystallization differentiation generally trends from
cumulates (bottom) to ferrogabbros (top).