41. Lower mantle melt rates would form mafic melts that incorporate silicic melts before erupting. 42. The metasedimentary rocks are quartz-rich and the amphibolites represent mafic igneous intrusions. 43. The Altiplano and the adjacent southern Puna has experienced mafic volcanism during the Cenozoic. 44. Mantle plume hypotheses may rely on identifying mafic and ultramafic intrusions and coeval basalt volcanism. 45. The sedimentary fill of the basins consists largely of alluvial fan and mafic volcanic flows. 46. Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. 47. This is because of the extremely low silica content ( the lava is mafic ). 48. With an increase in calcic plagioclase and mafic minerals the rock type becomes a diorite. 49. Volcanism of the mafic capping stage began with the eruption of aphyric hawaiite lava flows. 50. The mafic shield-building stage culminated with emplacement of the fourth and highest unit.
