Geology of the Rocky Mountains Japan, Indonesia and the Aleutians; others are fragments of oceanic crust obducted onto the continental margin while others represent small isolated mid-oceanic islands. Magma generated above the subducting slab rose into the North American continental crust about inland. Great arc-shaped volcanic mountain ranges, known as the Sierran Arc, grew as lava and ash spewed out of dozens of individual volcanoes. Beneath the surface, great masses of molten rock were injected and hardened in place. For 270 million years, the effects of plate collisions were focused very near the edge of the North American plate boundary, far to the west of
Planet Earth Rock and Roll Orchestra identify the 2 inch wide tapes on sides, standing vertically. The "PERRO Chorus" is credited on Crosby's song, "What Are Their Names") and several other solo albums after Crosby's (see discography). The name Jefferson Starship was later used for Paul Kantner and Grace Slick's new band formed in 1974. Paul Kantner recorded a solo album in 1983 as a tribute to this time, "Planet Earth Rock and Roll Orchestra". Planet Earth Rock and Roll Orchestra The Planet Earth Rock and Roll Orchestra is a nickname given to artists who recorded together in the early 1970s. They were predominantly members of