No space elevators here, but a small adamantine pillar poking above the surface at the embarked location. Tested safe to dig down to about z-level 50, which gives nearly 100 z-levels of adamantine that's safe to mine.

Beware, natural waterfall at embark location may lower FPS...

If it matters, this was generated using OzoneGriff's .16 update of Mike Mayday's graphical DF, found here

Edit: It should be noted that HFS and the lava sea have been broken by the messed-up z-levels that caused the adamantine pillar. There is no magma on this map that is accessible without releasing Fun. This is another reason for the lowered framerates. What little magma sea that still exists is constantly draining into HFS, making huge lava-falls flowing across the slade and down into the screaming pits. Very senic, but hell (ha ha) on the CPU.