The sand is soft but pitch black (due to the fact that the sand was once hot lava that poured out of the volcano some millennia ago).
(The sand; is; soft but pitch black (due to the fact that the sand was once hot lava) (the sand; was; T:once; hot lava that poured out of the volcano some millennia ago) (hot lava; poured; out of the volcano; T:some millennia ago)
The sand the sand hot lava
is was poured
soft but pitch black (due to the fact that the sand was once hot lava
T:once hot lava that poured out of the volcano some millennia ago
out of the volcano T:some millennia ago