Pumice raft

A pumice raft is a floating raft of pumice created by some eruptions of submarine volcanoes or coastal subaerial volcanoes.

Pumice rafts have unique characteristics such as the highest surface-area-to-volume ratio known for any rock type, long term flotation and beaching in the tidal zone, exposure to a variety of conditions, including dehydration, and an ability to absorb many potentially advantageous elements/compounds. For at least these reasons, astrobiologists have proposed pumice rafts as a possible ideal substrate for the origin of life.

Biologists have suggested that animals and plants have migrated from island to island on pumice rafts.