They are all volcanic: on two, craters have been seen in eruption, and on several of the other islands, streams of lava have a recent appearance.
— Charles Darwin, Geological Observations on Volcanic Islands
geology
They are all volcanic: on two, craters have been seen in eruption, and on several of the other islands, streams of lava have a recent appearance.
— Charles Darwin, Geological Observations on Volcanic Islands
Darwin's Galapagos 