These activities help scientists and educators understand volcanic processes.

They said phosphate must have been continuously recycled by volcanic processes.

Each Period is marked by different volcanic processes.

The present form of the lake is the result of glacial and volcanic processes.

If this suggestion is correct, the pits are evidence of volcanic processes at work on Mercury.

"This would be in exact analogy with what happens inside the Earth with volcanic processes," he said.

The caldera itself has become a model for research on volcanic processes.

Competing hypothesis: Chemistry of rocks is determined by volcanic processes.

The troughs may also have resulted from volcanic processes under the floor of Raditladi.

Most natural explosions arise from volcanic processes of various sorts.