1.   But the discovery of seismic activity suggests geological activity, which could provide large amounts of heat and minerals.

2.   Here is a clear example of a rare rock type that has been strongly concentrated by lunar geological activity.

3.   In the case of Venus, many scientists suspected, plate tectonics or some similar geological activity probably took place to help release the internal heat.

4.   The outer range is uncertain, he explained, because of uncertainties in the abilities of geological activity on the planet to keep the planet warm.