When a mason exhausts a quarry and begins working on the next closest quarry, it's usually a good idea to send out the geologist to have a quarry ready when the next one collapses. But what often happens is that your left with active quarries that contain only 20 or 30 marble (or stones) but aren't in use because another is closer. It would be nice if we could order the masons to fully exhaust the almost exhausted quarries before returning to the closest one.
