Complex sentence: The volcanic debre layers formed the base that precipartation occurred on and sloped towards the top of the geyser and formed a pool over time with precipatation forming a lip which would be self leveling and increased with precipartation over many years.
Split into simpler sentences: The volcanic debre layers formed the base that precipartation occurred on. When the precipitaion sloped down but towards the top of the geyser and formed a pool over time with precipatation forming a lip which would be self leveling and increased with precipartation over many years.