Rawhiti Cave become increasingly finer deeper down into the cave. A short walking track leads halfway down into the cavernous opening to a viewing platform. The diverse twilight-zone flora near the entrance of Rawhiti Cave makes this cave nationally significant. Over long periods of time, plant growth on the cave formations causes them to grow towards the sunlight as more calcium carbonate is deposited regularly on top of the plant growth. This phenomenon, called phytokarst, is most evident on the larger stalactites near the cave entrance, which are strongly curved outwards due to the heavy moss and fern growth on their sunlit
Calcium cycle layers of shell which over time cement to form limestone. This is the origin of both marine and terrestrial limestone, formed over long periods of time . The concentration of marine calcium depends on the depth of the ocean, as its solubility is altered with pressure. In deep ocean, roughly 1% more calcium is present when compared to surface concentrations. This is due to the solubility of calcium at higher pressure, thus associating higher concentration with increasing depth. The higher pressure stops calcium carbonate precipitation, whilst simultaneously enabling the dissolution of calcium carbonate sediment such as shells. As a result,