Rawhiti Cave
From Wikipedia, the free encyclopedia
Rawhiti Cave, also known as Manson Cave, is a single large limestone cave in the hillside of the Dry Creek Valley 7 kilometres (4.3 mi) southeast of Tākaka on the South Island of New Zealand.[1] It is referred to as Manson Cave in the NZ Topo Map,[2] after owners in the early 20th century,[3] however the cave is known as Rawhiti Cave locally, and on DoC information panels and in brochures.[4]
The cave's entrance is one of the largest cave entrances in New Zealand[4] with an opening of about 40 metres (130 ft) wide and up to 20 metres (66 ft) tall.[5] The ceiling is densely covered in stalactites which 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.[1] 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 sides.[6]
Apart from the short walking track to the viewing platform, the cave is undeveloped and in its natural state. Delicate ferns and mosses grow on the cave's sloping floor, and phytokarst stalagmites also grow towards the light, similarly following the growth pattern of the plant life that helps form and shape them.
During winter months, sunlight reaches the back wall of the cavern, creating viable conditions for some species of algae to survive at the lower limit of light availability for photosynthesis. These algae cover the rear walls in a range of red hues.[7]
