Kahurangi in the north-west of the southern island of New Zealand is a difficult of access landscape built up by karst. The Tasman range, elevated up to 1500 m is part of the alpine fault. The landscape to the west was lowering over a large area into a graben system. Repeated transgression and regression phases of the ocean filled in this dip with limestone sediments over millions of years. Atmospheric carbon dioxide that is part of the rainfall causes carbonic acid dissolution of limestone rocks. This produces deep holes and cave systems in the limestone landscape, called karst. Intense rainfall in the lowland rain forests causes erosion with high transport of humus in the creeks resulting in the auburn colors of the water.
Pentax K2, Pentax 24mm, f/22, 4sec, Kodak Ektachrome E6, ISO 100, polarization filter, tripod