Entry Date: 09.12.2018, at 16:00:00 hrs (local)

Whangarei - Whangarei

Silica Rapids

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PRID: 11686
LegID: 315
LegNo: 64
Latitude: S035°43.41'
Longitude: E174°19.57'
Day#: 821
Log (Leg): 15 nm
Log (Total): 47138 nm
Today we walk along the so-called "Silica Rapids Track". Compared to our tour yesterday, it´s only an easy 8km walk. The track leads through the fantastic landscapes of the Tongariro National Park. The most interesting spot is where a small stream forms cream-colored deposits pretty, cascading terraces. The deposits are mostly made of aluminum silicate. The water of the stream contains a lot of natural carbon dioxide. This acidic water is capable to dissolve and carry other compounds like aluminum silicate. As the water becomes more turbulent, it loses carbon dioxide. This makes the water less acidic. As a result, the water loses its ability to dissolve the aluminum silicate and so it creates the interesting deposits.