Chch pair may have terrace rock

Press, 25 January 1986, Page 9

Chch pair may have terrace rock

Rock samples which may have come from the Pink and White Terraces at Lake Rotomahana are coming to light in several places round New Zealand, including Christchurch.

Scientists from the Department of Scientific and Industrial Research are investigating re-forming the terraces as a tourist attraction. The original terraces disappeared when Mount Tarawera erupted 100 years ago.

The scientists need to analyse pieces of the original rock to find out what made them pink.

Two Christchurch women yesterday showed the D.S.I.R. rock fragwhich they believe came from the terraces. Mrs Allison Skudder, of South Brighton, said she had a glass container of pink, blue, green, lemon and white rock granules, which was given to her father in Rotorua in the 19205. Her father was told the granules were from the Pink and White Terraces.

Mrs Jan Spence, of Ham, was given a piece of pink rock in the 19305. It had come from a family member but its. origins

were not clear. Dr Gordon Leary, director of the D.S.I.R.’s Chemistry Division in Wellington, said about eight Wellington people and several Aucklanders had also come up with what could be terrace rocks. "One or two don’t sound right, but some of them do,” he said. “We will need to test them before we can say what they are.” Once the scientists knew what caused the pink colour, reconstructing the terraces would not be difficult.

Water from geothermal areas such as Wairaki contained silica, which eventually went solid and had to be chipped from trenches to keep the waterways clear, he said.

“If we could find out what to add or take away from that water to make the deposits pink, it would work. Antimony or iron can be pink in certain circumstances, and I imagine the pink will be a metal like, this in salt form in the rocks.”

Any rocks given to the D.S.I.R. would be analysed in Wellington. A small piece of each rock

would be ground up during the analysis, the remaining rock would be returned to the owner, Dr Leary said. Where the new terraces would be sited and the cost of the work was not yet decided, as planning was still in its early stages. “I imagine it would be in the Taupo or Rotorua region, , but local people would have to be approached about siting,” Dr Leary said. The scientists will visit Tokaanu Thermal Park in their bid to find how the terraces were formed.