Only Five Meteorites Have Been found In N.Z.

Press, Volume CIX, Issue 32304, 23 May 1970, Page 5

Only Five Meteorites Have Been found In N.Z.

j||MUSEUM OF ! NATURE ||

(Contributed by the Canterbury Museum)

It has been estimated that each year 150 meteorites hit the land areas of the earth. But in the museums of the world there are only about 1700 meteorites. Millions of meteorites must lie undiscovered.

One of the main problems in meteorite research, is that there are not enough meteorites available. Only a few scientists are engaged in full-time research on meteorites and they have little time to search in the field for new specimens. Most meteorites have been found, usually accidentally, by members of the public. Only five meteorites have been found in New Zealand and none of these has been found by a scientist. The first New Zealand meteorite (number 1 on the map) was found in 1863 by a Wairarapa farmer, W. H. Donald, in front of his house a few miles south of Masterton. This was the stony Wairarapa Valley meteorite, of which the main part weighing 131 b is in the Auckland Museum.

The second New Zealand meteorite, a stony one weighing 51b, was found near Invercargill in 1879 by. two brothers, A. and I. Marshall, while working on the railway line at Makarewa Junction. Small pieces of this Makarewa meteorite are in several museums.

New Zealand’s third meteorite is the only one recovered after having been seen to fall. At 12.30 p.m. on November 26, 1908, people living at Mokoia, near Hawera, were startled by a series of loud explosions. A fir-tree was found to have bee l splintered and at the foot of the tree, in an Ilin deep crater were found two dark-coloured stony fragments weighing together lOflb. This Mokoia meteorite, which was presented to the Wanganui Museum, is unusual in that it contains compounds of carbon and hydrogen. The fourth New Zealand meteorite was found in 1925 when William Stewart, a South Canterbury fanner, ploughed up an unusual stone weighing about 151 b. The

main mass of this Morven meteorite is in the Otago Museum.

The latest find and New Zealand’s fifth meteorite was brought to the Canterbury Museum in 1954 by L. F. Blatch, and had been found a year or so before at View Hill, near Oxford, by C. C. Anderson when ploughing a paddock. This 741 b, rustcovered, View Hill meteorite is the only iron known from New Zealand, and is our largest meteorite. A new display in the Geology Hall at the Museum shows examples of different sorts of meteorites. There are .two main kinds iron meteorites and stony meteorites.

Iron meteorites, or irons, are about 90 per cent iron and are strongly attracted to a magnet They are very heavy, and large irons when struck with a hammer will ring like a bell. A file-cut on the surface will show the inside to be bright and

silvery. All irons contain nickel and this can be easily tested for chemically. The surface of irons often show shallow hollows known as “thumb marks” which are probably formed by local melting during their high-speed passage through the atmosphere. Stony meteorites, or stones, are much more difficult to recogize in that they look like ordinary volcanic rocks. They have a lower nickeliron content and may be only slightly magnetic. If the stone has fallen recently, it may still have its fusion crust—a black glassy coating caused by melting of the surface during its flight. Weathered stones, in which all the nickeliron has rusted to oxides, can only be certainly identified after detailed study. In the hope that a sixth New Zealand meteorite will be found before long, specimens thought to be meteorites will always be welcomed at the Museum.—D.R.G.