HOW old is New Zealand? The land as we know it is of comparatively recent origin, but in mote places at both ends of the South Island geologists have discovered traces of life which existed in the Ordovician Period, some 450 million years ago. At Preservation Inlet and Cape Provi­nce in Fiordland and in the Mount Arthur and West Haven districts in the north are found the earliest fossils in New Zealand, the most numerous which are the graptolites. The graptolites were surface-dwellers in the oceans of that ancient period. After death their skeletons rained down into the bottom sediments were swept by winds and currents into bays, to preserved in black mud’s, where no scavengers could live to destroy them. Hence their fossil remains are usually found in dark-coloured mud-stones or slates, forming a white, flattened impression on a dark ground. The graptolites were quite like any marine animals of to-day and they left descendants. But the fossil remains of these creatures are of great value to the geologist as signs of that remote period so many million years ago.

There followed a long interval of time during which the history of New Zealand is unknown. Then another episode in the story is revealed by rocks exposed at Reefton and farther north in the Baton and Wangapeka Valleys of Nelson. In these places there are mudstones and sandstones rich in marine fossils, the most abundant being ances­tors of the modern lamp-shells. These creatures are comparatively rare and unimportant in modern seas, but in ancient oceans they were dominant. The local fossils are closely related to those which are found in Devonian rocks in parts of Europe. For this reason it has been suggested that they migrated here by means of an ancient sea-way, called Tethys, separating Eurasia from Africa and now reduced to a small remnant in the Mediter­ranean Sea.

The rocks at Reefton provide yet another link in the story. Here the lower beds with lamp-shells are followed by dark-coloured limestone’s contain­ing corals of varied size and character. These belong to the middle part of the Devonian Period, and the seas in which the corals lived also flooded Eastern Australia where similar forms are known.

The seas of the Devonian Period finally re­treated, and there followed another lengthy period not represented by rocks in New Zealand In the Northern Hemisphere at this time flourished the rests of the Carboniferous Period which form widespread coal-measures, but these completely absent in New Zealand. Our local coal-fields are much younger.

The Paleozoic Era finally closed; seas again invaded this area, as we know from a few preserved fossils of Permian age found in and at Clinton in Otago. These are the last remnants of that ancient era, so scantily developed in New Zealand.