AUCKLAND’S ISTHMUS

Te Awamutu Courier, Volume 58, Issue 4191, 31 May 1939, Page 5

AUCKLAND’S ISTHMUS

REMARKABLE VOLCANIC AREA. LEGENDS AND FACTS. “The isthmus of Auckland is one of the most remarkable volcanic areas of the earth. . .” —so wrote the German geologist, Dr Von HochsSetter, , who visited the Dominion in 1859. The seismic features of this area are probably unique, in that the gathered forces did not burst forth from a single vent. Had the disturbances been concentrated at one point it is likely that Auckland would now be overshadowed by a huge volcanic mountain —a new Vesuvius of the south. Actually the upheaval was strangely widespread, resulting in the formation of a multiplicity of minature volcano cones, and numerous volcanic basin and lakes. Dr Von Hochstetler found no fewer than 63 different points of eruption within a radius of 'lO miles of Auckland. Many of the hills are perfectly preserved, and they provide an extremely interesting subject for study. Owing to their circular shape the hills are called tuff cones or tuff craters. and tile crater of Mt Eden (620 feel) is one of the most perfectly preserved volcanic craters in the world. Tile terraces which form the sides of Mt. Eden, and which slope inwards down the crater itself, are evidence that a series of eruptions must have occurred. The ejected material was deposited in several layers to form the well known steps which are a feature of so many of Auckland's hills. Plainly to be seen is the lip of Mt. Eden’s crater, over which the molten lava flower to form the extensive stone fields which lie at the foot of the hills. Perhaps the most interesting of the volcanic cones is Rangitoto, the prominent island mountain which commands tlie entrance to the Auckland harbour. This mountain is 920 feet in height and boasts some extraordinary peculiarities; it is so nearly round that it presents the same familiar three peaked silhouette to practically every point of tlie compass; it is a strange fact, too, that tlie botanical features of tlie island are entirely different from those of tlie mainland and other islands of tlie gulf. Tlie formation of Rangitoto was probably tlie result of a more recent disturbance of a supra-marine nature. The mountain consits of a tuff cone surmounted by a lava cone ejected from tlie same crater. Within this common crater is a cinder cone, which lias its own small crater. The name "Rangitoto” means “Blood red sky,” and possibly signifies that the eruption occurred recently enough for the Maori race to have been present in New Zealand at the time when the heavens were afire. It is more likely, however, that the name is derived from an association of ideas; a concession to tlie comparative height of the mountain, and reference to the red colour of the scoria rock which is its substance. Legend tells us that tlie mountain once stood upon the mainland, where Lake Pupuke now lies, but removed itself afar off into the sea. Strange as it may seem the water levels in Lake Pupuke and Rangitoto’s crater lake have been found to rise and fall in sympathy —an instance of the Maori’s uncanny power of leavening his religious legends with the hint of truth. Of course, the exact connection between Rangitoto and Pupuke must ever remain a mystery. There are, at several points on the isthmus, volcanic caves representing huge bubbles in the molten lava. Some of the caves are hundreds of yards in length, and are a source of delight to enterprising and adventurous children. Dr Von Hochstetter, who found so much to interest him in Auckland, felt disposed to ruminate on the past history and future destiny of this city He reconstructed for himself a picture of the multitude of burning hills; the flow of molten lava and scoria rock, the tongues of flame and columns of smoke vomited heavenwards; before him spread an infant city, with its scattered buildings, and its wealth of rich volcanic soil awaiting new gardens; and he looked ahead to the time when a flourishing city would stand amid the silent volcanoes, with the rush and bustle ot its commercial and business life. His speculations have materialised. A prosperous city of Auckland, now approaching its centenary, is spreading over an ever widening area, planting its gardens and building its houses on the slopes of the lullshills which once were more vicious than Dante’s inferno.