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Tuatara: Volume 16, Issue 1, April 1968

Tertiary Temperature Curves in New Zealand and Europe

page 38

Tertiary Temperature Curves in New Zealand and Europe

There is a Striking Difference between Tertiary temperature curves in Europe-North America on the one hand and New Zealand-Australia on the other. It is known that there has been a gradual decline in the temperature from the beginning of the Tertiary to the Pleistocene in Europe; more precisely from the Eocene to the Pleistocene, for we do not know too much about the Paleocene, or at least not enough to give a detailed climatic picture for this early part of the Tertiary.

The climatic curve is, of course, not a straight line; there are undulations, probably influenced more by changes in aridity than in temperature. However, the general declining trend seems to be very clear. The same can be said from North America where a curve by Durham (1950) is well known and reproduced in many papers.

The temperature curves for New Zealand and Australia differ from the above by a maximum in mid Tertiary time. Accepting that these curves are correct we have to explain the difference between the Northern Hemisphere and Australasia. Theoretically it can be seen in the summation of two curves. We take as proven: (1) A general trend of declining temperatures in the world (see “Tertiary Trend’ in Fig. 1), that is, we take the European-North American curves as representative ones applicable also for the Southern Hemisphere, and regard the New Zealand-Australian curves as exceptions; (2) We suppose that continental drift is another important factor for climatic changes because the latitude (broken lines in the figure) can change considerably. There are no known facts which allude to a conspicuous drift in Tertiary Europe or North America. The European-North American latitude curve is perhaps not exactly horizontal but at most only very slightly declining. The resultant curve is therefore more or less similar to the curve representing the Tertiary trend.

Regarding Australia, (New Zealand is not so clear because there are not so many fixed points for a long climatic curve), it seems that this continent wandered since the Paleozoic times from a position near the South Pole to the present latitude — a very long way. Drift was completed not too long ago and we have to suppose a considerable shifting in Tertiary times. Paleomagnetic observations support these deductions. Therefore the latitude curve has a different trend from the European one.

page 39
Fig 1: Temperature curves for the Northern Hemisphere and Australasia during the Tertiary period.

Fig 1: Temperature curves for the Northern Hemisphere and Australasia during the Tertiary period.

Summing up the two curves we get the resulting curve of the figure with a maximum in the mid-Tertiary.


Mr. I. DEVEREUX. Unpublished paleomagnetic results given at the symposium during the visit of Professor Carey, placed New Zealand at the South Pole in the Lower Cretaceous. Published results for page 40 Australia suggest that Australia was much further south than today, prior to the Tertiary.

Dr. C. A. Fleming. I believe that many people feel that drift had largely ceased by the beginning of the Tertiary.

Mr. I. Devereux. The story of drift expounded by Dietz suggested there is no reason to think that drift has ceased at all.

Dr. D. F. Squires. The Smithsonian Institute is at present setting up an experiment to measure any drift by astro-physical methods.


Durham, J. W., 1950. Cenozoic Marine Climates of the Pacific Coast. Bull. Am. Geol. Soc., 61: 1243-64.