Saturday, 24 May 2014

John Hardcastle finds a Drumlin

It is generally believed that there are no drumlins in New Zealand; John Hardcastle claimed to have found one:

"It is familiar knowledge that the Mackenzie lakes have been occupied by great glaciers, whose huge terminal moraines form a series of irregular mounds, stretching for miles across the front of each lake, and serving as dams holding up these fine sheets of water. The Tasman glacier of today is about 18 miles in length; the glacier that filled the Tasman valley and Pukaki lake was about 50 miles long, and proportionately wide. And those of Tekapo, Ohau and Ahurri were proportionately large. Yet these glaciers were small, their moraines diminutive, compared to those of the Great Glacier Age. These do not appear to have left any 'terminal' moraines, such as we see in the lake dams, but some of their massive longitudinal moraines remain, eloquent witnesses to the vastness of the ice streams that piled them.
They are high and bulky ridges margining the valleys, and stretching down the middle of the original bottom of the plain. They have the form that English and American glacialists have agreed to call adfter a Scottish term, 'drumlins' - long, straight, elliptical ridges, with a steep side towards the valley in which flowed the glacier that built them up. A very clearly defined one lies along the foot of the range below Lake Tekapo, from where Edwards Creek comes out of the hills to a point overlooking the lake."   JH 1908.

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