The age of the Waiho Loop terminal moraine, Franz Josef Glacier, Westland

Abstract

The Waiho Loop terminal moraine lies c. 10 km in front of the 10 km long Franz Josef Glacier in Westland, New Zealand. In 1978 an age of 11450 ± 200 years B. P. (NZ4234A) was reported for in situ wood embedded in silt and overlain by glacial sediments 1.6 km behind the moraine. In late 1983 two more wood specimens were collected at the latter site and five radiocarbon ages were obtained. Four samples from the same log were dated, two at the New Zealand Institute of Nuclear Sciences, DSIR, at 11 500 ± 200 and 11 700 ± 200 years B. P. (NZ6573A and NZ6923A), and two at separate laboratories in the United States at 12 100 ± 275 (GX10053) and 12 510 ± 120 years B. P. (Beta 12 607). The second wood specimen was also dated in a U.S. laboratory at 12 120 ± 400 years B. P. (GX9981). The three New Zealand dates suggest an age of 11 550 years for the wood specimens while the three U. S. dates suggest an age of c. 12 420 years. Differences in sample pretreatment may account for the disparity between the New Zealand and U. S. age determinations. All these results indicate that the Waiho Loop was formed before the cold Younger Dryas Chron (11000–10 000 years B. P.) in Europe. Similarly situated moraines in Canterbury and southern Argentina are possible correlatives of the Waiho Loop. The Younger Dryas climatic oscillation cannot be shown to be represented by moraines in the middle latitudes of the Southern Hemisphere.

Keywords:

• glacial advances
• C-14
• sample preparation
• Waiho Loop
• Birch Hill
• Aranuian
• Younger Dryas
• Argentina

Additional information

Notes on contributors

J. H. Mercer

Deceased July 1987.