抄録
Magnetic measurements have been performed on a lacustrine sediment core from Harding Lake, Interior Alaska, referring to lithofacies, granulometric features, pollen zones. The sediment core spans the approximate period 30, 000 to 2, 500 years B. P., on the basis of 14C dating. Sudden changes in the NRM intensity correspond to catastrophic timings of the past climate in Interior Alaska, which have inferred from pollen zones. Three anomalous directions exist in the sediment core. Two of them can be regarded as correspondents to the proposed geomagnetic excursions, “Starno” and “Gothenburg”, and the other is thought possibly to be a new excursion. The evidence suggesting the existence of any excursions between 26, 500 and 14, 000 years B. P. is not found in the present magnetic results, because of poor time coverage of each specimen in the identical period, 250 years.
