Isotopic ratios of potassium in magnetic spherules from deep-sea sediments
Abstract
Isotopic ratios of potassium in individual magnetic spherules were measured. The magnetic spherules were collected from deep-sea sediments dredged at the middle South Pacific Ocean (35°04'S, 138°39'W). The diameters of the spherules ranged from 170 to 520 μm and their weights from 17 to 350 μg. Each sample was dissolved in distilled hydrochloric acid and then mounted on a filament of a mass spectrometer without any chemical separation. Measurements were carried out with a highly sensitive mass spectrometer operating in a ion counting mode. Anomalous values of isotopic ratios of 40K/ 41K are observed in a few magnetic spherules. The values found in them are higher by about 40 ∼ 70% than in reagent potassium. These high values may be caused by cosmic ray irradiation in outer space. We conclude that these spherules are of extra-terrestrial origin or are ablation droplets scattered from the melted surface of a meteorite entering the earth's atmosphere.
- Publication:
-
Earth and Planetary Science Letters
- Pub Date:
- September 1977
- DOI:
- 10.1016/0012-821X(77)90215-1
- Bibcode:
- 1977E&PSL..36..317S
- Keywords:
-
- Cosmic Rays;
- Magnetic Materials;
- Potassium Isotopes;
- Sediments;
- Spherules;
- Ablative Materials;
- Irradiation;
- Mass Spectroscopy;
- Ocean Bottom;
- Pacific Ocean;
- Potassium 40