(40)Ar/(39)Ar dating of the Brunhes-Matuyama geomagnetic field reversal
Baksi AK, Hsu V, Mcwilliams MO, Farrar E. 1992. (40)Ar/(39)Ar dating of the Brunhes-Matuyama geomagnetic field reversal. Science. 256(5055):356-357
Magnetostratigraphic studies are widely used in conjunction with the geomagnetic polarity time scale (GPTS) to date events in the range 0 to 5 million years ago. A critical tie point on the GPTS is the potassium-argon age of the most recent (Brunhes-Matuyama) geomagnetic field reversal. Astronomical values for the forcing frequencies observed in the oxygen isotope record in Ocean Drilling Project site 677 suggest that the age of this last reversal is 780 ka (thousand years ago), whereas the potassium-argon-based estimate is 730 ka. Results from 40Ar/39Ar incremental heating studies on a series of lavas from Maui that straddle the Brunhes-Matuyama reversal give an age of 783 ª11 ka, in agreement with the astronomically derived value. The astronomically based technique appears to be a viable tool for dating young sedimentary sequences.
- Type
- Journal Article
- Authors
- Baksi, A; Hsu, V; Mcwilliams, M; Farrar, E
- Units
- HALE , HAVO
- Keywords
- 40Ar/39Ar (Ar/Ar), Age Dating, Chemical Analysis, East Maui Volcano, Haleakala Volcano, Kula Volcanics, Paleomagnetism, Potassium-Argon dating (K-Ar), reversal