K-Ar age of the East Peripheral kimberlite at De Beers Mine, Kimberley, R.S.A.
- 1 September 1983
- journal article
- research article
- Published by Cambridge University Press (CUP) in Geological Magazine
- Vol. 120 (5) , 505-512
- https://doi.org/10.1017/s0016756800027497
Abstract
Summary. The kimberlite pipe at De Beers Mine, Kimberley is a complex, multiple structure. Three concordant argon-40/argon-39 age spectra have been obtained from samples from the 720 m level in the East Peripheral kimberlite. Each spectrum is dominated by a major plateau-feature between 84 and 89 Ma and none shows significant evidence of either excess argon or argon loss discrepancy. The available evidence suggests that the K-Ar age of normal magmatic emplacement-cooling of the East Peripheral kimberlite at De Beers Mine was close to 86 ± 2 Ma.Keywords
This publication has 14 references indexed in Scilit:
- Geochronology and thermal history of the Coast Plutonic Complex, near Prince Rupert, British ColumbiaCanadian Journal of Earth Sciences, 1979
- Introduction to GeochronologyPublished by Springer Nature ,1979
- Chemistry of micas from kimberlites and xenoliths—I. Micaceous kimberlitesGeochimica et Cosmochimica Acta, 1978
- 40Ar/39Ar analyses of phlogopite nodules and phlogopite-bearing peridotites in South African kimberlitesEarth and Planetary Science Letters, 1978
- Subcommission on geochronology: Convention on the use of decay constants in geo- and cosmochronologyEarth and Planetary Science Letters, 1977
- Identification of excess 40Ar by the 40Ar/39Ar age spectrum techniqueEarth and Planetary Science Letters, 1976
- Potassium-Argon Age and Paleomagnetism of Diabase Dikes in Liberia: Initiation of Central Atlantic RiftingGSA Bulletin, 1975
- Geological time scaleReports on Progress in Physics, 1974
- Atmospheric argon correction in the K-Ar dating of young volcanic rocksJournal of the Geological Society, 1971
- A minimum age for the premier kimberlite pipe yielded by biotite RbSr measurements, with related galena isotopic dataEarth and Planetary Science Letters, 1967