sup 40 Ar- sup 39 Ar dating of the manson impact structure: A cretaceous-tertiary boundary crater candidate

The mineralogy of shocked mineral and lithic grains in the Cretaceous-Tertiary (K-T) boundary claystone worldwide is most consistent with a bolide impact on a continent. Both the concentrations and sizes of these shocked grains are greatest in the western interior of North America. These data sugges...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 1989-06, Vol.244:4912
Main Authors: Kunk, M.J., Sutter, J.F., Izett, G.A., Haugerud, R.A.
Format: Article
Language:English
Subjects:
580000 - Geosciences
AGE ESTIMATION
ARGON 39
ARGON 40
ARGON ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CRETACEOUS PERIOD
DATA
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
GEOLOGIC AGES
GEOSCIENCES
INFORMATION
ISOTOPE DATING
ISOTOPES
LIGHT NUCLEI
MESOZOIC ERA
NUCLEI
NUMERICAL DATA
RADIOISOTOPES
ROCKS
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The mineralogy of shocked mineral and lithic grains in the Cretaceous-Tertiary (K-T) boundary claystone worldwide is most consistent with a bolide impact on a continent. Both the concentrations and sizes of these shocked grains are greatest in the western interior of North America. These data suggest that the Manson impact structure in north-central Iowa is a viable candidate for the K-T boundary impact event. Argon-40-argon-39 age spectrum dating of shocked microcline from the crystalline central uplift of the Manson impact structure indicates that there was severe argon-40 loss at 65.7 {plus minus} 1.0 million years ago, an age that is indistinguishable from that of the K-T boundary, within the limits of analytical precision. 36 refs., 2 figs., 1 tab.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.244.4912.1565