Lead isochron dating of the Seton Formation, East Arm of Great Slave Lake, Northwest Territories

Dating of "spilitic" basalts from the Proterozoic Seton Formation by the Pb/Pb method yields an age of 1804 ± 23 Ma (2σ), in excellent agreement with Rb–Sr data on the same rocks, when the latter ages are calculated with currently accepted decay constants. It seems unlikely that spilitizat...

Full description

Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Author: Cumming, G. L.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1980
Subjects:
Online Access:http://dx.doi.org/10.1139/e80-167
http://www.nrcresearchpress.com/doi/pdf/10.1139/e80-167
Description
Summary:Dating of "spilitic" basalts from the Proterozoic Seton Formation by the Pb/Pb method yields an age of 1804 ± 23 Ma (2σ), in excellent agreement with Rb–Sr data on the same rocks, when the latter ages are calculated with currently accepted decay constants. It seems unlikely that spilitization could have reset both the Rb–Sr and Pb/Pb systems to yield exactly the same ages with no geologic scatter about the isochrons in either case, and, therefore, it may be that the isochrons represent the true age of deposition of the lavas.