NEW AGE DETERMINATIONS BY THE LEAD METHOD

Journal Article · Sun May 01 04:00:00 EDT 1955 · Proceedings of the Geological Association of Canada (Canada)

OSTI ID:4805270

Kulp, J L; Bate, G L; Giletti, B J

Ages of a number of radioactive minerals were determined from Pb/sup 207/ Pb/sup 206/ Pb/sup 206/U/sup 238/, Pb/sup 207/U/sup 235/, and Pb/sup 206/ Pb/ sup 210/ ratios. Values obtained for minerals from classic localities agree well with those reported by other investigators. Major attention was given to the anomalies of the ages of a given mineral computed from the various possible isotope ratios. The development of the Pb/sup 210/ method adds greatiy to the fund of data required to obtain accurate ages. The 206/210 age is essentially independent of uranium leaching or radon leakage. The latter is a significant factor in 206/238 and 207/206 ratios and must be measured experimentally to evaluate ages from these ratios. It appears that throughout most of the span of geologic time the 207/235 and 206/210 ages are the most reliable if lead loss has not occurred. The 206/238 supersedes the 207/235 age in accuracy for very young minerals. For young minerals the 207/206 age does not merit the reliability ascribed to it by earlier investigators. (auth)

• Research Organization: Columbia Univ., New York
• NSA Number: NSA-16-029205
• OSTI ID: 4805270
• Journal Information: Proceedings of the Geological Association of Canada (Canada), Journal Name: Proceedings of the Geological Association of Canada (Canada) Vol. Vol: 7; ISSN PGACA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AGE ESTIMATION
DISTRIBUTION
ERRORS
GEOLOGY, MINERALOGY, AND METEOROLOGY
LEACHING
LEAD 206
LEAD 207
LEAD 210
LEAD ISOTOPES
LOSSES
MINERALS
QUANTITY RATIO
RADON
URANIUM
URANIUM 235
URANIUM 238
URANIUM ISOTOPES
VARIATIONS