Open AccessUranium/thorium dating of Quaternary carbonates
Author(s) -
GUSTAVSSON JOHN E.,
HÖGBERG S. A. CHRISTER
Publication year - 1972
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.1972.tb00004.x
Subject(s) - thorium , uranium , geology , quaternary , isotope , radiochemistry , mineralogy , isotopes of uranium , archaeology , geochemistry , chemistry , paleontology , metallurgy , history , materials science , nuclear physics , physics
Gustavsson, J. E. & Högberg, S. A. C.: Uranium/thorium dating of Quaternary carbonates. Boreas, Vol. 1, pp. 247–274. Oslo, 1st December, 1972. The U/Th methods and particularly the theory of the 230 Th‐deficiency method are reviewed. The closed system question is discussed against the background of the growth and structure of the molluscan shells measured. The choice of the half‐life value for 230 Th, 75,200 years, is accounted for in a review of the five half‐life determinations known to the authors. The measurement procedure starts with the mechanical and ultrasonic cleaning of the sample. Small portions are taken for X‐ray analysis. The sample is then divided into two parts. One is treated chemically to separate the uraninium and the thorium, in order to determine the ratio between the activities of the uranium isotopes and to determine the content of 226 Ra. The other part of the sample is used to make the total measurement on the uranium and thorium isotopes simultaneously from the same part of the sample without any chemical pretreatment.