Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

LEAD ISOTOPIC COMPOSITIONS OF GALENAS FROM THE WITWATERSRAND AND ORANGE FREE STATE, AND THEIR RELATION TO THE WITWATERSRAND AND DOMINION REEF URANINITES

Journal Article · · Geochim. et Cosmochim. Acta.
; ;
New Pb isotopic analyses are presented for forty-one galenas from various mines in the Witwatersrand and the Orange Free State. Certain of the galenas have large proportions of radiogenic lead, and one sample from the St. Helena mine contains a spectacular variation in the proportions of the lead isotopes within a hand specimen. The addition of radiogenic lead to these galenas is probably complementary to the loss of radiogenic lead from hypothesis on the uraninite age measurements are pursued. The possible times of abstraction of radiogenic lead from the uraninites were obtained through graphical analysis of the galena data. The hypothesis implies the former existence of parent uraninite grains, which have undergone chemical alterations; in this view the present Witwatersrand uraninites have maintained textural identity with the parent uraninites, but have been rejuvenated chemically through suecessive alterations and losses of radiogenic lead. The most probable age of crystallization of the parent uraninites is ~ 3000 million years. This is in agreement with an independent investigation of uraninites from the Dominion Reef, which are probably representative of the parent uraninites. The effect of mineral separation procedures in concentrating the uraninites for age measurement is also discussed. (auth)
Research Organization:
National Physical Research Lab., C.S.I.R., Pretoria
NSA Number:
NSA-16-013378
OSTI ID:
4802924
Journal Information:
Geochim. et Cosmochim. Acta., Journal Name: Geochim. et Cosmochim. Acta. Vol. Vol: 26
Country of Publication:
Country unknown/Code not available
Language:
English

Similar Records

EVIDENCE FOR THE EXTREME AGE OF CERTAIN MINERALS FROM THE DOMINION REEF CONGLOMERATES AND THE UNDERLYING GRANITE IN THE WESTERN TRANSVAAL
Journal Article · Sun Dec 31 23:00:00 EST 1961 · Geochim. et Cosmochim. Acta · OSTI ID:4796633
THE INTERPRETATION OF AGE MEASUREMENTS ON THE WITWATERSRAND URANINITE
Technical Report · Fri Oct 30 23:00:00 EST 1959 · OSTI ID:4284735
Age and origin of uraninite in the Elliot Lake, Ontario uranium ores
Thesis/Dissertation · Fri Dec 31 23:00:00 EST 1982 · OSTI ID:6937946

Related Subjects

AGE ESTIMATION
CHEMICAL REACTIONS
CRYSTALLIZATION
DECAY
DECOMPOSITION
DISTRIBUTION
ENRICHMENT
GALENA
GEOCHEMISTRY
GEOLOGY, MINERALOGY, AND METEOROLOGY
LATTICES
LEAD
LEAD ISOTOPES
LEAD SULFIDES
MINERALS
QUANTITY RATIO
SEPARATION PROCESSES
SOUTH AFRICA
URANINITES
VARIATIONS