Fundamental sources of uranium and thorium
Global Distribution of Uranium and Thorium
The three quantitatively significant natural radioéléments are, in order of decreasing abundance, potassium, thorium, and uranium. All the isotopes of thorium and uranium are radioactive, but K40 (0.0118% of all K) is the only radioactive isotope of potassium. The true average and specific lithologie abundances of radioéléments throughout the earth may never be learned from direct measurement, but these elements have been measured extensively at the surface and interpreted for the interior from indirect evidence. The three sources of data are:
Chemical and radiometric analysis of meteorites interpreted to be representative of different earth layers;
Chemical and radiometric analysis of surficial rocks; and
Estimation of values for the earth’s interior from heat-flow and rock-conductivity data.
Figures & Tables
Migration of Uranium and Thorium-Exploration Significance
The uranium resource industry since the late 1960s has presented a paradox to those concerned with the growing energy shortage and the relative ability of uranium resources to respond to the need on a timely basis. This publication reviews the possible ways that uranium in the earth might be concentrated into economic deposits, and considers what industry should be able to expect from an exploration effort. Some of the chapters in this volume include: Fundamental sources of uranium and thorium; Mechanisms of uranium and thorium transfer to the crust; Shallow uranium mobilization processes; Geochemical distinction of uranium moneralization processes; and Oceanic migration history of uranium and thorium.