The distribution and mobility of uranium in glassy and zeolitized tuff, Keg Mountain area, Utah, U.S.A.

Chemical Geology
By: , and 

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Abstract

The distribution and mobility of uranium in a diagenetically altered, 8 Ma old tuff in the Keg Mountain area, Utah, are modelled in this study. The modelling represents an improvement over similar earlier studies in that it: (1) considers a large number of samples (76) collected with good geologic control and exhibiting a wide range of alteration; (2) includes radiometric data for Th, K and RaeU (radium equivalent uranium) as well as U; (3) considers mineralogic and trace-element data for the same samples; and (4) analyzes the mineral and chemical covariation by multivariate statistical methods. The variation of U in the tuff is controlled mainly by its primary abundance in glass and by the relative abundance of non-uraniferous detritus and uraniferous accessory minerals. Alteration of glass to zeolite, even though extensive, caused no large or systematic change in the bulk concentration of U in the tuff. Some redistribution of U during diagenesis is indicated by association of U with minor alteration products such as opal and hydrous Fe-Mn oxide minerals. Isotopic studies indicate that the zeolitized tuff has been open to migration of U decay products during the last 0.8 Ma. The tuff of Keg Mountain has not lost a statistically detectable fraction of its original U, even though it has a high (??? 9 ppm) trace U content and has been extensively altered to zeolite. Similar studies in a variety of geological environments are required in order to identify the particular combination of conditions most favorable for liberation and migration of U from tuffs. ?? 1980.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The distribution and mobility of uranium in glassy and zeolitized tuff, Keg Mountain area, Utah, U.S.A.
Series title Chemical Geology
DOI 10.1016/0009-2541(80)90010-8
Volume 29
Issue 1-4
Year Published 1980
Language English
Publisher Elsevier
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Chemical Geology
First page 139
Last page 162