| 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. |
| Genre: | Article |
| ProdID: | 70012184 |
| Citation Author: | Zielinski, R. A.; Lindsey, D. A.; Rosholt, J. N. |
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| Citation End Page: | 162 |
| Citation Issue: | 1-4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Chemical Geology |
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| Citation Number Of Pages: | 24 |
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| Citation Publisher: | Elsevier |
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| Citation Search Results Text: | The distribution and mobility of uranium in glassy and zeolitized tuff, Keg Mountain area, Utah, U.S.A.; 1980; Article; Journal; Chemical Geology; Zielinski, R. A.; Lindsey, D. A.; Rosholt, J. N. |
| Citation Start Page: | 139 |
| Citation Volume: | 29 |
| Citation Year: | 1980 |
| Type: | citation/reference |
| Text: | The distribution and mobility of uranium in glassy and zeolitized tuff, Keg Mountain area, Utah, U.S.A.; 1980; Article; Journal; Chemical Geology; Zielinski, R. A.; Lindsey, D. A.; Rosholt, J. N. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/0009-2541(80)90010-8 |
| Date Other: | Tue, 1 Jan 1980 00:00 -0600 |
| Publisher: | Elsevier |
