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Iodine and uranium in sedimentary rocks
Chemical (;eolo,ry Flsevier Publishing Company, Amsterdam - Printed in The Netherlands
IODINE AND URANIUM IN SEDIMENTARY ROCKS V.J. BECKER, J.It. BENNETT and O.K. MANUEL Department oy Chemistrr, Unit,ersi O, of Missouri, Rolla, Mo. (U.S.A.)
(Received October 11. 1971) ABSTRACT Becket, V.J., Bennett, J.H. and Manuel, O.K., 1972. Iodine and uranium in sedimentary rocks. Chem. (;eol.. 9: 133-136. The abundance of iodine and uranium in sedimentary rocks was determined by neutron activation analyses. The iodine content is higher in the sediments than in igneous rocks and the iodine concentrations follow tire sanre general pattern as chlorine and bromine in sedimentary rocks and deep-sea sediments. The uranium concentrations in these sediments are in good agreement with previous estimates. except for two uranium-rich sandstones. INTRODUCTION An earlier study in this laboratory by Bennett and Manuel (1968) on iodine and uranium in deep-sea sediments concluded that the iodine abundances were about three orders of magnitude greater than previously estimated, but that the uranium values were in general agreement with the results from earlier studies. Since this report was published, there have been two additional reports of extremely high iodine concentrations in other sedimentary rocks: Cosgrove (1970) reported iodine concentrations in Kimmeridge shale as high as 34 p.p.m., and Collins et al. ( 1971) found high concentrations of iodine in sedimentary rocks from the North Oklahoma Platform of the Anadarko Basin. Both reports note a correlation of iodine with organic material, and Collins et al. ( 1971 ) suggest that leaching of iodine from the sediments is responsible for the iodine-rich subsurface brines found in Kingfisher County, Oklahoma. Although there are considerable data on iodine and uranium in sedinrentary material, the results for deep-sea sediments and the reports of high iodine concentrations in a few other sedimentary rocks seemed to warrant a further investigation of the abundance of iodine in sedimentary rocks, Additional incentive for this study was provided by the inability to fit the available iodine data into the geochemical balance defined by 55 other elements (Horn and Adams, 1966). It should be noted that most of the published estimates on the terrestrial distribution of iodine are based on very early work by Von Fellenberg (1924, 1927), Von Fellenberg and Lunde (1927) and on the report by the Chilean lodine Education Bureau (1956). Details of the experimental procedure used in this laboratory for the measurement of iodine and uranium by neutron activation have been published earlier by Bennett and Manuel (1968) and by Becket, Bennett and Manuel (1968)
134
V.J. BECKER, J.H. BENNETT AND O.K. MANUF, I
TABLE 1 A comparison of the iodine and the uranium content of sedimentary rocks with the previously estimated limits of ttorn and Adams (1966). Sample
Source
Sandstones Previously estimated limits White (Klondike, Mo.) Graywacke (Eifel Mountains, Germany) Red (Potsdam, N.Y.) Argillaceous (Portageville, N.Y.)
Wards* Wards Wards Wards
1.7 0.068 0.084 0.14 37.6
5.8 + 0.001 + 0.010 ± 0.02 -+ 0.5
(I.45 (I.94 5.9 1.2 3.2
1.2 ± 0.05 _~w0.2 ± 0.5 + 0.2
Limestones Previously estimated limits Gray (Buffalo, N.Y.) Dolomitic (Rochester, N.Y.) Chalk IDover, England) Argillaceous (Trenton Falls, N.Y.) Cherty (keRoy, N.Y.)
Wards Wards Wards Wards Wards
0.4 3.0 5.6 29 8 23
2.8 ± 0.6 ± 0.9 -+ 7 ± 2 ± 7
1.3 1.8 1.1 2.3 0.9 2.3
2.5 ± 0.5 _+ 0.1 ± 0.4 ± 0.2 ± 0.5
Wards Wards T.C. Hoering
2.2 13 38 7
6.6 ± 3 ± l0 -+ 4
/.5 5.5 4.0 _+ 1.7 5.7 ± 0.2 1.6 ± 0.2
E.D. E.D. E.D. E.D.
0.025 40 46 49 11
- 0.075 ± 3 ± 2 ± 10 _+ 2
0.10 0.16 0.06 0.25 1.5
Shales Previously estimated limits Argillaceous (Rochester, N.Y.) Calcareous (Lima, N.Y.) Pyritic Argilite from Fig Tree Shale Formation (Monrose Gold Mine, Barberton, Transvaal, South Africa) Deep-sea sediments Previously estimated limits LUS-183 (19°44'S. 12°55'W) LUS-212 (6°47'N, 19°18'W) LUS-217 (3°56'N, 34°04'W) ZEP-23 (26 ° 141N, 26°27'W)
Goldberg Goldberg Goldberg Goldberg
Iodine (p.p.m.)
Uranium (p.p.m.)
2.50 _+ 0.02 ± 0.02 ± 0.10 ± 0.4
* Wards Naiurai Science Establishment.' i n c ' Rochesterl N~Y., U.S.A. RESULTS AND DISCUSSION The results o b t a i n e d f r o m this s t u d y are s h o w n in T a b l e I. L i t e r a t u r e values s h o w i n g the m a x i m u m a n d m i n i m u m limits f r o m 4 4 sources as listed b y H o r n and A d a m s ( 1 9 6 6 ) are also s h o w n . E a c h value f r o m this s t u d y is the average o f at least t h r e e d e t e r m i n a t i o n s . The errors s h o w n in T a b l e I r e p r e s e n t o n e s t a n d a r d d e v i a t i o n (o) f r o m the m e a n value and include errors e s t i m a t e d f r o m v a r i a t i o n s in the m o n i t o r activity. T h e u r a n i u m c o n t e n t o f these s e d i m e n t s is generally w i t h i n the range o f earlier estimates. T h e o n l y n o t a b l e e x c e p t i o n is the u r a n i u m in s a n d s t o n e s w h e r e t w o o f t h e values are a p p r e c i a b l y h i g h e r t h a n p r e v i o u s e s t i m a t e s b y H o r n a n d A d a m s ( 1 9 6 6 ) a n d T u r e k i a n and W e d e p o h l (1961 ). A d e t a i l e d d e s c r i p t i o n o f t h e deep-sea s e d i m e n t s a n d t h e i r very high c o n c e n t r a t i o n s o f iodine has b e e n given earlier b y B e n n e t t a n d M a n u e l ( 1 9 6 8 ) . F r o m the analyses o f o t h e r
IODINE AND URANIUM IN SEDIMENTARY ROCKS
135
TAB1.E II Previous estimates of halides in sedimentary material Rock type
Chlorine (p.p.m.)
Bromine (p.p.m)
Iodine
ttorn and Adams (1966)
Turekian and Wedepohl {1961)
Horn and Adams {1966)
Turekian and Wedepohl {1961)
Horn and Adams {1966}
Turekian and Wedepohl (1961 }
20,000
21,000
331
70
0.05
0.05
Carbonates
305
150
6.60
6.2
1.59
1.2
Shales
170
180
4.30
4.0
4.40
2.2
15
10
1,00
1.0
3.75
1.7
Oceanic sediments
Sandstones
{p.p.m.)
sedimentary rocks shown in Table 1, it appears that the iodine concentrations in sandstone are generally lower than previously estimated, but the iodine content of shales and carbonares is generally higher than the values reported by Horn and Adams (1966), Von Fellenberg (1924, 1927), Von Fellenberg and Lunde (1927), the Chilean Iodine Education Bureau (1956) and Turekian and Wedepohl (1961 ). A more general study is needed in order firmly to establish the abundance pattern of iodine in sediments. However, except for the argillaceous sandstone, the data in Table l seem to fit the following arrangement of sediments according to decreasing iodine content: deep-sea sediments > carbonates and shales > sandstones. The anomalously high iodine content in argillaceous sandstone may be due to sorption of iodine on clays as has been suggested earlier by Vinogradov (1959). Previous compilations by Turekian and Wedepohl (1961) and by Horn and Adams (1966) on halides in sedimentary material are shown in Table 11. By comparing our iodine values from Table 1 with the halide estimates in Table 11, it can be seen that our results suggest that the iodine concentrations follow the same general distribution pattern in sediments as do chlorine and bromine. This pattern does not agree with the pattern shown in Table 11, where the iodine content is greatest in shales, next in sandstones, then carbonates and smallest in oceanic sediments. If the estimates of iodine in igneous rocks are correct, the high iodine content of oceanic sediments will tend to further increase the geochemical imbalance of iodine between that expected from weathering primary igneous rocks and that found in sediments by Horn and Adams (1966). This would agree with the suggestion that a significant part of the halides were derived from a volcanic source as postulated by Horn and Adams (1966). ACKNOWLEDGEMENTS We are grateful to Professors T.C. Hoering and E.D. Goldberg for supplying samples for this study, to Professors A.C. Spreng and S.K. Grant for assistance with mineral
136
V.J. BECKER, J.H. BENNETT AND O.K. MANUE[
i d e n t i f i c a t i o n , to Mr. A. Elliott and Mr. M. Little for assistance with the irradiations, and to the N a t i o n a l Science F o u n d a t i o n , N S F - G A - 1 2 0 9 9 , for financial suppor*. REFERENCES Becker, V., Bennett, J.H. and Manuel, O.K., 1968. Iodine and uranium in ultrabasic rocks and carbonatites, l:'arth l'lanet. Sci. Left.. 4: 357. Bennett, J.H. and Manuel, O.K., 1968. On iodine abundances in deep-sea sediments. J Geophys. Res.. 73: 2302. Chilean Iodine Education Bureau, 1956. Geochemistry o f Iodine. Chilean Iodine Education Bureau, Stone House. London, 150 pp. Collins, A.G., Bennett, J.H. and Manuel, O.K., 1971. Iodine and atgae in sedimentary rocks associated with iodine-rich brines. Bull. Geol. Sot'. Am.. 82: 2607. Cosgrove, M.E.. 1970. Iodine in bituminous Kimmeridge Shales of the Dorset Coast, England. (;cochim. Cosmochim. Acta, 34: 830. tlorn, M.K. and Adams, J.A.S., 1966. Computer-derived geochemical balances and element abundance: (;eochim. Cosmochim. Act& 30: 279. Furekian, K.K. and Wedepohl, K.tt., 1961. Distribution of the elements in some major units of lhe earth's crust. Geol. Soc. Am. Bull., 72: 175. Von t'ellenberg, T., 1924. Untersuchungen i~ber das Vorkommen yon Jod in der Natur, VII. i,)ber den Jodgehalt der Gesteine, der geologischen Formationen und der Mineralien und iiber die Beningungen der Jodanreicherung in Erde. Biochem. Z., 152: 153. Von Fellenberg, T., 1927. Untersuchungen ifber das Vorkommen yon ,lod in der Natur, II. Zur Geochemic des Jods, II. Biochem. Z., 187~,1. Von Fellenberg, T. and Lunde, G., 1927. Contribution h la gdochimie de l'iode. Norsk. Geol. TMskr., 9: 48. Vinogrddov, A.P., 1959. Geokhimiia redkikh i rasseiannykh khimicheskikh elementov v pochvakh (Geochemistry o f rare and dispersed chemical elements in soils'). Consultants Bureau, Inc., New York, N.Y., 209 pp. (translation from Russian).
IODINE AND URANIUM IN SEDIMENTARY ROCKS V.J. BECKER, J.It. BENNETT and O.K. MANUEL Department oy Chemistrr, Unit,ersi O, of Missouri, Rolla, Mo. (U.S.A.)
(Received October 11. 1971) ABSTRACT Becket, V.J., Bennett, J.H. and Manuel, O.K., 1972. Iodine and uranium in sedimentary rocks. Chem. (;eol.. 9: 133-136. The abundance of iodine and uranium in sedimentary rocks was determined by neutron activation analyses. The iodine content is higher in the sediments than in igneous rocks and the iodine concentrations follow tire sanre general pattern as chlorine and bromine in sedimentary rocks and deep-sea sediments. The uranium concentrations in these sediments are in good agreement with previous estimates. except for two uranium-rich sandstones. INTRODUCTION An earlier study in this laboratory by Bennett and Manuel (1968) on iodine and uranium in deep-sea sediments concluded that the iodine abundances were about three orders of magnitude greater than previously estimated, but that the uranium values were in general agreement with the results from earlier studies. Since this report was published, there have been two additional reports of extremely high iodine concentrations in other sedimentary rocks: Cosgrove (1970) reported iodine concentrations in Kimmeridge shale as high as 34 p.p.m., and Collins et al. ( 1971) found high concentrations of iodine in sedimentary rocks from the North Oklahoma Platform of the Anadarko Basin. Both reports note a correlation of iodine with organic material, and Collins et al. ( 1971 ) suggest that leaching of iodine from the sediments is responsible for the iodine-rich subsurface brines found in Kingfisher County, Oklahoma. Although there are considerable data on iodine and uranium in sedinrentary material, the results for deep-sea sediments and the reports of high iodine concentrations in a few other sedimentary rocks seemed to warrant a further investigation of the abundance of iodine in sedimentary rocks, Additional incentive for this study was provided by the inability to fit the available iodine data into the geochemical balance defined by 55 other elements (Horn and Adams, 1966). It should be noted that most of the published estimates on the terrestrial distribution of iodine are based on very early work by Von Fellenberg (1924, 1927), Von Fellenberg and Lunde (1927) and on the report by the Chilean lodine Education Bureau (1956). Details of the experimental procedure used in this laboratory for the measurement of iodine and uranium by neutron activation have been published earlier by Bennett and Manuel (1968) and by Becket, Bennett and Manuel (1968)
134
V.J. BECKER, J.H. BENNETT AND O.K. MANUF, I
TABLE 1 A comparison of the iodine and the uranium content of sedimentary rocks with the previously estimated limits of ttorn and Adams (1966). Sample
Source
Sandstones Previously estimated limits White (Klondike, Mo.) Graywacke (Eifel Mountains, Germany) Red (Potsdam, N.Y.) Argillaceous (Portageville, N.Y.)
Wards* Wards Wards Wards
1.7 0.068 0.084 0.14 37.6
5.8 + 0.001 + 0.010 ± 0.02 -+ 0.5
(I.45 (I.94 5.9 1.2 3.2
1.2 ± 0.05 _~w0.2 ± 0.5 + 0.2
Limestones Previously estimated limits Gray (Buffalo, N.Y.) Dolomitic (Rochester, N.Y.) Chalk IDover, England) Argillaceous (Trenton Falls, N.Y.) Cherty (keRoy, N.Y.)
Wards Wards Wards Wards Wards
0.4 3.0 5.6 29 8 23
2.8 ± 0.6 ± 0.9 -+ 7 ± 2 ± 7
1.3 1.8 1.1 2.3 0.9 2.3
2.5 ± 0.5 _+ 0.1 ± 0.4 ± 0.2 ± 0.5
Wards Wards T.C. Hoering
2.2 13 38 7
6.6 ± 3 ± l0 -+ 4
/.5 5.5 4.0 _+ 1.7 5.7 ± 0.2 1.6 ± 0.2
E.D. E.D. E.D. E.D.
0.025 40 46 49 11
- 0.075 ± 3 ± 2 ± 10 _+ 2
0.10 0.16 0.06 0.25 1.5
Shales Previously estimated limits Argillaceous (Rochester, N.Y.) Calcareous (Lima, N.Y.) Pyritic Argilite from Fig Tree Shale Formation (Monrose Gold Mine, Barberton, Transvaal, South Africa) Deep-sea sediments Previously estimated limits LUS-183 (19°44'S. 12°55'W) LUS-212 (6°47'N, 19°18'W) LUS-217 (3°56'N, 34°04'W) ZEP-23 (26 ° 141N, 26°27'W)
Goldberg Goldberg Goldberg Goldberg
Iodine (p.p.m.)
Uranium (p.p.m.)
2.50 _+ 0.02 ± 0.02 ± 0.10 ± 0.4
* Wards Naiurai Science Establishment.' i n c ' Rochesterl N~Y., U.S.A. RESULTS AND DISCUSSION The results o b t a i n e d f r o m this s t u d y are s h o w n in T a b l e I. L i t e r a t u r e values s h o w i n g the m a x i m u m a n d m i n i m u m limits f r o m 4 4 sources as listed b y H o r n and A d a m s ( 1 9 6 6 ) are also s h o w n . E a c h value f r o m this s t u d y is the average o f at least t h r e e d e t e r m i n a t i o n s . The errors s h o w n in T a b l e I r e p r e s e n t o n e s t a n d a r d d e v i a t i o n (o) f r o m the m e a n value and include errors e s t i m a t e d f r o m v a r i a t i o n s in the m o n i t o r activity. T h e u r a n i u m c o n t e n t o f these s e d i m e n t s is generally w i t h i n the range o f earlier estimates. T h e o n l y n o t a b l e e x c e p t i o n is the u r a n i u m in s a n d s t o n e s w h e r e t w o o f t h e values are a p p r e c i a b l y h i g h e r t h a n p r e v i o u s e s t i m a t e s b y H o r n a n d A d a m s ( 1 9 6 6 ) a n d T u r e k i a n and W e d e p o h l (1961 ). A d e t a i l e d d e s c r i p t i o n o f t h e deep-sea s e d i m e n t s a n d t h e i r very high c o n c e n t r a t i o n s o f iodine has b e e n given earlier b y B e n n e t t a n d M a n u e l ( 1 9 6 8 ) . F r o m the analyses o f o t h e r
IODINE AND URANIUM IN SEDIMENTARY ROCKS
135
TAB1.E II Previous estimates of halides in sedimentary material Rock type
Chlorine (p.p.m.)
Bromine (p.p.m)
Iodine
ttorn and Adams (1966)
Turekian and Wedepohl {1961)
Horn and Adams {1966)
Turekian and Wedepohl {1961)
Horn and Adams {1966}
Turekian and Wedepohl (1961 }
20,000
21,000
331
70
0.05
0.05
Carbonates
305
150
6.60
6.2
1.59
1.2
Shales
170
180
4.30
4.0
4.40
2.2
15
10
1,00
1.0
3.75
1.7
Oceanic sediments
Sandstones
{p.p.m.)
sedimentary rocks shown in Table 1, it appears that the iodine concentrations in sandstone are generally lower than previously estimated, but the iodine content of shales and carbonares is generally higher than the values reported by Horn and Adams (1966), Von Fellenberg (1924, 1927), Von Fellenberg and Lunde (1927), the Chilean Iodine Education Bureau (1956) and Turekian and Wedepohl (1961 ). A more general study is needed in order firmly to establish the abundance pattern of iodine in sediments. However, except for the argillaceous sandstone, the data in Table l seem to fit the following arrangement of sediments according to decreasing iodine content: deep-sea sediments > carbonates and shales > sandstones. The anomalously high iodine content in argillaceous sandstone may be due to sorption of iodine on clays as has been suggested earlier by Vinogradov (1959). Previous compilations by Turekian and Wedepohl (1961) and by Horn and Adams (1966) on halides in sedimentary material are shown in Table 11. By comparing our iodine values from Table 1 with the halide estimates in Table 11, it can be seen that our results suggest that the iodine concentrations follow the same general distribution pattern in sediments as do chlorine and bromine. This pattern does not agree with the pattern shown in Table 11, where the iodine content is greatest in shales, next in sandstones, then carbonates and smallest in oceanic sediments. If the estimates of iodine in igneous rocks are correct, the high iodine content of oceanic sediments will tend to further increase the geochemical imbalance of iodine between that expected from weathering primary igneous rocks and that found in sediments by Horn and Adams (1966). This would agree with the suggestion that a significant part of the halides were derived from a volcanic source as postulated by Horn and Adams (1966). ACKNOWLEDGEMENTS We are grateful to Professors T.C. Hoering and E.D. Goldberg for supplying samples for this study, to Professors A.C. Spreng and S.K. Grant for assistance with mineral
136
V.J. BECKER, J.H. BENNETT AND O.K. MANUE[
i d e n t i f i c a t i o n , to Mr. A. Elliott and Mr. M. Little for assistance with the irradiations, and to the N a t i o n a l Science F o u n d a t i o n , N S F - G A - 1 2 0 9 9 , for financial suppor*. REFERENCES Becker, V., Bennett, J.H. and Manuel, O.K., 1968. Iodine and uranium in ultrabasic rocks and carbonatites, l:'arth l'lanet. Sci. Left.. 4: 357. Bennett, J.H. and Manuel, O.K., 1968. On iodine abundances in deep-sea sediments. J Geophys. Res.. 73: 2302. Chilean Iodine Education Bureau, 1956. Geochemistry o f Iodine. Chilean Iodine Education Bureau, Stone House. London, 150 pp. Collins, A.G., Bennett, J.H. and Manuel, O.K., 1971. Iodine and atgae in sedimentary rocks associated with iodine-rich brines. Bull. Geol. Sot'. Am.. 82: 2607. Cosgrove, M.E.. 1970. Iodine in bituminous Kimmeridge Shales of the Dorset Coast, England. (;cochim. Cosmochim. Acta, 34: 830. tlorn, M.K. and Adams, J.A.S., 1966. Computer-derived geochemical balances and element abundance: (;eochim. Cosmochim. Act& 30: 279. Furekian, K.K. and Wedepohl, K.tt., 1961. Distribution of the elements in some major units of lhe earth's crust. Geol. Soc. Am. Bull., 72: 175. Von t'ellenberg, T., 1924. Untersuchungen i~ber das Vorkommen yon Jod in der Natur, VII. i,)ber den Jodgehalt der Gesteine, der geologischen Formationen und der Mineralien und iiber die Beningungen der Jodanreicherung in Erde. Biochem. Z., 152: 153. Von Fellenberg, T., 1927. Untersuchungen ifber das Vorkommen yon ,lod in der Natur, II. Zur Geochemic des Jods, II. Biochem. Z., 187~,1. Von Fellenberg, T. and Lunde, G., 1927. Contribution h la gdochimie de l'iode. Norsk. Geol. TMskr., 9: 48. Vinogrddov, A.P., 1959. Geokhimiia redkikh i rasseiannykh khimicheskikh elementov v pochvakh (Geochemistry o f rare and dispersed chemical elements in soils'). Consultants Bureau, Inc., New York, N.Y., 209 pp. (translation from Russian).