Radium Isotope in Na-Cl Type Saline Waters from Deep Wells around Coastal Area in Ishikawa Prefecture, Japan

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1 J Hot Spring Sci /2,+,//,**3 Na-Cl Ra +, ,* +,,,,+, +3 Radium Isotope in Na-Cl Type Saline Waters from Deep Wells around Coastal Area in Ishikawa Prefecture, Japan +, - Junpei T OMITA, Hiroshi S ATAKE, Keiichi S ASAKI, Aya S AKAGUCHI, Mutsuo I NOUE, Yasunori HAMAJIMA and Masayoshi YAMAMOTO Abstract,,2 Radium isotope ( Ra and Ra) in twenty three Na-Cl type saline waters obtained from deep wells around the coastal area of Ishikawa Prefecture, Japan, were measured,-2,- along with U isotope ( U and U), major chemical components and hydrogen and oxygen isotope ratios The waters sampled were the mixture of local meteoric water and seawater, including fossil seawater in origin from the relationship among dd, d O and Cl and chemical composition The Ra concentrations in water samples varied in the wide range from + 12,+-mBq/kg, and occurrence of saline waters having high concentrations over -1* mbq/kg was confirmed in some of them The Ra concentrations showed,,2 a trend increasing with the increase of TDS in the water samples The Ra/ Ra activity ratios (*2-3 ) of water samples were comparable to or slightly higher compared with,-,,-2,-2 Th/ U activity ratios of common rocks in Japan The U concentrations of water + 3,- +,, +, Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Wake, Nomi, Ishikawa 3,- +,,, Japan 3-* 2/// -+3* Faculty of Science, Toyama University, Gofuku, Toyama 3-* 2///, Japan 3,* +-3, +* Faculty of Fine Arts and Informatics, Kanazawa Gakuin University, Sue, Kanazawa, Ishikawa 3,* +-3,, Japan 1-2//- +, - Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi, Minami-ku, Hiroshima 1-2//-, Japan,,

2 samples were extremely low ranging from less than detectable to,* mbq/kg These findings suggest that the main processes for supplying Ra isotope to water were probably not by rock dissolution but by both a-recoil from Th isotopes and desorption reaction of Ra isotopes from water-rock interface Key words : Radium isotope, Na-Cl type saline spring water, Deep well, Coastal area, Ishikawa Prefecture,- Na-Cl,,2,-2,- Ra Ra, Ra U U, U dd d O dd-d O-Cl Na-Cl Ra + 12,+- mbqkg Ra,,2 Ra Ra *2-3*,-,,-2 Th U,-2 U,* mbqkg Ra Th a a Th Ra : Na-Cl +,-2,-,,,2 U Ra : +0** y Th Ra / 1/ y,,,-/,,- Ra -00 d U Ra ++- d Ra Ra Clark and Turekian, +33*,,, Ra Rn Nakai, +3* ; +313 Ra +3// ; Kanai, +322 Ra : 0, Bqkg ; +3// Ra : + BqL ; Kanai, +322 Ra : * // BqL ; +3// Ra :,1 BqL ; Behounek et al, +3-/ Ra : +,2 Bqkg ; Sturchio et al,,**+ Ra : /2 BqL ; Kraemer and Reid, +32 Ra : +, BqL ; Moise et al,,*** Ra Ra Kraemer and Reid, +32 ; Sturchio et al,,**+ Na-Cl,**1 Ra 242

3 /2,**3 Na-Cl Ra Ra Na-Cl Ra Na-Cl Ra 2 Ra + +* mg kg Ra -1* mbqkg,**/ Na-Cl Ra Ra,,2 Ra Ra Ra,,+ 0 Fig + a Fig + b Fig + a Fig + b,**/ 1,**2 +,- Fig + (a) Geological map of Ishikawa Prefecture, Japan, with sampling sites of Na-Cl type saline waters and river waters, and (b) geological cross-section at six lines (A-F) These maps were compiled based on Kaseno ( +33- ) and Ohwada et al (,**1) 243

4 Fig + a +,*** m Table + /,* -* L ph,,,* L RaU ph + U Fe,,-, -,,, 3, mg NH SO,, Ra U BaSO Fe OH BaSO Fe OH Fe OH BaSO U BaSO 0** Ge,,2 g Ra Ra Ra Ge Hamajima and Komura,,** NBL No, + * -U No 13 + *+ -,,2,+ Th KCl Ra Ra,3/ kev Pb,+,+,,2,,2 -/, kev Pb 0*3 kev Bi --2 kev Ac 3++ kev Ac,+,+ Ra Pb Bi Rn Ra Saito et al,,**, 0 kev Ra Rn Ra BaSO Ba Ra Yamamoto et al, +323 ; Inoue and Komura,,**1,,2 Ra Ba NO Ra : 10,* mbqg-ba, Ra :,,2 Barite, Ra : *1 *+ mbq/g-ba, Ra : *, *+ mbq/g-ba, Inoue and,, - Komura,,**1 Na CO Ba U HF, HNO HClO +* N HCl - Fe U U Si a,-2,- U U,-2,- * +- * *2 * +02 * */+ mbq U U - dd d O Micro Mass Prism model Ohsumi and Fujino, +320 ; Epstein and Mayeda, +3/- V-SMOW d dd d O, *+ Li, Na, K, Mg, Ca, Cl, Br, SO ph Ba Ba : ,,,, Ra 244

5 /2,**3 Na-Cl Ra Dionex ICS- +*** * + M HCl - -+ Na-Cl Na-Cl ph, dd d O Table + ph cationanion cationanion in meq L +* Table + Chemical and isotopic compositions of Na-Cl type saline waters and river waters Well Li Na K Mg Ca Cl Br SO Sampling Alkalinity dd d O Balance* No date depth ph (m) (mg/kg) (meq/l) ( ) ( ) Na-Cl type saline water + a,1 1,**/ +,** 14* *4/- /,2 1,4*, /-2,14, 3-1 * /40 *4+ + b +1,**0 043 *4// /01 1, * 2-,,14 3/* *403-4* 04* +4,, a,1 1,**/ +,** 14+ *4,* -31,34-,+4/ 12 /1-+ 4/ +,0 * / +4-, b +1,**0 14- *4-2+,34* / ,1 *401 *4-040 *43 -,**/ 2** 140 *4,2,,33 3/ ,-, --1, *3 *432 /+4 14/,40,**/ +,* * 4,,,+++ 2/0,24+,/2 * / +4* /,3 1,**/ +*** 14* *4,+,-1 +*,*4,,+/ *,4- / ,3 1,**/ +-** 14/ *4+-, / /, +/4/, / * ,**1 ++0* 14- *4/* -311,* ,2 0*1+,,42 nd* * +4/ 2 +0,**1 +/** ,-22 * +4 14/ --/0 +4/ nd +04, / ,**1 3** 14, *4*1 +,02 34/ 1243,-+,-2+ 04/0,0,4** 24* 24- *4, +* +0,**1 +*** 14+,4** / /2*1,14,, * *4* ++ 20,**1 +,** 143 *4*/,-*0 1-4/ 3/4* / ,4, , 20,**1 +-** 141 *412,+1 114/ --4, +* --2, +-4-,, /,4* +- 00,**1 +*** 14,,4+0 +3** +/ +-41 /4/,+/ +-4 nd -*4 /,42 24 * ,**1 +/** , * +,* /2,4, // / +4+ +/ 00,**1 +**+ 14+ *4*, +2-04, +* ++3,,-2 14/,,0* *43/ * ,**1 +,/ 24+ *4+ -1, +4 * /0,14-0,3 * / ,** / *4+, -03* +*/,31 1/ 03-,,4* , -14* 04-,40 00,**1 /** 140 *4*,,3+ 43,-4, +/4/ *4* -423 /-43 34* -4/ +3 10,**1 +*** * *40 0*4, +,++ +-+/+ +4/ +++1 *42* *4,* 10,**1 +/** 040 *40 2,33,3/ -2 /0 +*12-4/ /,40 +4+,+ 10,**1 +,** 14* *4+0 2*03,,2 3*3 +** +/,3 /* *- ++4,,40 +4,,, 10,**1,** *** +-, +,40,1*- +*231 -/4, +/ *4-*,+40 /4* *4/,- a 10,**1 +/** *3 +,2 -*4* / /41 +4, *4, *4,- b -* +,**2 14* ++4/ 131 +,3 -*4 --,, ,4, *4* / na* na *4+ River water R+ 10,**1 na nd ,1, , nd -401 *4/ /4* R, 20,**1 14- nd *,4, nd 4*/ *4/, / R- 00,**1 na *4* /- -4// *4+0,*4 +4,/ * *4+ R 00,**1 na nd +-4,,4,*,4+/ -42* +-4* nd /42/ * ,4 R/ +*,**/ 14* nd 04-3 *423, /4+ nd +,4, * , + ++,**/ 143 nd 0433 *43-,42/ */ nd +/4/ *413 0,42 +*4+ -4,, Sea water* *4 ++*-/ / 0241,120 -,,4 * equal to unity in this calculation, * : The data set was referred from Isshiki (,**/) + + * : Cation/anion balance ( cation anion)/( cation anion) in meq L Density of water was assumed to be -, * : The concentrations of carbon species (HCO-, CO -, CO,) were expressed in mm * : nd denotes not detected / * : na denotes not analyzed + 245

6 Total Dissolved Solid, TDS ; +,1gkg Na-Cl dd d O / +* 3 *, 0 dd d O 0- +* + 2 * Fig, a dd-d O dd2 d O+* GMWL Craig, +30+ GMWL +32- ; Mizota and Kusakabe, +33 LMWL : dd2 d O,* Mizota and Kusakabe, +33 ; +331 dd d O dd-cl Fig, b d O-Cl Fig, c No +0 +3,,,- Cl Fig, a +320 ;,*** Brumsack et al, +33, Fig - a Fig - b Br-Cl SO -Cl Fig, The plots of (a) dd-d O, (b) dd-cl and (c) d O-Cl for Na-Cl type saline waters obtained from coastal area in Ishikawa Prefecture, Japan Gray solid circle ( ) shows SMOW (Standard Mean Ocean Water) The solid and dashed lines in Fig, (a) show LMWL (Local Meteoric Water Line, dd2 d O,* ) and GMWL (Global Meteoric Water Line, dd2 d O +* ), respectively Dashed lines in Fig, (b) show mixing lines of seawater and local meteoric waters 246

7 /2,**3 Na-Cl Ra Fig - The plots of the relation of (a) Br-Cl and (b) SO -Cl Cl Br Cl Br +322 Fig - a BrCl * **-/ Cl Br SO Cl *+ Fig - b Yamanaka and Kumagai,,**0,,2,-2,- -, Ra Ra, Ra U U, U,,2,-2,- Ra Ra, Ra U U, U Table,,,2 Table, Ra Ra + 12,+- mbqkg,**,3, mbqkg Ra -1* mbqkg Fig a Ra : * mbql ; Kanai, +322 Ra : //* mbql ; +3// Ra : 2 mbql ; Nakano-Ohta and Sato,,**0 Ra :,2, mbql ; +313 Fig a Ra +,,,2 Ra Ra *2-3*,,2 Ra Ra * 1, / ; Nakano-Ohta and Sato,,**0 Fig b Ra,-,,-2,,2 Th U Ra Ra *, 3 * 2,, Miyake et al, +31/ Fig b No,, +/ +** m / m UTh,-,,-2 Th U *+3 *-- *+, +* No,,2,-,,-2,, Ra Ra, +1 Th U 247

8 Table, Concentrations of Ra and U isotopes in Na-Cl type saline waters,,2,,2,-2,-,-,-2 Ra Ra Ra/ Ra U U U/ U No activity ratio activity ratio Geology * (mbq/kg) (mbq/kg) (mbq/kg) (mbq/kg) Na-Cl type saline water + a + -/, +, * +, *4+, nd * *4*1 *4**1 + b -03 +* +, /, *4-3 nd *4*+/ *4**, a,+00 0/ 1* -4*, *4- nd *4*+ *4**0, b,* 1 0*100,432 *4- *4*+0 *4** *4** *4**0,4/+ * *4,*,4** * *4-* *4*+ *4**- *4*, *4** +403 *4/* /,4/ +42 /4* 42 *420 *4+* nd nd nd / /40, *42*,-4/,43 4 *413 *4*+/ *4**- *4*-, *4**,4+1 *4/ * , +4,2 *4,2 nd *4*,- *4**/ 1 * ,43 +4,, *4*2 nd *4*+1 *4** *+ 0 +4/ *4*3 *4*,, *4**- *4*/* *4**,4,2 *4+ 3 +*4* +4 +/4+,4 +4/, *4-, *4+/0 *4*+, *4,2 *4*+0 +4/3 *4+0 +* 0,41,4/ *4*3 *4*+3 *4**- *4*,/ *4** +4-, *4,3 ++ +*43 +4* +340,4, +42* *4,0 *4*,1 *4** *4*/- *4**/ +430 *4-+ +, +30 / 30+ /+ 43* *4,3 *4*/1 *4**/ *4*3+ *4**1 +4/3 *4+3 Granite , *43+ *4*3 *4*-, *4** *4*00 *4**/,4* *4-+ +,*2, * +0,+0,4** *4++ *4*3- *4*+* *4,,* *4*+1,4-2 *4-, +/,,4+ +4/ ,4++ *4,, *4*0- *4**0 *4,*- *4*++ -4,* * ,1 *431,241,41-4*3 *4- nd nd nd +1, , +4,3 *4+0 +4/+ *4*0 4,3 *4+1,42 *4+1 4,, *4/, -4/* *42 *42- *4,,,4* *4+*,4, * *4* ,4*1 *4+0 *4+0+ *4*+, +4*1 *4*/ 0400 *4/3,* ,,,4-+ *4+0 *4*-- *4** *4*/0 *4**/ +402 *4,0,+ +14, +4, ,403 *4,2 *4+ *4*+* *40 *4*, -43- *4-3,, +311,1,0,4+1 *4+/ *4*,1 *4** *4*- *4** +4,2 *4,-,- a,+- *,3, +1,4** *4*3 *4*+1 *4**- *4*,/ *4**- +4/, *4-/ Granite,- b +3+0,+ -32/ +00,4*2 *4*3 *4*3 *4*+0 *4*00 *4** *41 Sea water* - +4*/,4/- * *4,+,432 *41,4/ +4+ *4*- + * : Error shows + s standard deviation from counting statistics, * : nd denotes not detected Detection limit is three times of blank level (see text) - * : The data sets of Ra and U isotopes in sea water were referred from Inoue et al (,**1) and Ku et al ( +311), respectively * : The geology was referred from stratigraphic column of each spring Ra,,2 Ra,-2,-2 U,* mbqkg Fig / U,-2 Cl U No Fig / U U, UO, UO, U UO, 248

9 /2,**3 Na-Cl Ra,,2 Fig Distributions of (a) Ra contents and (b) Ra/ Ra activity ratios for Na-Cl type saline waters obtained from coastal area in Ishikawa Prefecture, Japan Gray shaded area ( ) in Fig (a) shows the concentration higher than -1* mbq/kg in Ra Gray solid area ( ) in Fig (b) represents the range,-,,-2 of Th/ U activity ratio of common rock (granite, basalt) in Japan reported by Miyake et al ( +31/ ),-2 Fig / The relationship between U concentration and Cl,-,-2 U U ,- + a U Kigoshi, +31+ ; Yamamoto et al,,**- 249

10 -- Ra Na-Cl Ra dd-d O-Cl Ra + - mbqkg Table,, Inoue et al,,**1 Ra Ra Ra +0** y Ra Ra,-2 3,- /,-* Ra U 1 +* y U, / +* y Th,,2,-, +* 1/ +* y Ra Th ++ +* y Ra Ra Th Th Ra a a Ra Sturchio et al,,**+ --+ Th,,2,-*,-, Ra Ra Th Th Ra Th +33+ Th Ra --, Ra Ra Ra Tricca et al,,**+ Ra Ra lrat - w r Ra r w Ra Ra Ra A r n w A l Ra mbqkg gcm Ra s Ra mbqg - + Ra s w r w A r + n w A + e r nl +* w Ra r Ra +,,2,,2 Ra Ra w Ra Ra A A Ra,,2Ra w w A A l l A A,,2 Ra Ra,,2 Ra Ra w w Ra,,2Ra r r,,2 Ra Ra,-, Th,-2U * **-0 A A * **-0 A A r r r r,-2 Ra U Ra Ra Ra Ra,,2 Ra Ra,-,,-2 Th U *,3 *2,, Miyake et al,,-,,-2 +31/ Th Th U 2 Nagai et al,,,2,**0 Ra Ra **- 250

11 /2,**3 Na-Cl Ra,,2 Ra Ra,,2,-,,-2 Ra Ra Th U Kraemer and Reid, +32 Ra --- a Ra Th a a Ra a Kigoshi, +31+ ; Yamamoto et al,,**- Th a Ra a Ra Kraemer, +32+ Ra A - r + n L A + e r nr +* Th lrat - w r r w Th L, A, r Ra Th Ra r,-* mbqg cm Th - Ra r,0 gcm r +* gcm n *+ L, +* cm A -* mbqg r **+ cm - 0,-* Th r Ra +*/ mbqkg r * ***,,-* Th cm A -** mbqg Ra /,0/ mbqkg, +*/- mbqkg a Ra a Ra,-* Th,,2 Ra Ra A A A A,,2 Ra Ra,-, Th,-* Th w w r r r a Ra,-,,-* Th Th,,2 *,3 *2,, Ra Ra *2-3* -- Ra Ra Moore, +330 Ra surface reactive element Tricca et al,,**+ Ra TDS Fig 0 Fig 0 Ra TDS Ra No +,,,-, Table, Ra TDS Fig 0, Ra Ra Sturchio et al,,**+, Ra Kraemer and Reid, +32 UTh r U,-,-2 U w 251

12 Fig 0 The relationship between Ra concentration and TDS ph Herczeg et al, +322 Ra TDS Ra Ra,,2 Ra Ra --/ Ra,,2 Ra Ra Na-Cl Ra Th a a Ra-TDS Ra Th a Ra Ra a Ra Th Th Tricca et al,**+ Ra Rn Th Sturchio et al,**+ Ra Th Th isotopeenriched surface layer Th Th Ra Na-Cl Ra,- Na-Cl Ra dd-d O-Cl 252

13 /2,**3 Na-Cl Ra,,2 Ra Ra Ra + 12,+- mbqkg *2-3* Ra,,2,-,,-2 Ra Ra Th U,-2 U Ra TDS Ra,-,,-* Th Th a a Ra Ra Pu Ra No,* 0*1*, Behounek, F, Santholzer, V and Ulrich, F ( +3-/ ) : Radioactivity of Oil-Waters in Czechoslovakia, Nature, +-0, 3+* 3++ Brumsack, HJ, Zuleger, E, Gohn, E and Murray, RW ( +33, ) : Stable and Radiogenic Isotopes in Pore Waters from Leg +,1, Japan Sea, Proc ODP, Scientific Results, +,1 / +,2, Pt +, 0-/ 0/* Clark, JF and Turekian, KK ( +33* ) : Time Scale of Hydrothermal Water-rock Reactions in Yellowstone National Park Based on Radium Isotopes and Radon Jour Volc Geotherm Res, *, +03 * Craig, H ( +30+ ) : Isotopic Variations in Meteoric Waters, Science, +--, +1*, +1*- Epstein, S and Mayeda, TK ( +3/- ) : Variation of O- Content of Waters from Natural Sources Geochim Cosmochim Acta,,,+-,, Hamajima, Y and Komura, K (,**) : Background Components of Ge Detectors in Ogoya Underground Laboratory Appl Radiat Isotopes, 0+, Herczeg, AL, Simpson, H J, Anderson, RF, Trier, RM and Mathieu, GG ( +322) : Uranium and Radium Mobility in Ground Waters and Brines within the Delaware Basin, Southeastern New Mexico Chem Geol (Isotope Geoscience), 1,, : Ra, Rn,3 +1/, Inoue, M and Komura, K (,**1) : Determination of Radionuclides in Chemical Reagents by Low-background g-ray Spectrometry and Application of the Coprecipitation Method to Seawater Sample Radioisotopes, /0, 112, Inoue, M, Tanaka, K, Kofuji, H, Nakano, U and Komura, K (,**1) : Seasonal Variation in the Ra/,,2 Ra Ratio of Coastal Water Within the Sea of Japan : Implications for the Origin and Circulation Patterns of the Tsushima Coastal Branch Current Mar Chem, +*1, //3 253

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