p // q ,**/

$ % r

p+s

 +1  0 ῑῒ

    +0  ++  3   +1  -  2 Non-volcanic Hot Springs from Deep Wells
in the Nobi Plains
Tetsuo MIYAZAKI
Emeritus Professor of Nagoya University

Abstract
There are about 0* non-volcanic hot springs from deep wells ranging from 2** to+,2** m deep in the Nobi Plains. The properties of the hot springs, such as depth of thewells, temperature, and concentration of ions, are summarized. The anions in the hotsprings consist mainly of three ions of HCO-, CO-,, and Cl ions in various ratios, whilethe valῌ of other anions are less than +.1ῌ of total anions. The distribution map of Cl
ions in hot springs deeper than 2** m under the Nobi Plains was made. The hot springs,
which contain Cl ions at high concentration, were found even in the region far from theseaside. The origin of Cl ions was discussed by a model of fossil sea water before ca. +0
million years and/or a model of concentration of Cl ions.
Key words : Nobi Plains, Deep well, Hot spring, Origin of Cl ions, Fossil sea water,
Concentration of Cl ions :   !"# $% Cl &'()* +,-. /0&'()1+ῌ ῏ ῍ ῐ ῎+30- 234567892: +,/** m ;<=>?@ABC$%DEF=> G>DH2IJK

 !$%)LMNOP?Q RS) !$%T UV)WXY$%)Z[2\]^ G>_D`
aObP?Z[2cdefgWXY$%7`h92ij=k H)$% 2lmOdefno7
1

»¼

2

 ῐ!"#$%

 2** m   & + '()*+, 0* -.

/ 01/23 !456 78

 2** m 

9:;<=>?+ῌ@ABCD EFG*HI
"#$%& + JK&)*+0῎LMN O PBQR> SBQTUVWXYZ[ ,**.\& + )*+$% ] . ^ῌ_] - ^ S*ῌ,. Ma\ B`abc/ S&

def\ ghijf ] - ^ῌ kl S,.ῌ,** Ma\ mB  SmKῌῌ%ῌnop+322\ $%mB qmcr  sqmtu  , +,0** vwx & + defy z{|A?}~IA 4 P /** vῌ+** vwx"#/@  @f cm !4mBc4 f
  SI\ `῏` / ` ῌP~~῍m῏m~4 K4  ¡p¢*£¤¥¦/ "#$%
§k4 B`¨&  & 0 ) , +. vwx A¨©I $%f 

Fig. + Hot springs from deep wells and geologic map in the Nobi Plains. The number corresponds to asite of hot spring shown in Table +. White area : Quaternary and Neogene (* ῌ,. Ma), Dotted area :Paleogene and Mesozoic (,.ῌ,** Ma). ῍, ῍ , andªrepresent the tops of Mt. Ibuki (+,-11 m inheight), Mt. Gozaisho (+,,+* m in height), and Mt. Sanage (0,3 m in height), respectively. R. in Fig. +represents a river. A small ﬁgure in the left-hand square shows a position of the Nobi Plains in theJapanese Island.
 + 
 '( « +  ¬.) deB­ : ] . ^ῌ_]- ^ S*ῌ,. Ma\ ijB­ : ] - ^ῌ tl S,.ῌ,** Ma\ ῍ ῍ ®*¯ª
P~~°±m
S²³ +,-11 m\ ´.m S²³ +,,+* m\ ®*¯cm S²³ 0,3 m\ mµ) &  R.
p) JK¶·|& 0῎L®¸"#$%¹º) // ¼ ,**/

JK/58n6ῌῌ
 

0,***3

        !"# $%&'()

   *#+,-.# /01234/ 563 #78/094/ :;<9=>?# /56 6@A BC334/ D ,**. D
! " EFῌ#G ,**. H$FIJK/563 #78# / %L564/ &M N'(O ?# )90?78/0 PQ*+56,RS/!9TU4/0VC/ WX78Y  *Z[\-?./"J #]^_` 0,1Z . 12_` ab3 #N'S/094/ 0ab3 #`cdefgh_2ijk
lefgY  0?m3no)S/ 045pqh6rst]D7#J 
5612rst@u 3\m3n4 8vw95 

,ῌ ῎

῍

: + x;4/56np78#4/ <6$y<zY.
#{ + |S 6}5 2**ῌ+,2** m, ~5
ῌ1.

*+

+*῍ +31/ῌ2.

+,-** m 94/ 6=>  +30/+*῍ +32/ῌ3.

.*῍ +33/ῌ,**.

.*῍ 94/6bo)Zn]9 \ 5 +** m 3 - =!"S/P?
# / 6Y/VC?/ 6a>ijk12D9?@?]94  DA::B#4/ *Cijkg*ijk?D
 +.*+/*.*0, 94  E)F +.* 8#; 9 ijk?@FGn^  : H%! *CijkI . J Na, Ca,, K, Mg, ]OK# / 0?
ijk*CijkgD8/% *.32.*.*., 
4/ ! *ijkI - J Cl , HCO- , CO

 32..῍ 0?ijk9

 ]:# / 0?ij,-k*ijkgD8/% *.32-*.*,/  32.-῍0?ijk94/ : +

6 pH ~F 1.3 94  *# 0.2ῌ3., >K# / 566ha>
L`6MN ZO94/ P f+ <z -. ; +32-

 +330 +33-

 RS6 <z -2 ; +301

 9 , 3 ?@?# /  - Q A6 : +330 TU <z .- ; +323

6~ .῍ Na ~2῍ Cl ~ -῍LV# / ::A u#4/

{ , *56W ijk HCO-CO-, gD_2ijk Cl gD
D¡|S ¢ 56F£X+ Y!.# / x;\Z
4/5Z 6 U6 ¤ ῌ6 ¥ ¦6 § F0YZ\¨?# / 0?6:;\Z©ª#J  ijkIW ijkh_2ijk«¬] F, SO., %\­7?# /894/ Ax; d ® W ijk
%8v%  Y!.# / 56%_2ijk
W ijkZ .# /
{ - JK/56I_2ijk>K|S ¯°jkI Cl ijk² +ῌ-ῌ,ῌ- [³ ¤ +ῌ- «gD ,ῌ- «! ±®  - \´>K# / Cl i

jkgD ,ῌ- «!^) ῌ]^ῌµ_ῌ¶` Aa"ῌv· 08  b%cS¸d" ¹e º¨ ºῌ»῍94/ *Z[\-?./"J

ῐΐῑῒ

4
Table +

Hot springs deeper than 2** m under the Nobi Plains +  2** m
Sitenumbera

Site
nameb

+
,
.
/
0
1
2
3
+*
++
+,
++.
+/
+0
+1
+2
+3
,*
,+
,,
,,.
,/
,0
,1
,2
,3
-*
-+
-,
--.
-/
-0
-1
-2
-3
.*
.+
.,
.-

KibosoGreen H.
Kataoka O.
Komono O.
Ageki O.
Yuyu.
Yoro O.
Ikeda O.
Nanno O.
Tado O.
Yo.
Namiki O.
Ta.
Shinsei O.
Anpachi O.
Kaizu-cho
Kaizu O.
Hashima O.
Asa.
Gifu O.
Sofue O.
Owa.
Eiwa O.
Nagas. +Nagas. ,Nagas. Nagas. .
Kiso.
Owari O.
Kanie-choTomi.
Yatomi O.
Ichi.
Daina.
Coro.
Toyo O.
Tobi. +
Tobi. ,
Reicho O.
Tokon.
Mihama O.
UotomoShirasu.

Na

+/**
+-**
+,**
+-**
+2**
+,**
+1**
+-**
+/**
+1-*
+-**
+,/*
33*
+,3*
+*0*
῎+***
+-1*
+,0*
+1**
+-**
+,**
+,**
῎+***
+-**
+.**
῎+***
+0**
+0/*
+,**
῎+***
+-/*
+.**
++**
++**
+***
++**
῎+***
+,0/
῎+***
῎+***
+/**
+-**
+-**

..042
+4/
+0-4+
*4/
+0.43
.43
++.4/
-42
-+42
143
+1*4/
.4*
+2/.
2*/
,2,43
+41
--2,
,,3.
+3043
.4+
0+
-4*
+10
.41
/0.41
,4,
,*+4/
+41
,3,4/143+21/104,,,13
20/43
3.04, ++1//,-34+
2,,40 +*.040
++/*
-0/
1341
-4/
--.
,14,1242
34.
+2*
/4,
,*+43
04*
+,,40
-40
034+04,+0042++4/+014140
-,0
-.42
++3
-4/
+-.*
+1+*
+1/
-*4.
/,4*
04+++
+342
,,-43
-4,
+31
-4/
,0**
,142
,*/3
03341
..3*
04/
,,-*
++,
21-*
.1*

.24*
-24/+42
,34,
-*4+
-/
.34.
/2
/,4-

/.41
0,42
/+42

/*4.
.,43
-,4*
.,4,
.*4.
-241

//
.04+

//4+
/*41
.-4.



Cations (mg/l)

Depth Temp.
(m)
(῏)
-,42
./40
..4+
.141
-140
.3
.,
-+40
-04+
-242
.*
/,4+
,/4.
-,42
,14+



ῌ

Ca

ῌ,

ῌ

K

Anions (mg/l)
Mg

ῌ,

04+
+40

*40
*4+

+4*43
,4+
.*
04/
+141
14*
-4.
,4+
+-4,
,4+
-4*
-.4.
-242
,+43
043
,-42
+-4*
,4+
/41
/4,
,4/
++43
+41
.+4/
0434,
/4/
,42
+04+
14/
.41
040
/40
.40
-340
+.43
,-42
+1
+,*

*4+
*41
*4+
,+*4/
*4,
,3,41
,41
*4.
*4+
+4*
+4+-4/
3*43+-.4,-34,
+42
+3*4/
1+42
+4,4,
+4-

*4,

+/4*41
+41
,4/
*41
,+/
-4.
+4,
,4+43
*42
+-4+
-.04.
,4,143+*.

῍Cl

MeasucHCO-῍ CO-῍, rement.342 3/.43 +24*++34, ,**4+ 04*+*242 ,+24.
-/,-/4/ 14,,43/4, 34*-/42 -2042 14,.-1/41 /014,+042 0/141 +242
330/+-*++40 /+-40 +,40
.4* +/14. +4/-042 .*-43 04*--4- +,3-40 0/4,-,42 -114, +240.-*4. ,224,.,+,,43 *4*,.
//23,*043 *4+.,.0+3240 *4+
1/*4, ,//41 -4*-0,04.
,+4/
,.+*
+-/
*4.14/ +.34/
-2+
-+3
+41
224, 0,/4. 342*41 --/40 +*4,
1*4/ ./*4/ .4.
,-4. ,1/4- 040.143 ,124- /4++,343 ,1-4- *42++04, ,2143 +40
..1
,0+
*4/
0142 ,.,+41//,*
1-41 *4+,20+*4/ *4,-,43 +,,4,+1*+,2,/+43 +2/4- *41
,++
+2/
*4.
,32*
,*0*
,4/
/-.,
1/
./-*
-3+*
+,41
-..*
/12
+4+./**
+03
*4-

c-+
c-+
c-+
c-+
c-,
c-+
c-c-c-,c-,c-+c-+
c-c-c-c-.
c-c-c-+
c-c-/
c-,
c-/
c-0
c-+
c-.
c-+
c-1
c-/
c-.
c-/
c-/
c-/
c-/
c-,
c-/
c-.
c-/
c-/
c-.
c-/
c-/
c-/

¯ // ° ,**/

Sitenumbera

Site
nameb

..
./
.0
.1
.2
.3
/*
/+
/,
//.
//
/0
/1
/2
/3
0*
0+
0,

San.
Ma.
Inuyama O.
Rakki O.
Crown H.
Shirato.
JA.
Gon.
Nagak.
Ware.
Sanage O.
Taka.
Oka.
Ena.
Inabu O.
Naka.
Hira.
Kuwana O.
Fujimi O.

|,s ªC«}¬­P®Cations (mg/l)

Depth Temp.
(m)
()

Na

+-**
+-,*
+/**
+***
+,**
+,**
+*0*
+/**
+2**
+-**
+,**
+.**
+,**
+***
+,**
++-*
2**
2**
2**

2-.*
32+
32/*
+*/*
+*,
.40
02,
133
/,40
+.41
,2+*
+2.
0,*/
--41
32.*
/14*
/+*
/24.
+.0*
+,.*
-/40
,41+342 .024/+*,4.
+0,34- -*,*4+21
+24+
2*2
-4.
,.142
,4*
-,240
/+4+04*/43-+4.04,
./
,2
,24,
.04+
..4*
/04.
--4,
,/4+
,,
-04,
,34,
//
-.4,
.,
-.4.
.241
-*4.

5



Ca

,



Anions (mg/l)
,



K

Mg

Cl

+./
2.4-42-4/+4/+41
+,241
1240
+4.4,
*4/42
-4+,4+40
/43
-40
+340
-4,

.3*
+0+**
+,/
+1+**
+4,
+4,
*4, ,.**+41
014+-*43 .2**,34, 1/+2,/4/ +-3***4,
231*4. .,1*04+.4/ +3,3+41/40.04* 1.1.43
/4*
+03
*4,
,2/4/
+4/
1*4+
,/4/
/134+
*42
34+


-

CO

+0+
134.
,/04/
+,42
3*4+
+03
.*,1
+3,*
340
--4/
-24+
*41
++2*
,-41
,0*
+.3+4.
.1*4.
+2343
/142

*4-

HCO

,
-

+-4/
+41

*4,

/4*
14+
*41
,14*
040-4*

,4*

-24.
-40

Measurementc
c-/
c-/
c-,
c-/
c-/
c-/
c-,
c-/
c-/
c-/
c-/
c-c-/
c-c-/
c-c-0
c-+
c-/

a.Sites of hot springs are shown in Fig. +. b.Abbreviations in this column are as follows. H. : hotel, O.
: onsen, Yuyu. : Yuyu kaikan, Yo. : Yokkaichi onsen, Ta. : Tanigumi onsen, Asa. : Asahi no yu, Owa.
: Owaritenou no yu, Nagas. +. : Nagashima onsen Nabana no sato, Nagas. , : Nagashima onsen
Kurhaus, Nagas. - : Nagashima-cho, Nagas. . : Nagashima onsen Yuami no shima, Kiso. : Kisosaki
onsen, Tomi. : Tomiyoshi onsen, Ichi. : Ichinomiya onsen, Daina. : Dainagoya onsen, Coro. : Corona noyu, Tobi. + : Tobishima-mura, Tobi. , : Tobishima onsen, Tokon. : Tokoname-shi, Shirasu. : Shirasunano yu, San. : Hotel Sanmikan, Ma. : Hotel de marronnier Utsumi, Shirato. : Shiratori no yu, JA. : JA
Aichi-chita, Gon. : Gongitsune no yu, Nagak. : Nagakute onsen, Ware. : Waremeike onsen, Taka. :Takasago onsen, Oka. : Okazaki Takechiyo onsen, Ena. : Enakyo yumoto onsen, Naka. : Nakatsugawa onsen, Hira. : Hirabari Tokai kenkosenta. c.Concentrations of ions and temperature were
measured by the following institutes. c-+ : Mie Prefectural Institute of Public Health, c-, : Nagano
Pharmaceutical Association, c-- : Gifu Prefectural Institute of Public Health, c-. : Architectural
Institute of Japan (Tokai), The Japanese Geotechnical Society (Tokai), and Nagoya Jiban Chosa
Kenkyukai(+303), c-/ : Aichi Prefectural Institute of Public Health, c-0 : Hot Spring Research Center,c-1 : Gifu Pharmaceutical University.
+  b   H :  O :  Yuyu. :a 
! !"# Yo. : $%& Ta. : '( Asa. : )*+ Owa. : ,-./+ Nagas. + : 0
12324 Nagas. , : 0156789 Nagas. - : 01: Nagas. . : 01+;1
Kiso. : <=> Tomi. : ?@ Ichi. : AB Daina. : CDEF Coro. : GHI+ Tobi.
+ : J1K Tobi. , : J1 Tokon. : LM& Shirasu. : NO+ San. : PQ# Ma. : RῌSῌTHUVWQ Shirato. : NX+ JA. : JA YZ[\ Gon. : ]^_`a+ Nagak. : 0bc Ware. : def Taka. : gO Oka. : hijkl Ena. : mῌn+o Naka. :pqr Hira. : stuQvwxyz! c {Ry|}} ~)  c-+ : xyz! c-, : 0" c-- : ~
~
v~  c-. : %"uQ ῌ¡¢£"p  ῌDEF¤¥¦§~" +303 c-/ : ¨[~  c-0 : p©~  c-1 : C

»¼

6

 Cl 

- -+  Cl-++ 

 Cl   !"#$%&' , ()*+,$%&' -.%/ 012ῌ3 +33+4 56

!789:*;<=> ? + *@>AB
! * !CD E $%FGHP*QRQ

!IJKLM+῎NOM

S-.%/C 0Tatsumi, +323 ; ῌ +33/4
TU Cl 

!7-.%/C V* Cl 

 0? -

XY4  Z[ . \ῌ][ - \ 0*῎,. Ma4 
W^*  _ /**`ab$%c5U'd#e#*LUfg A*hi$%jk lm'O-+, 

no+,89:p<=>'q* 56rs+,A/p t> s+,u O Nav, SO.,, Mgv,, Cav,,
Kv w Cl *x>y

s+,*;

p

Fig. , Relation of val ratio of (HCO-vCO-,)ions to val ratio of Cl ions in hot springs. | :hot springs from deep wells,  : hot springof Yunoyama onsen (shallow well),  : hotspring of Sakakibara onsen (shallow well), ±: hot spring of Kakino onsen (shallow well),: underground water around Nagoya (+1m deep, Sugisaki (+32/)).
HCO- CO- ,   , 
 Cl  !" | :   : 1! 0²³´4  : ῍
2 0²³´4 ± : µ 0²³
: "¶·¸B P, 0 +1- m,´4
¹º 0+32/44

z ? . *wy

0+** *@4 p+, 0{|{ ;Demayo 0+32/44 }~ 0 + * /, ; 4 !+ 0 .. ;4 1 0 .3; W4  - L 0 ,2 ; 4 p t - rs+,r *M /%+,7  +,A/DCU  tp)*>'q* A// Cl *x>y *; +,,xpO@'p d 0x4 O@ /%p+,$%

0d4 > 012ῌ3 +33+4

d0x4X0 x ῌ Cl 4
0+, x ῌ+, Cl 4+**dXd0Na4vd0SO.4vd0Mg4vd0Ca4vd0K4

+,r* 

-/

ῌ
῍

P¡¢ r+,-.

012ῌ3 +33+4 }~ !+ 1 A// ,3.* ,-.- ,0.- CM -/POM /%r+,r* $   ,-3 OM+,r£*¤Ur+,A/' - *;%*¥DF ¦§O

 SO. ῌCl, OM +, 0*.+.4 * z¨q ? / O©ª>L«*+,$%  Cl ¬: ­ !®¯ M Cl ¬:&° 

9 // © ,**/

n¥(T"¦ lm§¨7

Fig. - Distribution of Cl ions in hot springs deeper than 2** m under the Nobi Plains. The val ratios ofCl ions in hot springs are classiﬁed by the following three cases.  : larger than ,/-,  : +/-ῌ,/-, : less than +/-. Horizontal lines show the area where the ratios of Cl ions in hot springs arelarger than ,/-. A dashed line is drawn between tops of Mt. Gozaisho (῍ ) and Mt. Sanage () (cf.
Fig. 0).
 - 
  Cl
8 - " : ,ῌ-   : +ῌ-ῌ,ῌ-  : +ῌ- / h Cl
5  ,ῌ-  v
nm?
. j ῍  @P  2Z+ ¡¢  0 Z£¤ Cl

 ,ῌ-    -  ,3   !"#$% SO. ῌCl &' ()* *.**0, +, * "-$ SO.,,

./"01234

567 89":; %<=>?@, !"<=>?A@=7B%<=A@C%DEF!GH  IC% SO.,

$@=JK> LM N#"OP! %$ QRῌST +33+
Cl

"UVWK> XYZ[ , "\V K]"^B50_@K]`, ,* km ab"Kc"#$% de +32/ "`./> *@[ +/ ,*ῌ3* m +./>h"i'L" +,.**ῌ+,0** m + Cl

Cl 4jB  WK>"` BFB k  lmnmo WK> XYp! $ Nq K]`, ,* km r

5Kc+./ ,*ῌ3* m +s Cl
+,0** mlm+ Cl*Zf@g% 0_ .

nmo WK>

XYtu$ BFB +,.**ῌnmv  WK>@wxy"`s @z{  `|"lm 2** m  +K]-+sWK> XY$@}~
8"K>F! m@ Cl@ ZVlm m y @ Cl  x @ EZ / "\V   N8 y0,.*+1x,/.2-3 +-  E R  *.33- @,g%$E K>F! m@ Cl

+,·¸

8

    Cl  
 !" Cl  #$%&' ()&'* +,-.#-. /&'
0123456789!":;-<" Cl =#> ?@ Cl 

DEFG)H" IH
# ,ῌ- AB+,C

+,#JK LMFNOPQR ST
FUP VW F'UP5X +, Y; + FZ[ + +- /. /0\ F Cl =]& Cl  *.**1,῍*.*31 ^_"()
II Cl =ST

FUPI `!"QR abH cdKe)'feeg4hijkl Y; - ῍ mnol
4pq\

rU" ; 0 Bs  t+,-. YC ῌ upq\ <Qvwx
YHCO- yCO- \ z{,YCl \ 

=| Y}\ 4G~ s  567
8; Yeῌῌῌ  +322\ 4G~; <"l - ῌ5X
F*  . ῌ - X4G~ )'fe/cdKe/ST

F

UP#' -  ῌ 5XF* wx

ῌz{



|#$% ?@ IH5$+,Fwx#& z{#' ST FUPF BFig. . Comparison of ions in hot springs fromdeep wells with those in present sea water.
The values are represented by weight ratios(+** times) of ions to Cl ions.
¡ :present sea water (Demayo, +32/), ¢ :Nagakute onsen (No. /, in Table +), } :Hotel Sanmikan (No. .. in Table +), C :Shiratori no yu (No. .3 in Table +), m :Kisosaki onsen (No. ,2 in Table +).
 . 

 £ Cl ¤~t ¥¦ Y+** §FG~\ F¨~ ¡ : ©
 YDemayo, +32/\ ¢ : ª«¬+, Y¨+ Z[ /,\ } : ­®e¯ Y¨ + Z[..\ C : °± Y¨ + Z[ .3\ m : ²³´+, Y¨ + Z[ ,2\|#()& Cl  =#>Table , E#ect of present sea on Cl ions in underground water and hot
spring from deep wells

 ,   Cl 

Concentration of Cl ions (mg/l)
Depth
(m)
,*῍3*a3*῍+/*a+/*῍,-*a+.**῍+0**b

Nagashima(at seaside)

Kaizu(,* km far from seaside)+/**῍,***,*῍+**,*῍/*,-4.

+*῍+**
*῍+*
*῍+*
//23

a. Sugisaki (+32/). b. cf. Table +.
a µ¶ Y+32/\ b ¨ + pq

E // ¼ :,**/>"#$%#oC 'c»Jyz

9

  

 !  " !#$ %&%'()* +( %&, ! Cl- ./01
234 5  "%&%'()$67 8 CO, 
HCO-- 9 :; ῌ < ῌ =
+313>

?@A)BC D./0EF !GH&IJKB4C 4
L MNOB PQ35CRS
! 4C "#$%TUV&W
Fig. / Relation of di#erence (y) from sea water tothe inverse (x) of val ratios of Cl- ions in hot
springs from deep wells.
´ : data of hot
springs. A solid line is a best ﬁtted line for thedata, represented by an equation of yµ0,.*+1x-,/.2-3.
/  y  Cl   x  ! ´ : yz
¶·¸ ¹U¶·¸±`GºaU$ yµ0,.*+1x-,/.2-3 b34C

!KBC :'(X)YZ*[+ῌ,\]YZ-+[+ ῌ ./^Z :+303> _`:+31*>> 0 +,0** 12abc3d +#!4e+5f6g$ h
Q 7i  h,j8k !"#$%
9l 0 +. 12a:;m0 0,*** 2a<=m"#$%8+5no >pῌ8qῌ?rno5$ d +#oCs@ :757>ῌtῌr AB

 u% : > rCD./0GH&,C nv4w d - #oCs@ :757>ῌtῌrABxD+yz-{" Cl- ./0u% : >
ryz- Cl- ./00 +,0** 12abc3GH&|$}34

5

~34C-+- 

d - #!{"D./0AyzE . ῌE -  :*ῌ,. Ma> $ 8
F E - ῌ-JG :,.ῌ,** Ma> Cyz Cl- ./0! 5  !"#$%yz- Cl- ./0 ,.** 12?i OBC 0 /** 12a )"#HH, !7i  h ,jI (  &J,$%+8kKLM !C%&NO  JC ,5"#$%
EP#! %&&%|$}34 IJC "#$% -CQRῌSῌTU :> V+AL  WX4!C :d + 
>  :+32/> ,C - &#oC

Y5¡¢/0" Cl- :HCO-- £CO--,> SO.-, h4¤4 .., -,.0 +*./ mgῌl C ¥Z%& Cl- :HCO--£
CO--,> SO.-, h4¤4 ,.. 1+./ +., mgῌl C %&&%¦§[34C§"¨34 ©< Cl- ./0"{(5C %&&¦§NO !!

Cl- ./0ªH\«4C ) ^®./0 :HCO--£CO--,>

5 SO.- ./0ªH]¬\«|$­C¯GY\« :_Bw Ca£, ./0 CaCO- lE\«> A°o!&- ­34 ±²  Cl- ./0no"¨34 5 ³ 

¡¢

10

Fig. 0 Di#erences from sea water and ratios of vals of anions ([HCO-$,CO-$,]/[Cl$]) of hot springs
from deep wells along a line between Mt. Gozaisho and Mt. Sanage (cf. a dashed line between ῍and in Fig. -), shown in the upper ﬁgure. @ : di#erence from sea water,  : ratio of vals ([HCO-$,CO-$,]/[Cl$]). Geologic structure along the line between Mt. Gozaisho and Mt. Sanage, shown in
the lower ﬁgure. White zone : Quoternary and Neogene (*῍,. Ma), Dotted zone : Paleogene andMesozoic (,.῍,** Ma).
0  - ῌ  !" #$%&'()*+,-./(0123456(7 8HCO-9:CO-9,;ῌ8Cl9;" <= " @ : }ZM  : ()* ?HCO-$,CO-$,ῌCl$A# [\wb0 ?0A#
D :  . ῌ -  ?*῍,. MaA D :  - ῌ> ?,.῍,** MaA#



   !"#Cl %&'()*+ Ca,, +-./0 1 12#  Ca,, $34 567892# Ca,,  :6+;< =>
?@A

BCD+E Ca,,  FG< Cl$  ?HA

 Ca,, &

BCD+# </1IJ6+KLM NOP6# QR

ST)<  UVWXYJ6Z[\ST) E ]^_`abZMYM
cd2e; !"#

. 
ῌ fgh%&'ijk< l 0* mnP 2** m op gqPl +,-** m rPstuv

# Mvw ?P  CDA / +x\# =CD<_`yG ?HCO-$,CO-$,A +QR ?Cl$A +ZMz[J6# fghrP%QRD{0/|C\# }~ZM\%
6JQRY\#| // ¼ z,**/~

78 0==º»&

11Fig. 1 Val ratios of (HCO-³CO-,) ions and Cl ions against concentration (mg/l) of Ca³, ions in hot
springs from deep wells. Concentration of Ca³, ions is represented by a logarithmic scale. ´ :(HCO-³CO-,) ions, µ : Cl ions.
 1 
 HCO-CO-,   Cl  Ca,  mgῌl  Ca³, ! µ : Cl )¶·¸} ¹ ´ : zHCO-³CO-,~ ῌ 





 Cl 

  ! "#$%&'(῍ 

)*+,-./ 01! 23"4 )56*78

9:;ῌ<=%&<>=
?@' A +BCDE F.GHICJK  L

'M#NOPῌQPῌRSPTUVWE! PXYZ! [VWE! Q\:F.GHICJK RSPTUVWE]^_` )aObc' dF.GHI
CJK [VWEefgE )hbijk'l1mnoJK 5p:
:*+:qrstuqv wqv )hbixiy 'l1.mno
JK
z,**. ! 3 { ++ " "#\:Z| /1 Z}$ ~*+% @? z,**.~ :   & z| , '~! (Demayo, A. (+32/) : Elements in sea water, CRC Handbook of Chemistry and Physics, F-+.2,
CRC Press, Florida, USA.

)ῌ*+,ῌ- . z+313~ : * ! +῎+/-1! %Z! /ῌ0fu1 z,**.~ : 2P 0=3 4: ! "#\:Z| /1 Z¡¢5£¤! No +-.
¥¦ 6 z+31*~ : 78§ ¨95p©:*;! <ª«! +2! .0῎/..
"#¬:Z/­! <+®:Z­! 5p*;%VWZ z+303~ : 5p*;! +῎,.!
¯°±²! /

"#,-

12

 ῌῌ

ῌῌῌ ,**. : 

 !"#$%&' ()*)*$+' "#,-. /.. +ῌ,..
/012 +32/ : 3456$7(' 3456$897*7( :;<8=>?@. +.3ῌ
+22. ABC-DE?. ABC'
Tatsumi, Y. (+323) : Migration of ﬂuid phases and genesis of basalt magmas, J. Geophys. Res.,3., .031ῌ.1*1.

ῌ FG +33/ : 9HIHJ$KLK-' MKNOPQRSTUVWX. +ῌ+20. Y-DE?. Y'
Z7 [ῌῌ6\]ῌ^_`ab +322 : cd$) ef. -/ῌ,.,. ghDE. Y'ijk;ῌl6mn +33+ : "#-o 3 E. +//ῌ+01. pqr. Y'