% &  nl /0 m ,**1l.o +3  - ῑῒ +, +  , +2  3  ,3   +2  ++  3 Thermal Springs of southern Cheju Island, Korea
Koji SATO+ and Tadashi TAKAYA,+Nihon Chika Kenkyuusho, , Nihon Chika Tansa

Abstract
A thermal spring (-1.,, pH 0.+/) was found by the drilling of ,***m deep at thesouthern part of Cheju Island, Korea. This spring was a simple thermal spring (NaῌMgῌ
Ca-HCO- type) with CO,.
The basement rock at the drilling point was gneiss, probably from the Precambrianage. The gneiss was covered with unidentiﬁed tu#, late Tertiary sedimentary rocks, andthe uppermost layers were TertiaryQuaternary basalt from the Hallasan Volcano.
The 0 springs on Cheju Island described in this paper, had temperatures ranging from,/.. to .,. The characteristics are , simple thermal spring, a Na-Cl · HCO- spring, aNa-Cl spring, a CO, spring and a NaῌCaῌMg-HCO- spring. No SO. type thermal spring
was present.
Although Cheju Island is a young volcanic island, the thermal springs of this island
are deep ground water springs.
Key word : Cheju Island, thermal spring, basement rock, deeper ground water type ! : "#$ %& '() *+ ,-+ῌ ῏ ῍ ῐ ῎./01 + 2 3 +321 456789:;<=17>4 561%&1?@7ABC=  +322D EFGH56I1%&JKLMK4NOP9=QRST=L %&1?@LUVC:W
X13 ,, %&4YZN[T=D \<3]^[ +333 1 ,- %&_ Lim +331 1WG ,/ 1

`natural hot springa 4bcdXe1RSXD f<Lg ,*** 4h<i +333 43 +** 7jkX127

128 +**    !" #$%&'()* +,-. +,(. /0. 12 34 ,**-,**,/0(*)56789:; <= ,,*** m >?2@AB CD CE$FGHIJKLMNOPQRS8TUV)56W XYZ[\]O2G^ _QR`abcO dFHefghijT 2klmno2pF$q% Crstu ,./vῌ+** m $F<=owxyHqm z{|-+* m-ῌ % -1.,

 D+,*** m !

}R~Q2 1/.*3 m X ,+/.- lῌNaῌMgῌCa-HCO-   m, /0 &()3* km m  = - ---*῍ m Fig. + 

7o%= mFig. +ῌ῏ῒ

Cheju Island /0
Seoul Gwangju 0Location of Cheju Island.
+ ῍ Fukuoka ῐ Pyeongyang ΐ Tsushima ῎ῑ

Pusan LTegu # /0 ¼ ,**1 kl

129

Fig. , Sketch map of Sammebong spring.
 , 
hatched part : Seoguipo formation.
¸¹º : vwxy»ῌ 1. km, ῌ -, km km,   $%&'()#*%(+,-  +,2,/+,3/* m   !" #./ 01 /2*2.** m, 34 +** m  -5  6  789:,;<<()=>4? @ABCDE- EFG .
H<<IJK LM-NO)?PC Q79:, -0* FRS
T!- 89:, UV : WXYZ[\] <IJK P^ _`abcP<def[P^gO)?  +32, Lee, +32, Fig. , hbc ijklm
no0C$ +3-.0 m _pq -30 m g UV r, $s

Z[\]EYtoklmno$s PuFig. , vwxyogh:, Fz{o| } (C__~Po F 9Cr,g?
r, @Ar,:

9Pr,s bcPE( +330 :,Cbc 0bO)?g - oC, 0 ῌ!b /  + o" #S$() ,***

%4?vw ῌ &" g¡4?,C '()+32, Lee +32, b99: Wox¢9o Table + ub£ Fig. - h 9¤^- y*b}P} W¥ - x¦ <x vwx +§ῌ¨xub£,&x O)?©ª« W+§ῌ¨x-¬<  ­.<9:,®/< !"¯°]%ub£ ±% 01< ²)³Ze´µ¶% ·S)?,C¹º»¼130
Table +

Stratigraphy of Cheju Island (Shimano et al., +330. partly revised).

῔ + ῍῏ΐῌῒ῎ῑῐ -" +330 #Holocene¡

Shell-sand formation¢>LStage .

. Scoria volcanic cones

H{Stage -ῌ--   -Backlockdam basalt$£%#$Stage -ῌ,-   ,Hallasan trachyte
Hallasan basalt
Seongpanak basalt
Shiungri basaltui$u#$¤&¥#$¦§#$

Stage -ῌ+-   +Beobjeongri trachyandesite
Hahyogri basalt
Sumangri basalt
Cheju basalt'¨ij$©ª#$«(#$+,#$Sinyangri formation

L

Sanbangsan trachyte
Jungmun trachyandesite
Hwasun-Seongsan hyaloclastite
Seoguipo trachyandesite
Pyosunri basalt

i$.)ij$*¬ῌ¤­®¯°±®dIJKij$²#$Seoguipo formation

IJKL

basal basalt³´#$granitegneiss¸,$-.$, Stage ,+late tertiary+ Stage +

Mesozoic.Precambrianµ ¶e· µ   .  +   !"#$$%&'( )* +,-./0 123 -./456./718' 974)4:;#$$1**<= >?@$ABC?>$DE)E FGH1<IJKL%MN' 4 O &P X  Fig. , 8PD<Q4% ROS)TIJKUVOW,  Y%Z[ \#$$1&' ])$^O

1=_'( `a bca)T$defg%Xh =_( ij$& )T$klmnXh =_ o  pqrO-stSQ4
L%MN'(-  uvS1wx' #$$1&'uy%=_( ! i$$&v$klm%&(-5( ][%.  0PzH{%=_(h   H{ -0* |1}~x4

5 4 o \x )TDE) Fig. ,  A oH{gzOnh =_x~ o'wSApqrO [ Q4NL%P

+  $LO & '[!)4%S4D  ! 4 /0 q 8,**1:mn opFig. -131

Geological map of Cheju Island (Shimano et al., +330).
 - 
 895 +330:
/01;<3 8=>3:
QRM3
?@SFG1
ABC/01
TUῌH3DEFG1
DE/01VWXῌYZFGP1HIJῌKLM/01[\M/01VWX3NOMFGP1Fig. . Site of some thermal springs in Cheju Island.
 . 
A : Sehwari ]^_B : Jongdalli `a
C : Sanbangsan SD : Jungmun Sektal YZ]bcd
E : Silver Town edfgchi
F : Sammmebong jkl. 
  $%&'()* +,- ,** m .-

! "#

/012134&!5*67

»¼

132
Table ,Some thermal Springs of Cheju Island.

῔ , ῏ῐΐῌ῍ῒῌῑ῎Mark Thermal springLocation

w²

 

 M

ASehwari

north Cheju

u³´Dµ¶Jongdalli

ef··Sanbangsan

south Cheju

PQPFµ¶Jungmun Sektal

Seoguipo

stuvYVG¸¹Silver Town
UVWXYZ[south Cheju

Sammebong

Seoguipo\]^G¸¹

BCDEF

Temp++Depthm
'm

Flowm-ῌ῎῕m-ῌ

ECmSῌcm
gh'mSῌcm,042R,342

01*R3*-

0/*

,5.**

,/40R-*43

1**R1,*-/*-*5.**

Na-Cl,340R-+4*/3*R0**+51**+/5***CO,
Spring,/4.R,14/0..R2/.

.**

05+**

SimpleSpring.,,5**+4--**ºNa῍Ca῍MgHCO--14,,5**-42-,,

1+2

SimpleSpringCharacteristic

 dNa-Cl῍HCO-Fµ¶    !"#$# +323 %&' 02* m()&* ,/+ ,- '῍./01,ῑ ()023456$ 0!" 78 /9' :;0<ῌ#4/ 0 =-> ? @A Fig. . & ? :; Table , &B." 0 C DE,  FG. H!" I J&K0L

M./0N#4:;ῌO$H4"
CPQP()'0 /3*R0** m SKT5 E

UVWXYZ[ F_`4"  E 0 .,+ F 0 -1.,+ /0 J ,/..+R-+.*+
ef0 -*,.** mSῌcmBgh'B.ij4 Na-Cl  J Kklῒm῕0+,*** mgῌkg _`/*7 dn0῏`O4/0 F5 klῒm῕ 0/* mgῌkg/ & 0,+** mSῌcmEpq/" !r# DUVWXYZ[ FstuvYVpqH4\]^ yz{y Table - &B." |}s~ NaῌCaῌMg-HCO-  /.0 mgῌkg

z/" E klῒm῕0 ,,./0.,

CO, 7" F klῒm῕0 .3-.+0 mgῌkg

5 NaῌMgῌCa-HCO-  pq -21.- mgῌkg
y/0 E\]^gh'0 1+2 mSῌcm ogh'0wx4/" }s~dmgῌkg\]^0 ,,*** ma&bc/" dCO, 7" ῔} 5!{0j4"

 ῎῕&642   ,**. &* - a -,.,* zῐ 2 ? S,. a +,..* z῎῕# ? ῕0 +** m ,@ -** m-ῌ,-H ¡HOH4" ? *7H¢£ ¤¥¦O!ῐ ῕0 Table ,῎῕/" F\]^ §¨ ©b @ª.1.-/ m  ῐ ῕ -+* m-ῌ«,+/.-lῌz#ῐ ¢£2!" Se¬Hῐ

@ª+,,... m, #!0 @ 1/.*3 m  ­῎῕ ,.201 lῌzῌm H/" ῐ 'ῐ ® ,/ z .,.-+ H!&¯°&o# ῐ ® +  +,..* z  -1.,+ H ,¢£eΐ-  .,-,* z c±3O

F /0 G $,**1&?@" ABCDE=>

Table -133

Chemical compositions of Silver Town spring and Sammebong spring.

 - springSilver Town)*+,-./

Sammebong

012

mgῌkg

mval῍

mgῌkg

mval῍

NaK3Mg,3Ca,3Sr,3Ba,3Mn,3Fe,3Cu,3Zn,3-*-+43+-0,,3+4,.
*4/+*4+1*4-.
*4*,*4,/-/43,4,-*4/-+4+/
*4*2
*4*,
*4*,
*4**4***4**

1-4.
+*4*,14.
--4*4*3
4*4*1+4-/*4**/41*.,4/+-4.+-*4*.
,,4+*4*4*4**40.
*4**+4,+Total

1*,4.-+**4**+/+4-++**4**

mgῌkg

mval῍

mgῌkg

mval῍

F
Cl5Br5I5SO.,5HCO-5*4+/.042*4**4,,2,5+31

*4*,
-4.2
*4**
*4*++4/.
3.430

*4//
-142
*4*2
42413.+.43.

*4-0+-4+2*4+,
4,4,0
2.4*2

Total

,5,1,4+2+**4*+.0,4+0+**4**

mgῌkgmvalῌkg

mgῌkg

mvalῌkg

H,SiOHBO,HAsO,+.,.,*4**++42+2*43/3*-+
44*4-3144Total+2.4**+,4111-+

*4-31

mgῌkg

mvalῌkg

mgῌkg

mvalῌkg

CO,H,S/.0*4*++,4.+*4***-

-214*

242*,
*

Total

/.04*++,4.*3-214-

242*,

35T.S.M.

mgῌkg

mgῌkg

-51*/

+5*-+42

Characteristic

T.S.M. : Total Soluble Matter
6789%:

 pH .

 !" #$NaῌMgῌCa-HCO-&NaῌCaῌMg-HCO$& : Simple Spring;<=> 0.+-0.+/  -, $+,3,* %& '(  1+2 mSῌcm1,* mSῌcm»¼134/  Fig. -  !"#$%& ῌ

, ' ()"*012,.3 45678- ' ( + & + ,-)./ *$9 :,; <./=>? +** m @AB8C,DE ? +** m => +1* m @ F%&G? +1* m => .** m @HI- J F? .** m => 1.* m @KL FMNG

1.* m O? F,,**-.2 mG @ FPG8G

AB89  4&Q KLQ,-)-  R STU !"V#W>X./ Y9ZHI- J [\[ ]^($B  _E`abc

8 <./ d8 Fig. , 2e*$,;2))k2l*m2n>X %&' + ' (!

fgh% $!ij&'(, ' (!o2$B*$/ d8pZ +q,4&Q)k2-r.!.stVluS v%9s/ a)*w".!"#w""/ ? .** m => 1.* m @ KL8 Y!+V#W>Xx$BM(R>= )"/ d8R.stlu"V 9Z!yz
0{|.stV1}"d!V~i>X./ 9%>S ]R<- 2234  <- .stWwlu"/ dR52#W>Xx 65=>2,#w"./
1** m O? X$7782,Xj 1.* m O?%8-9 %:2 2* -m
-** -m !"#$;"<aeV 1%8 /** -m-,/** -m o2<- @$M2 3,***
-m != +*,*** -m ai.%8R<./ Y*w=!*w> V*S ?=2,Sn>X.,;2ῌ-9V@SABn>X)"/CD782,#w .** m OvAB8! C,D8 .** m1** m ?KL 1** m O?aYXXE.,;)VF>Xw"./ %8 u>2"S=o28 >X.,; <.V N*S>= )"/¡¢£¤¥ 2"w ?%3a7G*w¦§¤aH;!
IuX$/ /1* m O?P+ X$7782,Xj -9 ,/* -m => ,,/** m oa*S> *w"w ?=T|2,Sn>X.,;)ῌ-9V@SA¨n>X)"/ *$V#w¡¢£¤¥  , !R5J %2<#w aP!
*w"./©¤¡ª«V¬KuXw".­L78V +,.02 m Ov%8

X$/ Y­® Fig. / 2e/ ¯=S> *)V>?!°2p±*w".V Yp±M +,*** m Ov,./²ῌ+** m N +,*** m O?

,.-²ῌ+** m N<./ u>2 ,,**- m? 0,.-² !OuXw".  ? +,.02 m,,**- m o  +..,²ῌ+** m !";;"p±M!";d!2)./ Fig. / 2¡¢£¤¥ 78RP³weV ?% p±M;9#W>X)"/
5J%2"w Q´= F+333G  ? +,.** m..² -,*** m

10² !*w"./ YX ,²ῌ+** m p±M!)./5P!*w Kim et al. F,**,G +\µ¶]R·]?a¸!.S2  ]a¹w"./ Y*w5T%fUVEW Xº <. /0 ¼ =,**1?

1 9:<Fig. / 135

Temperature log of Sammebong and Silver Town springs.
 /   Nd-Sr

!"#$ %&'()*+,"-.+,! /012!"#$ "345 6 789:;< K =>? %&'()*+, ROS @9: D =AB? C
DE; J =? 9:;<  JS =()*FG? 9:;@  HD = H? CDE; Ch =I+ ? @9: S =J ? 9:;<C SJ =K9:?  3 L M"NOPQRS"TSU34
5 6 VSW 3 LX4WYZ ![\] VY^_5`a-2 m b =JS? 5
a333 m b =HD? "Pc45 6 VZ defg$45P56 33 h$
!i54 jPklm$45P5 nW\] 78oWpq8 nFGrstu* =J  C  1 km? vw =Ch C  - km? W!W

Px4 (yszT{|}~345 6 9:oq4!WPx4 Px"^9:C<W "34[o h""P 60   
19:54 5 c4h"[Pc86ῌ 9:^[o 6  ,/..., "\7]WPx +Pk

#4WPx4e+Z"5 6
῍ 9:O =NaῌMgῌCa-HCO- ? Na-ClῌHCO-  CO,  Na-ClPkW CO, Tn^\ 6 $45P56
῎ 9:KKvb ¡¢ £¤¥¦ ]P ["34!d =§¨*©ª«¬? [\ 6Y ­®¯°±P²³´ c4µ5¶·$86 ¸34¹ºT»o ^W\6O

136

῍ῌ

Kim, K.H., Tanaka, T., Suzuki, K., Nagao, K. and Park, E. J. (,**,) : Evidences of the presence ofold continental basement in Cheju volcanic Island, South Korea, revealed by radiometricages and Nd-Sr isotopes of granitic rocks. Geochem. J., -0, .,+ῌ..+.

  ,*** :    !"#$%& ++ /3ῌ02.
Lee, M.W. (+32,) : Petrology and geochemistry of Jeju volcanic island, Korea. Sci. Rep.,
Tohoku Univ., Ser. -ῌ+/, +11ῌ,/0.

' () +32, :  *+,-. !/ 01232456 11 //ῌ0..
Lim, J.U. (+331) : Characteristics of hot springs in Korea. Proc. of the --rd Confer. of SITH, 1+ῌ
1..

*+7 ,*** : 89:ῌ;<=>? / @A + !/>? *+7ῌBC#$DEFGHI +322 :   J56 ,, +0,ῌ+0/.
FGHI ,**- :   ,**+ KLMN O /, +0,ῌ+1+.
FGHI ,**. :   ,**+ J56 ,3 3,ῌ+**.
.PQR SP T UVWX +330 : YZ[\]N -. ῌ*+. YZ !;Z56
-2 ,++ῌ,,+.

^ _` a bc +333 :  !d !d -0 +3.ῌ,*,.
efO5g /3 h5KN ,**0 i 3 j 1 ekl