ῒΐ  .3  (,**.)
 ,  /+ῌ0. ῕ ῔

 AT      

,**-  1  ,  ,**.  +  1 Late-Pleistocene Tephrostratigraphy of Aso Volcano,Southwestern Japan, after Deposition of AT Ash
Yasuo MIYABUCHI῍, Hideo HOSHIZUMI῍῍ and Kazunori WATANABE῍῍῍The stratigraphy and chronology of late-Pleistocene (after deposition of AT ash) tephra layers erupted frompost-caldera central cones of Aso Volcano, SW Japan, are evaluated through study of the thick tephra sequence
preserved mainly atop the pyroclastic-ﬂow plateau east of the caldera. Twenty andesite to basaltic-andesite
scoria-fall deposits (YmS,*-YmS+ in ascending order) and two pumice-fall deposits (NbP, and NbP+) wereidentiﬁed as maker beds for the interval ca. ,3ῌ+- ka (calibrated +.C age). The tephra layers were produced
mostly by scoria and ash eruptions of Nakadake, the only active post-caldera central cone, and their bulk volumes
calculated from isopach maps range from *.*+ to *.3 km-. The radiocarbon ages of buried soils just below
individual tephra layers reveal that YmS,* to YmS+/ were erupted at ca. ,,ῌ,+ ka and YmS+* to YmS+ at ca. +2ῌ
+0 ka. Total tephra volume during ,3ῌ+- ka is estimated at about +.- km- (DRE). Production of tephra wasmainly concentrated in two periods : ,,ῌ,+ ka (*.2 km-) and +2ῌ+0 ka (*./ km-).
Key words : Aso Volcano, post-caldera central cones, scoria-fall deposit, tephrostratigraphy, eruptive history

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@ Aso-. A

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R¤ ¥__`#¦$%r'% (+331) m n (+333) Mopqr's

tu&

n (,**-) rv_9M%QRwxXY ©20*ῌ*20, ª«¬! .ῌ++ῌ+0­"®=pq¯°±²¯Kyushu Research Center, Forestry and Forest Products
Research Institute, Kurokami .ῌ++ῌ+0, Kumamoto
20*ῌ*20,, Japan.
 ©-*/ῌ2/01 a{³« +ῌ+ῌ+ -. 1´µ¶·®=pq¯V¸¹º»pq#Institute of Geoscience, Geological Survey of Japan,
AIST, Tsukuba Central 1, Higashi +ῌ+ῌ+, Tsukuba9§¨%(-*/ῌ2/01, Japan.
 ©20*ῌ2/// ª «¬! ,ῌ.*ῌ+ª Pº¼º
Faculty of Education, Kumamoto University, Kurokami,ῌ.*ῌ+, Kumamoto 20*ῌ2///, Japan.
Corresponding author: Yasuo Miyabuchi
e-mail: yasuo@a#rc.go.jp

<=¹X.º»¼X. dY52

  +, .) IvdN"*cAKRScA7  !"#$ %&' CQ *+, 0}A mCE-¯()*+, -./0 +311 ;  .12 +312 +33, ;TU°3 K-Ah4 5678 "9  :

±IK>m V'²³´µ !8¶·IK -W¬¸ YmS,*-D; -<=.  +3314 > !?@ABC 
DCEF">GH?C !IJ
J "> :K;L1MN O Tn*+, - .12 +310 +33, ;3 AT4 56"DCP (Fig. +) !?"QKRF
*+"*SK T"UVWDCXY,ῌ ῎῏ῐΐῒ῍ῑ῔ Z;" [*\]^_`"6a >bFc" !i

:QAheCe " fghef "d"<.

 .jk!l:8"" Jm (Fig. ,) Aso-.
*n#56" "ob =J +** m $%&C - .' +33,4 " 78p K qr(s)tu - .* +32, ;3 Kpfa4 AT *+, K-Ah *+,KCv - ">w+@A,?C - .j  +33*4 > xl
JHy"*+_`"tu>



EJ"-.z>:AKIK>PH?C-<=.* ,**-4 /:{H /|+* m !lhJ

*+,>0}Q"" o1~2"C~3K;7A !"45" +.C 678 ++,***
yrs BP KPH?C -+ .* +3314 J!"~345K8 ,/,*** yrs BP - +. C 67 ; 9.* +33/4 " AT *+,Vh "DC  !"*+,3V0}
6a'7@*+,  K7A :;3i!?"ob /|+* m $%Jm

(Fig. -)

<"=Jmgh H

+ -A31.0 7@ A33*- "=4 K!" J  >u.u :iiu?"@A B+
|+"6a'cA> ,* C?
(Figs. ., /)'"*+, DvIK>

mA Ea *+ E"¡¢NmC£¤N¥¦H?*+,3J§¨? JCv*+,3
K 

©FªK3J dG*+,@AQHJI«JmA JW*+,KX¬?KL"cA iQ"Jm !v3 M5hC­A dN"* E@cA
KX¬ ,* "6a'cA E®@A+O +|O ,* ' - 3 YmS+|YmS,*4 KPQ (Figs.

Fig. +. Stratigraphy and bulk volumes of major
tephra layers distributed around Aso caldera for
the interval ca. ,3ῌ+- ka. * Scoria-fall deposits
which accompany thick ash-fall deposits.

¶·>?V`¸¹º+» AT >?@<¼#j.k;oFig. ,. Site-location map of measured stratigraphic sections in and around Aso caldera.
show peaks of major Pre-Aso volcanoes and post-caldera central cones, respectively.

  YmS,*-a,-b, -c   

!"#$%&'()*+#
 ,-#./01

 


2!#(353Open and solid triangles

0) RH Fierstein and Nathenson (+33,) #236}~ (Fig. +) 789:;D I
v36 

X789:2  36 ,- f  3` 

456789:;<=!3>?@;AB!"6k0 2#$C>?@;DE

 VV4#%2 (Table +) (V 78

F

GHIA YmS2  YmS3 #J>?@;DKLA M
 NH YmS++ O#P;!KLAQM
(R  TRH( t(

9:;A"#

 £¤

#& ¡¢2

A GHI 4IH+RHDS U + VWU ,Ca¥¦§1¨#'©Cª X«?\¬­ +301

KL X Y NbP+ VW NbP, NI63 XZ

!#

[\] ,**- 789:;)*A^_63`( Ca!bcdb#efg6$%Jh(- 

Ai3 Ag6 j.k&V`-ῌ+l!m(nAR6 789:+#>?@;#c4#;* 789:J#BCP;D M
>?@;cKL;#;opq23

,*

 

+0

 YmS ,*-YmS+0 ; AT >?@#+ +, m (® 789:;2 ¯z3>?@#);A°M 4#);±;zA / mrs t(j.k#ucv36<+²Ai ³1´k*µV36u j.k#wR`xy HI;z{| (Fig.

F(!#(g63 (Fig. /) $%g6h(AFig. -. Stratigraphic relations of tephra layers from post-caldera central cones in and around Aso caldera that lie above theKusasenrigahama pumice-fall deposit (Kpfa). See Fig. , for site locations. Arrows represent sample locations for +.C dating.

54

·¸Sq¹³º», AT GL\]^¼
ΐ

55 /  !" #$%&'()*+,-./01 ΐ- 0
2345 6789:; ,* ; +/ <=>? @῎A
YmS,*

YmS+/B CD5E (Fig. .)YmS+3, YmS+1,

YmS+0 F +* cm G6HIJ (+*YR,ῌ-)KIJ(1./YR-ῌ.) L6<=>? @MN῏O , cm B ()PQR YmS,*, YmS+2 S8T YmS+/ F-UVWXNY @FZ +* cm + m G[BL6\]^QR
M67_`/ YmS,*  abcdeῑ<=>?f()

MNF +0+cm QR9 @A*+*, ghB ῔`/



8ijNYk6lmlm[lnop(YmS,*-a-c)  - 2l44q M67 YmS,*-a  -HIJ (+*YR-ῌ,) <=>?f5
j YmS,*-b MrFk s5Et)kr , <=>?῔`5j M[7
YmS,*-c s5EHIJ (+*YR,ῌ-) <=>?() ab4uvwxyxz{QR9(Fig. 0A) F4u(|}5E YmS,* ~(qbῌ *.,+ km- QR
YmS+2 rMNF +0+ cm @A33*- ghB /F\]^Q s5ER9 [6
L6<=>?() <=>?(YmS +2-b)  8 k s  5 j S 9^(Yoshinaga and Aomine, +30,) 01

-ῒQR E[l
IJ (+*YR.ῌ-) -/L6<=>? (YmS+2-c) t)kr . 2] nop R9 !6l, nop deῑk t)5M[lnopde<=>? @MNO , cmB `5j ab4uvwxyxz{Q(Fig. 0B) ~(qbῌ *.-2 km- QR
-ῌ,  +/  YmS+/ ;:; +/ <=>? @῎A YmS+/B  5E AT [7m <=>?fM[7_`/\]^Q Q ¡QMr¢ῐ)£QR 6lῑks5E (YmS+/-a)  !-¤V[lF<=>? (YmS+/-b) ()Q
Fig. .. Generalized composite stratigraphy of tephra
layers east of Aso caldera that were erupted
from post-caldera central cones since deposition of the Kusasenrigahama pumice-fall deposit(Kpfa). Names of individual tephra layers areshown on Fig. +. The +.C age of AT ash isfrom Ikeda et al. (+33/).

R (Fig. .)YmS+/-a ¥¦<=>? @F ,. cmB ῔`/ abc§ () ¨ ©^ª¥¦ @A31+0 ghB QF +-* cm S° ² 5´ ¶V«1jS9 ¬ m N4­®89xz¯ ± ³ µ @A*,+, ghB Qr .- cm F-῍5j 4uvw

¥¦§Z¨©ª§Z«¬­®

56

Fig. /.

Photographs of representative tephra sequences at sites A*+*, (A) and site A32,. (B).

 (Fig. 0C) *.02 km-  v wxyz1rstuI2 {:|    !

)"K1" @m}J"#$% $& '( +ῌ- ) +ῌM"% - *+",-./01)"2 )34

*.- cm *+H "z1b0 (  =*.-i

89;<

5671,: =>?@ABCDEFG +33/ p. -1H)IJ1)"K1 LMN!O1

+ cm *+H ~I3)a .  =i"1 YmS+/-b :n LMN! =A31+0 @mH  +*+ cm, X =A31.0,

AT (P , :,:"QR0 STST)UVW%

A33*-, A**++ @mH

1 =XYZ[\] +330 ; Kubotera and Yamada,km ( =A*,+, @mH O1a ,* cm,***H :^_`0 YmS+/-a 473./ C " YmS+/-a c

0&C ,: =STSTH PabcW%

1Ck01 (Fig. 0C) :nC)de%

& YmS+/-b 

YmS+/-b

 fgh (+*YR, ῌ -)i jgh (,./Y/ ῌ 0)

kl0 K3@mn3opIqrstu: /*i12 cm, LMN! +**.,, km-  xwI

¡}¢£)de%qrstu¤£¶·;,¸¹º» AT -./$¼

57

YR/ῌ+) <=>?W

<=>?q ;rTable +. Maﬁc mineral assemblages of scoria-falldeposits (ca. ,3ῌ+- ka) determined fromobservation of ,ῌ--f sieved fraction under apolarizing microscope.

s X1tu 8AWC
X1

+* cm vw

! Kxijkl (YmS+*-b)yz$1q ;DEZ nop<=>?$ ! _{|} &' (+*"mijkl (YmS+*-c)

YR.ῌ.) <=>?~A ! , WA3

4] A 1 W;"#; $F$ (YmS+*-d) X1 !
ijkl   YmS+* $%

;9F+,

 (Fig. 0D) 8*.*, km- !

-ῌ/  +  (NbP+)bM 3 ,2M 2 <=>? 5;$% -B/ cm
C + cm

&'<=>?$7 ;  GC

mm NO1YEZ

' (,./Y0 ῌ ,) $1

 XA KLM + NO 5P NbP+7 A+
5QRST ,**-7! XNO1YEZ $ $% -B1 cm  ;
F+(Fig. 0E)! FF1W X-./

NbP, ; AT qH<=>?

^_Z `1*+ !
-ῌ0  1

YmS1 ; bM 1 <=>? 5P YmS17

 &' (+*YR/ῌ0) Z } <=>? ! q34

.fghijkl ]WA1 h /IJ

,B. 9ijkl1UVWA

X

1 ! ¡ |;no1pH  Hm
<=>?1r¢A "m<=>? _{|;YmS+/-a  -b 

 YmS+/*.3 km-AT  

C / mm£¤¥O¦§q ;r¨X1tu !  1 8; c db 5A

  !
-ῌ-  ,  (NbP,)
YmS+/ "#} 12! YmS1$% , m31.0, A33*-, A**++ 347 &'()$*+,/B.3 cm $%Z1 8XW©ª«¬; , -./01234 5A32,. 67  ,,©­28 . 9$:;&' (+*YR.ῌ0) <=>? 5@A%W°V YmS1 $% -B1 cm, C +B,./ cm !

7 1DEF (YmS+.BYmS++) YmS++ GHIJ;KLM , NO 5P®¯;F+

(Fig. 0F)! $ *.*, km- , YmS1 "# /B+* cm IJ;

&' (+*

NbP, ; QRST ,**-7 1UVWA ! XNO &'YR1ῌ0) Z bM 0 <=>? 5P YmS0 ; $% /()$;YEZ [  \$F+]WA 34 cm H C +./ cm

1 T<=>?$^_Z `a$*7 10EZ !
-ῌ1  /+ !
-ῌ.  +*YmS+* ; bM +* <=>? 5P YmS+*7
31.0, A33*- 347  ,* cm c db 5A

$%F a$

 GH#;$
YmS/ ; bM / <=>? 5P YmS/7
]¢W

 c dKL 5A*+*, 347 W±²³"´ 5A32,. 347 ; +a$*+ -./ ! X-./-9

 -./e9 - 9.fghijklW !

H<=>?$8AW;EZ µhlByz

Hmijkl (YmS+*-a)$W ! Hm&' (+*YR.ῌ,) <=no1p&' (+*stuvwxyzvw{|}~

58

Fig. 0.

Isopach maps for major tephra layers erupted during ca. ,3-+- ka. Values in centimeters.

 (YmS/-a) 



$ R"- %+4"-4S0  (YmS/-c) 

(YmS/-aT-c) =>?@UVWB !"#$ %- (YmS/-c) -K / mm LM-YZ$WB

&'()* (,./Y.ῌ,)  (YmS/-e) +,"#$-./01234"X !

[\]^U_`abcbd3 A*+*, ef4$ 56 789-.:9;< =>?@ABC" A32,. ef-4S0g;< (+-T., cm)  h

DEFGHEEI J%;K 0 cm LMN OPQ0

#ijcklmn op-q$ YmS1 r

³´,hµ¶·¸¹& AT ,-º»89:*¼

Fig. 0.

  (Fig. 0G) YmS/ *.*- km- 

59

continued.

XῌPz{-c= (,./Y1ῌ,)  !X>P4 )y[S YmS.-d & b c= (,./Y0ῌ.)-ῌ2  .  YmS. ;dref23aK,-* .  ! "#$ YmS.% & '()
!*+,-*+ !*+,-* . ./01
2 (YmS.-a3-d) )4567489:
YmS.-a & ;<= (1./YR/ῌ0)  !*& >?

@ "ABCDEAFC%  !GHDDI>῍. ./012X4h& YmS.-a

X& YmS.-b X 3 & YmS.-c X&
YmS.-d XD4h& ~)W

 I  (Fig. 0H) YmS.
 *.*- km- D~WJKLM NO  DPQRSTUVW}W& YmS. 'U*<= (+*YR.ῌ.)JKLMXYZ  [(\]^_ῌ `aKh& 89:X; h I*¡

 !X>P4 YmS.-b DW,-*567¢£r[ῌ ¤XD4 4b c= (,./Y0ῌ.)-ῌ3  -  YmS- ;d& ef2)gaK YmS.-a hij YmS.-c 

!*Xkl4d -  ! "#$ YmS-% & ¥f¦:§

mnI& ob c=,-*pqroDXs)¨ ©ªp«)~¬­89t YmS.-c & -c= (,./Y1ῌ,)3<-= (+*YR: *7<-= (+*YR.ῌ+)/ ῌ +) !*& YmS.-a !uvw

P& ῎x4 ! "yz{ + cm% |LM "yz{ ,.0d& ,-D !®*)4oDX56& ¯4
PDI 2 .9°±f/012Xp«)~cm% X||>PN}~ *  mnI

y'(JKLMGH,-* ²  

X& 7V   [S\] ,-*[Dy[S/012z{ ῌ

0³ºd>e»¼d>fg/h60 (Table ,) |}~:

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

5=  -N/ m X6 >*

#? A3.*,  YmS+, YmS., YmS+*, YmS

YmS+*, YmS1, YmS/ +/ 7`:w A31.0 "$% (Fig. 0I)&'() YmS- * *.+ km-*+*+ xy) (Fig. -)   !"#YmS- +,-.

a?Htu.7`:w \F* +N, cm %xy)H

2 /0 134 5A3/0.

6 #789:);$%<  YmS/  YmS1 "^ A*+*,  I" YmS,* 7`:w A

22 YmS- =>?@ (+330) AB Kubotera

A Beta Analytic "@TB) :w?C

%T )("D%b )ECF%56;<"G 

56;< A3.*, and Yamada(,***) C)  DEDEFxy)? b HeI"[  iJh 1 GH"IJ KLM"^

YmS- FG /N+* cm #" OP (1./YR/ῌ0)

=Q ,  5R YmS,6 ST
  & - cm U - cm "!T"V WXJ 2#$
FG"Y=Z2X)

5 & +N- cm6 %%[ JK@ (AMS) I"[b[)

C 56v" Libby Ln //02 5%G d+.
+-

C( +-Cῌ +,C) " MGNOPbjJ X) Q56P" Beta Analytic R.
%G) i.-g

INTCAL 32(Stuiver et al., +332) %G Talma and-ῌ+*  +  YmS+ ;Vogel(+33-) "=Q +  5R YmS+6  & )& 5\S¤T):w?U¥)¦ §¨©VWª«¬" &' +/* cm6 Y=Z(  ] 8H / ^E­E£X®F@YZ 5Elementar R vario

Y=Z `*a+8&  A F*"b8\`*#"\H0 OP (1./YR.ῌ0)  1(J
Z d"e2f,g

Y=

5 & - cm h`6 S

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I"£

EL6 %G)¤¯[°ICF>\FWEK%<K_` )S a, -. c/%< e¡#¢%b[A3.*, "A ]J)|}~:

5Y=Z ±

 ^e)S6 >*OP C 56 ++,0+*+.

²2* yrs BP(Beta-+-2..1)  =>_ (+331) C)+,-.³|}~:>* +. C 56

 "!"#%

) (Table ,)

5' ++,*** yrs BP6 `a)H[) ´µ]J) +.C 56 5¶b6 %Q5PT  ' +-./ ka 

Y=Z %W() YmS+ * ' *.02 km- ^·" YmS+  YmS+* Xtu.7`89:w 56  YmS1 7`%  +.,02*².



2* yrs BP(Beta-++0,*1)N+-,-/*²0* yrs BP(Beta-+02/..)

3 tu.4v56%"T )(" tu¸c¹OP +.C 56]J) YmS1 7`:%xy +.C 56;<%z{)w  +*,.,*²/* yrs BP(Beta-+02/./) ¸OP +.C 5.7`89:w

Table ,.

Results of AMS +.C age determinations for buried soils just below tephra layers around Aso caldera.

g4=>¡¼|}~M AT =>?nWXY        (Table ,) !

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61

A**+* S¡ AT =>?WXY

u`vY\<¢,WXY23/  AU

$$%23" YmS1 ( +.C 4,]^/=>?_ \789: <c  //$ /$  YmS+ #" YmS+*  YmS,*  `+,y (Fig. -) 

5 +26+0 ka  " +* 789

qr"$ +.C @ AT =>?#"£ :;"<=>?@A  !  U$ A**+* S, AT =>?5M

B/"  C.DE#FGGHIJK>JAG u`vY¤H¢,¥,& L# ,*** G$%MG&N/$

'.

YmS+/-b /$n(789:

T%"#" 5M>JA YmS,* #" YmS+/ G)." YmS+/ ( #" +2,+,*O+** yrs BP(Beta-++0,*0) YmS,* (#" +1,2.*O3*

yrs BP(Beta-+0.+0-) P( +.C  "$ #¦JUKL  /$  5,,6,+ ka ZI

/ aFMAIMN/$

23"

"I5 + s QR)S*,T

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Pf1 23/

N)Zh/KL  gB/ \P#" ?C,opWXY5, [/ 



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45h=ijklmn(WXY67;"&N

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U,@~I / 5h=ijkAIB"#  WXY&NmV2x (C, D"0 



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/$<

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/$

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,&\#¡JX *.,6¹hiº»hL¼j62

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

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'+/ "%&km- 

2 3()!* b ; +,-*.,./0 1

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F0G;0

, B.CDE2; +,- *.*+4*.*0

km- HIJK +24+0 ka L,-+,- *.*,4*.*3"%&FM/0NO 1

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+*4

5

, "%

; "%&P

Fig. 1. Cumulative erupted volume versus time (ca.
,,ῌ+/ ka) for tephra layers distributed aroundAso caldera.

/@Q/R!S :0"?

T"%&U-H.? /R FTV W+0 ka #

FO *., km ῌky :.W

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-

N

; X

3 P5N-DE NFO *., km-ῌky :

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R4

RF1.0\+1 ]^_,1T :`aEN'YM9qToG1HI,./ km DRE  :10:D-;@ K;: (+.- km-) ,./

;
YmS+

Pbcde (,./Y0ῌ.) -M

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H +. C 5678pWb

1T

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56789-9q.C TUM

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7 ,W#?. :0V¡;r.

:/R9 .W¢0* N[W\++04+-./ ka v@,./MR/£.HIG:`a; ¤

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XQ +33/ 1,1.0  ;¥H9q:1

w&;T HI:x8;

T+-./ ka y$ z?Q/{|}

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89Hª;DE R4 +.- km- «81

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F.

+w&;r 2 9q T!W

'YM^_9q ­®J 3¯`MNFlJ¬]M . DEN

#9:.W

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DEF41 ,,+0 ka 

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



z?/ AT /Ry$ E.=

I,,4+0 kaDEF4NF

lJ` M DE #GH (Fig 0) ,;+,-4 (DRE ; ,./ g ῌ cm-)°±1

NFlJj: 0=
I ,,4,+ ka *.2 km- :

S$4 DE /R:"%& F1:?2  !"HI YmS+/F42

bGyPcG ,+4+2 ka NO *.**+4*.*+ km- ²³´³ "%&F0IT>4

F11 DEF4I&1

dµ[k,.T H I:nC¶e·f(Fig. 1) . DE Jz? $/RH

HI 2 3 +24+0 ka  YmS+* , YmS+ :

K;: +., gῌcm- L +33+ M1

S"%&:/R F0sgH 1 ¤¸jz?/56789H8;

,,4

>F4dµ1

*./ km-Dlm AT   P

/' )( ^05J  

AT    ,,,+ ka  +2+0 ka !

63"#$,

%&'( )( *+,-.%  

 (,**-) I?W"5 +- ka<=

 A *.+ km-ῌky (DRE)  X

D * " B)5

(+32/) 23(,5/NO( ,,+0 ka- . 4  ++.0 km, 56 7"XD  ghz"CO `,%/'( 0_=>8?%@ st1

1

/89 / m :; .

4 *.*0 km-%/J`56 %&'( 9"<=5> ?@AB  ,., gῌ`,3rn" D5^ pq 3 12_ 7

cm- C9D E0 1 +33-F/`,ub

5 ,- . 4 DRE G=5 *.*/ km- /D" HIJ + KLML5
6

3   lmk`,(lm?@A)( 5NO(P  HQRS

B 8/ H kE(

T!4"/'% YmS+/-b UV #/

589% +** m @;%%FhQRSTW

$5 X *.*+ km KL-

ML (DRE) 56J %4 &Y>VZ' X%HQRSTd

J PG/^ 56% P % / [( $)   *.+ km-/'( AT   PHKLML + KLML> %&'( (Fig. +) XD^ v "_9

(W 8%)  \] HQ!a(RST^(;*/IJ^+_&('AT  E ,3 kaF ? I

E +-./ kaF`,%-(abD "XD ` _ ,*  HQRST EHw¡J ,*,_]c(^ 56 d

J + QRST ; K¢ YmS,*-YmS+F  , 

efe%$9D gh^ E0

1 +33/ ; Ono et al., +33/F d/`,Qijk

lm V, >/./b

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NH OP?

2 





,,+0

 

ka

H{|

EHw£LJ , I¤J + {| ; NbP,, NbP+F %+.

C 24Q2¥¦(§¨ YmS,*  YmS+/  ,,,+ ka © YmS+* YmS+  +2+0 ka  YmS+.++ $ AT   d0/`,"56 ,,+0 ka  P HQRST( ,++2 ka"CO */`,%`56'(R;9D

^(;*/nlm5.// E0lmk 5ªM5>

1 +33/ ; Ono et al., +33/F d(!4" HS +.- km- (DRE) 56J/'

I _o/QRSTnX ,,,+ ka (*.2 km-)  +2+0 ka(*./ km-) 

%$;

,,+0 ka`, ?@AB

, ! "# )(*+ "pq 3 12_ 7/`,3r Est1 ,**-Fu^ 56J 9-"4 vab

,- . (*.*/ km-)9 NO(`,5^5r/^ w6xDlm?@AB5 y E 3* kaF  +- ka z)5 HQRSTn{|;*/ 9+_&('}-;% +"

%6'( %/'(ka  " +- ka«"6( ,,+0

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/%  +0+- ka `,%9 %: (P /'( +- ka^^;-' */QRST <%V¬­®36(J ¯°lm7±²³TU´µ¶·H V¸¹^ g7:»(W( TWµ¶XY+:

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

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

   !"

#$%&'()*+, -./ Smithsonian Institution

James F. Luhr0 1  2 3!"#4567#8$%. &'() 9*+:;<= ,-.>?/@A B0

1C2D32Eῌ῏῎῍ (+333) 4F56GE57H8 
IJK +,*, ,ῌ2.
 !9::;!LMN< (+333) =OPQ
4>/R5=S ?@A BC .I NI>
T UDEVIW .2, +--ῌ+.0.
Fierstein, J. and Nathenson, M. (+33,) Another look at thecalculation of fallout tephra volumes. Bull. Volcanol., /.,+/0ῌ+01.
FGT<!8$%. (+33+)  XY 2 HIZ?[ +323 I?  -0, ,/ῌ-/.
JK\] ! ^L M ! =$N<! O8P ! QRS<(+33/) 4$ _T`abcde .fghiUVjk8=  #W lXm YZ[=5 +.C
I\ ]nT'( -., -11ῌ-13.
Kubotera, H. and Yamada, I. (,***) Characteristics of theinduration of tephra-derived soils in Kyushu, Japan. (-)
Properties and typology of ﬁve indurated soils. Soil Science and Plant Nutrition, .0, -0/ῌ-13.
^K _!`8a< (+310) opYbE5qr_
T Tn q c<s ;t VI .0, --3ῌ-.1.
^K _!`8a< (+312) 4$uv`abc?
@opwxcry`z{q ]nT'( +1,+.-ῌ+0-.
^K _!`8a< (+33,) qy|c}rdes f: g~.I@hJ ,10 p.
LMN< ! 9::; (+331) ijkB +. C I\`wxc ?@I\  .,,.*-ῌ.*2.
LMN<!K0# (,**,) lL$ mno wx
cBC IJK +,3, ,ῌ+,.
LMN< ! pq0< ! K0# ! 9::; ! rs(,**-) /R5XYt 3 HIZ ghiU
uvA  .2, +3/ῌ,+..
wxG%!y]z{ (+311) y`z{  *|}?@ery`z{ k~I
'( U] , W k~IK .2, +ῌ1.
k~YJ (+33/) k~Y] - ?
h &'( +1, 13 p.

^L M (,**,) 4$YbE5t - HIZ w
xc I\I'( ]nT'( .+, ,,/ῌ,-0.
QL\ (+323)  HU IJ +323 I
.JI),  2ῌ+..
QL\!9::; (+32-) `abc   /
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