薩摩硫黄島におけるカルデラ形成期以降の噴火史
15
0
0
全文
(2) .
(3) . ,**- / +, ,**/ - . . Eruptive History of Satsuma Iwo-jima Island, Kikai Caldera, after a 0./ ka Caldera-forming Eruption Fukashi MAENO῍ and Hiromitsu TANIGUCHI῍῍ Kikai Caldera, +1 km wide and ,* km long, is a Quaternary volcano located, nearly submerged, in the East China Sea, southern Kyushu. Two volcanoes, Iwo-dake (a rhyolitic volcano) and Inamura-dake (a basaltic volcano) on Satsuma Iwo-jima Island at the marginal part of this caldera, were formed after the great caldera-forming eruption of 0./ ka known as the Akahoya Eruption. We made a geological study to understand the eruptive history of Satsuma Iwo-jima Island after the caldera formation. The volcanic activity in the island after the Akahoya Eruption is divided into three main stages and ten sub-stages based on volcanic edifice development and tephra deposits ; the old Iwo-dake stage (stage OIo-ῌ-῍), the Inamura-dake stage (stage In-ῌ-῏), and the young Iwo-dake stage (stage YIo-ῌ-῏). The old Iwo-dake stage was initiated by phreatomagmatic eruptions and pumice fallout (stage OIo-ῌ), followed by the e#usion of rhyolitic lava with continuous ejection of ash and lithic fragments, resulting in building up an old volcanic edifice (stage OIo-῍). In the stage OIo-῍, intermittent explosive eruptions also occurred. The Inamura-dake stage is characterized by the e#usion of basaltic lava flows and scoria-cone building (stage In-ῌ-῍). After that, at the western foot of the cone, phreatomagmatic explosions occurred (stage In-῎) and andesitic lava flow e#used (stage In-῏). In the young Iwo-dake stage, the explosive eruption occurred at the beginning (stage YIo-ῌ), followed by the e#usion of multiple rhyolitic lava flows from the summit crater and the formation of hyaloclastite in shallow sea that made up the marine terrace (stage YIo-῍). During the past +*** years, the volcanic activity changed to intermittent ones with pumice and bomb fallout (stage YIo-῎-῏). Total phenocryst contents of the Iwo-dake lavas increased up to 2 vol.ῌ through the young stages. The magma of the young Iwo-dake stage is di#erent from that of the Akahoya Eruption and the old Iwo-dake stage, bordered by the Inamura-dake stage. Key words : Kikai Caldera, Iwo-dake volcano, rhyolite lava, eruptive history, bimodal volcanism. +ῌ ῐ ῎ ῑ ῏. efg +* hi+jkIlgm#:nopq+cSr. !"#$%&'() .* km !. st\ 0./ ka + uvwxqyz{ `|(\I }#. *+,-. /'(012 34 56 7%89#:. pq<~.k } +312 ; 3 . ; <=>?@ABC#!DEFG+,-HIJ. +32, ; Kitagawa et al., +33/ ; ,**,J TUVWAV. KL #:MN OP.QRS TUVW. W VWA . A XA89< YZ.Q[G+K\Q]I^_. .Q[O+LHIq < v. `aI< b* ,* km, !/ +1 km +Rc>:;. wxpq+sF.k}.]qy`aIJ 3. `aI (Matumoto, +3.- ; Figs. +a, b)J d# . (+32,) (,***) Kawanabe and Saito (,**,). 32*῍2/12 ¡¢£ b/:¤:¤¥¤¦§¨B¤©ª Institute of Mineralogy, Petrology, and Economic Geology, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba, Aoba-ku, Sendai 32*῍2/12, Japan.. 32*῍2/10 ¡«¬ b/:¤b/vv¦§®¯°± Center for Northeast Asian Studies, Tohoku University, Kawauchi, Aoba-ku, Sendai 32*῍2/10, Japan. Corrsponding author : Fukashi Maeno E-mail : [email protected].
(4) C ¹Tº»¼. 72. )C ;{| }~/o 9*9j (0 #.9'9
(5) ` ;&VW & #+3/ XYZ[ ?-/ kcL(0 , . ,ῌ+
(6) . ,%XYZ[ -Z[5. %-/ 0 (HJ) %&1 2 (EZ) %Z[3 4V&/iP( (Figs. +b, c)0 & Fig. , 56(7e. Fig. - xL0 '- XYZ[ :V / ` Table + '/-0 %- 89;:&e;L(<= Z[? ;9 Z[3a? (0 Z[ Vn/3 - >?@ AOP(0 # @ B%/ , %;L(@ K-ab ; C D +32, B % + ; L ( @ . Fig. +. Maps showing the location (a) and topography (b) of the Kikai Caldera. Figure (c) shows the topography with outcrop distribution in Satsuma Iwo-jima. For the abbreviations in (c), see the text.. E @ K-Kyp, K-Ky ; £¤ +31- ; C D.
(7) +.C . J Kd&P(0 V XYZ[§L ¨©%. K-Ns ; CD +32, # ¡ ¢ +32, 9j(0 .P& @F #P. ¥P G +.* ka HID ,**+ G 3/ ka(Machida, +333) 0./ ka Kitagawa et al., +33/ ; ¦C ,**, . /.,. ª«%U2 G /2* ka ¬MD ,*** A-. ka !" # $ -.3 ka %&"'() . /iP( I@ K-Sd ; HI¤. *+ ,., ka , . +33, 3XYZ[ >?@/cd&. !"-./ &%(0. P( ,% B%;V0 ' .37. 123
(8) 4567 89. - N% G +-®2 ka O-( +.C xLO ¯. :;<= >?@ A BCDE3/FG .
(9) ° (K-Km) ;L( CD +32, ; ¦C. <=HIJ=KL(M NOP( (Kazahaya. +3300 O¯
(10) ° +-®2 ka G 0*** ±O-. et al., ,**, ; Shinohara et al., ,**,)0 '- . Pt#@-3 /cd&P # ²2. Q
(11) R? S (Saito et al., ,**+) @T . Z [ ³ % ,
(12) (Sz-S) * 2 L (. U2 (Saito et al., ,**,) VW%& 12 XYZ. Kobayashi and Hayakawa, +32. ; ¦CD +33.0 Z. [ \]\7 5^ \]\ _T. [Q /) U. \]\3`abV(/cd&P(. 2 N; /L(
(13) ° Z[3. (Saito et al., ,**, ; Kazahaya et al., ,**,)0. 9@A( (Figs. -, .)0. @\]\7 e f. ,ῌ,
(14) . Sgh &%iPj( @. CD (+32,) Z[3U2L(. k lm V n '- .
(15) ° _` . \]\ ) \]\ o!"#V. ` 5` . pq MrNOPV0. ¦CD (,***) ¦C (,**,) K-IoL, K-In, K-IoU . st#Vu @ +3-.ῌ-/ v$%. ´µ¶(0 Kawanabe and Saito (,**,) . XYZ[&w 123V #9j(..
(16) ·R;L(
(17) . /x(0 '&w lmVk y z(. ° (K-Iw) /;S§L ¸'
(18) ° (K-Sk) /´.
(19) °±89G)² O³=XTU RS´. Fig. ,.. 73. Geological map of Satsuma Iwo-jima (modified from Ono et al., +32,)..
(20) . (Inamura-dake stage) X89& VWX (Young Iwo-. K-Sk-l, K-In, K-Sk-u , , . dake stage) YEm ! 2 ;6 X89&. . 2 ! "# $%. stage OIo-ῌ, ῍ , $. &'( K-In-+ )*+ , , ,. %& stage In-ῌ῏ . . ! -. /0*1 2 34. X89& stage YIo-ῌ῏. 5 6 7 89&:;<. . Y# (Table +, Figs. -, .)!. ?@A BCD5 E ! FE. VWX L X89& stage. 89GGH IJK L?@A LMB. OIo-ῌ ῍> X89& +a+b, ,a,b (OIo+a. C;5 2;7NOPQRSTU. +b, OIo,a,b) . $%& stage In-ῌ. =>. VWX;Y# (Table +)! L Y Z [\]S^;_` 5a bcdefgh" ij 2;. ῎> $%& +, ,, - (In+, In,, In-) - X. 89& stage YIoῌ῏>. X89. & +, ,a,e, -a-c, .a.b (YIo+, YIo,a,e, YIo-a. _VWXk L"#lm. -c, YIo.a.b) ++ g6 ! . Y#! def nop;qrs2 e. E Lg # ,a, ,b . tguv#2 > wxyz[{RSVW |}. *Y#! "# In, In- i. "#~Xg#2;>!. * 5a fg 2g !. L?@A LM;7> VWX. ,ῌ- ῎ῌ῍. "lm NOPQRS (Akahoya Eruption) X8. 89& O S¡¢ £¤¥ . 9& VWX (Old Iwo-dake stage) $%& VWX. ¦"1 §¦¨©ª« ¬¦ 1** m ®¯ :.
(21) Fig. -.. Columnar sections of the outcrops in Satsuma Iwo-jima. Locations of +- sections are shown in Fig. +c.. 74. ῑΐ ῐῌῒ῍῎῏.
(22) µS¶ CF·¸¹§º» 1¼ Table +.. 75. Geological units in Kikai Caldera area.
(23) . e rq68
(24) iDU .
(25) !"# $%!&'. ^
(26) gf= 78 D!D 78 6. (Fig. /) ()*+,-. /0123! 4. . > (Fig. ,) IoLAqF. 5 678 9:;<12 68 4= . o SK
(27) N @ m (IoL) . 12>!?@= 68 12> A !. L NL SK M ; 0ῌ++P IoL. () /012 B=CD 12 68EF!. k .L,
(28) D > 4=. G. (Figs. ,, /) 4 HI JK MNL OKP . l L. 4 LF. QR= SK TUJ12 VWX! +,Y Z[\4 ].. 4=N SK
(29) y=
(30) MO5 +32,P f=pL!. () SK $%!&'CD ^_
(31) `. iD 6r F tu . abc d ef= >gh. ¡ ¢£¤¥¦§¨©£ª (Pichler, +30/) MS. CijH kLl mn
(32) . K¢£¤¥¦§¨©£ª ; IoHyP y=«¬.
(33) op 4= SK
(34) . MSKt«¬ ; IoTeP !)X4 !. IoLAqF L (Fig. /) rq68 sX
(35). .L (Figs. /, 0) ¢£¤¥¦§¨©£ª . (IoLA, B, C) tuvwxN# y z{
(36) . $%® Ap¡ (IoHy-l) (IoHy-u). sJKwx |}f= H q78 . op SK +, J ^ F. sX
(37) (IoLF) *12z{ ! ~. =! ()>¯?pSK
(38) 1. t N # $%F !. °
(39) M¢£¤¥¦§¨©£ª±²P
(40) ³´ab.
(41) ¦§ ¨©ª3«¬. 76. Fig. .. Photograph of the outcrop at Sakamoto (ST). OIo+a>,b, In+>-, and YIo+>.a are derived from the Old Iwo-dake volcano, the Inamura-dake volcano, and the Young Iwo-dake volcano, respectively.. ; 1ῌ- 2ῌ+
(42) ,ῌ. . ! "#$ ,-* m %&'()* +,- ./0(123 +45623789 ! . :;<= In+>- ?@9 stage In-ῌ>῎ . ABCDE (InIL) ?@9 stage In-῏ *F GD E (InSL) ,DE (InEL) ! H I stage In-ῌ>῍ *F (Table +) JKLM! NOP<2QRSTU 2VW XYZ/ [\9 0] ^ _ `a7bc9 -
(43) -ῌ+ +a, +b (OIo+a, +b). d/NOP<ef-ghi (HJ) Tjkl m (ST) n]M oL 4pqr (OU) *st Lun*_ vwx!yzp{>|}~2 Fig. /. Geomorphological map of Iwo-dake volcano. Shaded area at the western foot of Iwo-dake shows the distribution of volcanic bombs (YIo. a, b) ejected from the Kintsuba crater in stage Io-῏.. ({ (OIo+a) HRz (OIo+b) LM , s0!g /* cm *F OIo+a ! 2wx7] j 7*n]M cm x ¡ ¢£ / v F ¤0 p¥.
(44) ºF [» /012^%p*j"1¼. 77.
(45) . "D 2{ <", klmng . OIo+b !"#. d klmn InSL "=C t /,. $%&'() / cm *+,- . In, [{klmn"2C stage In-῍ . -ῌ, ,a, ,b (OIo,a, ,b). .ῌ. (InEL). . "/012 34 , 567.8. ( (+32,) ",*+a . "9 , , m, :;,< + m *=,- . ". OIo,a, ,b <>?@AB>CD8 EF
(46). Pa 3,
(47) "" C). !a -A*, z:9 +* m. G cm "H CIJ KHJL ,) -* cm . , ),.,klmn"UC t. "BMG BM OIo,a =N". B84^
(48) InEL klmn"^% wx0p. A K9 -* cm L sag structure . Q[\ K( +32,L In, 0 stage In-. =O,PQ ="RS. ῍"1,- . T,Q BM"UVWX. .ῌ/ - (In-). YZQ[\ A,- ,] sag structure. Kawanabe and Saito (,**,) " K-In-, "= , K. "^$_`a N
(49) BMbc . j+klmnL g d 5
(50). d O .6\ G mm
(51) G cm "&'. "#By4,"9z: +./ m Pa z. efa . +"9d ,- cm "j+klmn "9dG +* cm
(52) + m *=" [{z=". .
(53). 9d +* cm "j+klmn
(54) Y = +". .ῌ+ + (In+). j+klmn6 E,%&5 ="j+kl. Kawanabe and Saito (,**,) " K-In-+ g d . mn ="RSC¡W¢X. >?B> hiO 9dG cm "j+k. 5- G mmG cm "7. lmn
(55) Y\ opqr2sC t9 u?. "£O\, D , cm *+"klmn B>
(56). v=Q wx. 6\ !Q[.
(57) Y O) +* cm "M89 sag. \ 9"#By (YW) , 2* cm, (HJ) , /*. structure C^%a "klmn. cm ,- klmn "#By,>?B>. %&¤|¥£Q . !, . Ci# - $ ! (ST) , , $. C¦] +":?"§ B>"#
(58) . Y klmn"z:) - cm ,{|%&. % ="j+klmnu? v¨fa . u? }?"<"efa In+ 9dG +* cm "'. In- S{ZQ In, "TCiJ
(59) . ~B> T 6 . In, ©; In- "2pC stage In-῎ . .ῌ, (InSL). .ῌ0 (InIL). ( (+32,) ")*+a ). 9d +* G m "ªBA*, InSL [{ InEL . , ,y 1** m 6\ !a -A*, 9. A«Y 3y¬
(60) )y.,. d +G m ,- "), )y., a. <Q = ,. ,* (InEL) * (InIL) 6 InSL. , O ?@ -/ m "*6CAa *. "z+Nf S{ZQ*"j. klmn"±(C =bc"'. +klmnCiJ
(61) /, InSL C In+ 0. ~B>² 6 qr2C¦| p. stage In-ῌ"1 . klmn^%³ B´CD,- /,. .ῌ- , (In,). >®¯°X. "2C stage In-῏ . Kawanabe and Saito (,**,) " K-In-, "+ + Kj. +klmnL g d /012 34, , $. /
(62). "j+klmn hiO >?B>, .. /ῌ+ + (YIo+). !a 9 "#By, , m, , -* cm . qr2sC t9 u? v"=. ,- | "#By, =N"klmn. B8 E,"#µ,] ! (ST) = ,. + m C qr2s z<9 klmn). @) , m Pa > ¶?"M89 sag struc-. +, + cm *+,- =,z: - cm . ture C B> [{·
(63) Y ,. Pa !, ,- cm "9d,- In,. .8 Q EQ 5¸ ¹9 +*-*.
(64) · ¸v¹º»¼. 78. Fig. 0. A marine terrace (a) consists of volcanic conglomerate (IoTe) and hyaloclastite (IoHy-l) at south-coast of Iwo-dake. A volcanic conglomerate (b) covers a hyaloclastite layer including a block of pseudo-pillow lava (c) with radial cracks due to rapid cooling. Figure d shows a sketch of the pseudo-pillow lava.. cm
(65) . %&CD @ EL -* cm. (HO) sag structure. l cm pqrs' %&. !"#. $%&'()*+,- ./0 1* cm1 . L4l mm<+ cm uCD#$. /ῌ, ,a,e (YIo,a,e). W #$ QRL4l m . Kawanabe and Saito (,**,) K-Sk-u-, 234. ' Q < @fw ,mCD. 56789 :; / <=>?@AB. opq n t %& QR,. (YIo,a, ,b, ,c, ,d, ,e) CD EFG (HJ) HI. D (IoLD) f%&$. (ST) JK L - m stage YIo-ῌMN. C YIo,a 234. OPQR STUV LWXY8Z[ XY8 \]^
(66) C_
(67) ` abc@d efghi. /ῌ-
(68) (IoHy-l). QR< '¡¢£?8}¤¢¥. `]jk' U0l mm ,mno. ,q¦§¨© (0ῌ-). pqrs't] [ V_
(69) L4l +* cm. og῍MN STP ª+[ ^
(70) (IoHy-l). ]'] stage YIo-ῌ. D (YIo,e) l mm uWvQv=. V«L +/ m ' t :¬ ®8. >?@ w xCD. }# E¯D°±. (HO) yzR{| N^}~f YIo+ ()*+. @] _ . ²
(71) D³i,m. .l cm< l +* cm 1 ] ´| < ³ .l mm<l cm 1 µB¶"4 tK].
(72) »h2n < J!3G¼. 79.
(73) . M IoTe J3EFM
(74) /,32noG.
(75)
(76). ) !Y (3 / HI32n. + m !"# $
(77) %&. o )/JKY . ' () *+, -. (. /ῌ1 (IoTe). )/ ( pseudo-pillow (Figs. 0c, d ; Watanabe. /h +* cmi+ m -. Q =>?@ -A. and Katsui, +310) 0 ()12 (3, -. >B1L ~K0k0 (Figs. 0a, b). &4 pseudo-pillow 1$567/ 89. . 2nog3s_J 45 W. :; < =>?@ -A>B)CD. / 'M
(78) $ r] %]\ ^. 67 E +32, ; 8FE +330# )GH. \ .:& M ¡>v/Eh cmi.
(79) IJK (IoTe) L ()M. h m (/¢ £NN¤1d¥. N OPQ )RS 3T 0 !. . "3UV W)XY (3671=>?@ -A>. /ῌ2 B, C (IoLB, C). 2no7 B, C (IoLB, C) / oyM7. B) ! Z3" [#\&
(80) $ %]3. 7O 2no(M)I3¦31m. %[3^_&1W` [#\& ')a]b.. P)W IN3Q
(81) IoLB / ISA. 'M ^_&1W`1$c (W%. *+y3If2no=>?@ -A>BQ . &1d =>?@ -A>B3e 1. 2no7 A (IoLA) 1L (Figs. 1. ()If3e ISD *+# / =>?@. a, 1b) D -* m !"3457 Q
(82). h mmih cm -.# M. §M/ IoLA )/¨z ©R7. -A>B),g3 /j0k1lm. /ῌ.
(83) (IoHy-u). 2no=>?@ -A>BQ (IoHy-l) 3pq. / %@
(84) />? Sh 3
(85) e /4.. /ῌ3 D, E (IoLD,E). 3"1 e /K31J _J&/. 2no(ªT 0 T/UV. 45r]
(86) $ %] [#\&3. 7*1W« W33 6" /pq. s6 Z tuv^ [#\& '1. ¬c xg/ Y 2no7 D (IoLD). wca]b. $
(87) xg 2no. / )X (HO) y®YoG YIo+, YIo,a 1. 7 A# y/8&3cMz =. I (Figs. 1c, d) ¯M . >?@ -A>B3e 1m xgM9 ):. H"3 YIo, ),3G)RS. &$
(88) ;{ '<|m }~ . 2no7 E(IoLE) / IoLD }zWZ°[ . vol.. /ῌ/ A (IoLA). 2no7 A (IoLA) / lY 2no 3 W 0 (Figs. 1a, b) 2no=. ῌ!"\± IoLD )/¨ 70. /ῌ+* F (IoLF). sE*B<}ªi]I3^ 'Dm 7O. >?@ -A>B" (IoHy-u) 1 M` e. IoLAiE <}²³0k1~W´ . = 0 () >?<}%@ NA . 0 6" /pq .:&¬µ. , -. ()M 8/ IoHy-u 3. _h`3 flow lobe / ¶W /* m 1|S . xg0 ) !D 786 /7_&. 45·&0. }
(89) *B / C , m m ). /ῌ++ !" (IoTa). Z1z}~ h cmih +* cm 3. 2no^MT 'Dm ²³0k. Fig. , . 'D ( pseudo-pillow 1$5=>?@ -A. 3 l# ¸¹ }/ -* m !" m E. >B =. h cm Mh +* cm 345r]
(90) $ r]. /ῌ0 (IoSP). 1$5 %&/rM 2no(I. (3Q\/ ISC *+3c (Fig.. f/ Qº
(91) $.3} \ h cm -.# $. -) -* cm -. E +* cm !Q3%]<}^.
(92) 8&&1$c 2no7)abM . 3 \ M Q = > ? @ - A > B . 0 ()M 73cd4). (IoHy-l) 3E" 0k M IJK. efM®Yo T / IoTa 1g). (IoTe) W(3),^\$
(93) (). m g*0k Fig. , 3 k# . !Y.
(94) ¡¢ £¤¥¦. 80. Fig. 1. Figures a and b show a photograph and a sketch of the outcrop at south-coast of Iwo-dake (ISA), respectively. Iwo-dake hyaloclastite (IoHy-l) and Iwo-dake lava A (IoLA), which is a feeder of IoHy-l, are covered by Iwo-dake lava C (IoLC). Figures c and d show a photograph and a sketch of the outcrop at Higashi Onsen (HO), respectively. Inamura-dake East lava (InEL), YIo+ and YIo,a are covered by Iwo-dake lava D (IoLD), talus and fan deposits. Locations of outcrops are shown in Fig. /.. /ῌ+, ῐ῏ῑ῍῎ -aῌ-c (YIo-aῌ-c) YIo-a-c
(95) .
(96) . +6728X Ikljm Z
(97) 0 +* cm y , z
(98) @AB2345{g6728 (YIo-b, -c) F. !"#$%&
(99) K-. P |m}myM~:-GH672 . Sk-u-- (Kawanabe and Saito, ,**,) '() YIo-a. NOPD
(100)
(101) @AB
(102) 9pkljmB. + cm *+
(103) ,-./0 mm0 cm
(104) 123. l Zmj;I stage YIo-ῌ
(105) X . 456728-9: 8;< 0* cm =>. /ῌ+- ῐ῏ῑ῍῎ .a, .b (YIo.a, .b). +?@AB8C-DEF ?GH IJK.
(106) h7ij7R i I IJK bc. LMNOP QR
(107) STUV (HJS) 6. J67 -<X , z*
(108) 8ijB. W XBYI Z
(109) 6W [ +. F +y
(110) , z (YIo.a, .b)
(111) :F@AB8X Ik. m => \]^ -* cm _P`abc-de .. ) w YIo.a, .b |m}m sag. : fg2672 hR (IOW) . structure - \]^ 2* cm _P4a67. 0 cm
(112) `abcijB6W Fkljm. Fkljm 67
(113) #g ?. Z
(114) 6W 7n opP`abcijB. 2bcg SBmd<a Sag. K-Iw-P+ (Kawanabe and Saito, ,**,) '([m q. structure 2
(115) bc , g . r stuvw (IOT) 8 -* cm =>
(116) x. [mIJK S 67
(117) .
(118) ·(¸ '¹ 0123º»N%e¼. 81. Fig. 2. Microphotographs (cross nicol) of volcanic rocks. Scale bar indicates + mm. Pl : plagioclase, Cpx : augite, Opx : hypersthenes, Ol : olivine. (a) Two pyroxene rhyolite with clear plagioclase (pumice in K-Tk at HJ), (b) two pyroxene dacite with dusty plagioclase (ballistic bomb in OIo,a at HJ), (c) two pyroxene rhyolite with clear plagioclase (lava flow in IoLE at IOW), (d) two pyroxene andesite with large dusty plagioclase (banded pumice in K-Tk at TK), (e) olivine two pyroxene basalt with plagioclase aggregates (lava flow in InSL at INS), (f) two pyroxene andesite with dusty and clear plagioclase (lava flow in InIL at IM). For the abbreviations of sampling locations, see Fig. +c..
(119) (Fig. /) . vol. ῌ$! / stage OIo-῍$ ,* vol. ῌ.
(120) . I8 (Fig. 3)" fgh)ih V>L#. ! " YIo.a, .b . # $ cm %&. j0kl\$ $! / stage OIo-῍. '()*+,- . ./ 01. \$ ; ". 23 45$ 678 9:$
(121) ;+<. 0ῌ, . =;>" ?@ABC D@EFG H +*. OPY;\ OP. cm I8 JK/L> (K-Iw-P, ; Kawanabe and Saito, ,**,)". * (InSL) '(). OP * (InEL) $a=
(122) ih !* (Fig. 2e, Table ,) $ oH +῍- mm ro + ,-" e&j ro. 0 . y/G +,-"#:. MN OP QNRSRTU .
(123) y! " * oH .. . V>LWX Y;Z[N\*. mm I8 ro +8 fgh. ]^+_`" %& abc]^*dbT. ih¡*$! (Fig. 2f, Table ,)" pq;ro. U+]8 (Fig. 2, Table ,)" 0ῌ+
(124) OIo+b e& (stage OIo-ῌ) fghih. $¢b£ InSL G InEL TUb;ro
(125) ;>" OP\ j0kl¤¥¦§\. *$ j0kl\ mnTU+<8" oH +. fghih¡* ; Fig. 2d ,
(126) %¨. mm 9:pq;roYs$ Fe-Ti t.,. E}~+#Vro&'
(127) ;>".
(128) " u OIo,a F (stage OIo-῍) stage OIo-. 0ῌ-
(129) . ῌ mnvwxyz{$! |}~ . QN©Nª j«¬3 . |+8 ro - mm +Ys /fg. ro + mm 9: +8 ® (1῍3. hih2 $! (Figs. 2a, 2b, Table ,)". vol. ῌ) fghih*$! " Q/>\. ro j0kl\ stage OIo-ῌ $ /῍1. ¯° ±'()²7$³´ µ¶/ #Q.
(130) ºJ<©»¼. 82 Table ,.. Model Compositions of Representative Samples from Satsuma Iwo-Jima. YIo.a (stage YIo-῎) -./. }$~
(131) . mm +,῍+- vol. ῌ
(132) (Figs. 2, 3,. stage OIo-῍% @ A (). Table ,) +3-.῍-/ +1. pqOZ (OIo,a, ,b) *+,
(133) HOIo,a . vol. ῌ
(134) . -M )*+ . ` s/ H. !"#$ %
(135) &'. 0JK +310M OPO12 . ()*+ ", -./. "&34q]60 HI J K. / 01 2345
(136) 6. +32,M BB Aij5 OP - . 78+. ]@A=>+ z+ ' ). 1 . O9:;<6 OIo,a, ,b 1pq. &$) "$mB]1 9:;<=> ?@A 01 B+ CD +.C EFG " HIJK. gy+ JK (,**+) 9 ?
(137) " n. +32, ; LJK ,*** ; Kawanabe and Saito, ,**,M % . > HTiO,, K, O, Zr, Rb QM 8+ . N OP=> AQ R. , 9 ῍% s:` CD . ST 01U V +1 W X. s:` s:` B]. Y<N Z[ OP =
(138) 01!+. %
(139) 9
(140) 6. "\]6 1 CD ^A_X`. " +* vol. ῌ5¡
(141) " >) 9 . a b* #cde 01f gh1$ 1ῌ+
(142). % A /., ka HLJK ,***M ij. 7¢s:` £+ 9 ¤¥rsr 85
(143) AG¦gy+ §¨ ©9 ¥¨
(144) % 2 . stage OIo-ῌk Al2`a"$m. (IoLAªIoLC) « ¬. . %no pq (OIo+a) Bpq
(145) r. : 6% B+ IoLD . srtuv&$ 'wx`_2`apq
(146) gy+. CD A ]®¯°±
(147) ²³´; µ. z{| OIo+b "pq{ A.
(148) N¶·]
(149) °±$¸¹(.
(150) »l h3i|09L .;j K¼. 83. IoLD YIo. N: +!D, , @ O +!,D. +, YIo,a
(151) (Figs. 1c, d) . A3,4 (IoHy-l) L ,. IoLC !"#
(152) IoSP. 1*** P 4 ' 5)Q ,**,: BC. $% &' SiO, & 0+῍1+ wt ῌ . > R "P MAS. ()* +, -. /0123&. T +, +!, IoLA?IoLC , ,N. 4 567 891: ;< => . \' K7OT! z', <?U=. IoLA?IoLC -. @ A>BC DE. M IoLD?IoLF D, , =4 +! VW¡ lN (IoHy-l). FGH I "JK@ . L. 3 vol. ῌ N N , ,+! (IoLA?IoLC). M N. OP -. >QR ST. 3῍+* vol. ῌ \' , ,+! ++῍+0. OIo,a, ,b. sag structure. !3"P,>#$U4D %VWX@ YZ&. vol. ῌ F^ \'¢£>¤3 IoLA ¢3X¥,. W. (Table ,, Fig. 3) =4 +!¦>|09. 1ῌ, ῍ΐ῏ῌῐ. Y§=. -.3 ka [ \'D]^ YIo-ῌ \'. ` WD YIo,a?,e -. ¨©¦>. D] ,., ka 5_6( ,*** ; Kawanabe and Saito,. , lIa \.3]^b3ª
(153) , ,. ,**,: 3 )`a . b \'. c L U4. +!32H¨©¦>BC 4. stage In-ῌ ῍ K@def. >@. YIo,a?,e >. @Z . YZW[C . stage YIo-῎ YIo-a 5$% &« @*. Km,> |09Y§=3 4jkK@d:. * +!, >H\'-g ./hi 4 stage In-῎ jkef>>l3 01 . 2HKmn1o (In-) D3' 4=> . . ] kT3IHI¬D"P=> +!, >, stage YIo-῍;j K. p/p4qr56D67,l >89U4 . . c \'>BC 4 @_3". Kmn1o IU :; = s K7. P$% (K-Iw-P+ ; Kawanabe and Saito, ,**,). @ <=3"P,t>?DV stage In-῏ . stage YIo-῍. @<= =K7 uvw+!D, , . YIo-a 3[CU4 |09Y§=. stage In-῎. K7> stage In-῏. K7D. A. l. . +!, IoLF
(154) ^ ¨©D 3.*. .* yBP (Kawanabe and Saito, ,**,) @_ ¨©D. F
(155) XH @& FD xWa>l stage In-. ++-*.* yBP (Kawanabe and Saito, ,**,) @* Km. ῎;j \'Ay <=3z{,>BC . ,D +***2* yBP 5_6( ,***: F=>. 4. YIo-a. !"#
(156) |}~K B p/p>W^ 56( +320 ; 6( ,**+: Sr. TCVD + (Notsu et al., +321) =4 . P` +*** P>BC 4. = Km,K;j ^b K@dJa 1 KDF
(157) l. ®b )`W56K=. , W. => \' l ,p/p |. stage YIo-῏ ¯)cK@ J%WX jk¨©. }~K;j3 |09k3U4-,p/. ./Ni 4\'. F W¨© , d (YIo.a, .b) "PD X° l:;QR. p t>?DF 1ῌ- ῒῑ῎῏ῌῐ. <*3± 4 (Fig. /) |09Y §=3Q>. -. \' \' ,., ka [. ²X:;³ C´µ®bWK F
(158) = \'. 5_6( ,*** ; Kawanabe and Saito, ,**,: 3],. e /**῍0** P 5_6( ,*** ; Kawanabe and Saito,. stage YIo-ῌ E (ST). YIo+ 3 4H. ,**,: >U4 YIo.a A VW¡ +/῍. 3 ! 1 56K ./hi 4 YIo+. +1 vol. ῌ stage YIo-῍ +!, VW¡ ">. 4 F lGa <k3IHID6J,. fg3X¥, +3-.῍-/ P ¶g h. => stage YIo-ῌ . K.. 3L6W\'>89U4 YIo-῍ -. (IoLA?IoLF). . stage. \'. +!. , 3^ OP @ ):DL. U4 stage YIo-῍ OP^lM3T!K7 5N. K , ,,i!+! VW¡ +1 vol. ῌ ·C =. W¡. ¸j "P ¹k, . -. ,i! !"#
(159) |}~K> W/012 ºa^ 56( ,**+: Sr TC|}~K ,i!p/p^lVaW.
(160) »% ¼±²³´µ. 84. Fig. 3. Variations of modal abundance of phenocryst in volcanic rocks for the past 0/** years. The rock of the stage OIo-῍is more crystal-rich (¹,* vol.ῌ) than that of other stages (º,* vol.ῌ). In the Young Iwo-dake stage, the modal abundance increased gradually with decreasing age.. (Notsu et al., +321)
(161) . ΐ. . bcdTeB fghf i bcj. ῒ. !"#$% & '
(162) . klmn op qrstu vwx. (%)*+,. tuy ghbcz{|
(163) }~ ~ g p f i bcjklm;. 2ῌ ῎ ῍ ῏. p \bc p >. -. /01 !23 $. vtuy p . (stage OIo-ῌ4῍) (stage In-ῌ4῏) . p !" pvwx g. (stage YIo-ῌ4῏) 5+, $ 678%9:! (stage OIo-ῌ) ; <=> >! ? @AB. !CD(CEF@GH (stage OIo-῍) I
(164) '
(165) '(%JKL MNF (stage In-ῌ4῍) OC 678%PC. '
(166) '( (stage In-῎4῏) %?QR ST +*** < >!% '(BCEF@GH (stage YIo-ῌ4 ῍) UV +*** < '("+W <=>. XY 9:! QZ (stage YIo-῎4 ῏) !"#$. % & '
(167) ( [S \]^_`a?. #¡ ¢£¤¥¦¤$_ %§¨ ©g"ª& By 2«$_¬+®¯ w'y° ῐῑ ±²³´µ (+330) ¶·¤'
(168) 'x +,(¸!³%)(* !C .+ +1+῍+13. Kawanabe, Y. and Saito, G. (,**,) Volcanic activity of the Satsuma-Iwojima area during the past 0/** years. Earth Planets Space, /., ,3/῍-*+. Kazahaya, K., Shinohara, H. and Saito, G. (,**,) Degassing process of Satsuma-Iwojima volcano, Japan : supply of volatile components from a deep magma chamber. Earth Planets Space, /., -,1῍--/. Kitagawa, H., Fukusawa, H., Nakamura, T., Okamura, M., Takemura, K., Hayashida, A. and Yasuda, Y. (+33/) AMS +.C dating of the varved sediments from Lake Suigetsu, central Japan and atmospheric +.C change.
(169) )*EFGH
(170) 8OIJ6L during the late Pleistocene. Radiocarbon, -1, -1+ῌ-12. Kobayashi, T. and Hayakawa, Y. (+32.) Geology of Kikai caldera (source of the Koya Ignimbrite), Japan. In Volcanology of the Koya ash flow, A progress report of the U. S.-Japan cooperative science program (Ui, T. and Walker, G. P. L. eds), +-ῌ+.. Machida, H. (+333) Quaternary widespread tephra catalog in and around Japan : recent progress. Quatern. Res., -2, +3.ῌ,*+. (+312)
(171)
(172) !"# +1# +.-ῌ+0-. (+33,) $
(173) % &'( )# ,10 p. * + , -. / 0123 4,**+5
(174) 678 1 9:;< &'( )# -// p. = >? @ABCD (,**+)
(175) E FGH IJ6KL M! "# 0# ,/-ῌ,11. Matumoto, T. (+3.-) The four gigantic caldera volcanoes of Kyusyu. Jap. Jour. Geol. Geor., +3, sp., /1 p. / Westgate, J.Sandhu, A. (,***) 6 N O P Q
(176) 6 Isothermal plateau fission-track RST6 (UVW
(177) ()XYZ[# -*# ,*.ῌ,*/. Notsu, K., Ono, K. and Soya, T. (+321) Strontium isotopic relations of bimodal volcanic rocks at Kikai volcano in Ryukyu arc, Japan. Geology, +/, -./ῌ-.2. \ D / N]- ^_ (+33.)
(178) # `
(179) aEbcdHe 6fgh +.C R ij'(( 47(k (5# ,1# +23ῌ+31. \ D (+330) 6
(180) 6fgh +. C R 4 5 lm'(fghn opqr st 4ῌ5# 23ῌ+*3. \ D '!^_ (,***) 6u vuwuMxyz +* "{6
(181) |#L!. 85. "# +,# 3ῌ,-. \ D (,**,) E $dHyz% - "{6
(182) 6R(U!" !"# .+# ,,/ῌ,-0. ^}~m&'(. (+32,) )*7 67n 77n!" s 4/ " 6 + +5# 7n # 2* p. ',- (,**,) ij.S/0EFGH 1O62 !"# .+# ,-1ῌ,/+. Pichler, H. (+30/) Acid hyaloclastites. Bull.Volcanol., ,2, ,3-ῌ-+*. Saito, G., Kazahaya, K., Shinohara, H., Stimac, J. and Kawanabe, Y. (,**+) Variation of volatile concentration in a magma system of Satsuma-Iwojima volcano deduced from melt inclusion analyses. J. Volcanol. Geotherm. Res., +*2, ++ῌ-+. Saito, G., Stimac, J., Kawanabe, Y. and Go#, F. (,**,) Mafic inclusions in rhyolites of Satsuma-Iwojima volcano : evidence for mafic-silicic magma interaction. Earth Planets and Space, /., -*-ῌ-,/. Shinohara, H., Kazahaya, K., Saito, G., Matsushima, N. and Kawanabe, Y. (,**,) Degassing activity from Iwodake rhyolitic cone, Satsuma-Iwojima volcano, Japan : formation of a new degassing vent, +33*ῌ+333. Earth Planets Space, /., +1/ῌ+2/. ABCD (+32,) 34560n%
(183) v. 68 # ,1# ,.3ῌ,0*. (+31-) m67 ¡¢£¤ 668¥ # +2# +/-ῌ+02. ¦§ 3m&'^}~ (+320) 9# .
(184) ¨#6© Fª« RbSrYZr ¬S® ¯# 2+# +*/ῌ++/. Watanabe, K. and Katsui, Y. (+310) Pseudo-pillow lavas in the Aso Caldera, Kyusyu, Japan. Petr. Econo. Geol., 1+, ..ῌ.3. °_:;B±-<²³´ (+310) )*67 =KEFGHµ62n¶>E·¸ 7=# +-# +-+ῌ+.+. 4?[¹@ ºA»¼5.
(185)
図
関連したドキュメント
Proof of Theorem 2: The Push-and-Pull algorithm consists of the Initialization phase to generate an initial tableau that contains some basic variables, followed by the Push and
Keywords: Convex order ; Fréchet distribution ; Median ; Mittag-Leffler distribution ; Mittag- Leffler function ; Stable distribution ; Stochastic order.. AMS MSC 2010: Primary 60E05
Inside this class, we identify a new subclass of Liouvillian integrable systems, under suitable conditions such Liouvillian integrable systems can have at most one limit cycle, and
The study of the eigenvalue problem when the nonlinear term is placed in the equation, that is when one considers a quasilinear problem of the form −∆ p u = λ|u| p−2 u with
Greenberg and G.Stevens, p-adic L-functions and p-adic periods of modular forms, Invent.. Greenberg and G.Stevens, On the conjecture of Mazur, Tate and
To derive a weak formulation of (1.1)–(1.8), we first assume that the functions v, p, θ and c are a classical solution of our problem. 33]) and substitute the Neumann boundary
The proof uses a set up of Seiberg Witten theory that replaces generic metrics by the construction of a localised Euler class of an infinite dimensional bundle with a Fredholm
Using the batch Markovian arrival process, the formulas for the average number of losses in a finite time interval and the stationary loss ratio are shown.. In addition,
