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名古屋大学加速器質量分析計業績報告書. XXIII .2012.03

極東ネパールヒマラヤ苦鉄質グラニュライトの低い流体 H20 活動度(予報)Low H20 activity of ß凶din mafic granulite 祖 far-eastern Nepal (forecast)

申ぬ

志雄

武

ui

山四今

切1 名古屋大学年代測定総合研究センター

lC四ter for Chronological Research, Nagoya U:出versity， Chikusa, Nagoya 464-8602, Jap血・

事Correspondingauthor. E-mail: 仰の'ama@nendai.nag

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名古E大学加速器置量骨析計量績報告書. XXIII .2012 田

回rly 田logite m出血0甲，hism，也rou喜h Co，-rich 盟副dduring gr祖曲祖国出血0甲.hism，加 aqueo'四日uidwi血

阻血町CO， m剖nga血phibol出血d園田由血0申lhis且 H血田，也eP-T-Xmo evolution of m.et曲幽1岡田也e

IllICS is • key to un也悶t.nd也ee:曲u皿副onpr田e田 ofd田p crusta1 rocks in the Hi皿山抑 orog'担目In this 蜘均，也e岨phibole四回酔 of附噌醐国血afic gr祖曲皿白血r-eas畑 NepaJHim山Iya，

w加芭叩atial dis'回.buti咽 ofP-Tcooditi叩S伽'Y阻.et aJ.. 2010)副血由血押lhic ag田(Imayamaet aJ..

2012) h.ve be血 well doCl皿血抽d， w田 mv.白.lIg:武且TheP-T-Xmo con也tion of mafic granuli旬 i5 estim由d

bym叫ti-equihbr加血血.erm.obarom出y田也事 TWQpro伊皿(Benn凪 1991). which四回V四e1y叫叫.ted

from也e∞mp国itions of問凶libriu皿 mineral 田，semblages in 回国~.And也en，it is 出回国sedabout血e

origin oflow H20 fluid activi匂白血d也e effect岨問団g叫ε田U瑚叩

。 20kn、

Higher Himalayan Crystalline Sequences 圃 Ja剛 Granites

以刊HurgraOlles .K;間gcher別内78 Migma仰"

kyl釧 migmatic gnei同S国

釧.-{J rHlt金crdQneissas 釧 bl Qu仏門zo.felspalhiC gn刷""g'創1it i

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名古屋大学加速器置量分析計量植報告書. XXIII .却12.03

(o.g. co貨1. et al. , 2009; Corrio et al. , 2010) 阻dinBhu包n(..g. ch止皿gal et al. , 2010; G叩gic et al. , 2011)

AI由ough 晶r-o酷旬mNO]羽I (s回dyar四.) is locotod 四Iyol 智司proxi血蹴，Iy 50kmo田lof也oAn皿 Vall，町郎官民

bo由也eUHP and HP rocks 蹴戸町四国Iy国立中町恒4

Jn con位置，ttotheUHP皿dHProcks，也om也m国io脂 P/r.骨P. 血e園田中h皿住y皿脂 zone) in the

HHCS has regil田l8!lyb田a悶'"胆izod 匝由e Him.alaya田也eEobi皿川町岨 stage 担也.cLate

Eoc阻トOligocene (c. 3 8--32抽 V畑町血dH吋伊， 1996; S皿p醐 .lal. ， 20曲; Godin.1 al. , 2001). A伽

由isB町O羽田骨戸血由田中出血， high-T(mamJy silli血阻旬 zone) at mcdiu血ー旬 low-p:閣S官官

皿向田町phis盟国国od也.ewide甲田d 岨.atexis 血血o Early-Mi剖lc Mioc四e， Neohimalayan stagc at c.

2ι18抽 (..g. S盟事曲目叫， 2曲O;D阻.1 et 叫， 2曲3;Vis坤ic et al. , 2舶の H阿町民旭町岨aetal

(2畑12) rec四t1y indicated也01也cEohi皿alay;田町田.1 m国ng也eEarly Oligo白血W回 notonly charac国iaod

by匂阻i脂F叫S血曲四甲副阻担也.0HHCS，加1also by Ear1y OliW出血e 岨則氏泊co'四叫由atwas目印Z白d

m血.emiddle 1宜ICS

Fig. 2. Ph

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名古屋大学加速器置量分析計量植報告書. XXIII .却12.03

clinopyroxene +盤町lhibole + bi岨恒+ plagiocla田+"岨血+ i1m四回)四回ImpOSed of gar盟国 and

clinopyro:盟国F哩，hyY由1酷，18 岨d四位江田担E叫s.Awl田kfoliation is defined by plo耳目1踊e岨dlll司副bolc.

GIIlO曲目芭 large po中，hyrobl田tup 阻 1 cmin leI唱曲，血d 面

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名古屋大学加速器置量分析計量植報告書. XXIII .却12.03

皿afic gr四uli幅四国旬中国ted加 be 晶nned at田町'grade s祖酔 τhech皿E目白mcore 加 rim in Na (M4 si旬)

阻d AlVI 刊lucs. 副担直cator ofpr国間電 (e.g. Brown, 197η，町田cll1e田 obvio出.0世田包師団ricb同担血岨曲e 皿d伊醐lar (X血~ 0.53-0.54, Xo. ~ 0.27-0.28) wi也 I醐町阻O岨凶 ofpyr叩e (XPyp~0.15-0.1ηαcmical zoning p醐回s in Mn, Ca, Mg，血dFe of gamets 由主官官1yob曲目edfro皿間宮佃mn，

阻d由e crysta1s田R田tgrow曲目周回2皿odified柏田mecx'旬ntby di:ffusion. C叫cic clin叩yroxenc 0叫U血

酔醐皿d四回 Bo由 clin叩Iyroxen国師 aug出回由Mgi似g+ Fe) ratios ofO.65-0.66皿四回叫

0.61-0.63 ingar盟国 Na，O(目的ーO.29wt. %) co由ntsof也出 clinopyroxcn田町耳血目lly1ow. Plagi田1田e

isby加W四凧阻d也e皿町也i飽 COlI惚nt 祖国奪回目X血・ 0.72-0.73 担回r田 to X;担 ・ 0.76-0.78 皿n皿s.

(a) XH.託主= 1.0 (b) XH20= 0.3 (14) (1,2)(11)

(3l

(4)

醐)

m℃

田市7

山田副

6WH

剛叩

田両

民Jv-問叩叩

2' 400 450 500 550 600 650 700 750 800 850

Temperature ('C)

(3) ~

1: Alm + 2Gr + 30tz = 3Hd + 3An 2: 2Gr+ Py + 3Qlz = 3日 +3An3: 3Gr + SQtz + 2Tsc". 60i + 7An + 2H20 4 : Alm+3日 = Py+3Hd 5: Gr + 180i + 6An + 5Alm + 6H20 = 15Hd + 6Tsc 6: 6Qtz + 5Gr + lBDi + 7Alm + 6HzO = 21Hd + 6Tsc 7 : 4TscφQtzφ9Hd = 3Alm + 5An + 120i + 4H20

8: 5円 +Gr+3Di+6An+ 刷20 = 6Tsc 9: 6Qtz + 7Py + 5Gr + 6H20 = 3Di + 6Ts氾10: Qtz + 2Py + Gr + An + 2H2Q = 2Tsc け Otz + 4Tsc = 3 Py + 3 日 +5An+4H2012 : 6内令 3Hd+ Gr+ 6An +6H20 = Alm +6 T:田13: 6 Qtz + 6Py + 5Gr + Alm + 6H20 = 3Hd + 6Tsc 14: 4Tsc + Qlz + A甘n=5An+3Hd+4Py+4H包O

Fig. 4. TWQ resul包晶rmafic gr祖叫itc H26師団1四Ia凶 (a) atXmu= 1.0 皿d(b) atXmu= 0.3. Numb田de甲lili.briu皿 are listed担 low町P町旬。ffi郡江田. The followi唱曲.Jid回1u世田血叫.els ar唱団ed師団IC\血血

血由叩ilibri岨血世血obaro血甜y; 酔血et (Berm血， 1開1)，叫，bibole (!.品加 et 01., 1994), P何回国e

σ町四血血dLinds1町"， 1988), clinopyroxenc 皿dm盟国H20-C02fluid (Bcrman, 1988). Alm; a1mandine,

Py;pyr叩e， Gr; gros叫眠Di; diopsi，凪 Hd; hed

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名古屋大学加速器質量分析計業績報告書. XXIII .2012.03

由e ca1culation. If也es阻lple is well equilibrated and used ∞mpositional da岡町e good. a11 cu町田 for

m担制 equilibria sho叫d帥四回t.Equilibria for sample H2608 is given 也 Fig. 4, which are ca1culated in 由e Si02・FeO・MgO-CaO・Alz03・H20・(C02) system with the following end members: a1mandine, p戸。pe，gro田叫町， diopside, hed四h町E向， tsch国司法ite， quar包， ano:地ite，皿dm皿.ed H20-C02 fluid. Only three

eq皿libria 紅e independent of all 14 r闘ctions in the diagram. When the activity ofwater = 1.0 in mixed

H20-C02 fluid is assumed (i.e. Xmo= 1.0), equilibriu皿 curves (2) and (4) fortr抽出na1garnet-clinopyroxene-plagiocl踊e-ql田血 barome町 and garnet-clinop戸ox

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名古屋大学加速器質量分析計業績報告書. XXIII . 2012.03

including pseud'Osecti'On m 'Odeling, will be published in 也e Minera1'Ogy and Pe仕'OI'Ogy 'Or 'One 'Of the '0也er

泊岡田ti'Onalj 'Ournals in ne紅白加re.

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