`š. `tOO pm

]\
-!:'i:\E
\C,GREGATES
'š.
1O
O- _
o
'tOOpm
E4
ó3
70
- ] .{n opticď micÍogÍaph showing abnormď grain growth. one grain grew much larger than the others. Large grains resulting
from an abnormal grain growth situation always contain many poÍes and often show facets.
r : i, A is arat e
srnbols are for
: ra:er-free conlcs during diffu-
sigruficantly
úerB'ater-adřB-erporos1ty
ť s.ater.
rnlundaries, although some of the large grains
rlrnmined internal pores. The size of pores inrůxsed with the increase in grain size.
The average grain size is plotted as a function
:ť dme in Fig. 12. The data fit eqn. (1) wilh n:2
:r 3. The temperature dependence of the grain
grorwh rate is shown in Fig. 13, which indicates
ňat the activation energy is ca. 520 or 600 kJ /mol
ir-rr/r : 2 or 3 respectively.
Discussion
of the samin Fig. 11.
n gÍain size
in porosity
B-slze distriore homogeSignificant
zled at high
E durations
mll on grain
Grain growth commences in the later stage of
hot-pressing. While significant pore space remains, grain growth presumably involves mass
transport through a fluid phase (water and hydrogen in water-added conditions; see Karato et al.,
1986) or along grain surfaces. The grain growth in
this stage is much slower than the grain growth in
the later stage (i.e., in low-porosity samples) under
otherwise identical conditions (Fig. 9). The inferred slow mass transport through water (and
hydrogen) can be attributed to the low solubility
of olivine in water (Nakamura and Kushiro, T9'74).
When porosity becomes small and the contact
area between grains increases, more effective grain
growth occurs. The pore-rich zones surrounding
the pore-free cores (Fig. 3,A')can be interpreted as
a result of rapid grain growth soon after the
effective densification. During this process, the
grain-size distribution changes from a wide (Fig.
1) to a narrower distribution (Figs. 5 and 7). This
suggests that fine grains were selectively consumed
by this process. The rapid grain growth inferred
from pore entrapment can be attributed to the
large driving force caused by the presence of fine
grarns.
The presence of relatively pore-free rims surrounding pore-rich zones (Fig. 3A) indicates a
slower grain growth in the later stage. At grain
boundaries, pores occur both at triple junctions
and at two-grain contacts (Fig. 3A). Pore entrapment still occurs in this stage (Fig. 3B, C) but with
a slower rate (Fig. 3A). Therefore the grain growth
rate at this stage is not largely controlled by the
presence of pores (Brook, \9691' Carpay, 1977),
although it is obúous from Fig. 3 that pores do
exert a drag force on movins boundaries.
i,;!6I .SIocu€ J d pue fue8ury |t,t:;sc -€ s c)
reqtle
Áq petBurp serod;o esuecel€oc eql q8norql
.serod tuor; u€ 01 J31€1Y\;o podsuur1 3 sel€clpul
.s8rg ees) q}mort urer8 qlrat'
.(0I pu€
SIqJ
v€
es€eJcul o]
es€aJcep o1 Á1rsuep Jeqlunu JIeq} pu€
eqJ
sreaddt serJzpunoq urur8 le serod;o ezrs
sáu3punoq
.11 .31g
.e4111T.0 l" pápáuu€ se1dures1o sqder8o:crurpcpdg
.srazue1odeue1d (g) ls:ezue1odpessorc (y)
átoN
=refr te seJod
ulrl Og
@
@
&
lš
{-.-u9
oJvuvx
s
ílolnhMliii]ll|
] rI1 ]fu:_- \'oLI\
26',7
INE AGGREGATES
o
o,'\-
"ó;
c
ť),p
I
o
o
o
$-^+
12
log',ot ( h )
"i
l o g, o t( h)
11. Time variation of grain size in samples annealed at 0.1 MPa. The data fit the grain gÍowth law Gs" _ Gsď : kl with n:2
3, where GS and GSo are the grain size at time t: t and Í:0 respectively, and k is a rate constant.
or
Y
n-e
r
o-
^i
E
ta
E
i
o
I
o
I
21
Lfres at graln
cois, 1965)
rough the
ore coaleun growth
ois. 1965)
60
104/r(K)
62
6.4
1o4/T(K)
Fig. 13 Temperaturedependenceof grain growth Íateat 0.1 MPa' Ě is a rateconstantdefinedby eqn.(1) in the next:(A) Íotn:2;
( B ) f o r n:3 .
lrE )
e^d 1u ÁEreuo ÁJ€punoq urer8 eql leql
ueeq s€q u eJeH .(€dc
I Jo BdIN 00€
qloq)
eql l3
suorlrpuoc
ee4-JolB^\
w
tLsI
IP/N)/G/u)
pep
*-0I xr, - w puesuorlrpuoc
.P.JalB.{{ eql l" (,ut/y{/(s/u)
gr_0I x s.Í - W
: elEJ qlnorB urer8 pe'rresqo oql tursn peleru
-Gse eru serlqrqou fuzpunoq unr8 eql (6) 'uba
roJJ '(286I 'lpetqqo;4 pue redoo3 :zu/t t-)
ffiraue Árepunoq urur8 eq1 sr l. pue (s96I .treIItH
:s.0-) lu?lsuoc leuolsueulp-uou E sI í eJeqd\
(€ )
W LV :1
:(7: u rog) Áq .,;zg.Á1r1rqourÁrepunoq urer8 eql
o] pol€ I eJ st (1) .ube ut .7 .lue1suoc elBJ eq1,
'lueuodurt
tn
a
{
q
q
d4
lryt^
nl|Gú|ř
aí4
7,nr.ň
FFq
F1 1 {
r lutut
traPr
't s tu,
.---0t
[[suls
iT ASEJ
plo.É
Etrusa
)qf
lrpuoc
r,\Ivuc
aq u"c uorlurode,le Jo slceJJe eqt w 'qpeg aql
ol Pdl^tr I.0 lB sllnser plueuruedxe eql turÁ1dde
ul pesrcJaxe oq lsnIII aJBJ 'JorJelul s.qlJ"a eql
ur }uelrodun eq lou III^\pu€ .Sunl álnsseJd q8.rq
aql w pe^Josqo se 'sarnssard tururyuoc qtq tu
passerddns ásJnoc 1o sr (s)eseqd seB ;o uorsuedxo
eql ol enp 1uorudo1e,repÁ1rsoro4 .(9961 .s1oqct51)
.utn1
lrodsuerl sseu eseqd rodu,r eql Áq pa11or1uoc
.sr
qcrq'rr serod 1o uollolu eqt Áq palloJluoc
ur
sI ?dI^I I.0 1B suolllpuoc eeJJ.Jel€^\ le r{y'ror8
urur8 eql teql palsottns sr lI oroJeJeql '(gt6t ''1r.€c) uorlurode'\a
le elueculd i1otll/14 099
Jo 13eq
eql ol esolc sr tnq '(686I 'o1uru;1 iyg61 'tpoclg
pu" lpels1lo) .aes,tral^eJe rc1ipts/1{ 00'-00€ )
euIAIIo ut uoIsnJJIp cluol Jo luql uuql retre1 Á1luuc
-gr.uBls st (1otu/11 oo9-gzs) Átraue uoI1PAIlc?
peletrrrlse aL1L'(LL6I'Kedlru3 16961 loorg) eler
qlnort urur8 eql sloJluoc serod ;o uorlour eql luql
Butlse88ns .(tt .tlg) Seuupunoq urert 1z Ápsour
peul€IueJ sero4 .tursserd-1oq 8urrnp (pen1osstp
ro) peddu4ue su,t\ l€ql (s)eseqd se8 ;o uorsuedxo
uE o1 enp pedo1enep Á1quurnsard s€^\ esec slql uI
Álrsorod eqJ .seJnsserd Bumr;uoc qtt.{ te elBJ eql
uer{l Je.&ols qcnru sE^\aler qprort urert eql puz
paseeJcul Áltsorod .elnsseld Buruquoc Bdl^tr T.0
lB páI€euu? ererrl sa1dtuespasserd.1oq aql ueq^\
.(9961 .uosre1e4)ernsserd uo Á1tuor1sspuedep
z1nnb uI Jele.t yo Á1pqn1os eql aculs .ursrueqcaur
.usruuqcetu
el€ls pqos e Áq paum1dxe eq 11e.,rr,{eru
lrodsuerl eseqd prng JoJ ecueplla s€ peJeplsuoc
"
(zsor) punÁ pu€ sqlnJ qcrq^{ ,z1lenb ur q},rrort
urer8 ;o ecuepuedep arnsserd etrel pe^Josqo
eqa 'qlrnor8 urert ur pa^lo^u scllaupl el"ls pqos
oql socu?qua surur8 zlrcnb ur pellosslp JelB^{oql
luqt elqrssod aq o1 sreadde lI 'sele8erEEe zlnnb
uI luIIJ snonuuuoc B IuJoJ u€c Je}?1I\Jo luno(u€
.urelsÁs euI^TIo-Je1B^\
il€rus € JI u,t\ou>l1ou sI u
agl ur u€ql tueIcIJJe eJolu uralsÁs zlrunb_ralezrr
eql ur lrodsuerl sseur eseqd pInIJ oql e4eur Áeru
Jel?^\ ur zlnnb yo fiqrqnlos re8rul eql qS.oqtIV
.ruelsÁs euIAIIo-Jel3^\ eql ut
1rodsu€Jl sselu
eseqd prng Jo eloJ luulrodurrun peJJeJuI eql qlr^\
luelsrsuoc eJB suorlu^Jasqo asaql '(7461 'orrqsn;
pue €Jnul"{e5|
zirunb Jo luql u3q1 JeIIBtus
qcnu sI Jelv,ry\uI auI^ITogo Á1qtqn1os eql leql
uÁ\ou>Isr 1r .os1y .(rup; snonutluoc E IuJoJ 01 JelB^\
.o
.€c sI ouIAIIo
Jo lunoluu [I€Ius B ro; etrz1 oo1 06
-euhrlo-Jele'u 1e a13ue lPrpewp eqt) serod pe1e1
-osl s? SJncco Jeql?J lnq uIIIJ snonulluoc € IuJoJ
lou seop serJppunoq utert aun11o lB Jalu.4aeql
l"ql (g 'Erg) uaes sr 11 'atru1 eq lsnu pmg eql uI
pllos Jo (Á1prsn;pp eq1 puz) Á1ryqn1oseql .puocas
.selJepunoq urer8
le uIIJ snonulluoc € tuJoJ lsnru
pmg aql '1srrg 'e'rrlcaJJe aq ol lrodsuurtr sseuJ
aseqd pmg B JoJ letu eq lsnru suoulpuoc o^\I
'JelB^\Jo acuosard eql ur qy{oJt urer8 pecueq
-ue eql ro; e1qrsuodseJ aq ol peJeplsuoc sI Jel€^\
qtnorqt lrodsuerl sseur .(7361) punÁ puu SII1nI
o1 Burproccu 'ereqm zlnnb ur es?c aql ol lsuJluoc
uI sI sT-tIJ.(qsor) .IB 1e o1BJe) Áq pa,r:esqo ueeq
s€q eurnllo ur .uorsn;;rp pus uollour uollzcolslp
s3 qcns .scqeur1 et€ls pl1os turcueque uI Je13^\
pe^Iossp Jo lceJJe eqa .eseqd Je1B^r€ qEnorqt
lrodsuerl ss€tu 01 ueql Jeq1BJ ecIllBI outallo eql
uI Jel€^\ pe^Iosslp Jo slceJJe eql ol enp eq lsnlu
Jol?1y\Jo ecuaserd eql ol enp qltrorE urert ;o lueu
-eJu?rTue eqr '(g '3rg ees) solrupunog Bur'rotu uo
ecroy Burp ? lJexe ol u/$oqs are serod peIIIJ-JelE^\
eql ecÚS .(Á1rsuepl"clleJooq1 oÁL6<) 1uurs st Á1t
-sorod ueq.r 'suorlrpuoc aeJJ-JelBA\lE ueql reqtrq
Á1luecrputrs sI suolllpuoc pepp"-Jele^\ Jepun
eler qynorE urer8 eql tuqt 6 'Btg ruoJJ uees sr U
.(LL6I,.Ie
1e uea) serod ;o ecueserd eql Áq
pesodur ezrs urer8 8'p'...'I € l€ pe1€unuJel eq esl^\
-Jeqlo plnoa qcrqrrr 'qplort urert snonurluoc dleq
pu€ BeJ€ ecBJJns l€lo1 Jlegl acnpeJ p.tr serod ;o
8uruesreoc .esec Áuu uI .seu€punoq urert q8norqt
Á1qeunserd .selod ueeltleq Je13^\ Jo uoIsnJJIp
eql ol enp Á1ururu sr serod ;o qyrrorB aql l€ql
eroJereql pe1sa88ns q lI '(8 '3rg ees) qlmorE urerE
.r,u1-erenbspe^Jesqo eql qll^\ luelsrsuocw sr qcq^\
I-\i OLN-INE
r groB.tbf
is ůe same as at water-free conditions.
grain boundary mobility may also be
from the observed abnormal srain
{.rf
Yund r
E\č ua.E{fl
y a soLid f,lE
lter
In qrl!ill
m. l98ór
rc annealod rru
rq ucreasd
I sloq'er rlrr
The porosít.l
:d due to a
ntrapped (cr
les re6ain6{
ll sugesting
Igrarn grouth
ibe estimated
ll is signinůrn rn olivine
(ohlstedt and
i close to the
L Piacente et
ňat the grain
0-1 MPa is
rhich is, in
rrss transport
rt due to the
r suppressed
cned in the
rmportant in
exercised in
0-l MPa to
rtion can be
is related to
Íorn :2);
(3)
rrnt (- 0.5;
tdary energy
1982).From
ies are estimth rate at
re water-ad/s)/(N/rď)
1573K and
en assumed
water-added
sssuming that the driving force in this
b ňe grain boundary energy of consumed
Erains in the matrix. This gives M - 7 x
*
269
AGGREGATES
tm7s;76N7rď) at 1573 K (-3x10_14
N,/m') at 1473 K), 300 MPa and water-
mďtions.
These results are in good agreerith the grain boundary mobility estimated
tbe normal grain growth. Since pores are left
tbe moving boundaries in abnormal grain
ffi
(see Fig. 10), this agreement indicates that
tFtň
boundary mobility at water-added con&
-rrain
ÚÚfuns in the normal grain growth situation is not
nů
ďfected by the presence of pores. Therefore
Ůc present results in water-added conditions may
h applied to the Earth's interior, where the
of water is presumably smaller and there-nrnt
be the number of pores is much smaller than in
'- present study. The observed magnitude of the
rnhancement of the grain boundary mobility due
n ůe presence of water is similar to the magniwde of the strain rate enhancement in diffusion
uerep. both approximately one order of magnitude
tKarato et ď., 1986). Note that the observed enbncement of the grain boundary mobility may
crylain the enhancement of dynamic recrystallizadon due to the presence of water (Chopra and
Paterson, 1981, 1984). However, the mechanisms
of dynamic recrystallization in these cases have
not been studied in detail.
The grain boundary mobility may also be
estimated from the rate of primary recrystallization (the grain boundary migration driven by ďslocation energy). Using the data of Toriumi (1982)
at 0.1 MPa ("dry" conditions), the grain boundary
mobility at 15'13 K is estimated to be - 0.8 x
70_1a (m7s)/(N/Í,il,
which is in reasonable
grain
agreement with the
boundary mobility
estimated from the present results. This is rather
surprising since Toriumi (1982) noted a thin melt
film in many of the grain boundaries. The agreement, in order of magnitude, of the results of the
two studies suggests that the enhancement of the
grain boundary mobility by the presence of a melt
phase is not very large under these experimental
conditions, although significant enhancement of
boundary mobility by a melt phase is often reported in other systems (see, e.g., Urai et al.,
1986).
When pores do not significantly inhibit grain
boundary migration, grain boundary mobility may
be controlled either by intrinsic mobility or by
impurity drag (e.g. Yan et al., 1917). Intrinsic
mobility refers to the mobility that is limited by
the rearrangement of ions near a grain boundary,
including detachment from one side and attachment to the other side of the grain boundary
which is not affected by the presence of impurities. The intrinsic mobility is often related to the
density of steps of grain boundaries where detachment and/or attachment occurs. Since the density
of steps is related to the crystallographic structure
on grain boundaries, the intrinsic mobility can be
anisotropic and often results in facets (e.g. Yan et
a|., 1977; Smith et ď., 1980). In contrast, grďn
boundary mobility controlled by impurity drag is
less anisotropic and grain boundaries will not
show facets (e.g. Yan et a1.,1911).Olivine crystals
studied here sometimes show facets (Figs. 6 and
10) and many of the dislocations (presumably
screws) are perpendicular to the grain boundaries
(Fig. a). These observations suggest that the grain
boundary migration in olivine may be controlled
by the intrinsic mobility under the experimental
conditions. However, more detailed studies on the
effects of impurities are needed to clarify the
mechanisms of grain boundary migration.
Similarly, Tullis and Yund (1982) found that
impurities (hematite and calcite) in quartz aggregates have little effect on grain growth, and the
quartz crystals in their experiments show facets.
They attributed the observed small effects of impurities to their high solubility in water. Thus in
this case again, the surface process(es), rather than
a fluid phase mass transport, is likely to control
the grain boundary mobility. Urai's (1983) observation of faceted grains in the presence of a
fluid phase may also be interpreted in a similar
way.
Geological applications
The present study has demonstrated the important roles of temperature, water and pores in
Árepunoq urer8 ro; ecro; 8ur,rrrp eql leql
P uaeq s?q 1r 'uorssncsrpe^oqBaril uI
'selrlopuad peurJoJep
qlznorB
urer8 ro; acuap
eql
eruos
ur
Jo
{em1eu
.lr:l pezu€uutns
(3161) s"IoJIN .(9161 .reTrlo6
.3.e)
sqtr1ouex cIJ€Iu?Jun o1 pereduoc
trrB s€IooIN
(ssar1s q8q aqt pue) sern1eredure1
Á1e,rr1e1er
'u'o1
pu"
uon€
IuJoJ
ere
Jncco
o1
Á1a41
8ur1ueuuu
F
.se1r1opued
adÁ1-eurdp ur 1uaurdo1ea
€p qcr.q^\ur
.op IBJnlcnJlsoJcIIu eql q e1or 1uu1rodurr ue Áu1d
Áuu q1r'rort urur8 eroyereq1 .sseJls 1upr.q q8r-q
n/pue sern1eredrua1rrro1Á1e'rr1u1er
1e Áre'rocer uor1
-Bcolstp ueql luepodrur eJorrr sr qlnort uwrt eql
.suolllpuoc eeJJ-Jále/Y\aql JoJ esoql
lBql uees sI lI
Iuo{ lueJeJJtp Á1atre1 oq lou IIII\ suolllpuoc pep
-pp-Jet",r\ er{l roJ sqnser eql eJoJeJaql pue '(9961
.t.e) Á:e,rocer uollzcolslp ecuequa
..[B
le ol€JB)
o1 Á1e1u osp sI Jelzat Jo acueserd eql .JeAe^\oH
.poJáplsuoc eJe suolllpuoc aeJJ-Jel?.,n aql Á1uo
aJoJeJeqt pue pelpnls uaeq lou suq Ára,rocer uollec
..IB oJule)
-olslp uo Jel€ ^ \ Jo lceJJa aql .(086I
le
,ezleo9
pue 1pe1s1qo;) uot1ezq1e1sÁrc
:vtst
qf
qÍl
-rpuoc eerJ-Jel?A\ pu" pepp?-Jal?^\ Jepun sezs urBr8 eql
^\oqs
seu{ ua{orq puB seuq pqos 'pewnss? sl 't1: fs.) - 7s9 'ne1
qlnor8 urerB e.renbs y '(luelsuoc eleJ: I 'azrs urer8 1eqrur
:oSC
'rt/!SC <<t) tugpeuue eurl-8uo1 relJu 'S'C 'eumtlo
ur ezrs urBr8 go ecuapuadep ernleradural pu? eIrJrJ 'tI 'tld
_'..Ť
-a
Ú
'(7961'rurntrol)
.suoll
Ioul,/f{ 0Tz aq o1 peunss? sr ÁBreue uotl?^Ilc" áql
.Á1enr1cedser
suorl
-Ipuoc ee{-JeluÁ\ lepun eas urBrB eql Joc
F
i lt
(t!Í|)ezls u;e.r60loo;
3
o
o
t
o
q,
x
lioĚc
Ntvuo
orvuvx
s
-er crureuÁp pIIB uo4zruJoJep Jo e1u1sÁpee1s eql
o1 turpuodseJJoc SenI?A e^Bq ol peunsse eJB ezÍs
urer8 pue Á1rsuepuoll"colslp I"DIuI eq1 .uorle1ncpc
sTt{1uI .Á1e'tr1cedser.orn1go Jolc?J B Áq ezrs urzr8
esBeJcur ol pepeeu eurl eql pu" o^\1 Jo Jolc"J
Áq Á1tsuap uollecolslp eszeJcep ol pepeeu etull
oql Áq peulJep eJE SeIuIl cllsuelJeffqc aq1 .91 'ttg
ur pe11o1dueoq sBI'Iql^\oJ8 ulerB ;o puu ÁJa^oc
-eJ uorlBcolslp Jo seurl crlsuelcBEqc eql '3u1
-I"elrue cr1uls 3urmp ezIS uTPJt puu Á1rsuep uol1uc
.suolllpuoc
-olslp Jo Á1ryqz1s e^IlBIeJaql Á\oqs oJ
pcr8o1oe8 eluos Japun Burpea1srureq Áeu (3161
'su1ocr51 't'a) firsuep uorlucolsrp uuql tuIIBeu
-u€ cllBls lsurete elqBls eJolu sI ezls urer8 pazr1
-1u1sfucerleql Jelleq uoluruoc ? 'lsJld 'suotleclldurt
pcrBoloaE lueuodrur IeJeAes e^Eq slFseJ eql
'){
gosl lE sJnoq € 0 l-zg1 ul Á1uoJncco ilI/Y\.a1druexe
JoJ .uIÍÍooT ol qu\oJc .asues 1ecÉo1oatz uI lsBJ
Áren ere auIATto uI selBJ q}nort urerB aql .suorl
.l€ql
-Ipuoc pel3JnlBs-Jál€^\ Jo ea{.Jel?^\ Jeqlle uI
uees sI 11 .pa1cepau eJ€ seJod Jo slceJJe eql eJeH
'tI '8lJ ur u^\oqs oJe puu sllnseJ pluauruadxe
aql uIoJJ pel€1ncl€c eJ? sezls urerE c4oldurÁs€ aql
.e1er q1lrorE urert aql
Jo el€tullse qtnor e unlqo
ot'Ot/0,(Sg) <<t) qtnoue Buol sr erurl tulueuuu
eql uaq^\ 099 ezts IBIllur Jo e,rrlcedserrr ,7rQ>t)
- s:9 enl€^ ctloldurÁsu u€ e^Bq 1ri*r azts ururt
eql tuql sotpcrpur (1) 'ube qprort urur8 eq1
'(986I
''Ie le olere;) daerc uoqBcolsrp JoJ pe1se88ns
ueaq wq se .4eelr sl Á1rcutn1JáIP/Y\uo e1er qprort
urur8 ;o acuapuedap aql ;r uol1dunss€ alq€uos
-pal B aq plno^\ sq.L 'eIluBIu reddn eql ur suoll
-Ipuoc pepp".Je1€^\ 1E e1eJ q1'tror8 umrt eql ruor;
lueJeJJIp qJilu lou eJB Bdl^tr00€ l€ suolllpuoc
pepp"-Jel€^\ 1€ p3ul€lqo Bl"p aqi l€q} pelunss€ eq
'Bc sI rel?^r
III^\tI '(986I ''IB 1e o1ere11)EdIAtr0SI
.etnsseJd
turuquoc Bdl^tr00g
;o Á1rcuBn;eql eJeq^\
1e Á1uo pelpn1s ueeq s"g JelB^\ Jo lceJJe eqJ
.olluuu reddn redaep eql W
llleuodrur eq Áeur
.paraprsuoc
eq lou IIlh l}áJJe arnssard
1r q8noqtp
eql 'uorssncsrp Bur'no11o; egl uI 'sun.t
I I'0
"dI
egl ur luetudo1errep Áltsorod eql ol enp Á1snor'rqo
sr setnsserd q8r-qpue €dl^i I.0 uee/Y\leqSuolllpuoc
eeJJ.JelB^\l€ elPJ q/rrort urerE ur ecueJeJJlp luBc
-ur-utls pe^resqo eqJ 'Irulep ut perpnls ueeq lou
suq ernsserd Jo tceJJe eql 'eur^T1our qyrror8 urer8
'fl!lt-:-
-
ryliLrat
I\
OLI-I\E
2,7Í
AGGREGATES
pÍocesses of static annealing in o|ivine
:,slocation recovery dominant
t.
-'.9
4'
!
n:n:-
@r
#*t
nl
x
I
I
F
t
J ' =,
I
I
I
-''
-ol
J
log.,oin it ia l st ress
Í =::n size =
65. :: GS :
e 3:-:rn eÍorr_h
rC :r..ken lins
*=-iree condrt-iree
condiE : t rl
kJ ,/mo l
Domrnant processes of static annealing in olivine
ft- ii
Initial dislocation densities and grain sizes are
IEFEE3Iň
steady state of
'Err-pti ro have values corresponding to the
uá:r:uúon
and dynamic recrystďlization, which are derers:erl
l€ l r on dislood rherefore
considered.
bo likely to
rrato et al.,
ts \\'ater-adřerent from
L<seen that
M-n dislocaures and/or
tro\\'th may
ructural den n'hich delct occur at
igň stresses)
\icolas and
nrized evirc naturally
Ír assumed
lary migra-
by the shear stress acting prior to static annealing
sciÍc lrnes show the characteristic times of dislocation recovery
Krnro arrd Ogawa, 1982) and dotted lines those of grain
gr':r$:
gÍzČ. I974:
(MPa)
both for water-free conditions. At relatively high tem-
initial stresses, dislocation recovery is faster
leerures/low
m"- o-rain growth, while at relatively low temperatures/high
ml.:el stresses, grain growth is faster than dislocation Íecovery.
:ron is grain boundary energy. At the early stage
.rf static annealing where many dislocations still
erist, grain boundary migration driven by dislocadon energy may also occur (primary recrystallizadon; Toriumi, 1982). However, primary recrystallization is a heterogeneous process and the
quantitative estimation of its effects is difficult.
Second, although dynamic recrystallization
might reduce the grain size to something small
enough to promote grain-size-sensitive creep,
thereby resulting in softening (Twiss, 1976; Karato,
1989), this effect will be ephemeral since grain
growth in diffusion creep is very fast. Rapid grain
growth will increase the grain size again, and
dislocation creep and resultant dynamic recrystallization will occur again. Thus cyclic softening-hardening might occur as a result of grain-size
reduction and subsequent grain growth. At preSent clear experimentď evidence is available only
for hardening due to grain growth during diffusion creep (Karato et aI.,7986; Karato, 1989). No
convincing demonstration has been made for
softening due to grain-size reduction during dynamic recrystallization (see, e.g., Twiss, 1976;
Zeuch, 1982; Karato, 1989). A possible complex
rheological behavior associated with grain-size
changes during deformation will be an important
subject for further study.
In all of the above discussion, the role of pores
or secondary phase particles and the possible effects of differences in the nature of impurities
between experimental samples and natural rocks
are neglected, although fluid-filled pores and impurities are common in grain boundaries of natural rocks (e.g. Waff and Holdren, 1981). The effects of pores or secondary phase particles depend
on their mobility and distribution (e.g. Yan et al.,
1977). Their effects in retarding or inhibiting grain
growth are a maximum when they are immobile
and finely dispersed. The present study has shown
that the size of water-filled pores increases with
grain growth, and that they do not have a significant effect on grain growth when their amount is
limited (ca. > 9'7Votheoretical density). Also, the
effects of impurities appear not to be very important under experimental conditions in which
grain size is small and the driúng force for grain
boundary migration is large. However, the effects
of secondary particles or impurities can be important in some geological situations in which
grain size is large and the driving force for grain
r
boundary migration is relatively small.
Acknowledgments
I thank M.S. Paterson and K. Kogure for the
use of the Paterson-gas apparatus and the Elzon
Particle Counter respectively. This paper was completed during my visit to University of Colorado,
which was supported by CIRES and NSF. I thank
H.A. Spetzler for his hospitality during my visit.
Careful reading of the first draft and the detailed
comments by M.S. Paterson were useful in improving the paper. M.R. Drury offered a comment on
the possible role of fluid-phase mass transport.
\o .986I ..s.c .JálsIT pu? .o.1r\ .suPeI^I...I'f .Ť?Jo
.ssÁqdouo1caa
oolrzrlplsÁ.rcor
L9Í-9zI
.ellloqJslq auqp1sÁrcÁ1od ur Burua1zairr
crureuÁp polsrss? Jele^t .t86I .'.I.f .I€ J n
'wz-LTz
..sÁqdoeg .1ddy arn4 .re1aurozerdoapdezrs uru:B
z ;o Á1pquc11ddupuz fuoaq1 .LL6I ..f.u .ssl'tJ
rrm{-88:€t ..lláT .lcs .lau€ Id qll"a .eIluBuIs.qu?e eql uI
..f.u .ssI,''ÁJ
tfuoosn J"áuq PuE Á1rc4su1dredns
1ulnlcnJls '9.6I
'8IE-T0g :06 ''loeC '1 'se1eBar88r
aycpc puu zltenb
!B scrraup{q1\or8 urer5 'Z86I ''V'U 'pun^ pu? 'f 'slIInJ
..Jelul .letl?ld qrreg 'sÁq6 .ernsserdclraqdsoul1e
Et-9z :0E
D aln^Ío ur uorler8rtu Árupunoq urclo .z8óI ..I/{ .luInIJoů
'V t- L tE 'd d 'o q 6
.cos .urv .sc4áury pu€ eJnlcruls fuupunog
Tsd sIBleI{
oerg '(rorrpg) gJnneg '71\'U :uI 'uorter3rru fuypunoq
uErc '086I ''w'u'3 'roue^orDpu? 'g'I^tr'J'eBu ''v'o 'qlTurs
.
.Á1.z11r5'sseco:d
66z_68z :61
mnezr.rodenaur^TJoJo uorluBrlsarrurculeuro:1ceds ssu141
.it6l ..^ .oÍoud pu€ .W .Ilqods ..f .{^snolBI^I
..n .a1uecet6
Ic
.
.'IPJáuII^I'ureq3
.sÁq4
:t
99(,_snz I
.uosJel?d
.98óI
..s.I^I
zuenb ur Jal?^rJo scrureuÁpouraqláqJ
'929-Lrg tL
-us 'u54l 'qcaw {rou 'f 'lul 'uon"uroJep {cor:o; snlu:td
.uosJel?d
-du ernsse.rdqBru arn1eradurelq€ - rq v .0t6I ..s.I^l
'LLZ)-z,17)
:69 ''cos 'rrr?JeJ 'ruy '[ 'alrcl"c ur q]t'o:8 urerBuo sa1cr1:ed
aseqd-puocesJo lceJJA '986I ''S 'su?^g pu" '1'q 'prue316
'dd wv
.uopuoT .Áe1t16.s1coa crgdrorue1eyquI Aro[ď el"ls
PIos
pue Á1rc4se14auTIp1sfu3.9t6l ..d.f .Jeulod pu" .y .se1oct51
.tzI-III :9T ..Jes.uÁpoag .uorun .sÁqdoeg
.tuy .ue1sÁ5areqdsouoqlsy-eraqdsoqlr1eqt
;o scrueuÁq
.eJ$cruls .uolllsodulo3 .(sro1ryg)xn"^áploJg .J pu€
Pu"
sqcnJ .x :uI .^\eI^aJ
B-alnopued e1lueulreddn ut Ádorlos
-ru" Jo uorl"ruroC 't86I ''I'N 'uesuelsuqJ pu? 'y 'se1ocr11
'19-6V t88Z'V
'res ''puo'I 'cos 'U 'supJJ 'solntd 'salqopued eltueru auros
ur serpnls l?Jnlrruls ruo{ sel?untse sseJls '816I "v 'sPIocrN
.(o9n-66sb :1g ..sÁq4
.1 .s1ced
1ddy
.uroc snorod ur q1rnor8urer8 ;o ÁJoeqJ .996I ..v'd .sIoqcIN
.8s(,_sgz:€ . ,.qJ?eÁ
.qs?^il.1sul eÉeuJ?J .q{
9I 13 ozH_zo]s_'oTsz3}t uI
eseqd seBgo uorlrsoduro3'VL6I''l 'orrqsn) pu" '^'Ernuru{pN
'7r7- L 6r'd d ''J'C
.uo1Burgse11.uorun .sÁqdoec .ruv .scruEJIoAJaqlo pu?
sálqJáqury ur suolsnloul :e1due5 ellu?W eql .(srot1pa)
reÁe1i .y.g.11 puu pÁog .u..{ :q .uorsnJlul elTlJequp1Jo
scrureuÁpáql pue sqlrlouex elTlopued .6L6T.J.J.Í .JáIcJoIAI
'qW-EW :ZS ''cos 'ru?JeJ 'ruv 'f 'scnupraJ
euqp1sfucÁ1odur ezs urer8 e8uraay .696I .'I.]^{.uoslepuáI^I
.ý.-6I |99..3os .lu?JeJ .Iuv 'f .suorlnlos
p11osEgzeg-gt11 pue OBt{ uI q!$or8 urer8 pup uort
.nqulsP ezts uIPJo .IÁ6I ..S.u .uoploc pu€ .c.o .lueqc:ey1
.o8.-I9z'dd .Á.N .{JoÁ
.sseld
^\áN
cTrrrereJrn uorlerriloJeq '(s:o1rpg)
umueld 'II 'slelralpl^tr
oJ.vuvx s
lperg '3'a pu? Jelsserl 'A'U :uI 'eul^rJo elacrlls ;o deerc
a:n1eredure1-q?IH .ý86I ...I.C .l1nocry pu" ..I'o .lpelslqo)
.Ís0(,_svI(.
:6L ..se)Í.sÁqdoeg .1 .qelsÁrc-afuls eul^qour deerc arnle
.ledurel-q81qsseJls-/t\o1.v L6Í,? .ezleoD puP ..I.o,lPats1qo;
..Á.N .{loÁ,rcp .Áa1116
.sctruulal ol uoqcnp
.dd
z€ o t
.9L6I '.u.o .uu?IuFInpuE .x.H .uá/r\og.'o.^t.fua3u51
-oJlul
'Ltg-gVg :8t ''ros 'uural 'urv '1"s1ceduroc
snorod ur qlltort ure:g 'S96I ''S'srocueJg pue 'CI'1r\'&aBury1
.9II8_I9I8 :16 ,.sad .sÁqdoeg.f .Jol?'t\
Pu"
ezrs uru.r?Jo acuenlJur :salB8ar88eaur,rqocr1sq1uÁs
1o ÁEo
.IoaÍN .986I {.o.f .pl?Jeczlt.{ pu" .s.nt .uoslel€ d ..s .ol?J?)
.sÁqdoag.daarc
.í,s9-6ý9:
L,.ne.I.saa
a:nleradural-qt1q3uunp splsÁrc eputs áut.l'tloJo uoIlBzTII€ l
.sÁrcar crureuÁCl.086T ..J .11[nJpuv .t^I.runuoů ..s .ol?l")
'LÍI_.SI :8z ,.lalq 'reuuld quua .sÁq6 .eurn1o,r
uoIl€ A IlcE
deerc pue sursTlr?qcou daerc ro; suorlecrldurr :eur,r11o
.z86I ..W .eaaeBgpue 's ,o1ÚJ3)
;o Árarrocera:nsserd.q8t11
,80z-9LÍ
.qlr€ a eql
.dd .p.ro;xg .sser4 Á1rsrslrun
Jo pue
PJoJxo
spllos Jo ÁBo1oeqg.(srotTpa)FunTJoJ.IAIpu? olBJ€ ) .s :uI
.aul^qour uou?tuJoJepct1se1dpue slceJec .686T ,.s .ol€ J ?)
'zzI_L0Í
.eur'l11o
.leu€
I
d
.sÁq6
..Ialul
qlJ€
a
uoneluauo
:lg
Jo
perra;e:dáql uI uoll?alp1sÁrca:;oeIoJaqJ.886I ..s .olerey
.
.sÁqdoeo
.dd .'c'c .uo1Bu1qse16,uorun
I Ln- 99ý
.ury/oÁ4o1 ..IqndclJlluelcs r:aa.sctsÁq6
IEJeuII{uI gcJ€ es
-eu eJnsseJd qBrg .(srotrpg) ouoÁ5 .a puu tuuuqtuu;41
.H.I^I:uI
;crurtuÁp Jo 3ll?tueuDl :sIPJeuIruJo uoll4ualJo
perra;ard eolll?I ol anp Ádor1osruucFus}as .L86T ..5 .o1e;e;1
.gLÍ-99I :761 .scrsÁqdouolceJ.allwru :addn
aq} Jo ÁBoIoeqJpuu uotlnqu}slp ezrs-ul?Jo ''86T ,.s .o1€ J € )
'gtz- LZ(,:gI''lplel/{ ylcy'qpno.r8
urer8 pur:ouqe pu? Iururouyo ftoeqt eql uO '996I ''yq 'UallIH
'8ZZ-n(,
.dd .oÁ:1o1 .suollec1qnd ciluep?cv JoJ lalueJ 'sctsÁqd
-oeg uI rlcrEeseg ernsserd q8tg '(slo1pg) rueuqBuzyq
.H.I^I pu? olouD1v '5 :u1 'ure1sÁslI?sEq-euI^TJoaql
ur Á8reueplceJJelul .z8óI .'T'o .lParslqo) pu? .J.u .radoo3
.9L8L-Í98L:68 ..sau .s,(qdoeo.f .alrunp uoll€ uloJep eql
Jo
ur rel?^\Jo eloJ eqJ 't86I ''S'W 'uosrelud pue 'N'd 'erdoq3
.EL7-E1Ý :34 .sctsÁqdouolca1.elrunP uoll€ t uJoJáp
Jo
p1uauruedxa eq1 .T86I ..s.I{ .uosJaled pu€ .N.d .zrdoq3
' gLZ- I9Z'dd''o1o3'lriar lsel1' 9a. seJnlcnJlsorcll4l
crluereC
.v.f puP gl?Jlnc .ni'u :uI .seJnlcrulsoJcllu
.(sJollpa)
Is€ d
cTtu€ J oc uo turp arod ;o lceJJá eql .Át61 .'V.W.c .Áed:e3
-(,Íg_oI9:90z .aI/\iIV.suer1 .sa1durzsenbedo
ur suorlcunJuollnqulslp azrsa1crpedturuptqo ro; stsÁpue
I"eurl Jo esn aql uo '9s6I '''I'u 'uPrrrllnd puB 'A\.f 'uq?J
'L9-59 :75 ''cos 'urureJ 'ruy '1 'qt.tor8
pue
suollc?Jelul Árepunoq rrre:8.alod'696I ..r.u ,IooJg
urer8
.'II-98 :g1 .scrsÁqdouolcaů'sql{ouax
e1r1opuad
IuolJ acueleJul :opuzru:addn aqt 3o ÁBo1oeqg.086l ..^.f
..o.H .luBuIoII?.I
.sso.l{pu? ..I.N .Jeu€ J ..J.f ,JeIcJeJ^I
?^V
soJueJeJeu
7t7
273
Di OLTVINE AGGREGATES
S
*. u.
in minerals. In: B.E. Hobbs
Mileral
and H.C.
and Rock Deformation: Labora-
I sIZe
rd
Holdren. G.R. Jr.. 1981. The nature of srain
in dunite and lherzolite xenoliths:
}
tl'oá. vqp
fu Kimberb
n \l'eshingn
mof
eas phag
lnst. B'eÓ-
ř
I porous cmra] stuďes il
ir- I-ond., Serntion
of anir- In: K. Fucbs
$ructure, and
r Srstem. AmL
Plasticity and
liler'. London.
'rcond-phase
Eem, Soc.,69:
r pressure apH- Min. Sci.,
I€Í
rn quirrtz.
do.
V., 1975.
l raporization
* 1980. Grain
ftor), GrainDíetals Park,
in olivine at
r- 30: 26-35.
I bnetics of
L -318.
er
úscosity
, 3 3: 88-100.
Í€crystďlized
nphys., 115:
illi'ation
and
rryhysics,96:
86. Dynamic
M.F.,
Cannon,
R.M.
and Bowen, H.K.,
197'1. Grain
boundary migration in ceramics. In: R.M. Fulrath and J.A.
Pask (Editors), Ceramic Microstructures '76. Westview,
C olo. , p p . 2'76-30'1.
Í}-Fe.o=
I rbe ot
Yan,
rc|r"
qm
tÍÍlllsport in refractory
implications
upper upper
J. Geophys. Res., 8ó: 367.7_3683.
mantle
Zeuch, D.H., 1982. Ductile faulting, dynamic recrystallization,
and grain-size sensitive flow of dunite. Tectonophysics, 83:
293-308.