nat sci minerals part1
Post on 21-Oct-2014
759 views
DESCRIPTION
TRANSCRIPT
!
IIIi
. :: .r...,,,-r n r\ ! ! :, *i.l\ tI > ir fd{lut i' ': :
!ti-I1 /!l" i\ r l-
Minerals:l"
1. naturallY occurrtng
2. homogenuous,solid :
3. cornPositicna. chenric':'l (clefinite but.generally not fixed)
b. PtrYsica4, orderecl aiorni.c ?fl'?rrlerl€flts. .trtrrrt f :'rme'l oy ill(lrganic prrrcersses
Mi neral oi rls - natttri:liy occurri n g 4]1ryThgf sr"tbstances
*Tire orderly p.arterns ihat
crystallin u- stru cture
ffq'NERALS
witrtout crYstalline structure
aton:s of elements assume in a rr''ineral is called iis
* Polymorplrs r ntinerals lra"ing the
crystalli;',e struc:t r]'es I
examPles:
same composition/elernents br-rt different
-* Pvt'tqano ir.-arcasite . -;
-- -l -^^^nrla I- Calcite atrd -.-,ragonite .---__ I
*Alias es:1. Caiclte - islan'l sPa;
2. FYrite - 1os1'1i cl'rld
3. Quart;. - ice cnilstals
Georgius t\gr:cola (Georg Bar'rer) D",f.q Metallica- , ..,,,,' ,,, , ,i, ,, . ,
Optical Fic';:e*ies;
2- dotrble refrtl;tion
':---
fff:1":',oJ11J':1,. rrerar oytlrald unngu*rg"3,; consists rr a sroup oi' crvstai
t,,,,"r, Tii';i':*n'.f,-nuuu the same relation to the'"j"ll::::,^oj' ,-th* same chemical an* physical properttes
s':rintlettv ancl cltsPti'
because ;:[l are ui ;.erlain bY
af'ang€'Tlentex. pr,smatic
cubic '
*Nicolas steno - pointed out that the angles between correspo.nding faces on
"rfttuft of a nrine:tai [quartz] are always the same
* Rome de I'Lsle
*Law of consta*cy of Interfacial Angles - angles between equivalent faces of
crystals of the .ru"l* substance, measured at the same temperature are
constant.
2. crystal habit - e.iternal shaPe
ex. botrYoidar, iihrous, grar"uiar
3: color - i': ti:e brightr'.ess or Carl"ness of a mineral :r-,- -^-.-{-r'.._. - resurl of ilie ieflection of light within the visible spe -trum
a. idroch,om:tic - ex. rruscovite (white or c.olorless), azurite (azure blue),
' rnalachite (green): sulfur (yellow)
b'. allochr:matic - ex' quartz
4. streak' is the color qiven by a pulverized mineral
eX'a.hernatite:streak=reddish.brown/indianred| : color = red to black
b lir'ronite : streak = Yq'llow: color = bl''-,wn
5. luster - qual:':, 3nd intensity of right that is reflected frcm I re surface of a
lnir,eral- can be lrouPed into: 'r
a metailic - luster "rf untarnished rnetal; the usual characteristic' of
Iike atoms in the same geom€
I
dark and opaque rnineralsex. nylite, golcl
h. non-metallic - ir,utatl"rizes the colored nrir erals , , l :,
, b. i resit'rous - appearance of resin .
b.; vitrer-rus - glass
u.s ouiil"urt'i:b.4 adamantiire - diamondb.5 silkY - silklikeb.i pearly - iridescent pearl-like lusJer..,
u.z 'grenJv
-rpp"ars to be covered wiil. thin layer of oil
!
i
I
I
I
I
I
x&
A*
6. lrarciness - abiliiy of a rninerill to-withstand abrasion or scratching- in .licated in ternrs of the Mohs' Scale of Hardness
q
114-r5 diamond hardest
Practical scale:
r;, specific
ex.:
gravity. - refers to the ratio of the weight of a volumeof material tothe weight of an eclual volume of waier
- spr:ing scale; hefting the mineral by hand
| 2.65 feld 2.56-2.76old
c. boti a and b
19.3
q. cleavage -,i:iers to the characteristic tendency.of mat,minerals tc spiii. c:'
sepa:'ate easily along certain planes- govenred by interrial arrangement_ weak,:lssl
a. .ype of brr cring \b. greater alomic sPacing
rfectvery good at 9C degrees to each other'
fair at 90 dectrees I9,n9-.--.--iat 56.dsgleeg !r 124 degree.- amohibole
e
Perleei-oei-ellA Oegrees; rhombohperfect _ diamond
calcitefluorite
CLr-coin
feldspar
'r nerft':ctv 'F
sphalarite
g. fracture - refers to the nature.of ir''" surr"ce formed by the ''rreaking in the:
oir""i'"n other than those of the cleavage
' -i-\a' cort:hcidal (ex' quartz)
b ri;'i;;;i'itint"'Yc' hai;'liY' d' irregu'ar
- ^r ^r'"^{rrral rnta: ruintiing or-
l0.parting-breakingalongp|anesofstructuralweakness;resultofttpressure
ll.tenacity-resistarcethatamiiteralofferstobreaking'crushing'bendirig'tei ring
a. brittle - breaks or powders eas.ilY ,
n' tnuiiuuble - hammered into thin sheets
c. sectile - can be cut'into thin shavings with a knife
' cl' 'Cttctile - drawn into wire
". ;;ilL - n*nos but does not return to origina' shape
nr
12.
4'I
14.
', 5.
16.
1'l .
f. elastic
fluorescence' artd phosphoresceneet.
magnetism
reaction to HCI
taste
srnell
striations
. CI.ASSIFICATION OF MINERALIE.I-CCORDING TO CHEMICAL GROUPS
native elements old, sulfur, diamondoxides maqnetite, hematitesulfides rite, qalenasulfatescarbonates calcite. dolomite
apatite
EIGHT MOST ABUNDANT ELEMENTSIN THE EARTH'S CRUST
27.72B.135X0
silica Tetrahedron . basic burlding block of the earth's crust
*polyrnerization
Silicates - most abunCant mineral group r
Feldspars - rnost abundant mineral
(bl Silicon.Oxygen Tctraledron cxpandcd
3.632.832.59
hclsphatessilicates uartz, feld l-
(rl Teuahcdron
(d) Top view
Silicate Structures
orthosilcate ornesosilicatesorosilicate
cyclosilicate
irrosilicate
phyllosilicate' (si2o5)-
lectosilicate
'1. quarlz2. feldspars3. nephelilg4. sodalite5. leucite
epidote, hemimorphite
beryl ,
roxenedouble chain SjaOrr amphibole
sheet silicatequartz, feldspar
framework
t
COMMO}{ ROCK-FORMING MI NERALS
6. mica
amphibole9. olivine
(sio4)independent SiOq grou
(Si2Oz)lir.king of 2 SiO4(si6o16):rinq silicateschain silicates
sinqle chain (Si
II
,l'Definitions:
. -*.. cfrnred, r:onsolidatedirlocirs - r1:ltursuv ::il;;i.;;r, glass oroiganic ttiatter, rocx
4.1 lGNDOus R(Juri"u '
t ^r mrnerals'niaterials whiclr maybe conposeo ut
a cornbination of these' l
Iglteorts roclcs:fLatin "ig7lf$" fire) - fgrrned by direct
nlilgttt' Magntu
crystaUiztrtion and solidification of
- "l{llr,acled nrixttrrd'
E l,s gi il ile;tuilssleri$ii- rnol:ih
-'1,:, t*.,?f,
,lTilo",',u*d r:l:?:51 tlissslvecl sases ' : or in rhe upper rnantle due to
' forr:retl n' o "*uti
Jtltrtr partial *ati'ie ii 't'qti'wer cnist or in the upPer rnar
- ' ';;i;;,';'ic iieat,anrl/ot decreasT:.[:Tlfapped lruithrn
the earth's cnrst
-;.;,i;;'l.placecl on tho earth's surla(
-;;,;;n.,,. cltnmbers
*,*;r{:L::::f;j::,t',# l,"f,f'Na' K,'
-r ^:- S(Oi - PnllclPat- <rjssalvecr gases ;;;ii;:;riiu,*",r uirlo*tv and explosive characteristics
- rilnfie ',f t"nt1t"*tit"J' 6i]0'- 1200'C
- ,]"rir, L'I20-,:aPor, COr, SOz
- Xlrvn
Lli.'ir.r-,j:,Pggn. tltsnltic Inagmfl
l"t. Grnnitic nraEitna
" 50% Si0z. 't:900-12C0"C
highlY fluid
eolr6Y, sloa
' T: lower than B00oC
- highlY viscous
l.Ld.tiri,--nn{erysldliag'lstr . -c^L^ni:'.i.aciion $eries = '-o;j-"'tiy series of change"
J- ' ,1".',-tts Reactiorr Series .,i. ,
.," r in whish the'earlier fornred inrler$s
:; n ll; t' -*:i'iil1: :, : Tf i;' :'il:r:'; il; ';;'i #'oi;"' r'm "''t i' trre
, tt,rti.*. in the mineral
is graduallY
rnrgma'fbr
ex.: plagioclase (Ca-rich torl(rich)f.)iscontinuous Reaction Series : reactiorr in which an early crystallized mineral reacts
with the remaining licluid which constantly. changes its conrposition during cooling to form
ancther mineral
ex.. 'ii,,,, Enstatite + Forsterite + Melt
2 Mg SiOr MgzSiOa SiOz
Magmatic ;lifferentiation : a general piocess in which the original magma with its full
.ung. of cornponent elements is separated into rocks of different mineral composition
a. fractionation
b, filter o:essing. c. assimilation of the wall rock
d. magnra-mixing
Morlqresl-af.tnsglqaa. external.forces - sqrteezing of rnagma chamber and causs filter pressing
b. internal forees - gur **punsion; stoping (magma move along fractures until they engulf
the ho$ rock)
tgnerrus rocks ,
- 80% of the mass of the earth's crust
- Genetically classified intorr''| a. plutonio: intrusivb
li, volcanie = extrusive Ic. liypabyssal
- Mineralo$ically:a, felsic - large proportions of K-feldspar and Na-plagiocl456 + quartz
b. mafic - Ca-plagioclase, large hmounts of{endrnagnesian mlrerals but littlequartz or K-feldspar
c. ultramafic - composed entirely offerromagnesiatt rninerals with minor amounts
- Major textures of feldsPars
Textirre Dcscription Inte'rpretationPhaneritic grains visible to the
naked eve
relatively slow cooling
Aphanitic grains not visible tothe naked eye _ _
relatively fast cooling
Forphyritic some grans coarse,
others line(phenocryst,
sioundmass/matrix)
two cooling rates
no minerals fonledr id s"tft; co4llg witElgSie eg
9X
Most Abundant lgneous Rocks
s.trapes brrfiirtiilve rock bcdies
" Flutoir ='any llass of intntsive rrrck regardless of its size or shape
a. batholithsb. :tcsksc, dikesd. sillse. lacolithf. tupolith
imflb rlancb:' r.retaliic and
' ' : -"L. :- i' (' '
\ro!r:n:iowith the
I
non-metallic minerals (mining): gold district
5.1 Yolungoes ''
!-
: a vdni which connects a reservciir of maguu in the deptlis of tlie earlh's crust
surface of the earth: ejc"ts lava, fragmentaVpyrociastic rocks and gases
: cons (volcanic edifice)
A. Lavanffiu that h1S reached the surface of the earth
- different compositions ancl temperatures iesulted into lavas with a rango of physical
properry (i.e., r'iscosity) and fcafules.
a.. paloeho* riua -:t:glly fluid, T = 1000"c; thin; smooth, biilciwy, ropy suilace
b. aa l.vr - fi'-il; "ibtlu$;
iini.'guq $low moving; seu*rh neters thick;rough'
':' jugg*d, sPinose
c. pittorv-,ta.iu1"-Iffii;pted under water or ice; (toothpaste-like) '
#-
Extrusivefeiric r" ck[ K.ftiltdMptfiioclase, qtr arte, less
amountp of biotite or ampbibqle-. -. .
ffie(30-50% anorthite),
a,rnphibole,, gqoi*. (quartz may be present in
Intrusive
Granite Rhyolite
Diorite'Andesite
amounts of olivine"t'Gali,bro- ' Basalt
I .f
a ,l ll. F!'rqginstic materials
-:il:,:m#*'ffffiT$rrue**,s blown-out from a volcanic vent under pressure or
raoidlv expanding gases present in the magma
- rr*tpoi.d eitfiei+n in solid or plsstic state
- classification in telTns of sizes and shapes of the fragments r -a, blocks - > 64 mm; pieces of crustal layers or older lavas
b. bombs - > i4mm; spindle/spherical masses from the congealing of blebs tllj:d
Iava
" b"l bowdung
' i b'z breadcrustb'3 armored
,0 c. lapilli -2-64 mrn; saccretionary lapilli
4 ash-<2mm
+*r- Pu,nice, scori&, obsidian (volcanic glass)
..'j:a
T:
.;, ..:,ts, domppsite/strntevolcnnoes: altemntingla-yers of pyroclastic rocks and lava
ex.. Mt. ttu.ii, V.r,,nius, Stromboli' Etnq Mayon' Mont Pelpt'Krakatau
' nuee srdente (glowine cloud) : a higtrly hh?{ gas 'charged with incandescent
i ,rt porti"ie, ,oitrut i, i"g"*ii*r u *ouile ernulsio--n ydtidense enough to maintain
lntact with surface '
r.ldera - co.llapsed volcano (ex' Taaf,Laguna Bay)
.;r .:ir
b. Shield ".olcailoes - broad, gently sloping.v-;rcantjes comPo$ed of solidified lava flows;
rarelY stePPer than,f:dtigrees '
ex. Mauna Loa': '
, a
'il. Cindur cones - volcano that is constructed of loose fragmentilpyroclastics;slopes
about 30-33 degrees
ex. Parictrtin
- PACTF'IC RING.OF FIRE/CIRCIJM-PACTTTC BELT
Type of Volcanic Eruptions: -rr --^,.-|.^.rri.onh,erl .,cq.eq*. influencealfnir"ority of the magma aitd a{nourlf oi dissolved gases
- .\iolencs" "'r.n
,*pii* i, ,rtuit io ,rr" o*gree of fragmentation and the \
distance
a. Fflaw*iian - ubundant outpouring of lava flows; lava fountains; quiet liberation of gases
b. Stnoxnholinn - milil, explosive eruption of pasty, incandescent bombs and scoria
ql, accompanied by a white vapor cloud; discrete explosions
- c. vutrcaninn - btsw-out of solidified cnrsts (over the crater); acbompanied by a great-
;;;iifl.wei shaped eruption cloud containing an abundanco of ash; lava'flows may
issue
d. Flininn - eruption of extrerne violence; gas-blast eruption; eruption cloud resembles an
Italian stone pinetree (shooting upward of the column then spreading out); huge'
sustained eruPtion column
Felean - extreme explosiveness; nuee ardente
Phneatic'
F.trreatomagmntic l
Uliru-Ptiniatr - excessive emission of ash resulting to negative landformslLE
g
h.
n*Vqlpgnlg-Hazards (
a. ieplua fallb. pyroclastic fhll
lrnportnnt: geothermal energY
c. lava flowsd. lahars
(ex. Makban, Bacman, Tiwi)
e.
f.caldera collapse
tsunami
s[rMM3'nY
lava fottntains
ffiffi
.. j,::,r. i.:r:.il..l_,'1
:,t,il,i
i+:ir:ri,'i.i;i
!Ii:r;';i'?.ii:li','
!
I
i
I
b9&o'ir 5L)-rr#6p
iiii-ig' btj;iElni.i.'i1.1 Z .E Y
iili$[
6
0,
(sE
E'z
I {}::rl'i':i;l:i+.i
::: olii:i .E r,
l:..ir. 'itr.'..:+i
0)o .c.
6@-rao
o=do)
'7q
LY:t
!i:t
,i iii
wil,AT'r{rcntruc nivn ER,osnoN
iVE,:X'I.!!Eit,lNi- is the physical disintegtation arfci r,hernical decontposition by ivhich
rocks iire changed upon exposure to "agents" at or near the earth's surface, with little orno lranspo;t of loosened or altercd Inateriai
*- agents - hydrosllhere, a-tmosphere, biospher-e
.4. l\4cch*nical Weathering - is the breakdown. of rccks into smaller fiagnents by
vat'ious ph1151"'1 stresses
- ::tictly a lthysicul pl'oces:; willxnt a change in chemicalc1tilP)r'iliott
fr4 erhilnicaN Weath ering Frocesscs
a. ice wedging/ttost wedgingb. salt crystal gror,vth
L:. slrceting/unloading - releasc of confining p:ressure
exfoliation - fonnation of cprved sheets of rock by release of pressure
d. anirnals and plants
e. tlrermal expansion and contraction - seasonal/daiiy temperature changes
tr]. Chenrical Wcattering'- is the process"by rvhich chenrical reactions transform rocks
and nrinerals into ne;, shemicat cornbinations that are stable under conditions prevaillng at
or near the earth"s sur{-ace
lioie: more ef-fectittc itt x'armer clintcle:i - lrcat increase,s tlw xtte of ma:;t
reucf irnts
Chcnricnl Wcatherinq Proccsses
a. Flydrolysis - H' or Otf of the water anAffinUe ions of the rninerals
Ex. I(-ibldspar
2l(Alsi?o8 + 2tt2co3 -F 9FI20
Ortlroclase Carbonic Acid Water
Al2iii205(ot-t),r -l- 4l-I4sio4 J- ?tc + 2{-ICo3'Kaolinite Silicic Acid Potassium Ion Bicarbondte l.on
{, :--*ffi
l). ulSSOllltl0n - Fr2U
Ex.b.l NaClb.2 FITO
CaCOr
. ,1;'
-- --Llnlversat solvent
T
T
HzO -,----+
Na -F
COz HzCOrFizCOr ------+ Caun F
1- FLO
2HCO:-
c. Oxidation *
Ex.2FeSz
4Fe'*
is the cornbiration of oxygen ioris ivith cations
gl&qlar dalrygolbstlqg or "onion-skin weathering" -- produces
relat ively untveathertd material
4SOt' + 4F-t+
2H?O
spheroidal boulders
X{.esults/f roducts:a. regolirlr - fragincntal and uncor.rsoiidated rocl< material that has coarse grains
rvith angular edges and a composition sinrilar to the unweathered rock
" b. very large increase in the surface area of the v/eathered rnatedal, f,,. soluble rnaterials
Xlilr:tons afT'ccting the nntes o{' weathering:
I. susceplibility ot'the consl-ituertt roirrurals to rveatltering
- Goldich Stability Series-- nrinerals forrned at liigher temperatures and pressures tend to be less stable in
uveathering environment than those formed at lower temperatures
2. climale or intensity of the weathering processes
-- total amount of precipitation
- intensity ol'rain-- sr:asonal variations-- infiltration -r
-- run-ofl'and rate of evaporation-- teulperature
''r'wnnn, hunrirlclimate Vs. coid clirnaLe
-J. amount ol'srrrface exposecl to the atmosphefe
f,i?0$'/Ory - forcehrl physical removal of material frorn ihe parent rock, alwa.gs
acconrparried by transportat.ion and eventually end in deposition
CI
+ 7O:r +-t- oz {-
zHzO F 2Fe'-' +4# -_| 4FErr'r +
of
a. running vraterb. grouncl waterc. glaciers
d. 'ivind€.'waves' ald currents
f- mass wasting:' :
g. oigarric activi\'
'" n Dcpositio n itrtti [ix.hit'icatiorl :
I
Il--
Lithifliq:ation - is the term for p group
sedirlen.rarr/ rocksof processes tlrat conrreft loose sediments into
u. C1:me6talion - the process by which sediments are convefted ilt<i roclr by the
cliemical precipiiation of rnineral material / cqment among the grains of the
sediment I
+
t{t-, .
silic.r, carbonates and irolt oxides
Ccrnpactittn = is tlie loss in over-allvolunie and pore space as sedinrent
particles are packed closer together by the weiglt of, overlying rnaterial
Cry:;tallization - refers to crystal developmelit and growth by precipitation
fi'om solution; no cement; grains are held together by inierloclcing crystals
Ser{inrept:ltion - tlre process of fornring sedinqnt in layers, including ttre separation
rocli partioles fit'lnr the palerrt Inaterial, transportation of these pa.rticles to the site
deposirir:n, actual cleposition/setiiing, litlrification and consolidaticn into rock,
oio.l
'\.
SEDIMEhITARY ROCKS
SedimentarY Rocks:
- Latin woi-d, sedimentum = "settling"
- formed from consolidation of materialsprecipitation and from secretion of organisms'
Sediments - finely divided matter consisting of mineral grains and organic
matter derived from pre-existing rocks and from life processes,.transported by
and deposited from alr, water or ice'
- origin:
(1) weathering and erosion of pre-existing rocks
izi cnemical prebipitation from solution(3) secretion of organisms
Ocean = ultimate destination
Partlcie size classification for sediments
Two Maior Textures of Sedimentary Rocks.
1. clastic [Greek k/asfos, "broken"] = discrete fragments and particles
2. non-clastic texture = minerals forming an interlocking crystal pattern' '
from pre-existing rocks, from
.
CommonSedimenf Narne
Gravelor
Rubble
[dden-WentworthSize Glass .
Particle Name
1116-21/256-1/16
Iypes of Sedlrrient'ary Kocr(s
a. Detrital sedimentary rocks'.particle size is the primary basis
Detrital RockUOOenlWentworth
Size Class(Particle Namq)-
CommonSediment
NameConglomerate
UI
Breccia
Boulder Gravel
RubbleCobblePebbleGranule
SandstoneSand Sand
sitt Mud siltstone Shale or mUdstone
Clay clavstone
b. chemical sedimentary rocks: formed by direct precipitation of minerals
from solution.
*Precipitation occurs in two.ways:
(1)lnorganicprocessessuchasevaporationandchemica|actirTity can produce chemical sediments'
- iximprei: dripstone and halite (salt)
(2) Organic processes of water-dwelling organisms form
biochemical sediments
Rock NameGroup Texture Composltton
Limestone
lnorganic
Clastic or non-clastic
calclte, u?uu3
Dolomite,CaMq(COs)z
Dolomite (Dolostone)Non-clastic
Non-clastic MicrocrYstallinequartz, SiOz
Chert
Rock saltNon-clastic Halite,NaCl
Non-clastic Gypoum,CaSOo'2HzO
RocK gYPsum
Calciie, CaCOg Limestone
OrganicClastic or non-clastic
ChertNon-clastic
Torc6sttc
MicrocrYstallineouartz, SiOzAltered Plantremains
Coal
-..
SedimentarY $tnuctu res
*provide additional information with regard to the depositional environment'
':rmed as bedding or stratificationl1, l-aYering [also t(
:l1.1 strataor bed: thickness of tftu layer is 1 cm or more
l.2taminafion:thicknessofthelayerislessthanlcm
*may result from differences,Qetween |ayers in texture (e.g., change in
grain sizei'ti*iui tomposition' color or cementation'
-beddingptanes.=flatsurfaces.alongwhichrockstendtoseparate
e end of one episode of sedimentation and the beginning of
another
(b)pauseindepositioncanleadtothecreationofbeddingplanes
2'Ripp|emarks.=smatlridgesofsandformedbymovingwindorwater
2,lCurrentripp|emardE:lfairorwaterismovingessentiallyinonedirection
2.2oscillatoryripplemarks:Resu|tfromtheback-and-forthmovementofsurface*.u"'inshal|owwaterenvironments
3'Cross.beddingisanarrangementofsmallbedsatanangletothemainsedimentarY laYering
by a Progressive4. Graded beddingdecrease in grain size
5'Mudcracksarepolygonul",.u.k,thatformwhenmudshrinksasiidries'
is a tYPe of bedding characterized
upwaid through the bed'
fiNETAMOffiFffiC RCCKS
Metarnorphic rocks = rocks resutting from changes in temperature andpressLtr'e ancl frotr changes in the chemistry of tlreir poi'e fluids.
= can be formed from igneous, sedimentary, orprevior-rsly nretanrorphosed rockb.
= solid-state .reaction= consist of a fabric of irrterlocl<ing crystal grains,
usually with preferred grain orientation.
*Changes -,,.t.* new minerals, textures and structures-')\
occur in the solid rock; witltout melting of rock
I. Principal agents of metamonphisrn
a. lentperature- rarely below 200oC, upper limit is ihe melting'temperature of
tlte tock
b. Pressurcli b.1 confiping/static = pressLr-e applied equrally on all surface of tlre
BT5r"r, ecl/dynamic - pressLrre applied unequally on the surfaceof a body
b.2.1 compressive - flattens objects perpendicular to appliedpfessLl[e
b.2.2 shearing flattens objects parallel to tlre applied
pressLlre
*Fcrliation - parallel arrangement of textural or structrrral featuresin apy type of rock; planar structure that results from flattening of
tlre constituent grains of a metamorphic rock'
c. Chentically active/migrating f/uids- loss and gain of ions and atoms- snrall arnir-rnt of pore fluid provides an inrportant medir-rrn of
transPotl
'Mletasornatisln