GEOL3442 Sedimentologyand Stratigraphy
Laboratory2
S i l i ci clastic
Sedimentar Rocks
y
r ocks i n
Pu r p o s eI:n th i s e xe rci seyo
, u w i l l examinesamplesof var ioussiliciclastic
pr
ovenance,
and
to
cer tai n
of
analyze
w
i
th
concepts
b
eco
me
mo
re
fa
mi
l
i
a
r
o r d e rt o
aspectsof rock texture and composition.
M e t h o d : T h e e xe rci seco n si stso f four par ts. For Par tl, you will study
conglomeratesamplesto determineaspectsof transportand provenance. For Part
l l , y o u w i l l co mp l e tesi mi l a rp ro cedur esas completedin Par t l, but her e
c o n c e n t r ati n o
g n sa n d sto n efe a tu r es. In Par t lll, you will descr ibeand classify
micr oscopeto addr ess
m u d s t o n e . In P a rtl V , yo u w i l l u se the petr ogr aphic
q u e s t i o n sof p ro ve n a n ce .
Part I
E x a m i n et wo o f th e co n g l o me ra tespecim ensand deter m inethe following:
1 ) U s i n gt h e co mp a ri so nch a rt fo r visualestim ationof per centagecomposition ,
o f th e rock that consistsof gr avel( gr ains) 4m m in
d e t e r m i n et h e p e rce n ta g e
d i a me te r)
.
i n t e r m e d i ate
gr ainsand calculatethe abunda nc e
2 ) D e t e r m i n eth e co mp o si ti o no f the gr avel- size
s n b e d e ter m inedby identifyingall the gr ainsin a par tic ul ar
o f e a c h . Pe rce n ta g eca
p
with the appendedvisualestim ationchar t.
a r e a ,t h e n esti ma ti n g e rce n ta g es
3 ) U s i n gt h e fo l l o w i n gta b l e ,d e te r m inethe degr eeof m iner alogicmatur ityof eac h
c o n g l o m e ra te
sa mp l ea s re fl e cte dby gr avelcom position.
MineralogicalMaturity
PercentOuartz,Metaquartz,and Chert
Supermature
99-100%
Mature
95-99%
Subm atur e
7 5 - 9 5 o /o
lm m atur e
O - 7 5 o /o
4 ) U s i n gPo w e r'sro u n d n e sssca l e,deter minethe aver ager oundnessof gr avelin
e a c hc o m po si ti o n agl ro u p . In o th er wor ds, how ar e r oundnessand com position
related.
e a rt, deter minethe textur almatur ityof gr avel- sized
5 ) U s i n gt h e so rti n g -i ma gch
m a t e r i ailn ea ch sa mp l e .
6 ) U s i n gi n fo rma ti o nd e ri ve df ro m 1- 5, deter m inefor each sam ple:
a ) R e l a ti ved i sta n ceo f tra n spor t,accor dingto the followingtable:
S h o rt- L o ca ld e ri va tion( poorr ounding,poor sor ting)
- U p to appr oxim ately
10 miles( moder ater ounding,
l n te rme d i a te
p o ssi b l yg o o d so rti n g)
L o n g- Mo re th a n 1 O m iles( well r ounded,possiblyver y good sor ting)
b ) W h e th e ro r n o t re cycl i n gmay havetaken place. Explainyour r easoni ng.
c ) P ro b a b l ero ck typ e s i n th e sour cear eaor explanationwhy this can not
b e a sse sse dfro m th e sa mple.
l5o
d ) C l a ssi fyth i s ro ck a cco rdingto Pettijohn,1975.
fg
P::rtll
, u ,v ill examinehandspecimensof som e com m on
I n t h i s p a r t o f th e e xe rci seyo
s a n d s t o n etyp e s, a n d cl a ssi fye a c h one accor dingto textur aland com positional
f e a t u r e s . F o r e a chsa mp l e ,yo u will:
A. d e te rmi n eth e ro ck te xtur e,
B . d e te rmi n eth e co mp o si tionof gr ains,
C . d e te rmi n eth e n a tu rea n d gener alcom positionof inter stitialm ater ial,
D . c la ssi fyth e ro ck.
P r o c e d u r e:
1 ) S e l e c tt w o sa n d sto n esa mp l e s .
2 ) U s i n gy o u r si zea n a l ysi sca rd (s) ,deter m inethe aver agegr ain sizeof each
sample.
3 ) U s i n gt h e so rti n gi ma g ech a rt, deter m inethe sor tingof gr ainsin each sample.
4 ) U s i n gP o w e r'sro u n d n e sssca l e,estimatethe aver agedegr eeof gr ainr oundn es s
( o r g i v e a r a n g eo r ro u n d n e ss)
i n each sam ple.
5 ) D e t e r mi n eth e co mp o si ti o no f pr incipalfr amewor kgr ains( i.e. quar tz and che r t,
feldspara
, nd u n sta b l ero ck fra g ments)for eachsam ple. Per centage
of each
c o m p o n e ntca n b e e sti ma te db y meansof the attachedvisualestimationscale.
6 ) D e t e r m i n ew h e th e ro r n o t th e rock containsinter stitialcement or m atr ix,the
a p p r o x i m a tep e rce n ta g eo f su ch mater ial,and whetherthis mater ialis car bona te
( a c i dt e s t ) , si l i ce o u s(n a i l ),o r cl a y ( soft, nonvitr eous,
no r eactionto acid) .
y
o
u
r
k n o w l e d g eo f s a n d s t o n ec l a s s i f i c a t i o a
nn
, d t h e M c B r i d e( 1 9 6 3 )
7) Using
ch a rt,g i ve e a ch ro ck an appr opr iately
descr iptivename. For exam pl e:
c l a s s i f i c a to ry
p
o
o
rly
sor ted,subangular
M e d i u m -t o co a rse -g ra i n e d ,
to subr oundedar kose.
8 ) O f f e r a bri e f d i a g e n e ti ch i sto ryof the sam ple.
P a r tl l l
I n t h i s p a r t o f th e e xe rci seyo u w i ll descr ibeand classifythr ee m udstonesam ples .
Pr o c e d u r e:
1 ) S e l e c t h r e em u d s t o n es a m p l e s .
2 ) D e t e r m i n eth e co l o r o f th e sa mple.
3 ) D e t e r m i n eth e co mp o si ti o no f the sam ple. Rub or chew a sm all por tionof th e
clay) ,loamy ( 33- 65o/oclayl, or
s a m p l et o de te rmi n ei f th e sa mp l eis gr itty ( O- 32o/o
cl a y).
s l i c k ( 6 6 - 1OOo /o
4 ) D e t e r m i n eth e d e g re eo f i n d u rationaccor dingto the followingscale:
Nonindur ated
So f t, e a si l yd i sa g g re g a te d
F i r m,b u t ca n b e d i sa g g re gated
Poor lyindur ated
with little effort
F i r m,d i ffi cu l tto d i sa g g re gate
Moder atelyindur ated
H a r d ,ca n n o t b e d i sa g g re gated
W ell indur ated
by hand
fissileor blocky
5 ) A s s e s swh e th e rth e sa mp l ei s best consider ed
6 ) C l a s s i f yth e sa mp l ea cco rd i n gto Potter ,et al., 198O PA- /57
l e p o si ti o n ael nvir onmentfor each sam pYe.Suppor tyour
7 ) O f fe r a po te n ti a d
a n s w e r . ( Fi ssi l i tyi s g e n e ra l l yco nsider edan aspectof m ar iner ock.)
Part I Conglomerates
L
o
ca
ti
on:
a
n
d
S a m p l el d en ti fi ca ti o n
Classification
PercentGravelin the Sample:
PebbleComposition
o/o
Roundness
O 1 2 3 4 5 6
AverageRoundness
Sor ting
TransportDistance
M i n e r a l o g i Ma
c tu ri ty
TexturalMaturity
C o m m e n t s:
S a m p l e l d e n t i f i c a t i o na n d L o c a t i o n :
P e r c e n tG r a ve li n th e S a mp l e :
PebbleComposition
M i n e r a l o gi cMa tu ri ty
TexturalMaturity
C o m m e n t s:
o/o
ication
Classif
Roundness
O 1 2 3 4 5 6
AveraqeRoundness
sorting-Tr anspor tDistance
gsmple #
Part ll Sandstone
Si z eR a n geo f Gra i n s
AverageGrainSize
(P
h
i
So r t i n gl m a g eE sti ma ti o n
va l ue)
R a n g eo f R o u n d n e ss
Average RoundnessEstimate
G r a i nC o mp o si ti o n
%oFrom Estimation
Ouartzand Chert
Feldspar
Rock Fragments
Type of InterstitialBindingMaterial
Classificationand DescriptiveName
D i a g e n e t i cH i sto ry:
S a m p l e#
S i z eR a n g eo f Gra i n s
Aver ageGr ainSize
S o r t i n gl m ag eE sti ma ti o n(P h iva l ue)
R a n g eo f R o u n d n e ss
Aver ageRoundnessEstimate
G r a i nC o mp o si ti o n
%oFrom Estimation
Ouartz and Chert
Feldspar
R o c k F r a g me n ts
T y p e o f I n te rsti ti aBl i n d i n gMa te ri al
C l a s s i f i c a ti oann d D e scri p ti veN a me
D i a g e n e t i cH i sto ry:
Part lll Mudstone
S a m p l e#
Sa m p l ec o l o r
Composition
Degreeof Induration
Fissilevs BlockyFabric
Classification
Depositionalenvironment:
Sa m p l e#
S a m p l ec o l o r
Composition
D e g r e eo f In d u ra ti o n
Fissilevs BlockyFabric
C l a s s iifc a t i o n
D e p o s i t i o n ael n vi ro n me n t:
S a m p l e#
Sa m p l ec o lo r
C o m p o s i t io n
Degreeof Induration
F i s s i l ev s Bl o ckyF a b ri c
C l a s s i f i c a ti o n
D e p o s i t i o nael n vi ro n me n t:
Part lV
F o rt h i s p a rt o f th e e xe i '';i seyo
, u will count and identifygr ainsin 2 petr ogr aph i c
p
o
l
a
ri
zi
n gmicr oscopethat has a m echanical
s
e
c
t
i
on
s
thin
u si n ga
stage.
Pr o c e d u r e:
c cro sco p e .
A. T h e Pe tro g ra p h iMi
T h i s i n stru me nht a s ma n y knobs,dials,scr ews,and lever s. You will need to
u s e o n l y th e fo l l o w i n g :
1 ) Ob j e cti vel e n se s
2 ) F o cu si n gkn o b s
3 ) A n a l yze r
Do not changeor try to adjust any other parts of the microscope.
B. P o i n tc ou n ti n g .
1 ) Sta rt i n th e u p p e r l e ft cor nerof the section. Mar k your star tingplace.
2 ) Ma ke a ve rti ca ltra ve rse,countinga point at each click. Classify
w h a te ve rro ck co n sti tu e n tis dir ectlybelow the inter section
of the cr ossh a i r s,a n d a ssi g ni t to th e p r opercategor y. Don' t count holesor cement.
F o r sa mp l eA , th e categor iesar e:
i)Ouartz + Chert
2 ) F e l d sp a r
3 ) R o ck F ra g ments*
4) Matrix
5 ) Oth e r
* R o ck fra g mentscom posedof quar tzand feldsparar e counted
a s q u a rtza n d /o rfe l dspar ,not r ock fr agm ents
F o r sa mp l eB , th e ca tegor iesar e:
1) N o n - u n d u l a t o r y . O u a r t z *
2 ) U n d u l a to ryOuar tz
3 ) P o l ycrystalline
Ouar tz*( 2- 3 cr ystalsper gr ain)
4 ) P o l ycrystalline
Ouar tz( > 3 cr ystalsper gr ain)
5 ) Ma tri x
6 ) Oth e r
* l f th e e n ti regr aingoesto extinctioninsideof 50,the gr ain
h a s a n o n -u n d u l a torextinction.
y
Other wise,extinctionis
u n d u l a to ry'
* l f tw o o r mor e segm entsof a gr ain on eitherside of a sha r p
b o u n d a ryg o to e xti nctionover 50 apar t,the gr ainis
p o l y crysta l l i n e
3 ) M o ve th e sl i d eh o ri zo n tally5 clicks( or mor e)to the r ight,make a ver ti c al
t r a v erseu p w a rd ,a n d so o n until you have countedthe pr opernumberof
p o i n t s( 2 0 0 ) .
4 \ T r y to sp a ceth e tra ve rsesso as to coverthe entir eslide. You will tall y
a b o u t 1 2 t o 1 6 p o i n t sp e r t r a v e r s e .T h u s ,i f y o u n e e d2 0 O p o i n t s ,y o u
s h o u l dw a n t a b o u t 1 2 t o 1 8 t r a v e r s e s .l f t h e s l i d ei s a b o u t2 5 m m l o n g , t h e
t r a v erse ssh o u l db e 1 1 1 2to 2 m m apar t.
C . R e q u e ste dd a ta .
F i l lo u t th e a tta ch e dd a ta sheetand answerall questions.
COT{TIIIENTALSLOCK PBOVEIIAHC€S
o
o
a
ffi[$i'
msrn*
tsib'fJ€ff'
r{aGMATrCE}C PROVEI{ANCES
a
a
a
ltrossEqtEo ?nAfislfioilAl Dls3€ctEo
onocElleRovEtlAlsgg
RtcYcLEo
-9
suBoljclloli
COUPLEX
' T*'8[tlR* * 'stllfo
par-tic-t119m'
(sand-size
?.14 Fouf triangularplots showing-meanframervorkmodesptovenancesi
FTGURE
(A) QFL
i"ti"iA from differenttypesof
r"f""t*a r"ndiJ""""ito
;;;in;";i*
"*ffitiiiliilf"tu"'.'"
ffi*!iH']u**'$l${t#j'ty'iHfd'l*hfr
frisments,ind l* ts-sedimentarv'metasedimentarv
""fi",iri--rela;;lfii;;"k
iii"iri"}"-"iUTr
R.,and C. A].Suczek.rszs, Platetsctonicsand sandstone
#{ift;;;il
ilrt"r ut[r"*o;:*.
c;;roiitis gutt.' r'' 63' Figs'1-4, pp' 2771'2172'reprinted
.ompoeition:Am. Assoc.F;ilil;
Okla')
Tulsa,
AAPG,
by plrmissionof
Part lV Point Countinc
Sl i d eA
Relative%o
# Points
Constituents
Ouartz + Chert
Feldspar
R o c kF r a g me n ts
Matrix
Other
ri d e 1
, 9 6 3)
n
R o c kC l a s si fi ca ti o(McB
l d e n t i f ya t le a sttw o fe a tu re so f the samplethat ar e a dir ectr esultof diagenes i s .
D i c k i n s o na n d
S u c z e k ,1 9 7 9 .
l d e n t i f y a t l e a s t t w o p o t e n t i a ls o u r c e s o f e r r o r w h i c h m u s t b e c o m p e n s a t e d f o r
a n d S u c z e k( 1 9 7 9 )m e t h o d '
w h e n u s i n gt h e D i c k i n s o n
l d e n t i f y a t l e a s t o n e d e p o s i t i o n a le v e n t w h i c h c o u l d h a v e a l t e r e d t h e o r i g i n a l s a m p l e
t o s u c h a d e g r e et h a t e v e n a p r i s t i n es a m p l e w o u l d n o t y i e l d t h e c o r r e c t p r o v e n a n c e
b y t h e D i c k i n s o na n d S u c z e k ( 1 9 7 9 ) m e t h o d . -
S l i d eB
Relative 7o
# Points
C o n s t i t u e n ts
Ou a rtz
N o n - u n d u l a to ry
U n d u l a t o r yOu a rtz
P o l y c r y s t al l i nOu
e a rtz(2 -3 g ra i n s)
P o f y c r y s t al l i nOu
e a rtz() 3 g ra i n s)
Matrix
Other
R o c kC l a s s i f i c a t i o( nM c B r i d e1, 9 6 3 )
D e t e r m i n eth e d o mi n a tero cks i n the sour cear eaas ar guedby Basu,et al, i 975.
l d e n t i f y a t l e a s t t w o s i t u a t i o n s , d e p o s i t i o n a lo r d i a g e n e t i ce v e n t s , o r s a m p l i n g
c o n d i t i o n sw h i c h c o u l d r e n d e rt h i s m e t h o d i n a c c u r a t e .
TERRIGENOUSROCK DESCRIPTIONS
Sample#
Indurahon:
Color:
Textural Features
Packing:
Porosity:
Grain orientation:
Overall: CtravelYo
Sand %
Mud %
Grain size:
Sorfing:
Rounding:
Sphericity:
Texturalmatmity:
Composition
Q"urt" %
Rockfragments%
FeldsPar%
RockFragmentTlpes: IRF %
MRF %-SRF
OtherTerrigenousMinerals(% andfype):
Mineralo gical matunfy :
CompositionalName
Rock Name:
SedimentaryStructures:
Interpretation:
Cement:
%
TERRIGENOUSROCK DESCRIPTIONS
Sample#
Induration:
Coior:
Textural Features
Packine:
Porosity:
Grain orientation:
Overall:Grave|%6
Sand %
Mud %
Grainsize:
Snrfino'
Rounding:
Sphericity:
Texturalmaturity:
Composition
Quartz%
Rockfragments%
Feldspar%
IRF%
RockFragmentTypes:
MRF%-SRF%
Minerals(Yoandtype):
OtherTen'igenous
Mineral ogic al maturity :
CompositionalName
Rock Name:
Structures:
Sedimentary
Interpretation:
Cement:
TERRIGENOUSROCK DESCRIPTIONS
Sample#
Induration:
Coior:
Textural Features
Packing:
Porosity:
Grain orientation:
Overall:GravelYo
Sand %
Mrtd 7o
Grainsize:
Sorting:
Rounding:
Sphericity:
Texturalmatr,rity:
Composition
Quartz%
Rock fragmentso6-
Feldspar%
RockFragmentTlpes: IRF %
MRF %-SRF
Minerals(% andtype):
OtherTerrigenous
Mineralogical maturity:
Name
Compositional
RockName:
:
SedimentaryStnrctures
Interpretation:
Cement:
%
TERRIGENOUSROCK DESCRIPTIONS
Sample#
Induration:
Color:
TexturalFeatures
Paelrino'
Porosity:
Grain orientation:
Overall: Gravelo/o
Sand%
Mud %
Grainsize:
Snrfino'
Rounding:
Sphericity:
Texturalmaturity:
Composition
QuartzYo
Rock fragments%
Feldspar%
RockFragmentTlpes: IRF %
MRF %-SRF
Minerals(Yoand fype):
OtherTerrigenous
Mineralo gical maturity:
CompositionalName
Rock Name:
SedimentaryStructures:
Interpretation:
Cement:
%