Rocks and minerals 3 sedimentary

S e dime ntary Ro c k

• S e dime ntary ro c k is ro c k that is

fo rme d fro m the ac c umulatio n and
c o ns o lidatio n o f s e dime nts (we athe re d
partic le s o f o the r ro c ks ).
• Lithific atio n is the pro c e s s by whic h
s e dime nts be c o me ro c k.
– Ex: s ands to ne , s hale , c o ng lo me rate


Co mpre s s io n
Co m p re s s io n o c c urs as the pre s s ure
c re ate d by wate r and o ve rlying
s e dime nts be c o me s g re at e no ug h to
fo rc e partic le s o f s e dime nt c lo s e
to g e the r, drive o ut any wate r, and
c o mpac t the s e dime nts into ro c k.
A g o o d e xample is s hale .


S hale s


Ce me ntatio n
Ce m e ntatio n o c c urs as the additio n o f
mine rals , s uc h as s ilic a, lime , o r iro n
o xide , te nds to “g lue ” ro c k partic le s
to g e the r to fo rm s o lid ro c k.

Example s are s and s to ne and
c o ng lo m e rate , whic h are c o mpo s e d
o f partic le s o f s and, pe bble s and
s mall ro c ks .


S e dime ntary Ro c ks

Co ng lo me rate

S ands to ne


Fo rmatio n by Che mic al Pro c e s s

S o me s e dime ntary ro c ks fo rm as the
re s ult o f c he mic al pro c e s s e s s uc h as
e vapo ratio n and pre c ipitatio n.
Ro c ks fo rm e d b y the e v ap o ratio n o f
w ate r are c alle d e v ap o rite s .
Example s are lime s to ne , ro c k s alt and
ro c k g yps um.
um


Example s o f S e dime ntary Ro c ks
Fo rme d by Che mic al Pro c e s s e s


Fo rmatio n by Bio lo g ic al Pro c e s s e s

• S o me s e dime ntary ro c ks fo rm as a
re s ult o f pro c e s s e s ac ting o n the
re mains o f o nc e living o rg anis ms .
• Co al is fo rme d fro m the c o mpre s s io n
o f de ad plants .
• Lime s to ne is fo rme d fro m the
re maining s he lls o f de ad s e a-life .


Fo s s ils

S e dime ntary ro c ks als o fo rm and
c o ntain re mains o r impre s s io ns
o f plants and animals . The s e
impre s s io ns are c alle d fo s s ils .


Fo s s ils


Mo re Fo s s ils


3 Kinds o f S e dime ntary Ro c ks
Clas tic s e dime ntary ro c ks fo rm fro m the
c o mpac tio n and c e me ntatio n o f frag me nts
o f o the r ro c ks .
Che m ic al s e dime ntary ro c ks fo rm fro m
mine ral g rains that pre c ipitate o ut by
e vapo ratio n o r o the r c he mic al ac tio n.

Org anic s e dime ntary ro c ks fo rm fro m the
re mains o f plants and animals .


Pro pe rtie s o f S e dime ntary
Ro c ks
Ro c ks may have o ne o r all o f the s e
pro pe rtie s at the s ame time :
• Dis c re te laye rs
• Frag me ntal partic le s
• Org anic c o mpo s itio n
• Rang e o f partic le s ize s , o r
– Pre do minanc e o f o ne partic le s ize .


S e dime ntary S ample s


Me tamo rphic Ro c k
• Any kind o f ro c k c an be c o me a me tamo rphic
ro c k.
• Me tamo rphic ro c k is ro c k pro duc e d by
m o rp his m
– Mo rp his m me ans to c hang e , s o the s e ro c ks are
fo rme d by the trans fo rmatio n o f pre e xis ting ro c ks
into dis tinc t ne w ro c ks .

• Me tamo rphic ro c ks fo rm as a re s ult o f the
re c ry s taliz atio n o f unme lte d mate rial unde r
c o nditio ns o f e xtre me ly hig h te mpe rature and

pre s s ure o ve r lo ng pe rio ds o f time .


Clas s ific atio n o f Me tamo rphic Ro c ks
Te xture re fe rs to the appe aranc e and
mine ral arrang e me nt o f me tamo rphic
ro c ks .
Fo liate d ro c ks have mine rals that
pre s s ure has alig ne d into lay e rs that are
e as y to s plit.
Band ing o c c urs whe n the re are thin
lay e rs o f alte rnating m ine rals .
Me tam o rp hic ro c ks are in m any w ay s
s im ilar to the ir p are nt m ate rial.


Ho w Do e s Mo rphis m Oc c ur?
Me tamo rphic ro c ks fo rm as a re s ult
o f:
– Hig h te mpe rature s
– Hig h pre s s ure s
– Co mbinatio n o f bo th

– BUT w itho ut the ro c k m e lting in
the p ro c e s s .


Type s o f Me tamo rphis m
Co ntac t Me tam o rp his m o c c urs whe n mo lte n
ro c k c o me s in c o ntac t with s urro unding

ro c ks .
The he at fro m the mag ma alte rs the ro c k
in c o ntac t with it.
Re g io nal Me tam o rp his m ac c o unts fo r the
g re ate s t amo unt o f me tamo rphis m and
o c c urs whe n larg e are as o f ro c k are unde r
inte ns e he at and pre s s ure .


Me tamo rphis m


Me tamo rphic Ro c ks


Me tamo rphic Ro c ks


What is the Ro c k
Cyc le ?
• The ro c k c yc le is a the o ry
re lating to vario us ro c k
fo rming pro c e s s e s o f the
c o mmo n ro c k type s



The Ro c k Cyc le