NAME
ctAss
SEDIMENTARY
ROCKS
18:4 Formation
of Sedimentary
Rocks
rocks
water
silica
buried
olilegt
'minleral
solution
surface
hardening
fogsils
sediment
Rocks made of loose Earth materials. or
sd;^o*
Sedimentaryrocks form at Earth's
by wind,
tims,
,r*l"r
l',atidef,,lt,b
limestone
weathered
sedimentary
, are called. *Jt,^""kg
.
WedlL"-A.
sed.iments
are deposited
, and ice. After deposition, materials are
occurs.Sed.imentis ileposited.in layers with the
bottom. Sedimentary rock materials include broken
substances
deposited6-orn Sofqd'o-r
l&k5
I
,
. Cements,suchas calcite,
hold the material together. Tbaces of once-Iiving organisms called
rocke,
k";sl
, and with
. oHosf
beds on the
,nine- wl
grains, and
si/i.o.
, or limonite,
are coulmon rn
It
sedimentar5rrocks, They are most commen ir,
sedimentary rocks.
'
ltnze5fo€
but do occur in a wide varietv of
NAME
DATE
CLASS
18:5 Features
of Sedimentary
Rocks
quartz
nucleue
geodes
Wavy features of some
are called *iffle-
caused by water or air movement over the original gsdimsnt
-ardC*.*a
,ro-L5
mud beds and can be Coveredwith water aa6
i:regularly shaped.
massesof
-
cesn<zrl#,
|
|
called <nnc+e*:on<
nrtL.
.
J-
occurin dried
"ro.k<
*A;,rnn*
*z'liw*yrY
and preserved. Ball-Iike objects or
material eollected aronnd 4
sre
^'ct<.lu)..
crystals.
18:6 Classification
of Sedimentary
Rocks
coal
wind
shale
chert
calcite
organic
breccia
clasties
siltstone
permeable
deposition
sandstone
nonclastics
chemically
cementation
compactiotr
transported
composition
evaporltes
rock salt
precipitates
impermeable
consolidation
conglomerates
Sedimentary rocks made of fragments of rocks and minerals, and broken shells are called
oft
. Those deposited from solution or by
processes are
-ia<*as
idl
,or glaciers.
occurs as the tralsporting medium slows down. Clastic rocks are named.according to
-_
their sediment size. conTlo*sCe<
@
are mixtures of round.ed
pebbles,u"t
Ar:*-ij^
i",
fragments that are sharp and angular. small quaxtz grains usually make up
. When
smaller grains, such as clay particles, are present, si[]<{..e
often forms. Thin
of clay
slzr[e,
and mud-sized particles form
. Only the finest particles are
in deep
\-on*"tadqtic9^
water. cnr+lif,*-,,
varies with different rocks. Shale and siltstone solidi& 6o, ccr'
or squeezing. Compaction is so great in shale that water cannot move through it; thus, it
is
'.
ll
et meobl€-' . The larger particles of sand and pebbles allow
water to passthrough and are consolidated
i lt
most common form. When watbr evaporates and. leaves its dissolved solids behind,
form. Organic matter may also form nonclastic rocks, such as in coral reefs or in deposits of peat that
cQr I
Iater changeto
aom4t!:tfroi-t:lb, .
. Nonclastic rocks are named according 6
A few examples are limestone, made of calcite, flint
n&dc-
3.i+-
, made of halite.
or
.too|:
et:€-r f
, made of silica. and