Download Sedimentary rocks form from earlier rocks

3.3 Sedimentary rocks form
from earlier rocks
Sedimentary Rock

It comes from the word sediment which means something that
settles out of water or air.

It develops from layers of sediments that build up on land or
underwater.

A sandy beach or a muddy lake bottom consist mainly of rock
particles.
3 Types of Sedimentary rocks are
formed from:

Rock particles

Plants or shells

Re-formation of dissolved
minerals from water
Rocks form from Rock Particles

Rainwater washes away rock particles
that are carried to lakes.

Strong winds pickup rock dust and
send them to distant places.

As winds or water currents slow down,
the rock particles form layers which
forms a rock once they are pressed
together like the sandstone.
Classwork
Answer number 1 and 2 p.95
Forming loose sediment into Rocks
By pressing layers of sediments
together.
Or by holding the particles
together by minerals acting as a
cement.
Rocks form from Shells or Plants

The fossil which is the remain of
an organism from long ago also
produce rocks.

Coal forms from plants instead of
earlier rocks.

Shells and skeletons of ocean
organisms form limestone once
pressed together.
Rocks form from Re-formation of
dissolved minerals from water

Rock salt and gypsum are formed
when minerals forms layers of
sedimentary rock at the edge of lakes
where the climate is dry.
Sedimentary Rocks & Past Conditions
Fossils
of fish or shells in a
layer of rock show that
the area was covered by
a lake or an ocean long
ago.
How do sedimentary rocks form in
layers?
 The
formation of layers depend
on the movement of water
 Fast
water carries big particles
 Slow
A
water carries small particles
flood carries big particles and
small particles
CLASSWORK
1- How does the movement of water form
layer of rock?
2- How can we know that lakes were present
in past conditions?