Transcript Sedimentary rock - hs science @ cchs

Learning Objective
To recognize the evidence for changes in the Earth
Learning Outcomes
To be able to recall that rock provide evidence for changes in
the Earth (erosion and sedimentation, fossils, folding,
radioactive dating and craters)
Success Criteria
Good if you can explain how fossils can be used to date
rocks.
Excellent if you can recall other information which suggests
that the Earth is constantly changing.
Exceptional if you can explain the evidence for these
theories and any limitations they have.
Volcanic
eruptions
produce
Igneous rock.
Sedimentary rock is made from layers of sediment at the Earth’s
surface or within bodies of water. Over time the sedimentary layers
become compressed and ‘stick’ together.
Sedimentary
Rock Movement
Immense temperatures and pressures within the Earth change
sedimentary or intrusive igneous rock to metamorphic rock.
The natural process of
erosion has worn away the
rock.
If the Earth were not
constantly changing all
mountains would be worn
down by the force of
erosion.
The Grand Canyon
Over millions of
years the Colorado
river has worn
down from the
surface to create
the Grand Canyon.
At present the
Canyon is 1.83 km
deep. The rocks at
the bottom were
deposited over 1.5
billion years ago.
Surface
Canyon Floor
Throughout its history Earth
has continually been
bombarded by objects from
space. This 70km diameter
crater is estimated to have
been created 200 m years ago.
Radiometric Dating
The mineral Zircon is
radioactive. It becomes less
radioactive over time. If we
know the rate of radioactive
decay we can estimate how
old the rocks are.
Success Criteria
Good if you can explain how fossils can be used to date
rocks.
Excellent if you can recall other information which suggests
that the Earth is constantly changing.
Exceptional if you can explain the evidence for these
theories and any limitations they have.