Transcript What Happened Before

TEK 5.11B
Draw conclusions about
“what happened before
”using data such as from
tree-growth rings and
sedimentary rock sequences.
The diagrams that follow
represent two different
geologic cross sections in
which an igneous formation
is found in sedimentary rock
layers. The layers have not
been overturned.
Study the two cross sections.
8
What
conclusions could
be drawn about
the deposition
of the igneous
formation in the
overlying
sandstone in the
two diagrams?
8
A.
In A, the igneous rock is younger than the sandstone and in B,
the igneous rock is older than the sandstone.
B.
In A, the igneous rock is older than the sandstone and in B,
the igneous rock is younger than the sandstone.
C. In both A and B, the igneous rock is younger than the
sandstone.
D. In both A and B, the igneous rock is older than the sandstone.
The correct answer is D.
The sandstone is layered
on top of the igneous rock
formation, therefore the
igneous rock formation
must be older than the
sandstone.
These answers are incorrect
because...
 In
choices A, B, and C the
igneous rock is under the
sandstone so it could not be
younger.
Which layer of rock contains
the youngest fossil remains?
Pectin seashell
fossils
Fish fossils
Turitella and
ammonite fossils
Basalt (lava)
sandstone
shale
limestone
tilted layers of
limestone
Which layer of rock contains
the youngest fossil remains?
A.shale
B. limestone
C. tilted layers of limestone
D.sandstone
The correct answer is C:
tilted layer of limestone
The tilted layer of
limestone is layered on
top of the other
formations, therefore it
must be younger than the
other layers of rock.
These answers are incorrect
because...
In choices A, B, and D the
shale, limestone, and
sandstone is under the
tilted layers of limestone so
they could not be younger.
 The
next slide represents a
drawing that consists of four
underground rock layers. The
top layer is a volcanic rock
called basalt. The next layer is
a sedimentary layer called shale
with tree-root fossils. The
bottom two layers are oceanic
layers, which contain fish and
seashell fossils.
What story does this slice
of the earth tell?
Fossil tree roots
Pectin seashell
fossils
Fish fossils
Basalt (lava)
Sedimentary layer
shale
tilted layers of
limestone
A.
Lava from a volcano first covered the area. Trees then
grew on the land. Lastly, an ocean covered the area.
B.
An ocean first covered the area. The sea level then
lowered and trees grew. Lastly lava from a volcano
covered the land.
C.
Trees grew first on the land. Then the sea rose and
killed the trees. Lastly, lava from a volcano covered the
land.
D.
An ocean first covered the land. Then lava from a
volcano covered the area. Lastly, trees grew on the land.
The correct answer is B.
An ocean first covered the area.
The sea level then lowered and
trees grew. Lastly lava from a
volcano covered the land.
 Each
layer is deposited in a
certain order. The older the
rock is, the deeper it will be in
the crust. Since the oceanic
layers are on the bottom, it must
have been first.
These answers are incorrect
because...
Although answer D begins with the
oceanic layer it then places the volcanic
layer second.
 Answers A and C do not begin with the
bottom layer of rock.

On a construction site, workers revealed
several layers of rock and soil. In the
soil, fossils were found and recorded
at each layer. Then scientists made
the diagram to show the types of
fossils and where they were located.
Review the following table and determine
which fossilized organism is the
youngest.
Review the following table and determine which
fossilized organism is the youngest.
Layer 1
10 meters
deep
Layer 2
20 meters
deep
Layer 3
30 meters
deep
•Fossil A
•Fossil B
•Fossil C
•Fossil D
Which fossilized organism is the
youngest?
A. Fossil A
B. Fossil B
C. Fossil C
D. Fossil D
The correct answer is C
Fossil C
The layer at the top is the
youngest layer of rock.
Therefore, fossil C is the
youngest fossil.
These answers are incorrect
because...
Fossils A, B, and D can be found on
layers 2 and 3, which are older
than Layer 1.