1. Observe this block diagram. Place events in order of occurrence in the
respective places below. Work from
oldest to youngest, bottom to top. Be
sure to note any unconformities and their types.
16.
15.
14.
13.
12.
11.
10.
9.
8.
7.
6.
5.
4.
3.
2.
1.
2. Observe the block diagram above. Place events in order of occurrence in the
respective places below. Work from
oldest to youngest, bottom to top. Be
sure to note any unconformities and their types.
13.
12.
11.
10.
9.
8.
7.
6.
5.
4.
3.
2.
1.
ir3. Observe
the block diagram above. Place events in
order of occurrence in their respective places below. Work from oldest to youngest, bottom to top. Be sure to note any unconformities and their
types.
28.
27.
26.
25.
24.
23.
22.
21.
20.
19.
18.
17.
16.
15.
14.
13.
12.
11.
10.
9.
8.
7.
6.
5.
4.
3.
2.
1.
Absolute Dating
In this part of the exercise, you will be calculating the
actual, or absolute, ages of the rock.
The figure above shows the relationship between the
percentage of parent material and the number of half-lives that have
passed.
4. What percentage of the parent material is present after
one half-life?
Two?
Three?
Four?
5. If you start with
80 grams of an isotope, how much would be left after-one half-life?
What about three half-lives?
6. If an isotope has
a half-life of 600 million years, how old is a rock that contains the isotope
after 50% of the parent has decayed?
How old is the rock after four half-lives have passed?
7. You discover the
parent isotope in a lava flow has gone through 0.75 half-lifes. If a half-life is 800 million years, how old
is that rock?
8. In number 1, at
the beginning of the exercise, Layer F was dated at 260 million years old. Layer E was determined to be 235 million
years old. When did the fold occur?
9. The image to the
left show a series of sections containing various fossils. If the star is 325 million years old (ma),
and the heptagon (the 7-sided fossil) is 337 ma, how old is the 15-sided fossil
in between?
If the star existed for three million years, from
324ma-327ma, how old must the arched arrow in section three be?
10. Based on what you
learned about fossil preservation, how might the following be preserved as
fossils?
Dinosaur bones?
Microscopic organisms like bacteria and protists?
Skin or feathers?
DNA?