Fossils
What is the difference between catastrophism and uniformitarianism?
Catastrophism - organisms and conditions change in quick/violent events.
Uniformitarianism - geological changes we see now are similar to those that occurred in the past. (Slow, gradual change)
Which layer is older, the bottom layer of rocks or the top layer of rocks? Why?
The bottom layer is older. The lowest layer had to be there before newer, younger rock settled on top of it.
What is absolute age?
The numerical age, in years, of rocks or objects.
The preserved evidence of the activity of an organism.
What is a trace fossil?
What is the difference between relative-age dating and absolute-age dating?
Relative-age dating determines an estimated age of rocks or features compared to other rocks or features nearby.
Absolute-age dating provides an actual numeric age using radioactive dating.
A dike is an example of an ___________.
Intrusion
An unstable isotope is called the _______ isotope. As it decays, it creates new stable elements called ________ isotopes.
Parent Isotopes - unstable
Daughter Isotopes - stable
The older pieces of rock that are often found in an intrusion.
How have scientists roughly determined the age of the Earth?
By using radiometric dating, scientists have dated incredibly old rocks from the Earth, moon, and from meteorites.
Plant leaves are often preserved as______________.
Carbon Film!
What are the three types of unconformities and what do they all three have in common?
Disconformity, Angular Unconformity, & Nonconformity
All three show include older eroded rock layers below newer rock layers, this shows a gap in the rock record (a gap in time).
Describe what is happening in the graph below:
This graph shows the half-life process of decaying isotopes. As the parent isotope decays, the daughter isotope increase.
The time required for half of the parent isotopes to decay to daughter isotopes.
What is half-life?
What types of characteristics would an ancient creature need to eventually become a fossil?
A hard shell, bones, teeth, a sudden burial after death
What can a trilobite found in Ohio tell us about the climate here millions of years ago?
Trilobites lived in shallow seas and resemble a horseshoe crab. Therefore, Ohio must have once been covered by water!
Name 2 geological principles that are visible when viewing the Grand Canyon.
-Superposition - the older rocks are on the bottom.
-Original Horizontality - the rock layers began as horizontal layers.
-Lateral Continuity - the layers are spread out in large sheets that, when cut away, still remain visible.
Why is sedimentary rock not a good candidate for radiometric dating?
Sedimentary rock has grains from many different rocks mixed together. Dating the rock would actually result in dating the individual grains and not the rock itself.
Scientist who studies fossils.
What is a paleontologist?
Isotopes are atoms of the same element that have different numbers of _________.
Neutrons
What clues have been found that tells us the majority of the Earth was once a much colder climate?
-Species such as the woolly mammoth
-Course grass
-Remnants of huge glaciers that once covered large areas
Stratigraphy: Place these layers, inclusion, and fault in the correct order from oldest to youngest.
Youngest: E - Fault
D - Dike
A
B
Oldest: C
What is an example of something that could be dated using carbon-14?
Ancient artifacts, mummies, ancient scrolls, cloth/fabric from ancient times...
Fossils that represent species that existed on Earth for a short length of time, were abundant, and inhabited many locations.
What are index fossils?
A whole baby woolly mammoth, in tact, is an example of what type of fossil?
Preserved Remains