History of the Earth Too much time on my hands. Let’s go to the fossil record. That’s some radioactive decay you have on. Take up your super positions. Correlate the correlation. $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 Final Jeopardy

What are the necessary conditions for a once living organism to turn into a fossil? Organisms need to be buried quickly to avoid decay Organisms usually need hard parts that can be imprinted into the rock layers

Is the Principle of Superposition more related to relative dating or absolute dating? Why? Relative Dating. The principle tells us position of the rock layers compared to other layers. It does not tell us their absolute age. 120 mya > 120 mya < 120 mya

What is the principle of horizontality? The force of gravity does the work to lay down sediments in flat layers. Eventually, the flat layers of sediment may turn into sedimentary rock. This is similar to how we see the horizon.

Traces, imprints, or the remains of once- living things are called… Fossils

Explain uniformitarianism Uniformitarianism states that Earth slow processes that happen today are similar to those that occured in the past

Organize these layers in the events in which they occurred. (Oldest to Youngest)D-C-B-A D C B A Bonus $100 The principle that cut these layers? The Principle of Crosscutting

What are the three ingredients that make a good index fossil? 1.Hard parts 2.Lived abundantly and widespread on the Earth 3.Lived for a short period of time Bonus 200: Why were eurypterids not good index fossils? Although they had both hard parts and were widespread on the Earth. They lived during many periods of time. Bonus Question

Compare and Contrast a trace fossil with a regular fossil Both are the remains, imprints, or traces of once-living organisms preserved in rocks Only trace fossils provide tracks and other evidence of animal activity

Why do we study fossils? Answer questions like: When did life begin? What did ancient organisms look like? How did they live? Don’t they Also help you date rock layers?!

What is the principle of lateral continuity? Rock layers will continue sideways in all directions If layers are missing in the middle, we can assume that they were once connected.

What is the principle of inclusions? As younger rocks form, pieces older rocks are included in them. clasts xenoliths

What is the half-life of an isotope? The half life refers to the time it takes for radioactive material, the isotope, to “ half ” or 50% decay. Material usually has many “half lives” before it completely decays. Bonus 200: What is the half life of Carbon-14 Every 5,730 years before ½ of Carbon-14 material decays. Bonus

What is the Principle of Superposition? In layers of undisturbed rock the youngest rock are on top and the oldest rocks are on the bottom. Older Younger

Normally, the three particles of the atom work to _________ the overall charge and _____________ of the atom. balance stabilize

Occasionally, scientists find the original remains of creatures. What substance or conditions have been known to preserve organisms? Amber Tar Ice Don’t even think about touching my DNA!

What are the building blocks of all matter whether its living or non-living? The mighty little ATOM

Geologists estimate the Earth to be approximately how many millions of years old? 4,600 million Or 4.6 billion

What is the principle of faunal succession? Fossils can be used to correlate and date rock layers

If you were studying the age of rock layers and did not have access to absolute dating methods, how could you get an approximate age of the rock layers? Relative dating methods, like using the principle of superposition and other principles.

When rock layers are spread over a large area, we match them up. What’s that called? Correlating rock layers

What is usually unstable parent material or daughter product? Parent material

When unstable atoms break down, what’s the process called? Radioactive decay

What is an unconformity in the rock layers? When rock layers do not follow the normal relative age order, according to the 6 principles. They can’t be relatively correlated. -Bonus 300- What is a angular unconformity? -Bonus 300- When younger layers of rock form horizontally on top of the eroded and tilted layers. Getting an accurate relative age is a problem.

Absolute dating is a process that uses the properties of ______ in rocks and other materials, like petrified remains, to determine their ages. atoms

What is the difference between a mold and a cast? A mold of a species is created when rock forms around the body and then the body decays. If sediment fills the mold and hardens a cast of the species is formed.

Final Jeopardy Compare and Contrast: Relative Dating And Absolute Dating

Final Jeopardy Answer Absolute and relative dating are both used to calculate and understand the geologic and evolutionary history of the Earth. Relative dating uses rules like the Principle of Superposition, older layers on the bottom; newer layers on top, to arrive at a relative, not exact, age of Earth. By understanding unconformities, geologist can correlate rock layers to match when and where geologic events took place. Absolute dating is more of an exact science. It uses the radioactive decay of isotopes to calculate the age of a fossil and rock layer. Each isotopes has a half-life that scientist use to measure the age. Both absolute and relative dating work together to help scientists understand the history of the Earth.

Jeopardy does not contain all the information you need to know for the test. Continue to review your notes, class work, and/or the online PowerPoints Our next area of study will be… PLATE TECTONICS!! (Yes, that includes volcanoes.) 