Relative Dating
Determining whether an object or event is older or younger than other objects
Explain 4 ways Sedimentary Rocks are Disturbed
Tilting: Happens when Earth’s forces move rock layers up or down evenly
Fault: Crack or break in Earth’s crust where rocks can move
Folding: Bending of rocks that can happen when rock layers are squeezed together
Intrusion: Igneous rock that forms when magma is injected into rock and then cools and becomes hard
4 Major Divisions of Earth’s History in Order
Precambrian
Paleozoic
Mesozoic
Cenozoic
Explain how the Precambrian timeline was made and how they are useful
Useful: Made up 90% of Earth’s history
Made: Started with the Earth’s formation while supercontinents, oceans, and atmosphere was being made
Explain how the Paleozoic timeline was made and how they are useful
Useful: There was a lot of diversity because of the Cambrian explosion where many organisms evolved
Made: When the supercontinent Pannotia began to break up and Pangaea began to form
Explain how the Mesozoic timeline was made and how they are useful
Useful: Mountains started to form, there was heavy volcanism adding carbon dioxide to the atmosphere, and there were a lot of dinosaurs
Made: When Pangaea started to break apart
Explain how the Cenozoic timeline was made and how they are useful
Useful: Continents started to break apart and are now in the place they are in today,the Alps were formed, humans were formed, Ice Age occurred
Made: When the mass extinction of the dinosaurs happened
Unconformity
A missing layer of rocks that happens when rock layers are eroded or sediment is not deposited for a long time
What is One Type of Extraterrestrial Rock that Scientists have Determined an Absolute Age? How do the Ages of These Rocks Compare to the Ages of the Oldest Rocks on Earth?
Lunar rock/moon rock; their dated back 4.4-4.5 billion years ago, these rocks are generally older than the oldest rock found on Earth. This is because Earth has been recycled by plate tectonics, while many space rocks have remained unchanged.
Law of Superposition
Principle that states that younger rocks lie above older rocks if the layers have not been disturbed
How do Fossils and Other Materials Tell Us About the Conditions of an Area At the Time It Existed?
Fossils and surrounding materials tell scientist about past conditions by showing what organisms lived there and what rocks they lived in (like limestones and sandstones) gives clues about climate & conditions.
How Do You Find the Age of The Fossils and Other Materials
Finding the age:
-Sedimentary rocks are dated in indirectly
-Igneous rocks layers are dated by radiometric dating
Also relative dating
What Is the Law of Crosscutting
States that a fault or body of rock, such as an intrusion, must be younger than any feature or layer of rock that the fault or rock body cuts through
How Could You Find the Age of Fossils and Other Minerals?
- Radiometric dating- measures radioactive decay (carbon-14 for recent fossils, uranium lead for very old rocks.)
- Law of superposition- determines relative age based on rock layers (older layer are below younger ones).
- Index fossils- using fossils of known ages to correlate and estimate the age of rock layers.
Picture Reference: Fault
Has only one slit where the layers don’t match each other after the slit
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Picture Reference: Tilting
All the layers are slanted evenly
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Picture Reference: Intrusion
Massive gap or thing in the middle of the straight rows
Picture Reference: Intrusion and Folding
When there is a bridge shape in the rows and a pathway forming at the bottom of the layers
Why Was the Climate Warmer during the Mesozoic Era 5 Things?
- A ton of volcanic eruptions releasing a lot of carbon dioxide into the atmosphere
- High sea levels and ocean currents that transported heat to the poles faster
- Position of Continents allowed the heat spread to the poles better
- Plate tectonic rifting which allowed carbon gas from underground to mix in with the atmosphere and oceans
- A lot of greenhouse gases were emitted into the atmosphere due to sauropods digestive processes and the seafloor
Uniformitarianism
States that geologic processes that happened in the past can be explained by current geologic processes
Fossil
Traces or remains of organisms that lived long ago
Trace Fossil
Fossilized structure that formed in sedimentary rock by animal activity on or in soft sediment
Climate
Describes the weather conditions in the area over a long period of time
Ice Core
Long cylinders of ice
