Rock Layers
What is rock strata?
Layers of rock formed over time.
True or False: The geologic time scale organizes Earth's history.
True
What is absolute age dating?
numerical dating or geochronology—is the scientific process of determining the actual, numerical age of a rock, fossil, or archaeological artifact in calendar years.
What is a fossil?
Preserved remains or traces of ancient life.
9:05
In an undisturbed sequence of rocks, is the top layer older or younger?
Younger
In which era did dinosaurs live?
Mesozoic Era.
What law states that the oldest rock layer is on the bottom if layers are undisturbed?
Law of Superposition
What evidence do fossils provide?
Evidence of past life and environments.
What is Ms. Chavez's favorite color?
Blue
According to the Law of Superposition, in an undisturbed sequence of sedimentary rock layers, where is the oldest layer found?
at the very bottom of the sequence
What are do we live in today?
Cenozoic Era.
Which method helps scientists determine the relative age of rocks?
relative age dating
A rock layer contains dinosaur fossils. Which era is it most likely from?
Mesozoic Era.
What is the sign of the product? Explain why.
(-3)(-2)(9)(-4)
Negative, because there is an odd amount of negatives.
One thing that can be found in sedimentary rock layers.
Fossils, dinosaur bones, tree roots, etc
What are the four major divisions of the geologic time scale?
Eons, Eras, Periods, and Epochs.
What geologic principle states that a fault or intrusion cutting through rocks is younger than the rocks it cuts?
Cross-Cutting Relationships
Why are fossils important to geologists?
They help scientists understand past organisms, environments, and the relative ages of rocks.
What is the #1 thing you need to be/do to be successful in this class?
Advocate for yourself.
What do scientists often use to determine the age of rock layers?
Fossils found within the layers.
What is the primary purpose of the geologic time scale?
To show the sequence of events in Earth's history.
Explain the Law of Superposition in your own words.
The oldest rock layers are at the bottom and younger layers are deposited on top.
Scientists find marine fossils in a rock layer located on land. What does this suggest?
The area was once covered by water or part of a marine environment.
If Ms. Chavez wasn't a teacher, what would her career of choice be?
Military, Police Officer