reading rock layers based on their position in the layers of rocks. oldest on the bottom and youngest on the top.
What is relative dating?
100
scientists cut sheets of ice from polar ice caps to study them
How are ice cores collected?
200
fossils, rock layers, and ice core data
What evidence do scientists use to determine the age of Earth?
200
Index fossil
What is a type of fossil that is unique to a certain time frame?
200
increased competition for resources, human interaction, climate change, loss of food, increased predation, disease or habitat loss.
What are some causes of extinction?
200
states that if a sedimentary rock layer has not been disturbed, than the oldest rock layer is on the bottom and the youngest is on the top.
What is the Law of superposition?
200
trends in temperatures, levels of atmospheric gases, and volcanic ash
What do ice cores measure?
300
Geologic Timescale
What is the calendar of events of Earth's history?
300
They are the same age.
If an index fossil is found in a rock layer, what do we know about the relationship between the rock layer and the fossil?
300
unconformity
What is the term that describes a break in the rock layers?
300
That there was a volcanic eruption 1 billion years ago.
If scientists were to find volcanic ash in an ice core sample from 1 billion years ago, what would scientists be able to learn from this?
400
Cenozoic, Mesozoic, Paleozoic, Precambrian
What is the four Era's on the Geologic timescale? (listed in order from most recent to the beginning of time)
400
floods, mudslides, earthquakes, ash deposition
What are the events that can lead to fossil formation?
400
65 million years ago
When did the dinosaurs become extinct?
400
using radioactive isotopes and comparing them to daughter products to determine exactly how old a rock layer is
What is absolute dating?
400
the ash would be in the atmosphere blocking sunlight and causing the temps to be lowered.
If there was a massive volcanic eruption, how could that change the climate of a region?
500
Eon, era, period and epoch
What are the four increments of time on the geologic timescale? (listed from greatest in size to smallest)
500
fossil record
What is the term used to describe all fossils that have been found on since the study of fossils began.
500
yes
Do scientists base geologic eras on extinction events?
500
3.5 grams
if the half-life of Lead 206 is 4.5 billion years, and you started out with 7.0 grams of Lead 206. How many grams of lead would you have after 9 billion years?