Earth History
The approximate age of earth
4.6 billion years old
What event usually marks the end of an era?
extinction
This is the process that causes the moving of earth's plates
convection
These fossils are evidence of activity, not the animal itself. Examples: animal tracks or waste
Trace Fossils
How come the youngest rock layers are not necessarily on top?
Plate tectonics (which causes folding, breaking, and uplifting of rock layers)
Which era are we currently living in?
Cenozoic
This type of plate boundary is where plates slip or slide past each other
Transverse
sedimentary
Are soft or hard body parts easier for fossilization?
Hard body parts
This principle states that the past is the key to the present
Uniformitarianism
Rock layers from this era contain the most dinosaur fossils
Mesozoic
This type of plate boundary is where sea floor spreading takes place
divergent
These are typically taken from a glacier or ice sheet and can be interpreted as a vertical timeline of earth and earth's atmosphere's history
ice core
This is the most accurate method used to determine the age of a fossil
Absolute dating (radiometric)
Based on the fossil record, which organisms were most likely alive on earth first?
Bacteria - small microorganisms
What landforms are a result of convergent plate boundaries?
Mountain ranges, earthquakes
This type of rock forms when magma cools
igneous
Why would the fossils of coral or shells be found on a mountain top?
At one time the mountain was under water
The one "supercontinent" during earth's history is known by this name
Pangea
Who came up with the theory of continental drift?
Alfred Wegener
This type of dating uses the radioactive isotope content of a rock to determine the amount of time passed since the rock formed
Absolute or Radiometric
These two characteristics make for a good index fossil.
Widespread & living during a short period of time