lab 1 - geologic time pt. 2

Cenozoic era, Neogene period

What era and periods did did the first hominins appear?

Five

How many mass extinctions have occurred?

Relative dating

The science of determining the relative order of past events without necessarily determining their absolute age; uses principle of supposition

Lower layers of rock are older, geologists date rock layers

What is superposition? Can this method work all the time in dating fossils?

Absolute dating

Measure the physical properties of an object itself and use the measurements to calculate its age

• assigns actual age

• Radiocarbon dating

Radiometric dating

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