Question
The geologic time scale is based on evidence from rock strata. Students are using part of the geologic time scale to explain how
the scale organizes the history of Earth,
Era
Period
Million Years Ago
Major Events
Quaternary
2.6-Recent
Cenozoic
End of glaciation
Paleogene
56-23
Earliest humans
Cretaceous
146-66
Dinosaur extinction
Mesozoic
Triassic
251-200
First dinosaurs and mammals
Permian
299-271
Trilobite extinction
Paleozoic
Devonian
416-398
Evolution of land plants
Cambrian
542-488
Increase of invertebrate animals
Precambrian
4600-542
First signs of complex life
Which two ways are rock strata used to support the design of the geologic time scale?
A. Rocks that are oldest have the greatest variety of fossils.
D. Rocks formed in volcanoes provide evidence of past
climates and environments
1 B. Rocks formed in broad layers with older rocks on top
E. Rocks formed at the bottom of the ocean contain
of newer rocks.
information about ancient sea life.
Rocks have fossils that show which organisms lived during
different times.
C RESET
Reem Alasmar, ID#***01
Growth: Science 9-12: for use with NGSS Intl 2013 Question # 40
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Answer
B. Rocks formed in broad layers with older rocks on top and D. Rocks formed in volcanoes provide evidence of past climates and environments.