Earth Science Ch.12 Earth’s Evolution Through Geologic Time – Flashcards
Unlock all answers in this set
Unlock answersquestion
The ________ period was a time of major extinctions, including 75 percent of amphibian families.
answer
Permian
question
During the early Paleozoic era, South America, Africa, Australia, Antarctica, India, and perhaps China comprised the vast southern continent of ________.
answer
Gondwanaland
question
The most common Precambrian fossils are ________, layered mounds of calcium carbonate.
answer
Stromatolites
question
During the ________ era, the westward-moving North American plate began to override the Pacific plate, eventually causing the tectonic activity that ultimately formed the mountains of western North America.
answer
Mesozoic
question
Earth's primitive atmosphere evolved from gases ________.
answer
expelled from within the earth
question
Mammals became the dominant land animals during the ________ era.
answer
Cenozoic
question
Which of the following gases was NOT part of Earth's original atmosphere?
answer
oxygen
question
In the early history of the earth, the solid surface of the earth weathered more rapidly than now because ________.
answer
the early rain was very acidic
question
The major source of free oxygen in the atmosphere is from ________
answer
green plants
question
One important reason we do not know much about the geologic history of the Precambrian is that ________.
answer
there are very few fossils preserved in Precambrian rocks
