Exam 8: Precambrian Earth and Life History the Hadean and the Archean Eon

What are two reasons that Earth lost its first atmosphere of hydrogen and helium?

____________________ refers to the formation of life from non-living matter.

When it first formed, the Sun was 75 times more luminous than it is now.

The newly-formed Earth's atmosphere was very different from Earth's current atmosphere because it had ____.

Greenstone belts are composed of sedimentary and volcanic rocks.

Why does Earth have plate tectonics?

Detrital zircon from sedimentary rocks found in Australia yields an age of 4.4 billion years, which indicates that rocks formed on Earth at least 4.4 billion years ago.

Earth was a hot, barren, waterless planet during the Archean eon.

Earth's first atmosphere likely consisted of ____________________ and ____________________, the most abundant gasses in the universe.

During the process of ____________________, rising magma from a subducting plate or mantle plume accumulates beneath a continent.

Over time, Earth's rotation rate has slightly increased.

Organisms that do not depend on oxygen for growth are ____.

The nucleus or foundation of a continent is a(n) ____.

The ____________________ forms the exposed part of the craton in North America.

____________________ organisms rely on external sources of nutrients.

Mound-like structures that represent the remains of photosynthesizing cyanobacteria are ____.

Describe prokaryotic cells and discuss the role they played in early Earth.

Early in Earth history, the Sun was less luminous, which should have caused Earth to be much colder and all water to be frozen. Yet all evidence points to the presence of liquid water on Earth. Give two explanations that could resolve the "faint young sun paradox."

Both the intracontinental rift and back-arc basin model are based on volcanism associated with mantle plumes.

Cyanobacteria (blue-green algae) are an example of a heterotrophic organism.