What is the name of the first supercontinent?
The inner and outer core, mantle, and crust of Earth all have __________.
|A)||been rigid since the formation of Earth|
|B)||have the same specific gravity|
|D)||the same densities|
Minerals with low densities crystallize from a magma at __________ denser minerals do.
|A)||the same temperature as|
|B)||always 10 degrees less than|
|C)||cooler temperatures than|
|D)||hotter temperatures than|
Why is the age of a zircon grain older than the age of the sandstone in which it was found?
|A)||because of the principle of included fragments|
|B)||It is much less stable than the sandstone.|
|C)||because of the principle of superposition|
|D)||It is much more stable than the sandstone|
What was the composition of Earth's first crust?
|B)||iron and quartz|
|C)||feldspar, quartz, and mica|
|D)||iron- and magnesium-rich minerals|
How are microcontinents fused together?
|A)||by mountain chains that formed as tectonic plates collided|
|B)||by seams that developed as rock layers faulted|
|C)||by cooling molten rock that glued the land together|
|D)||by the erosion of mountains|
What process is primarily responsible for the formation of Earth's oceans?
Fossils of __________ from late Proterozoic rocks are found in all parts of the world.
|A)||the Ediacaran fauna|
|B)||the Burgess Shale fauna|
What event caused the extinction of early eukaryotes near the end of the Proterozoic?
|B)||formation of ozone|
|D)||the Varagnian glaciation|
Scientists currently think that the energy and nutrients necessary for the origin of life can be found near __________.
Earth's atmosphere has changed greatly since the planet formed. What gas was most likely rare or absent in Earth's earliest atmosphere?
What happened as Earth differentiated during its formative period?
|A)||Heavier materials sank toward the core, and lighter materials rose.|
|B)||Widely separated land areas started looking different from one another.|
|C)||The Atlantic and Pacific Oceans developed from the original global ocean.|
|D)||Outgassing formed an oxygen atmosphere.|
Earth's first atmosphere was probably similar to gases produced by _________
Because early Earth had no ozone layer in its upper atmosphere, the surface of the planet was constantly scoured by _________
|D)||tornadoes and hailstorms|
Geological evidence suggests that early Earth was very different from Earth today in which way?
|A)||Earth's oceans probably formed long before Earth's atmosphere and covered most of Earth's surface.|
|B)||Earth's earliest atmosphere was primarily composed of oxygen and contained very little water vapor, carbon dioxide, or nitrogen.|
|C)||Earth's earliest oceans were much deeper than today, and the continents rose much higher in elevation.|
|D)||Earth's earliest atmosphere probably contained large quantities of water vapor, carbon dioxide, and nitrogen, but contained very little oxygen gas.|
Which process did not contribute to the formation of Earth's atmosphere?