Earth Science NC Check In Review

Front

What is an Index Fossil?

Back

An Index Fossil is a fossil that is used to identify and define a specific geologic time period. It is typically widespread, abundant, and existed for a relatively short duration.

Front

According to the law of superposition, which layer is the youngest?

Back

The youngest layer is the one that is on top of the other layers. In a sequence of sedimentary rock layers, the topmost layer (Layer A) is the youngest.

Front

What is the longest subdivision of geologic time?

Back

The longest subdivision of geologic time is called an Eon.

Front

What processes change a metamorphic rock into an igneous rock?

Back

A metamorphic rock changes into an igneous rock through the processes of melting and cooling.

Front

Which rock layer is typically the oldest?

Back

In a sequence of sedimentary rock layers, the oldest layer is usually the one at the bottom (Layer C).

Front

Define Eon in geological terms.

Back

An Eon is the largest division of geological time, lasting hundreds of millions to billions of years.

Front

What is the difference between a Mold Fossil and a Cast Fossil?

Back

A Mold Fossil is an impression of an organism left in sediment, while a Cast Fossil is formed when sediment fills the mold and hardens into rock.

Front

What is the significance of the law of superposition in geology?

Back

The law of superposition helps geologists determine the relative ages of rock layers, indicating that older layers are found below younger layers.

Front

What are the three main types of rocks?

Back

The three main types of rocks are igneous, sedimentary, and metamorphic.

Front

How does sedimentary rock form?

Back

Sedimentary rock forms from the accumulation and compaction of mineral and organic particles over time.