Quizizz due April 6th, 2018

The age of a rock compared to the ages of other rocks.

• relative age
• half-life
• absolute age
• radioactive decay

The time it takes half of the atoms of a radioactive element to decay

• relative age
• half-life
• absolute age
• radioactive decay

An igneous rock later formed when lava flows onto Earth's surface and hardens.

• extrusion
• index fossil
• intrusion
• uncomformity

A record of the geologic events and life forms in Earth's history.

• index fossil
• half-life
• radioactive dating
• geologic time scale

Fossils of widely distributed organisms that lived during a geologically short period.

• index fossil
• half-life
• radioactive dating
• geologic time scale

An igneous rock layer formed when magma hardens beneath Earth's surface.

• extrusion
• index fossil
• intrusion
• unconformity

In horizontal layers of sedimentary rock, each layer is older than the layer above it.

• mass extinct
• geologic time scale
• era
• law of superposition

One of the units of geologic time into which geologists divide eras.

• era
• geologic time scale
• period
• uncomformity

A gap in the geologic record that shows where rock layers have been lost due to erosion.

• extrusion
• unconformity
• intrusion
• law of superposition

The boundary  between two air masses is known as:

• front
• storm
• climate
• flood