Earth Science Final Review Chapters 13/14

What is the age of something compared to the age of other things? 

What are periods subdivided into? 

What is an organisms that only produces with its own kind? 

A species is a group of the same type of color. 

Index fossils are the remains of dinosaurs that only existed for a short period of time. 

What era of life means era of recent time? 

Epochs are smaller units of time periods. 

Trace fossils are cavities left behind in a rock. 

What Era also means the era of middle life? 

For fossils to form they must be protected. 

What are the remains of species that existed on Earth for short periods of time? 

A cast is the copy of an original object. 

What is one giant landmass made of all of the continents? 

What is the process of breaking down? 

What are units of geologic time characterized by types of life existing worldwide at the time? 

What do geologists determine? 

What is a permineralized remain? 

What is an animal with a hard exoskeleton? 

Sediment might form new rock and produce a copy or a __________________. 

Premineralized remains is ___________________. 

What is the time it takes for half the atoms in an isotope to decay? 

What are imprints or traces of prehistoric organisms?

What era were traces of life easy to find? 

Periods are ______________. 

What conditions are needed in order for fossils to form? 

What is the time that it takes for half the isotopes to decay? 

What is the cavity of the rocks called? 

What is the change in species over geologic time? 

What is the biggest subdivision? 

What are gaps in rock sequences? 

An unconformity is a gap in a rock sequence. 

What is the division of the Earth's history? 

What are the horizontal layers of sedimentary rock? 

What are periods of time in the Cenozoic Era that have been given specific names? 

The principle of superposition is undisturbed layers of rock. 

What is the longest part of Earth's history? 

What period began about 544 million years ago and ended about 248 million years ago? 

What is a thin film of carbon residue that forms a silhouette of the original? 

What is the blue-green algae thought to be one of the earliest forms of life on Earth? 

A fossil is the remains, minerals, or traces of prehistoric organisms.