Inside the Restless EarthChapter 3 Section 5

A: The rock layers (strata) in the Grand Canyon represent about 2 billion years of Earth’s history.◦ D:The Colorado River has cut (weathering and

erosion) the canyon in as much as 2km is some areas.

◦ D: The river has been at work for almost 6 million years.

A: Fossils of plants and animals are common in the sedimentary rock structures of the Green river in Colorado, Utah, and Wyoming.◦ D: The rocks were part of a system of lakes for

millions of years.◦ D: Fine-grain sediment preserved delicate

structures

A: The geologic time scale in divided into eons, eras, periods, epochs.◦ D: eon

Hadean (4.6 billion – 3.8 billion year ago) Archean (3.8 billion – 2.5 billion years ago) Proterozoic (2.5 billion - 543 million years ago) Phanerozoic (543 million – present time)

◦ D: Panerozoic eon is divided into three eras Cenozoic Mesozoic Paleozoic

A: Throughout history the number of different species either increased or decreased.◦ Hallucigenia appeared in the Cambrian period◦ Other organisms disappeared

Extinction-the death of every member of a species (ex. Dinosaurs)

A: This is the first era represented by fossils and is known as the old life era.◦ D: Marine (ocean) life flourished◦ D: Near the end of the era-reptiles began to live

on land◦ D: This era ended with a mass extinction. 90% of

all species were killed

A: This is called the age of reptiles because dinosaurs roamed the land during this time.◦ Birds and mammals began to evolve◦ 15%-20% of species went extinct

Climate change or an asteroid caused the extinction

A: This era is known as the Age of Mammals.◦ D: Mammals flourished

Regulate body temperature