1 / 7

KEY CONCEPT The geologic time scale divides Earth ’ s history based on major past events.

KEY CONCEPT The geologic time scale divides Earth ’ s history based on major past events. Index fossils are another tool to determine the relative age of rock layers. Definition: Fossils of organisms that existed only during specific spans of time over large geographic areas

jgloria
Download Presentation

KEY CONCEPT The geologic time scale divides Earth ’ s history based on major past events.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. KEY CONCEPT The geologic time scale divides Earth’s history based on major past events.

  2. Index fossils are another tool to determine the relative age of rock layers. • Definition: Fossils of organisms that existed only during specific spans of time over large geographic areas • Example: Fusulinids and trilobites. • Characteristics: Common, easy to identify, found widely around the world, only existed for a relatively brief time • Nonexample (I don’t get it either): Anything that is rare to find or that are only found in a certain region

  3. 100 250 550 1000 2000 PRECAMBRIAN TIME This time span makes up the vast majority of Earth’s history. It includes the oldest known rocks and fossils, the origin of eukaryotes, and the oldest animal fossils. Cyanobacteria Geologic Time Scale: Representation of the history of the Earth that is organized by major changes or events • Eras: Last tens to hundreds of millions of years & consist of two or more periods • Periods: Most commonly used units of time, lasting tens of millions of years • Epochs: The smallest units of time, lasting several millions of years

  4. Eras: • Era: Cenozoic (Most recent, currently still underway) Description: Evolution of primates, diversification of mammals, flowering plants & continues today

  5. Eras: 2. Era: Mesozoic (“Age of the Dinosaurs”) Description: Evolution & extinction of dinosaurs, evolution of ferns, cycads & mammals

  6. Eras: 3. Era: Paleozoic (Oldest era, “Ancient life”) Description: All existing animal phyla developed, earliest land plants arose

  7. Here’s the whole thing…

More Related