Good Day everyone! Today is Wednesday 10/4/17

Transcription

1 Good Day everyone! Today is Wednesday 10/4/17 Agenda: 1. Warm Up 2. Video: Intro to the Geologic Time Scale 3. Notes: Geologic Time Scale a. How the Geologic Time Scale is Organized b. Principle of Uniformitarianism 4. Review: Geologic Time Scale 5. Reading the Geologic Time Scale

2 Warm Up: write the answer on your warm up paper for Wednesday 10/4/17 1. Define unconformity. 2. How does an unconformity change a scientist s understanding of the history of Earth? A. It reduces the understanding because rock layers representing thousands or millions of years are missing. B. It increases the understanding because the changes in the positions of rock layers show how forces have changed Earth. C. It reduces the understanding because fossils have already been removed from an unconformity. D. It increases the understanding because an unconformity contains rock layers that are absent in other areas.

3 Intro to the Geologic Time Scale: Watch this video as an introduction the geologic time scale. n8

4 THE GEOLOGIC TIME SCALE HIGHLIGHTS Earth s life forms have become more complex and diverse over time For a billion years, no life forms existed on the planet Only in the last 500 million years have more complex organisms existed Humans came about 200,000 years ago

5 SECTIONS OF TIME Each section of the Geologic Time Scale is marked by major events: Extinctions New life forms Major change in climate

6 HOW THE GEOLOGIC TIME SCALE IS ORGANIZED The Geologic Time Scale is divided into: Eons, Eras, Periods, and Epochs

7 TIMESCALE: FILL THIS IN ON YOUR TRIANGLE EON ERA PERIOD EPOC H

8 MEMORY TRICK!! EON = year ERA = month PERIOD = week EPOCH = day

9 THE TIME SCALE 1. Eons: Longest unit of time: 4 eons total in Earth s History 2. Eras: Usually marked off by mass extinctions 3. Periods: Block of time when unique rock layers were laid down 4. Epochs: Shortest division of time

10 IMPORTANT DATES: PRECAMBRIAN TIME Precambrian Time + Consists of 3 EONS- most of Earth s History + Very few fossils found in this period + For 90% of Earth s History there was no life at all!

11 IF THE TIME SCALE WERE ONE YEAR PRECAMBRIAN TIME! FIRST ANIMALS and DINOSAURS! FIRST HUMANS!

12 IMPORTANT DATES: PHANEROZOIC EON Rest of Earth s History 3 Eras in it: Paleozoic, Mesozoic, Cenozoic At the beginning was the Cambrian Period which had the Cambrian explosion- many new life forms came about Holocene Epoch- current time

13 CHALLENGE QUESTION: write out the question and answer on your notes page. Why would there be little to no fossils found in a rock layer that was formed during Precambrian time?

14 EXTINCTION Extinction: Permanent Dying out of a species Mass Extinction: Occurs when large numbers of species die out over a fairly short period of time Shows in the rock record when suddenly many fossils disappear and new ones show up

15 Principle of Uniformitarianism Earth s Processes that we see today, are the same as the processes that happened in the past +Ex: Rock Cycle- Scientists can form hypothesis about how things looked in the past because they know how the rock cycle works now.

16 READING THE GEOLOGIC TIME SCALE It gives you the name of the eon, era, period, and epoch Tells you how long ago that time period was Tells you major events in Earth s History Instructions: Click on the link below to watch the video. On a clean sheet of notebook paper, copy the chart and fill it in as the teacher discusses each time period and elaborates on the events that happened during that time period. Add this page to the back of your notes packet #3

17 What do I do next? After you have completed this set of notes, move on to complete the notes on Fossils. You will need to go back to the website and find the link for the Fossils notes. I will be checking for both sets of notes when I return on Thursday.