Earth’s Evolution & Rock Dating ESSENTIAL QUESTION: SC.7.E.6.4 Explain and give examples of how physical evidence supports scientific theories that Earth has evolved over geologic time due to natural processes. ESSENTIAL QUESTION: What methods allow scientists to tell the age of rocks and what does this tell us about the Earth’s history?

Wednesday, April 6 Please open your journals to the notes you took during your independent study Come to the front…pick up a quiz that matches the standard you covered during your independent study on Monday Complete the Quiz on the left side of your journal. You may use the notes you took! Return the Quiz paper to the front and place in the correct pile! Pick up, or ask for a sheet on Evolution of Earth.

Warm Up Paleontologists discovered fish fossils in the arid deserts of western Egypt. What does the fossil evidence most likely indicate about this area’s geologic past? The desert was once a vast ocean. A giant ocean wave carrying sea life crashed onto the desert. Mountains in the region once provided water from snowmelt. The area was moved from the ocean to the desert by plate tectonics.

I Do Guided Notes

Determining the order of past events, but NOT exact dates. Relative Dating: Determining the order of past events, but NOT exact dates.

The Law of Superposition In horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it.

Relative Dating Fossils Younger fossils will be found in the top layers of rock. Older fossils will be found in the bottom layers of rock.

Folding: Faulting: The bending of rock layers due to pressure. The breaking of rock layers by transform fault lines. The arrow shows where a fault line (earthquakes) moved the rock layers. When did this happen?

Absolute Dating: Finding the approximate age of a rock using the radioactive atoms inside them.

Radioactive Dating Certain elements decay (break down) at certain rates. (Ex. Carbon 14, Uranium) Scientists know how long certain atoms take to decay. They compare the amount of atoms left to the beginning amount to calculate its age.

Earth’s Age Using radioactive dating, scientists have identified rock as old as 4.28 billion years old. With this evidence and more, the approximate age of the Earth has been calculated as 4.5 billion years old.

Earth’s Evolution The Earth’s surface has been slowly but constantly changing in all of that time. Earth used to be covered by a supercontinent named Pangea. Evidence: Rock with the same composition and the same age can be found on different continents today.

WE DO Collaborative Activity

Revisiting the Bellringer Paleontologists discovered fish fossils in the arid deserts of western Egypt. What does the fossil evidence most likely indicate about this area’s geologic past? The desert was once a vast ocean.* A giant ocean wave carrying sea life crashed onto the desert. Mountains in the region once provided water from snowmelt. The area was moved from the ocean to the desert by plate tectonics.

You Do Time!

Mini-Quiz #1 On an expedition to Antarctica, scientists have discovered fossils of plants that are found in tropical rainforests. What statement best explains this discovery? Tropical plants grow on Antarctica during summer months. Antarctica used to be located closer to the equator. Fossilized remains were carried by ocean currents. The ice age froze the tropical plants in ice. Correct Answer: B

Mini-Quiz #2 In 1912, Alfred Wegner first proposed his hypothesis of continental drift. He gathered a great deal of data and observations to support his claim that the continents were in motion. Which statement would best support Wegner’s hypothesis? Glaciers are found on parts of continents that are close to the poles. The movement of the continents cannot be measured in our lifetimes. South America and Africa fit together like a puzzle. North America and South America are connected. Correct Answer: C

Mini-Quiz #3 The oldest rock formation identified on Earth is found on the shoreline of Hudson Bay in Canada. This rock formed 4.28 billion years ago. Which information does a scientist need to most accurately determine the age of a rock? the percentage of each mineral that makes up the rock the thickness of younger rock layers that cover the rock the amount of each radioactive element present in the rock the amount of weathering present on the surface of the rock Correct Answer: C

Mini-Quiz #4 The picture below shows the Rock layers that make up the Grand Canyon. What does the law of superposition say about how the Grand Canyon has changed over time? A. The Grand Canyon was once underwater because the newest rocks are found at the bottom-most layers. B. The Grand Canyon divided into layers of different rocks because of cracks that arose from volcanic eruptions. C. The Kaibab Limestone used to be underground but was elevated as the layer pushed upward through Earth’s crust. D. The top layer may once have been Redwall Limestone, but over time sediment continued to build up and now Kaibab Limestone is the top layer.

Mini - Quiz #5 Compare the images of the Appalachian Mountains on the left and the Himalayan Mountains on the right. The Appalachian Mountains formed before the Himalayas. What do these pictures indicate about how Earth’s mountains change over time? A. Mountains erode over time. B. Mountains do not change over time. C. High-mountain lakes form over time. D. Mountains become rougher over time.

Mini-Quiz #6 Paleontologists discovered fish fossils in the arid deserts of western Egypt. What does the fossil evidence most likely indicate about this area’s geologic past? A. The desert was once a vast ocean. B. A giant ocean wave carrying sea life crashed onto the desert. C. Mountains in the region once provided water from snowmelt. D. The area was moved from the ocean to the desert by plate tectonics.

Mini-Quiz #7 Coal, a fossil fuel made from the remains of swamp plants, has been found in Antarctica. Which of the following is the most reasonable explanation for how this is possible when 98% of Antarctica is now covered in ice? A. The coal was transported by animals that ate the swamp plants. B. The climate of Antarctica has become milder due to its closeness to the ocean. C. The climate of Antarctica was probably much warmer in the past than it is today. D. The coal was transported through large convection currents and uplift in the mantle.

Mini-Quiz #8 Earthquakes and volcanic eruptions are common on the western edge of the Pacific Ocean. Which theory does this pattern of geological phenomena support? A. Weathering B. The rock cycle C. Plate tectonics D. Biological evolution

Mini-Quiz #9 Scientists have found many marine fossils on mountains far from any ocean or sea. What is the best explanation for these fossils? A. Meteors with marine fossils landed on the mountains. B. Wind carried fossils from the seashore to the mountains. C. The mountains were made out of land that was once below the ocean. D. Predators caught marine prey and carried it to the top of the mountains.

Mini-Quiz #10 What methods allow scientists to tell the age of rocks and what does this tell us about the Earth’s history?