Bellwork Box #7 Read page 248: What did Alfred Wegener’s continental drift hypothesis state? Read pages 249-251 What are the 3 types of evidences supporting the hypothesis?
In 1912,Alfred Wegener proposed an idea: Continental Drift In 1912,Alfred Wegener proposed an idea: All of the continents drift and were once joined together in 1 single supercontinent
Plate Tectonics
Wegener’s hypothesis needed evidence before it became an accepted theory…
Evidence of Continental Drift Fossil Climatic Geological (Rock Types) Paleomagnetic Seafloor Spreading
These reptiles could not have swum across the Atlantic Ocean. 1.Fossil 270 myo identical fossil remains of the reptile, Mesosaurus, have been found in both eastern South America and western Africa. These reptiles could not have swum across the Atlantic Ocean.
1.Fossil
2. Climatic Ancient glacial grooves on current continents in the Southern hemisphere
Gondwana Reconstruction of Southern hemisphere super continent Gondwana Reconstruction of Southern hemisphere super continent. Notice how ring of glaciers match the patterns of a polar ice
Geological
Ex: Appalachian Mountains to New Foundland 3. Geological: Mountain belts at the end of one coastline have reappeared on landmasses across the ocean. Ex: Appalachian Mountains to New Foundland
4. Seafloor Spreading At locations on the seafloor, where new crust is created, rocks get progressively younger as a ridge is approached. Ex:Mid Ocean Ridge -MOR
Paleomagnetic
5. Paleomagnetic As the seafloor spreads, creating new continental crust, all magnetic minerals align with the magnetic north and south poles. This alignment creates alternating stripes of magnetic and non-magnetic rocks on the ocean floor.
Wegener was right! All of the continents were once joined together in a supercontinent named Pangaea After 50 years of research with new technology, scientists came up with the…
The theory helps explain the formation and movements of the plates Theory of Plate Tectonics (1960) Earth’s surface consists of rigid, but moving pieces called tectonic plates The theory helps explain the formation and movements of the plates
Tectonic Puzzle Assignment Use your notes and knowledge about evidence to reconstruct a supercontinent! Cut out the shapes on the green sheet of paper and form Pangaea Glue the completed puzzle to the purple sheet of paper
3) Rock Types and Structures Homework (pg. 251-252) 3 Limited Word Organizers for the types of evidence to support the continental drift hypothesis: 1) Fossil 2) Climate 3) Rock Types and Structures