Ch16a - b wolf creek crater(Australia – 300,000 years ago...

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Notes from Wed. February 13 th III. Processes of Change A. continental drift 1. movement a. sea floor spreading – new crust added from mantle at rifts on floor b. this causes continents to move c. currently 2 cm/year between N. America and Europe 2. continents a. Pangaea i. all continents together ii. harsh climates in interior (properties of water) b. Laurasia made up of i. North America, Europe, Asia c. Gondwanaland made up of i. South America, Africa, Madagascar, India, Australia, Antarctica 3. Effects of drift a. climate b. sea level and ocean currents c. volcanic activity d. distribution of organisms B. Volcanic Activity 1. can effect earth’s climate 2. ash in atmosphere reduces penetration of sunlight, reducing temperature 3. mt. Pinatubo (1991) a. eruption of ash went 12 miles into the air b. global temp dropped 1 degree for 2 years. C. meteorites 1. small meteorites regularly hit the earth 2. large meteor collisions are rarer but do occur a. meteor crater (Arizona) – 1,500 tons, 50,000 years ago
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Unformatted text preview: b. wolf creek crater (Australia) – 300,000 years ago 3. Yucatan Meteor a. 65 million years ago b. 10 km in diameter c. crater – 180 km in diameter d. 2,000 ft waves e. dust clouded sun for several months/years f. possibly caused mass extinction at end of Mesozoic IV. Mass Extinction A. Permian mass extinction 1. end of Paleozoic 2. 90% of all marine life – many terrestrial 3. merge to form Pangaea, many volcanoes B. Cretaceous mass extinction 1. end of mesozioc (dinosaurs) 2. Yucatan meteor 3. reduction in photosynthesis – collapse of food chains V. Big Picture Phylogeny A. some major events 1. origin of Earth 4.5 bya 2. origin of life – 4.0 bya 3. oxygen began accumulating – 2.7 bya 4. origin of eukaryotes – 2.1 bya 5. multicellular eukaryotes – 1.2 bya 6. most animal phyl – 500 mya 7. colonization of land (plants, animals, fungi) – 500 mya...
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Ch16a - b wolf creek crater(Australia – 300,000 years ago...

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