Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Post-glacial rebound wikipedia , lookup
Schiehallion experiment wikipedia , lookup
Spherical Earth wikipedia , lookup
History of geomagnetism wikipedia , lookup
Age of the Earth wikipedia , lookup
Future of Earth wikipedia , lookup
History of Earth wikipedia , lookup
Mantle plume wikipedia , lookup
History of geology wikipedia , lookup
PLATE TECTONICS LIZ LAROSA FOR USE WITH MY 5TH GRADE SCIENCE CLASS HTTP://WWW.MIDDLESCHOOLSCIENCE.COM 2009 EARTH’S LAYERS The Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed. This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle. THE CRUST • Outermost layer • 5 – 100 km thick • Made of Oxygen, Silicon, Aluminum THE MANTLE • Layer of Earth between the crust and the core • Contains most of the Earth’s mass • Has more magnesium and less aluminum and silicon than the crust • Is denser than the crust THE CORE • Below the mantle and to the center of the Earth • Believed to be mostly Iron, smaller amounts of Nickel, almost no Oxygen, Silicon, Aluminum, or Magnesium TECTONIC PLATES PLATE TECTONICS • Greek – “tektonikos” of a builder • Pieces of the lithosphere that move around • Each plate has a name • Fit together like jigsaw puzzles • Float on top of mantle similar to ice cubes in a bowl of water CONTINENTAL DRIFT Alfred Wegener 1900’s Continents were once a single land mass that drifted apart. Fossils of the same plants and animals are found on different continents Called this supercontinent Pangaea, Greek for “all Earth” 245 Million years ago Split again – Laurasia & Gondwana 180 million years ago http://members.enchantedlearning.com/subjects/astronomy/planets/earth/Continents.shtml EVIDENCE OF PANGEA SEA FLOOR SPREADING SEA FLOOR SPREADING • Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins • Magma rises to the surface and solidifies and new crust forms • Older Crust is pushed farther away from the ridge HOW PLATES MOVE http://pubs.usgs.gov/gip/dynamic/unanswered.html DIFFERENT TYPES OF BOUNDARIES http://pubs.usgs.gov/gip/dynamic/understanding.html DIVERGENT BOUNDARY – ARABIAN AND AFRICAN PLATES DIVERGENT BOUNDARY – ICELAND http://pubs.usgs.gov/gip/dynamic/understanding.html DIVERGENT BOUNDARY - OCEANIC http://www.geology.com DIVERGENT BOUNDARY - CONTINENTAL http://www.geology.com CONVERGENT BOUNDARY – INDIAN AND EURASIAN PLATES CONVERGENT BOUNDARY – OCEANIC & CONTINENTAL http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com CONVERGENT BOUNDARY – OCEANIC & OCEANIC http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com CONVERGENT BOUNDARIES - CONTINENTAL http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com TRANSFORM BOUNDARY – SAN ANDREAS FAULT www.geology.com REVIEW • Name the 3 main layers of the Earth • What is a tectonic plate? • What was Pangea? • What is Sea-Floor spreading? • Name the three different types of plate boundaries and one location on Earth for each one REVIEW • Name the 3 main layers of the Earth • Crust • Lithosphere • Asthenosphere • Mantle • Upper mantle (asthenosphere) • Lower mantle • Core • Outer core • Inner core REVIEW • What is a tectonic plate? • Part of Earth's crust where the continents and oceans sit upon solid igneous rock • REVIEW • What was Pangea? • “All Earth” • The large landmass where all the continents had come together about 245 million years ago REVIEW • What is Sea-Floor spreading? • the place in the oceanic crust where the sea floor is being pushed apart by lava flowing up from the mantle REVIEW • Name the three different types of plate boundaries and one location on Earth for each one. • Convergent boundary – Eurasian and Indian plates • Divergent boundary – Arabian and African plates and Iceland • Transform boundary - San Andreas Fault in California