Tectonic Plates
http://4.bp.blogspot.com/-HK_XFeHi9e0/TZNTcHbwnYI/AAAAAAAAAAM/xjKyKqAf5xQ/s1600/earth-plates.jpg
The tectonic plates are blocks of the lithosphere that consist of the crust and the rigid or, the outermost part of the mantle. There are ten major tectonic plates, the ten plates are the Pacific plate, the North American plate, the Cocos plate, the Nazca plate, the South American plate, the African plate, the Eurasian plate, the Indian plate, the Australian plate, and the Antarctic plate. If you look on a map of the tectonic plates you might say that it look like a giant jigsaw puzzle. Also non of the plates are the same shape or size. For example the Cocos plate is much smaller than the Eurasian or Antarctic plate. The thickest part of the plate is the South American plate. The thinnest part of the plate is in the mid-Atlatic Ocean. Tectonic plate "float" on the asthenosphere like an ice cube in a glass of water. The lithosphere displaces the asthenosphere. The thick tectonic plates displace more of the asthenosphere than the thinner plates.
Holt Science & Technology: Earth Science Pages 194-195
Holt Science & Technology: Earth Science Pages 194-195