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Crusty Old Discovery Reveals Early Earth's History (3.8 billion years old outer crust)
http://www.freerepublic.com/focus/news/1806290/posts


33 posted on 03/24/2007 8:48:36 PM PDT by NormsRevenge (Semper Fi ...... BumP'n'Run 'Right-Wing Extremist' since 2001)
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To: NormsRevenge; Suzy Quzy; Fred Nerks; thackney
Borrowing from your thread....

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The Earth’s radius is about 4,000 miles (6,400 kilometers). The main layers of its interior are in descending order: crust, mantle and core.

The crust thickness averages about 18 miles (30 kilometers) under the continents, but is only about 3 miles (5 kilometers) under the oceans. It is light and brittle and can break. In fact it's fractured into more than a dozen major plates and several minor ones. It is where most earthquakes originate.

The mantle is more flexible – it flows instead of fractures. It extends down to about 1,800 miles (2,900 kilometers) below the surface.

The core consists of a solid inner core and a fluid outer core. The fluid contains iron, which, as it moves, generates the Earth’s magnetic field. The crust and upper mantle form the lithosphere, which is broken up into several plates that float on top of the hot molten mantle below.

SOURCE: LiveScience reporting

2 posted on 03/24/2007 7:44:21 PM PDT by NormsRevenge (Semper Fi ...... BumP'n'Run 'Right-Wing Extremist' since 2001)

36 posted on 03/25/2007 7:30:04 AM PDT by Ernest_at_the_Beach (The DemonicRATS believe ....that the best decisions are always made after the fact.)
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