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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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Abyssal_plain
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INFOTEXT
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1992-09-02
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The abyssal plain is a broad expanse of sea
floor lying 3-6km(2-4miles) below sea level.
Abyssal plains are found in all the major
oceans, and they extend from bordering
continental rises to mid-oceanic ridges.
Underlain by outward-spreading, new oceanic
crust extruded from ridges. Abyssal plains
are covered in deep-sea sediments derived
from continental slopes and floating
microscopic marine organisms. The plains
often are interrupted by chains of volcanic
islands where plates ride over hot spots in
the mantle, and by sea mounts originally
formed in oceanic ridge areas. In the
Atlantic Ocean, for example, the abyssal
plain extends about 1,500km (930miles) off
the East coast of the US.
Subject by: Vince Pike