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Geology Mars
Mars is mainly composed of
basalt and andesite rock on its surface,
covered in many places by meters or more
of a dust as fine as talcum powder.Mars
Global Surveyor spacecraft observations
says that the magnetic fields on Mars exposed
that parts of the planet's crust has been
magnetized in alternating bands, usually
measuring 100 miles wide by 600 miles long
(160 km by 1000 km), in a similar pattern
to those found on the ocean floors of Earth. |
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In 1999 one fascinating theory,
published saying that these bands could be evidence
of the past operation of plate tectonics on Mars,
although this has yet to be confirmed. New findings,
published in October 2005 support this theory,
and seem to indicate an early era of tectonic
activity similar to that found on Earth due to
sea-floor spreading .If true, the processes involved
may have helped to sustain an Earth-like atmosphere
by transporting carbon rich rocks to the surface,
while the presence of a magnetic field would have
helped to protect the planet from cosmic radiation.
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